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Sample records for midge culicoides sonorensis

  1. Estimating Culicoides sonorensis biting midge abundance using digital image analysis.

    PubMed

    Osborne, C J; Mayo, C E; Mullens, B A; Maclachlan, N J

    2014-12-01

    ImageJ is an open-source software tool used for a variety of scientific objectives including cell counting, shape analysis and image correction. This technology has previously been used to estimate mosquito abundance in surveillance efforts. However, the utility of this application for estimating abundance or parity in the surveillance of Culicoides spp. (Diptera: Ceratopogonidae) has not yet been tested. Culicoides sonorensis (Wirth and Jones), a biting midge often measuring 2.0-2.5 mm in length, is an economically important vector of ruminant arboviruses in California. Current surveillance methods use visual sorting for the characteristics of midges and are very time-intensive for large studies. This project tested the utility of ImageJ as a tool to assist in gross trap enumeration as well as in parity analysis of C. sonorensis in comparison with traditional visual methods of enumeration using a dissecting microscope. Results confirmed that automated counting of midges is a reliable means of approximating midge numbers under certain conditions. Further evaluation confirmed accurate and time-efficient parity analysis in comparison with hand sorting. The ImageJ software shows promise as a tool that can assist and expedite C. sonorensis surveillance. Further, these methods may be useful in other insect surveillance activities.

  2. Papular dermatitis induced in guinea pigs by the biting midge Culicoides sonorensis (Diptera: Ceratopogonidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Histological, ultrastructural, and virological examinations were performed on abdominal skin from guinea pigs after a blood meal by colony-bred biting midges, Culicoides sonorensis. Small, superficial, cutaneous, crateriform ulcers with necrosis of superficial dermis developed at feeding sites and ...

  3. Transcriptome analyses of blood and sugar digestive processes in female Culicoides sonorensis midges (Diptera: Ceratopogonidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Female Culicoides sonorensis Wirth & Jones (Diptera:Ceratopogonidae) midges vector numerous diseases impacting livestock and humans. The molecular physiology of this midge has been under-studied, so our approach was to gain an understanding of basic processes of blood and sucrose digestion using tra...

  4. The salivary secretome of the biting midge, Culicoides sonorensis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Culicoides biting midges (Diptera: Ceratopogonidae) are hematophagous insects with over 1400 species distributed throughout the world. Many of these species are of particular agricultural importance as primary vectors of bluetongue, epizootic hemorrhagic disease and Schmallenberg viruses. Detailed s...

  5. Papular Dermatitis Induced in Guinea Pig by Biting Midge Culicoides Sonorensis (Diptera: Ceratopogonidaie)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Histological, ultrastructural, and virological examinations were performed on abdominal skin from guinea pigs after a blood meal by colony-bred biting midges, Culicoides sonorensis. Small, superficial, cutaneous, crateriform ulcers with necrosis of superficial dermis developed at feeding sites and h...

  6. The Biting Midge Culicoides sonorensis (Diptera: Ceratopogonidae) Is Capable of Developing Late Stage Infections of Leishmania enriettii

    PubMed Central

    Seblova, Veronika; Sadlova, Jovana; Vojtkova, Barbora; Votypka, Jan; Carpenter, Simon; Bates, Paul Andrew; Volf, Petr

    2015-01-01

    Background Despite their importance in animal and human health, the epidemiology of species of the Leishmania enriettii complex remains poorly understood, including the identity of their biological vectors. Biting midges of the genus Forcipomyia (Lasiohelea) have been implicated in the transmission of a member of the L. enriettii complex in Australia, but the far larger and more widespread genus Culicoides has not been investigated for the potential to include vectors to date. Methodology/Principal Findings Females from colonies of the midges Culicoides nubeculosus Meigen and C. sonorensis Wirth & Jones and the sand fly Lutzomyia longipalpis Lutz & Nevia (Diptera: Psychodidae) were experimentally infected with two different species of Leishmania, originating from Australia (Leishmania sp. AM-2004) and Brazil (Leishmania enriettii). In addition, the infectivity of L. enriettii infections generated in guinea pigs and golden hamsters for Lu. longipalpis and C. sonorensis was tested by xenodiagnosis. Development of L. enriettii in Lu. longipalpis was relatively poor compared to other Leishmania species in this permissive vector. Culicoides nubeculosus was not susceptible to infection by parasites from the L. enriettii complex. In contrast, C. sonorensis developed late stage infections with colonization of the thoracic midgut and the stomodeal valve. In hamsters, experimental infection with L. enriettii led only to mild symptoms, while in guinea pigs L. enriettii grew aggressively, producing large, ulcerated, tumour-like lesions. A high proportion of C. sonorensis (up to 80%) feeding on the ears and nose of these guinea pigs became infected. Conclusions/Significance We demonstrate that L. enriettii can develop late stage infections in the biting midge Culicoides sonorensis. This midge was found to be susceptible to L. enriettii to a similar degree as Lutzomyia longipalpis, the vector of Leishmania infantum in South America. Our results support the hypothesis that some

  7. Potential for Transovarial Transmission of Vesicular Stomatitis Virus in the biting midge, Culicoides sonorensis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vesicular stomatitis virus (VSV) is an insect transmitted rhabdovirus which causes economically devastating disease in cattle and horses in the western U.S. Important insect vectors identified thus far include Lutzomyia shannoni sand flies, Simulium vittatum black flies, and Culicoides sonorensis bi...

  8. Identification, expression and characterization of a major salivary allergen (Cul s 1) of the biting midge Culicoides sonorensis relevant for summer eczema in horses

    PubMed Central

    Langner, Kathrin F. A.; Jarvis, Donald L.; Nimtz, Manfred; Heselhaus, Julia E.; McHolland, Linda E.; Leibold, Wolfgang; Drolet, Barbara S.

    2009-01-01

    Salivary proteins of Culicoides biting midges are thought to play a key role in summer eczema (SE), a seasonal recurrent allergic dermatitis in horses. The present study describes the identification, expression and clinical relevance of a candidate allergen of the North American midge Culicoides sonorensis. Immunoblot analysis of midge saliva revealed a 66 kDa protein (Cul s 1) that was bound by IgE from several SE-affected (SE+) horses. Further characterization by fragmentation, mass spectrometry and bioinformatics identified Cul s 1 as maltase, an enzyme involved in sugar meal digestion. A cDNA encoding Cul s 1 was isolated and expressed as a polyhistidine-tagged fusion protein in a baculovirus/insect cell expression system. The clinical relevance of the affinity-purified recombinant Cul s 1 (rCul s 1) was investigated by immunoblotting, histamine release testing (HRT) and intradermal testing (IDT) in eight SE+ and eight control horses. Seven SE+ horses had rCul s 1-specific IgE, whereas only one control animal had IgE directed against this allergen. Furthermore, the HRT showed rCul s 1 induced basophil degranulation in samples from seven of eight SE+ horses but in none of the control animals. rCul s 1 also induced immediate (7/8), late-phase (8/8) and delayed (1/8) skin reactivity in IDT on all SE+ horses that had a positive test with the whole body extract (WBE) of C. sonorensis. None of the control horses showed immediate or delayed skin reactivity with rCul s 1, and only one control horse had a positive late-phase response, while several non-specific late-phase reactions were observed with the insect WBE. Thus, we believe rCul s 1 is the first specific salivary allergen of C. sonorensis to be described that promises to advance both in vitro and in vivo diagnosis and may contribute to the development of immunotherapy for SE in horses. PMID:18708061

  9. Inducing RNA interference in the arbovirus vector, Culicoides sonorensis.

    PubMed

    Mills, M K; Nayduch, D; Michel, K

    2015-02-01

    Biting midges in the genus Culicoides are important vectors of arboviral diseases, including epizootic haemorrhagic disease, bluetongue and most likely Schmallenberg, which cause significant economic burdens worldwide. Research on these vectors has been hindered by the lack of a sequenced genome, the difficulty of consistent culturing of certain species and the absence of molecular techniques such as RNA interference (RNAi). Here, we report the establishment of RNAi as a research tool for the adult midge, Culicoides sonorensis. Based on previous research and transcriptome analysis, which revealed putative small interfering RNA pathway member orthologues, we hypothesized that adult C. sonorensis midges have the molecular machinery needed to perform RNA silencing. Injection of control double-stranded RNA targeting green fluorescent protein (dsGFP), into the haemocoel of 2-3-day-old adult female midges resulted in survival curves that support virus transmission. dsRNA injection targeting the newly identified C. sonorensis inhibitor of apoptosis protein 1 (CsIAP1) orthologue resulted in a 40% decrease of transcript levels and 73% shorter median survivals as compared with dsGFP-injected controls. These results reveal the conserved function of IAP1. Importantly, they also demonstrate the feasibility of RNAi by dsRNA injection in adult midges, which will greatly facilitate studies of the underlying mechanisms of vector competence in C. sonorensis.

  10. Salivary gland extracts of Culicoides sonorensis inhibit murine lymphocyte proliferation and no production by macrophages.

    PubMed

    Bishop, Jeanette V; Mejia, J Santiago; Pérez de León, Adalberto A; Tabachnick, Walter J; Titus, Richard G

    2006-09-01

    Culicoides biting midges serve as vectors of pathogens affecting humans and domestic animals. Culicoides sonorensis is a vector of several arboviruses in North American that cause substantial economic losses to the US livestock industry. Previous studies showed that C. sonorensis saliva, like the saliva of many hematophagous arthropods, contains numerous pharmacological agents that affect hemostasis and early events in the inflammatory response, which may enhance the infectivity of Culicoides-borne pathogens. This paper reports on the immunomodulatory properties of C. sonorensis salivary gland extracts on murine immune cells and discusses the possible immunomodulatory role of C. sonorensis saliva in vesicular stomatitis virus infection of vertebrate hosts. Splenocytes treated with C. sonorensis mitogens were significantly affected in their proliferative response, and peritoneal macrophages secreted significantly less NO. A 66-kDa glycoprotein was purified from C. sonorensis salivary gland extract, which may be in part responsible for these observations and may be considered as a vaccine candidate. PMID:16968936

  11. Gene discovery and differential expression analysis of humoral immune response elements in female Culicoides sonorensis (Diptera: Ceratopogonidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Female Culicoides sonorensis midges (Diptera: Ceratopogonidae) are vectors of pathogens that impact livestock and wildlife in the United States. Little is known about their molecular functioning, including components of their immune system. Because the insect immune response is involved ...

  12. The reference transcriptome of the adult female biting midge (Culicoides sonorensis) and differential gene expression profiling during teneral, blood, and sucrose feeding conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Unlike other important vectors such as mosquitoes and sandflies, genetic and genomic tools for Culicoides biting midges are lacking, despite the fact that they vector a large number of arboviruses and other pathogens impacting humans and domestic animals world-wide. In North America, female Culicoid...

  13. Trap placement and attractant choice affect capture and create sex and parity biases in collections of the biting midge, Culicoides sonorensis.

    PubMed

    McDermott, E G; Mayo, C E; Gerry, A C; Mullens, B A

    2016-09-01

    Culicoides sonorensis Wirth & Jones (Diptera: Ceratopogonidae) is the primary North American vector of bluetongue virus (BTV), which can cause high morbidity and mortality in ruminant livestock or wildlife. Worldwide, most Culicoides surveillance relies on light (usually UV) traps typically placed near animals or larval development sites. However, the trapping method can cause sex, species and parity biases in collections. We collected C. sonorensis from three dairies in California using suction traps baited with CO2 , UV light or CO2  + UV placed near animals, wastewater ponds, or in fields. Higher numbers of parous females were collected using CO2  + UV traps, although this difference was only significant on one dairy. UV traps were poor at collecting nulliparous females, but the addition of UV to a trap increased the abundance of males in a collection. Traps set in open fields collected significantly higher numbers of males and females than in either of the other two locations. In some cases, there was a significant interaction between the trap type and site. We discuss the limitations of traditional trapping methodologies for C. sonorensis and make suggestions for vector surveillance. PMID:27257164

  14. Identification, expression, and characterization of a major salivary allergen (Cul s 1) of the biting midge Culicoides sonorensis relevant for summer eczema in horses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salivary proteins of Culicoides biting midges are thought to play a key role in the induction of summer eczema (SE), a seasonal recurrent allergic dermatitis in horses. The present study describes the identification of a candidate allergen in artificially collected saliva of the North American speci...

  15. Infection of Guinea Pigs with Vesicular Stomatitis New Jersey Virus Transmitted by Culicoides sonorensis (Diptera: Ceratopogonidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Interpretive Biting midges,Culicoides sonorensis were shown to be capable of transmitting vesicular stomatitis New Jersey virus (VSNJV) to guinea pigs. Despite seroconversion for VSNJV, none of the guinea pigs developed clinical signs when infected in the abdomen by either infected insects or by nee...

  16. Impact of the blood meal on humoral immunity and microbiota in the gut of female Culicoides sonorensis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although Culicoides sonorensis is an important vector of orbiviruses that cause significant disease in domestic and wild ruminants in the USA, little is known about factors contributing to midge vector competence. In other vectors such as mosquitoes, interactions between the humoral immune response,...

  17. Culture-independent analysis of midgut microbiota in the arbovirus vector Culicoides sonorensis (Diptera: Ceratopogonidae).

    PubMed

    Campbell, Corey L; Mummey, Daniel L; Schmidtmann, Edward T; Wilson, William C

    2004-05-01

    Differences in midgut microbial communities inhabiting Culicoides spp., insect vectors of virus pathogens, may affect the variation observed in the ability of these biting midges to propagate arthropod-borne viruses. As a first step toward addressing this hypothesis, midgut bacterial communities were compared between Culicoides species expected to be efficient and inefficient vectors of virus pathogens. We used 16S rDNA sequence and restriction fragment information to provisionally identify 36 bacterial genera from guts of wild adult female biting midges, Culicoides sonorensis Wirth and Jones and Culicoides variipennis (Coquillet), from two geographical locations. Bacterial identification was made by sequence analysis of 16S rDNA fragments and by terminal restriction fragment length polymorphism analysis of polymerase chain reaction-amplified 16S rDNA fragments from adult guts. Of 36 bacterial genera identified, 12 had been previously identified in other insects: Comomonas, Enterobacter, Klebsiella, Acinetobacter, Pseudomonas, Stenotrophomonas, Staphylococcus, Chryseobacterium, Moraxella, Acholeplasma, Flavobacterium, and Rickettsia, Significant differences in bacterial community composition were found between all three groups of wild adult females analyzed: live-trapped C. sonorensis, laboratory-emerged C. sonorensis, and laboratory-emerged C. variipennis.

  18. Effect of Temperature on Replication of Epizootic Hemorrhagic Disease Viruses in Culicoides sonorensis (Diptera: Ceratopogonidae).

    PubMed

    Ruder, Mark G; Stallknecht, David E; Howerth, Elizabeth W; Carter, Deborah L; Pfannenstiel, Robert S; Allison, Andrew B; Mead, Daniel G

    2015-09-01

    Replication of arboviruses, including orbiviruses, within the vector has been shown to be temperature dependent. Cooler ambient temperatures slow virus replication in arthropod vectors, whereas viruses replicate faster and to higher titers at warmer ambient temperatures. Previous research with epizootic hemorrhagic disease virus (EHDV) serotype 1 demonstrated that higher temperatures were associated with shorter extrinsic incubation periods in Culicoides sonorensis Wirth & Jones, a confirmed vector of EHDV in North America. To further our understanding of the effect of temperature on replication of EHDV within the vector, C. sonorensis were experimentally infected with one of three EHDV strains representing three serotypes (1, 2, and 7). Midges were fed defibrinated white-tailed deer (Odocoileus virginianus) blood spiked with EHDV (≥10(6.5) TCID(50)/ml) through a parafilm membrane using an artificial feeding device and were then held at 20, 25, or 30°C. In addition to this in vitro method, a white-tailed deer experimentally infected with EHDV-7 was used to provide an infectious bloodmeal to determine if the results were comparable with those from the in vitro feeding method. Whole midges were processed for virus isolation and titration at regular intervals following feeding; midges with ≥10(2.7) TCID(50) were considered potentially competent to transmit virus. The virus recovery rates were high throughout the study and all three viruses replicated within C. sonorensis to high titer (≥ 10(2.7) TCID(50)/midge). Across all virus strains, the time to detection of potentially competent midges decreased with increasing temperature: 12-16 d postfeeding (dpf) at 20°C, 4-6 dpf at 25°C, and 2-4 dpf at 30°C. Significant differences in replication of the three viruses in C. sonorensis were observed, with EHDV-2 replicating to a high titer in a smaller proportion of midges and with lower peak titers. The findings are consistent with previous studies of related

  19. Effect of Temperature on Replication of Epizootic Hemorrhagic Disease Viruses in Culicoides sonorensis (Diptera: Ceratopogonidae).

    PubMed

    Ruder, Mark G; Stallknecht, David E; Howerth, Elizabeth W; Carter, Deborah L; Pfannenstiel, Robert S; Allison, Andrew B; Mead, Daniel G

    2015-09-01

    Replication of arboviruses, including orbiviruses, within the vector has been shown to be temperature dependent. Cooler ambient temperatures slow virus replication in arthropod vectors, whereas viruses replicate faster and to higher titers at warmer ambient temperatures. Previous research with epizootic hemorrhagic disease virus (EHDV) serotype 1 demonstrated that higher temperatures were associated with shorter extrinsic incubation periods in Culicoides sonorensis Wirth & Jones, a confirmed vector of EHDV in North America. To further our understanding of the effect of temperature on replication of EHDV within the vector, C. sonorensis were experimentally infected with one of three EHDV strains representing three serotypes (1, 2, and 7). Midges were fed defibrinated white-tailed deer (Odocoileus virginianus) blood spiked with EHDV (≥10(6.5) TCID(50)/ml) through a parafilm membrane using an artificial feeding device and were then held at 20, 25, or 30°C. In addition to this in vitro method, a white-tailed deer experimentally infected with EHDV-7 was used to provide an infectious bloodmeal to determine if the results were comparable with those from the in vitro feeding method. Whole midges were processed for virus isolation and titration at regular intervals following feeding; midges with ≥10(2.7) TCID(50) were considered potentially competent to transmit virus. The virus recovery rates were high throughout the study and all three viruses replicated within C. sonorensis to high titer (≥ 10(2.7) TCID(50)/midge). Across all virus strains, the time to detection of potentially competent midges decreased with increasing temperature: 12-16 d postfeeding (dpf) at 20°C, 4-6 dpf at 25°C, and 2-4 dpf at 30°C. Significant differences in replication of the three viruses in C. sonorensis were observed, with EHDV-2 replicating to a high titer in a smaller proportion of midges and with lower peak titers. The findings are consistent with previous studies of related

  20. Lack of Evidence for Laboratory and Natural Vertical Transmission of Bluetongue Virus in Culicoides sonorensis (Diptera: Ceratopogonidae).

    PubMed

    Osborne, C J; Mayo, C E; Mullens, B A; McDermott, E G; Gerry, A C; Reisen, W K; MacLachlan, N J

    2015-03-01

    Culicoides sonorensis (Wirth & Jones) is the principal North American vector of bluetongue virus (BTV). BTV infection of livestock is distinctly seasonal (late summer and fall) in temperate regions of the world such as California, which has led to speculation regarding vertical transmission of the virus within the midge vector as a potential mechanism for interseasonal maintenance ("overwintering") of the virus. To evaluate potential vertical transmission of BTV in its midge vector, we fed adult midges BTV-spiked blood and used a BTV-specific quantitative reverse transcriptase polymerase chain reaction assay to evaluate parent, egg, and progeny stages of laboratory-reared C. sonorensis for the presence of viral nucleic acid. Whereas BTV nucleic acid was weakly detected in egg batches of virus-fed female midges, virus was never detected in subsequent progeny stages (larvae, pupae, and F1 generation adults). Similarly, BTV was not detected in pools of larvae collected from the waste-water lagoon of a BTV-endemic dairy farm in northern California during the seasonal period of virus transmission. Collectively, these results indicate that BTV is not readily transmitted vertically in C. sonorensis, and that persistence of the virus in long-lived parous female midges is a more likely mechanism for overwintering of BTV in temperate regions. PMID:26336312

  1. Lack of Evidence for Laboratory and Natural Vertical Transmission of Bluetongue Virus in Culicoides sonorensis (Diptera: Ceratopogonidae)

    PubMed Central

    Mayo, C. E.; Mullens, B. A.; McDermott, E. G.; Gerry, A. C.; Reisen, W. K.; MacLachlan, N. J.

    2015-01-01

    Culicoides sonorensis (Wirth & Jones) is the principal North American vector of bluetongue virus (BTV). BTV infection of livestock is distinctly seasonal (late summer and fall) in temperate regions of the world such as California, which has led to speculation regarding vertical transmission of the virus within the midge vector as a potential mechanism for interseasonal maintenance (“overwintering”) of the virus. To evaluate potential vertical transmission of BTV in its midge vector, we fed adult midges BTV-spiked blood and used a BTV-specific quantitative reverse transcriptase polymerase chain reaction assay to evaluate parent, egg, and progeny stages of laboratory-reared C. sonorensis for the presence of viral nucleic acid. Whereas BTV nucleic acid was weakly detected in egg batches of virus-fed female midges, virus was never detected in subsequent progeny stages (larvae, pupae, and F1 generation adults). Similarly, BTV was not detected in pools of larvae collected from the waste-water lagoon of a BTV-endemic dairy farm in northern California during the seasonal period of virus transmission. Collectively, these results indicate that BTV is not readily transmitted vertically in C. sonorensis, and that persistence of the virus in long-lived parous female midges is a more likely mechanism for overwintering of BTV in temperate regions. PMID:26336312

  2. Inducing RNA interference in the arbovirus vector, Culicoides sonorensis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biting midges in the genus Culicoides are important vectors of arboviral diseases, including Epizootic Hemorrhagic Disease, Bluetongue, and likely Schmallenberg, which cause significant economic burden worldwide. Research on these vectors has been hindered by the lack of a sequenced genome, the diff...

  3. Distribution of Culicoides sonorensis (Diptera: Ceratopogonidae) in Alberta, Canada.

    PubMed

    Lysyk, T J; Dergousoff, S J

    2014-05-01

    The distribution of Culicoides sonorensis Wirth and Jones was examined in Alberta, Canada. Sampling was conducted weekly using blacklight traps at eight locations in 2009, and 10 locations during 2010-2012. Nine supplemental sites were sampled twice annually during both 2011 and 2012. Abundance of C. sonorensis was consistently greatest at a site near the U.S. border, and declined in a northerly direction. Mean annual abundance at this site ranged from 6.4- to > 1,000-fold greater across positive sites. Data from a less extensive survey conducted during 2002-2006 were included in the remaining analyses. C. sonorensis was distributed below a diagonal spanning 49 degrees 30' N, 113 degrees 0' W to 51 degrees 21' N, 110 degrees 40' W. The relationship between the proportion of weekly samples positive and mean annual abundance at a site was determined and indicated that the proportion of positive samples could be used as a surrogate measure of abundance to overcome issues associated with the extreme variation in abundance. A series of logistic regression models were developed and evaluated to determine the effects of spatial (latitude and longitude), climatic (historic temperature and precipitation during the warmest quarter), and weather (temperature during the sample interval and spring precipitation) on abundance as measured by the proportion of positive samples. Spatial and climatic variables set the overall level of abundance, while weather variables added seasonal fluctuations within years, and also fluctuations between years. These data will be useful for long-term monitoring of C. sonorensis and as a baseline for detecting shifts in abundance that might occur because of climate change. PMID:24897848

  4. Biting midges of the genus Culicoides in South Carolina zoos.

    PubMed

    Nelder, Mark P; Swanson, Dustin A; Adler, Peter H; Grogan, William L

    2010-01-01

    Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) were collected during the summer of 2007 at the Greenville and Riverbanks Zoos in South Carolina with Centers for Disease Control and Prevention (CDC) traps equipped with ultraviolet or incandescent lights and baited with carbon dioxide. Sixteen species of Culicoides were collected, four of which represented more than 80%. They were Culicoides guttipennis (Coquillett), Culicoides mulrenanni Beck, Culicoides obsoletus (Meigen), and Culicoides sanguisuga (Coquillett). C. guttipennis was found on a dead colobus monkey and a dead golden-headed lion tamarin; Culicoides husseyi Wirth & Blanton was collected from an unidentified, abandoned bird's nest. Ultraviolet light-equipped traps captured significantly more Culicoides specimens than traps with incandescent light. Half of the collected species previously have been associated with vertebrate pathogens, indicating a potential risk to captive animals.

  5. Impact of the blood meal on humoral immunity and microbiota in the gut of female Culicoides sonorensis.

    PubMed

    Nayduch, Dana; Erram, Dinesh; Lee, Matthew B; Zurek, Ludek; Saski, Christopher A

    2015-01-01

    Although Culicoides sonorensis is an important vector of orbiviruses causing significant disease in domestic and wild ruminants in the USA, little is known about factors contributing to midge vector competence. In other vectors such as mosquitoes, interactions among the humoral immune response, microbiota, and ingested pathogens within the vector gut directly impact pathogen survival and therefore vectoring potential. We recently described components of the humoral immune response in the reference transcriptome for adult female C. sonorensis and analysed their temporal expression profiles across several dietary states (unfed, blood, or sugar fed). Blood feeding altered the transcription of several humoral immune components of the Immune deficiency (Imd), dual‑oxidase (DUOX), and Janus Kinase and Signal Transducer and Activator of Transcription (JAK/STAT) pathways. Genes for immune effectors, such as antimicrobial peptides, were in particular highly induced. Since blood feeding also stimulated proliferation and diversification of bacterial populations colonising the gut of female midges, we infer that changes in immune gene expression were a result of fluctuations in gut microbiota. Thus, diet can indirectly (via microbiota) impact gut immune status and therefore should be carefully considered in subsequent studies assessing vector competence in biting midges. PMID:26741251

  6. Effects of Melezitose and Stachyose on Adult Longevity and Virus Persistence in Culicoides Sonorensis (Diptera: Ceratopogonidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A wide variety of blood feeding Diptera feed on extrafloral sugar sources such as homopteran honeydew. he significance of these sugar sources to insect survival and disease transmission are poorly known. Culicoides sonorensis can survive on plant sugars but might feed on homopteran honeydew. The su...

  7. Vector competence of Culicoides sonorensis (Diptera: Ceratopogonidae) to epizootic hemorrhagic disease virus serotype 7

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Culicoides sonorensis (Diptera: Ceratopogonidae) is a vector of epizootic hemorrhagic disease virus (EHDV) serotypes 1 and 2 in North America, where these viruses are well-known pathogens of white-tailed deer (WTD) and other wild ruminants. Although historically rare, reports of clinica...

  8. Culicoides midge trap enhancement with animal odour baits in Scotland.

    PubMed

    Mands, V; Kline, D L; Blackwell, A

    2004-12-01

    Examples of the commercial trap Mosquito Magnet Pro (MMP emitting attractant 1-octen-3-ol in carbon dioxide 500 mL/min generated from propane fuel), were run 24 h/day on the Isle of Skye, Scotland, during June-August 2001 and evaluated for catching Culicoides biting midges (Diptera: Ceratopogonidae). From 30 days trapping, the catch averaged 2626 +/- 1358 Culicoides females/trap/day (mean +/- SE, range 558 +/- 139 to 6088 +/- 3597, for five sets of six consecutive nights), predominantly the pest Culicoides impunctatus Goetghebuer (68% overall), plus C. vexans (Staeger) > C. delta Edwards > C. pulicaris (L.) > C. lupicaris Downs & Kettle > C. albicans (Winnertz) > other Culicoides spp. Attempts were made to enhance the odour baiting system by adding hexane-extracts (2.1 mg/day) of hair samples from large host animals, resulting in the following effects on Culicoides collections: sheep - 53 %, red deer - 26 %, calf + 20%, pony + 40%, water buffalo + 262%, with greatest increases for C. impunctatus and C. pulicaris. Serial concentrations of these animal extracts (10(-1) - 10(-3) x 2.2 g/mL) were assayed on parous female C. impunctatus response in a Y-tube olfactometer (air-flow 150 mL/min), and by electroantennogram (EAG) on Culicoides nubeculosus Meigen laboratory-reared parous females. Positive behavioural responses to host odours were dose-dependent: the water buffalo extract being most active (threshold 0.22 g/mL), similar to deer, whereas other host extracts were > or = 10-fold less active. Correspondingly, the EAG threshold was lowest for water buffalo, 10-fold greater for deer, calf and pony, but not detected for sheep. If the active component(s) of these host extracts can be identified and synthesized, they might be employed to improve the capture of Culicoides midges for local control by removal trapping.

  9. Culicoides biting midges, arboviruses and public health in Europe.

    PubMed

    Carpenter, Simon; Groschup, Martin H; Garros, Claire; Felippe-Bauer, Maria Luiza; Purse, Bethan V

    2013-10-01

    The emergence of multiple strains of bluetongue virus (BTV) and the recent discovery of Schmallenberg virus (SBV) in Europe have highlighted the fact that exotic Culicoides-borne arboviruses from remote geographic areas can enter and spread rapidly in this region. This review considers the potential for this phenomenon to impact on human health in Europe, by examining evidence of the role of Culicoides biting midges in the zoonotic transmission and person-to-person spread of arboviruses worldwide. To date, the only arbovirus identified as being primarily transmitted by Culicoides to and between humans is Oropouche virus (OROV). This member of the genus Orthobunyavirus causes major epidemics of febrile illness in human populations of South and Central America and the Caribbean. We examine factors promoting sustained outbreaks of OROV in Brazil from an entomological perspective and assess aspects of the epidemiology of this arbovirus that are currently poorly understood, but may influence the risk of incursion into Europe. We then review the secondary and rarely reported role of Culicoides in the transmission of high-profile zoonotic infections, while critically reviewing evidence of this phenomenon in endemic transmission and place this in context with the presence of other potential vector groups in Europe. Scenarios for the incursions of Culicoides-borne human-to-human transmitted and zoonotic arboviruses are then discussed, along with control measures that could be employed to reduce their impact. These measures are placed in the context of legislative measures used during current and ongoing outbreaks of Culicoides-borne arboviruses in Europe, involving both veterinary and public health sectors.

  10. Modelling the Northward Expansion of Culicoides sonorensis (Diptera: Ceratopogonidae) under Future Climate Scenarios.

    PubMed

    Zuliani, Anna; Massolo, Alessandro; Lysyk, Timothy; Johnson, Gregory; Marshall, Shawn; Berger, Kathryn; Cork, Susan Catherine

    2015-01-01

    Climate change is affecting the distribution of pathogens and their arthropod vectors worldwide, particularly at northern latitudes. The distribution of Culicoides sonorensis (Diptera: Ceratopogonidae) plays a key role in affecting the emergence and spread of significant vector borne diseases such as Bluetongue (BT) and Epizootic Hemorrhagic Disease (EHD) at the border between USA and Canada. We used 50 presence points for C. sonorensis collected in Montana (USA) and south-central Alberta (Canada) between 2002 and 2012, together with monthly climatic and environmental predictors to develop a series of alternative maximum entropy distribution models. The best distribution model under current climatic conditions was selected through the Akaike Information Criterion, and included four predictors: Vapour Pressure Deficit of July, standard deviation of Elevation, Land Cover and mean Precipitation of May. This model was then projected into three climate change scenarios adopted by the IPCC in its 5th assessment report and defined as Representative Concentration Pathways (RCP) 2.6, 4.5 and 8.5. Climate change data for each predictor and each RCP were calculated for two time points pooling decadal data around each one of them: 2030 (2021-2040) and 2050 (2041-2060). Our projections showed that the areas predicted to be at moderate-high probability of C. sonorensis occurrence would increase from the baseline scenario to 2030 and from 2030 to 2050 for each RCP. The projection also indicated that the current northern limit of C. sonorensis distribution is expected to move northwards to above 53°N. This may indicate an increased risk of Culicoides-borne diseases occurrence over the next decades, particularly at the USA-Canada border, as a result of changes which favor C. sonorensis presence when associated to other factors (i.e. host and pathogen factors). Recent observations of EHD outbreaks in northern Montana and southern Alberta supported our projections and considerations

  11. Modelling the Northward Expansion of Culicoides sonorensis (Diptera: Ceratopogonidae) under Future Climate Scenarios

    PubMed Central

    Lysyk, Timothy; Johnson, Gregory; Marshall, Shawn; Berger, Kathryn; Cork, Susan Catherine

    2015-01-01

    Climate change is affecting the distribution of pathogens and their arthropod vectors worldwide, particularly at northern latitudes. The distribution of Culicoides sonorensis (Diptera: Ceratopogonidae) plays a key role in affecting the emergence and spread of significant vector borne diseases such as Bluetongue (BT) and Epizootic Hemorrhagic Disease (EHD) at the border between USA and Canada. We used 50 presence points for C. sonorensis collected in Montana (USA) and south-central Alberta (Canada) between 2002 and 2012, together with monthly climatic and environmental predictors to develop a series of alternative maximum entropy distribution models. The best distribution model under current climatic conditions was selected through the Akaike Information Criterion, and included four predictors: Vapour Pressure Deficit of July, standard deviation of Elevation, Land Cover and mean Precipitation of May. This model was then projected into three climate change scenarios adopted by the IPCC in its 5th assessment report and defined as Representative Concentration Pathways (RCP) 2.6, 4.5 and 8.5. Climate change data for each predictor and each RCP were calculated for two time points pooling decadal data around each one of them: 2030 (2021–2040) and 2050 (2041–2060). Our projections showed that the areas predicted to be at moderate-high probability of C. sonorensis occurrence would increase from the baseline scenario to 2030 and from 2030 to 2050 for each RCP. The projection also indicated that the current northern limit of C. sonorensis distribution is expected to move northwards to above 53°N. This may indicate an increased risk of Culicoides-borne diseases occurrence over the next decades, particularly at the USA-Canada border, as a result of changes which favor C. sonorensis presence when associated to other factors (i.e. host and pathogen factors). Recent observations of EHD outbreaks in northern Montana and southern Alberta supported our projections and

  12. Culicoides sonorensis (Diptera: Ceratopogonidae) is not a competent vector of Cache Valley virus (family Bunyaviridae, genus Orthobunyavirus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We investigated the susceptibility of Culicoides sonorensis to Cache Valley virus (CVV) (family Bunyaviridae, genus Orthobunyavirus) infection and the potential that it could be a vector or site of virus reassortment. CVV is native to the New World and causes disease in livestock. Infected blood mea...

  13. Repellent pesticides for the control of Culicoides sonorensis on sheep

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bluetongue disease is a sporadic and unpredictable disease in the northern Rocky Mountains. Epizootics can be separated by decades of little to no disease activity. Woolgrowers need access to control technologies that can be used after an outbreak is detected. We tested 6 formulations of midge repel...

  14. First detection of endosymbiotic bacteria in biting midges Culicoides pulicaris and Culicoides punctatus, important Palaearctic vectors of bluetongue virus.

    PubMed

    Lewis, S E; Rice, A; Hurst, G D D; Baylis, M

    2014-12-01

    Heritable bacteria have been highlighted as important components of vector biology, acting as required symbionts with an anabolic role, altering competence for disease transmission, and affecting patterns of gene flow by altering cross compatibility. In this paper, we tested eight U.K. species of Culicoides (Diptera: Ceratopogonidae) midge for the presence of five genera of endosymbiotic bacteria: Cardinium (Bacteroidales: Bacteroidaceae); Wolbachia (Rickettsiales: Rickettsiaceae); Spiroplasma (Entomoplasmatales: Spiroplasmataceae); Arsenophonus (Enterobacteriales: Enterobacteriaceae), and Rickettsia (Rickettsiales: Rickettsiaceae). Cardinium spp. were detected in both sexes of Culicoides pulicaris and Culicoides punctatus, two known vectors of bluetongue virus. Cardinium spp. were not detected in any other species, including the Culicoides obsoletus group, the main vector of bluetongue and Schmallenberg viruses in northern Europe. The other endosymbionts were not detected in any Culicoides species. The Cardinium strain detected in U.K. Culicoides species is very closely related to the Candidatus Cardinium hertigii group C, previously identified in Culicoides species in Asia. Further, we infer that the symbiont is not a sex ratio distorter and shows geographic variation in prevalence within a species. Despite its detection in several species of Culicoides that vector arboviruses worldwide, the absence of Cardinium in the C. obsoletus group suggests that infections of these symbionts may not be necessary to the arboviral vector competence of biting midges.

  15. Field morphological variation and laboratory hybridization of Culicoides variipennis sonorensis and C. v. occidentalis (Diptera:Ceratopogonidae) in southern California.

    PubMed

    Velten, R K; Mullens, B A

    1997-05-01

    Two field populations of Culicoides variipennis (Coquillett) from southern California, C. v. occidentalis Wirth & Jones from the Salton Sea and C. v. sonorensis Wirth & Jones from a dairy wastewater pond in the Chino Basin, were sampled monthly from February to July (6-7 mo). Morphometric analyses of slide-mounted adults reared from field-collected larvae and pupae indicated that females of the 2 forms were indistinguishable. Two of the standard characters, wing length and mandibular teeth, were correlated with seasonal temperature changes. Males of C. v. sonorensis were distinguishable by the presence of spicules on the aedeagus, which were entirely lacking in C. v. occidentalis. Two populations of C. v. occidentalis (Salton Sea and Bolsa Chica Marsh) and a laboratory strain of C. v. sonorensis hybridized successfully in the laboratory and were maintained for 6 generations. Differential hybrid viability (F1) was observed in reciprocal crosses. Males of C. v. occidentalis mated with females of C. v. sonorensis resulted in a lower egg hatch (7.4%) than did the reciprocal cross (75.6%). Hybrid males displayed spicules on the aedeagus (a character of C. v. sonorensis), but the number of spicules was sometimes reduced compared with parental C. v. sonorensis (AA strain). Spicules in a field population of C. v. sonorensis were similar in number to the laboratory C. v. sonorensis-C. v. occidentalis hybrids. Based on successful hybridization, the 2 forms should be considered closely related. The 2 forms are separated ecologically by the nature and distribution of their larval habitats. PMID:9151490

  16. Insecticidal sugar baits for adult biting midges

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the latest trends in mosquito control is the use of insecticidal sugar baits (ISBs) to reduce adult mosquito populations. Tested here is the ability of ISB’s to knock-down the biting midge, Culicoides sonorensis, a disease vector of bluetongue, epizootic hemorrhagic disease, and vesicular sto...

  17. Identity and diversity of blood meal hosts of biting midges (Diptera: Ceratopogonidae: Culicoides Latreille) in Denmark

    PubMed Central

    2012-01-01

    Background Host preference studies in haematophagous insects e.g. Culicoides biting midges are pivotal to assess transmission routes of vector-borne diseases and critical for the development of veterinary contingency plans to identify which species should be included due to their risk potential. Species of Culicoides have been found in almost all parts of the world and known to live in a variety of habitats. Several parasites and viruses are transmitted by Culicoides biting midges including Bluetongue virus and Schmallenberg virus. The aim of the present study was to determine the identity and diversity of blood meals taken from vertebrate hosts in wild-caught Culicoides biting midges near livestock farms. Methods Biting midges were collected at weekly intervals for 20 weeks from May to October 2009 using light traps at four collection sites on the island Sealand, Denmark. Blood-fed female biting midges were sorted and head and wings were removed for morphological species identification. The thoraxes and abdomens including the blood meals of the individual females were subsequently subjected to DNA isolation. The molecular marker cytochrome oxidase I (COI barcode) was applied to identify the species of the collected biting midges (GenBank accessions JQ683259-JQ683374). The blood meals were first screened with a species-specific cytochrome b primer pair for cow and if negative with a universal cytochrome b primer pair followed by sequencing to identify mammal or avian blood meal hosts. Results Twenty-four species of biting midges were identified from the four study sites. A total of 111,356 Culicoides biting midges were collected, of which 2,164 were blood-fed. Specimens of twenty species were identified with blood in their abdomens. Blood meal sources were successfully identified by DNA sequencing from 242 (76%) out of 320 Culicoides specimens. Eight species of mammals and seven species of birds were identified as blood meal hosts. The most common host species was

  18. Abundance of biting midge species (Diptera: Ceratopogonidae, Culicoides spp.) on cattle farms in Korea

    PubMed Central

    Oem, Jae-Ku; Chung, Joon-Yee; Kwon, Mee-Soon; Kim, Toh-Kyung; Lee, Tae-Uk

    2013-01-01

    Culicoides biting midges were collected on three cattle farms weekly using light traps overnight from May to October between 2010 and 2011 in the southern part of Korea. The seasonal and geographical abundance of Culicodes spp. were measured. A total of 16,538 biting midges were collected from 2010 to 2011, including seven species of Culicoides, four of which represented 98.42% of the collected specimens. These four species were Culicodes (C.) punctatus (n = 14,413), C. arakawae (n = 1,120), C. oxystoma (n = 427), and C. maculatus (n = 318). C. punctatus was the predominant species (87.15%). PMID:23388441

  19. Seasonal variation and impact of waste-water lagoons as larval habitat on the population dynamics of Culicoides sonorensis (Diptera:Ceratpogonidae) at two dairy farms in northern California.

    PubMed

    Mayo, Christie E; Osborne, Cameron J; Mullens, Bradley A; Gerry, Alec C; Gardner, Ian A; Reisen, William K; Barker, Christopher M; Maclachlan, N James

    2014-01-01

    The Sacramento (northern Central) Valley of California (CA) has a hot Mediterranean climate and a diverse ecological landscape that is impacted extensively by human activities, which include the intensive farming of crops and livestock. Waste-water ponds, marshes, and irrigated fields associated with these agricultural activities provide abundant larval habitats for C. sonorensis midges, in addition to those sites that exist in the natural environment. Within this region, C. sonorensis is an important vector of bluetongue (BTV) and related viruses that adversely affect the international trade and movement of livestock, the economics of livestock production, and animal welfare. To characterize the seasonal dynamics of immature and adult C. sonorensis populations, abundance was monitored intensively on two dairy farms in the Sacramento Valley from August 2012- to July 2013. Adults were sampled every two weeks for 52 weeks by trapping (CDC style traps without light and baited with dry-ice) along N-S and E-W transects on each farm. One farm had large operational waste-water lagoons, whereas the lagoon on the other farm was drained and remained dry during the study. Spring emergence and seasonal abundance of adult C. sonorensis on both farms coincided with rising vernal temperature. Paradoxically, the abundance of midges on the farm without a functioning waste-water lagoon was increased as compared to abundance on the farm with a waste-water lagoon system, indicating that this infrastructure may not serve as the sole, or even the primary larval habitat. Adult midges disappeared from both farms from late November until May; however, low numbers of parous female midges were detected in traps set during daylight in the inter-seasonal winter period. This latter finding is especially critical as it provides a potential mechanism for the "overwintering" of BTV in temperate regions such as northern CA. Precise documentation of temporal changes in the annual abundance and

  20. Seasonal Variation and Impact of Waste-Water Lagoons as Larval Habitat on the Population Dynamics of Culicoides sonorensis (Diptera:Ceratpogonidae) at Two Dairy Farms in Northern California

    PubMed Central

    Mayo, Christie E.; Osborne, Cameron J.; Mullens, Bradley A.; Gerry, Alec C.; Gardner, Ian A.; Reisen, William K.; Barker, Christopher M.; MacLachlan, N. James

    2014-01-01

    The Sacramento (northern Central) Valley of California (CA) has a hot Mediterranean climate and a diverse ecological landscape that is impacted extensively by human activities, which include the intensive farming of crops and livestock. Waste-water ponds, marshes, and irrigated fields associated with these agricultural activities provide abundant larval habitats for C. sonorensis midges, in addition to those sites that exist in the natural environment. Within this region, C. sonorensis is an important vector of bluetongue (BTV) and related viruses that adversely affect the international trade and movement of livestock, the economics of livestock production, and animal welfare. To characterize the seasonal dynamics of immature and adult C. sonorensis populations, abundance was monitored intensively on two dairy farms in the Sacramento Valley from August 2012– to July 2013. Adults were sampled every two weeks for 52 weeks by trapping (CDC style traps without light and baited with dry-ice) along N-S and E-W transects on each farm. One farm had large operational waste-water lagoons, whereas the lagoon on the other farm was drained and remained dry during the study. Spring emergence and seasonal abundance of adult C. sonorensis on both farms coincided with rising vernal temperature. Paradoxically, the abundance of midges on the farm without a functioning waste-water lagoon was increased as compared to abundance on the farm with a waste-water lagoon system, indicating that this infrastructure may not serve as the sole, or even the primary larval habitat. Adult midges disappeared from both farms from late November until May; however, low numbers of parous female midges were detected in traps set during daylight in the inter-seasonal winter period. This latter finding is especially critical as it provides a potential mechanism for the “overwintering” of BTV in temperate regions such as northern CA. Precise documentation of temporal changes in the annual abundance and

  1. Seasonal variation and impact of waste-water lagoons as larval habitat on the population dynamics of Culicoides sonorensis (Diptera:Ceratpogonidae) at two dairy farms in northern California.

    PubMed

    Mayo, Christie E; Osborne, Cameron J; Mullens, Bradley A; Gerry, Alec C; Gardner, Ian A; Reisen, William K; Barker, Christopher M; Maclachlan, N James

    2014-01-01

    The Sacramento (northern Central) Valley of California (CA) has a hot Mediterranean climate and a diverse ecological landscape that is impacted extensively by human activities, which include the intensive farming of crops and livestock. Waste-water ponds, marshes, and irrigated fields associated with these agricultural activities provide abundant larval habitats for C. sonorensis midges, in addition to those sites that exist in the natural environment. Within this region, C. sonorensis is an important vector of bluetongue (BTV) and related viruses that adversely affect the international trade and movement of livestock, the economics of livestock production, and animal welfare. To characterize the seasonal dynamics of immature and adult C. sonorensis populations, abundance was monitored intensively on two dairy farms in the Sacramento Valley from August 2012- to July 2013. Adults were sampled every two weeks for 52 weeks by trapping (CDC style traps without light and baited with dry-ice) along N-S and E-W transects on each farm. One farm had large operational waste-water lagoons, whereas the lagoon on the other farm was drained and remained dry during the study. Spring emergence and seasonal abundance of adult C. sonorensis on both farms coincided with rising vernal temperature. Paradoxically, the abundance of midges on the farm without a functioning waste-water lagoon was increased as compared to abundance on the farm with a waste-water lagoon system, indicating that this infrastructure may not serve as the sole, or even the primary larval habitat. Adult midges disappeared from both farms from late November until May; however, low numbers of parous female midges were detected in traps set during daylight in the inter-seasonal winter period. This latter finding is especially critical as it provides a potential mechanism for the "overwintering" of BTV in temperate regions such as northern CA. Precise documentation of temporal changes in the annual abundance and

  2. Non-structural protein NS3/NS3a is required for propagation of bluetongue virus in Culicoides sonorensis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Bluetongue virus (BTV) causes non-contagious haemorrhagic disease in ruminants and is transmitted by Culicoides spp. biting midges. BTV encodes four non-structural proteins of which NS3/NS3a is functional in virus release. NS3/NS3a is not essential for in vitro virus replication. However...

  3. Management of North American Culicoides biting midges: Current knowledge and research needs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Culicoides biting midges (Diptera: Ceratopogonidae) are biological vectors of two important viruses infecting North American ruminants: bluetongue (BTV) and epizootic hemorrhagic disease (EHDV). While these viruses have been identified for over 60 years, we still lack an adequate understanding of t...

  4. Understanding and exploiting olfaction for the surveillance and control of Culicoides biting midges

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Culicoides midges (Diptera: Ceratopogonidae) are found worldwide with the exception of only a few countries including New Zealand, Patagonia, the Hawaiian Isles and Antarctica. They are a nuisance pest to human beings, but transmit a number of diseases that mainly affect livestock. Like many haema...

  5. Comparison of different light sources for trapping Culicoides biting midges, mosquitoes and other dipterans.

    PubMed

    González, Mikel; Alarcón-Elbal, Pedro María; Valle-Mora, Javier; Goldarazena, Arturo

    2016-08-15

    The response of Culicoides biting midges, mosquitoes and other dipterans to different wavelengths was evaluated in a farm meadow in northern Spain. A total of 9449 specimens of 23 species of Culicoides, 5495 other ceratopogonids (non-biting midges), 602 culicids and 12428 other mixed dipterans were captured. Centers for Disease Control and Prevention (CDC) suction light traps fitted with five light emitting diodes (LEDs) (white, green, red, blue, ultraviolet) were run for 15 consecutive nights. Significantly more Culicoides were collected in those traps fitted with green, blue or ultraviolet (UV) lights than in red and white-baited LED traps for the most abundant species captured: C. punctatus (37.5%), C. cataneii (26.5%) and C. obsoletus/C. scoticus (20.4%). Similar results were obtained for non-Culicoides ceratopogonids, mosquitoes and other mixed dipterans. Wavelengths in green (570nm) resulted effective for targeting some Culicoides species, culicids and other midges. In a second trial, the effectiveness of 4-W white and UV tubes was compared to traps fitted with UV LED and a standard incandescent light bulb. More specimens of all taxa were collected with fluorescent black light (UV) traps than with the other light sources, except culicids, which were recovered in high numbers from fluorescent white light traps. PMID:27514882

  6. Development and evaluation of real-time PCR assays for bloodmeal identification in Culicoides midges.

    PubMed

    VAN DER Saag, M R; Gu, X; Ward, M P; Kirkland, P D

    2016-06-01

    Culicoides (Diptera: Ceratopogonidae) midges are the biological vectors of a number of arboviruses of veterinary importance. However, knowledge relating to the basic biology of some species, including their host-feeding preferences, is limited. Identification of host-feeding preferences in haematophagous insects can help to elucidate the transmission dynamics of the arboviruses they may transmit. In this study, a series of semi-quantitative real-time polymerase chain reaction (qPCR) assays to identify the vertebrate host sources of bloodmeals of Culicoides midges was developed. Two pan-reactive species group and seven species-specific qPCR assays were developed and evaluated. The assays are quick to perform and less expensive than nucleic acid sequencing of bloodmeals. Using these assays, it was possible to rapidly test nearly 700 blood-fed midges of various species from several geographic locations in Australia. PMID:26854008

  7. Identification of the Genome Segments of Bluetongue Virus Serotype 26 (Isolate KUW2010/02) that Restrict Replication in a Culicoides sonorensis Cell Line (KC Cells)

    PubMed Central

    Pullinger, Gillian D.; Guimerà Busquets, Marc; Nomikou, Kyriaki; Boyce, Mark; Attoui, Houssam; Mertens, Peter P.

    2016-01-01

    Bluetongue virus (BTV) can infect most ruminant species and is usually transmitted by adult, vector-competent biting midges (Culicoides spp.). Infection with BTV can cause severe clinical signs and can be fatal, particularly in naïve sheep and some deer species. Although 24 distinct BTV serotypes were recognized for several decades, additional ‘types’ have recently been identified, including BTV-25 (from Switzerland), BTV-26 (from Kuwait) and BTV-27 from France (Corsica). Although BTV-25 has failed to grow in either insect or mammalian cell cultures, BTV-26 (isolate KUW2010/02), which can be transmitted horizontally between goats in the absence of vector insects, does not replicate in a Culicoides sonorensis cell line (KC cells) but can be propagated in mammalian cells (BSR cells). The BTV genome consists of ten segments of linear dsRNA. Mono-reassortant viruses were generated by reverse-genetics, each one containing a single BTV-26 genome segment in a BTV-1 genetic-background. However, attempts to recover a mono-reassortant containing genome-segment 2 (Seg-2) of BTV-26 (encoding VP2), were unsuccessful but a triple-reassortant was successfully generated containing Seg-2, Seg-6 and Seg-7 (encoding VP5 and VP7 respectively) of BTV-26. Reassortants were recovered and most replicated well in mammalian cells (BSR cells). However, mono-reassortants containing Seg-1 or Seg-3 of BTV-26 (encoding VP1, or VP3 respectively) and the triple reassortant failed to replicate, while a mono-reassortant containing Seg-7 of BTV-26 only replicated slowly in KC cells. PMID:26890863

  8. Identification of the Genome Segments of Bluetongue Virus Serotype 26 (Isolate KUW2010/02) that Restrict Replication in a Culicoides sonorensis Cell Line (KC Cells).

    PubMed

    Pullinger, Gillian D; Guimerà Busquets, Marc; Nomikou, Kyriaki; Boyce, Mark; Attoui, Houssam; Mertens, Peter P

    2016-01-01

    Bluetongue virus (BTV) can infect most ruminant species and is usually transmitted by adult, vector-competent biting midges (Culicoides spp.). Infection with BTV can cause severe clinical signs and can be fatal, particularly in naïve sheep and some deer species. Although 24 distinct BTV serotypes were recognized for several decades, additional 'types' have recently been identified, including BTV-25 (from Switzerland), BTV-26 (from Kuwait) and BTV-27 from France (Corsica). Although BTV-25 has failed to grow in either insect or mammalian cell cultures, BTV-26 (isolate KUW2010/02), which can be transmitted horizontally between goats in the absence of vector insects, does not replicate in a Culicoides sonorensis cell line (KC cells) but can be propagated in mammalian cells (BSR cells). The BTV genome consists of ten segments of linear dsRNA. Mono-reassortant viruses were generated by reverse-genetics, each one containing a single BTV-26 genome segment in a BTV-1 genetic-background. However, attempts to recover a mono-reassortant containing genome-segment 2 (Seg-2) of BTV-26 (encoding VP2), were unsuccessful but a triple-reassortant was successfully generated containing Seg-2, Seg-6 and Seg-7 (encoding VP5 and VP7 respectively) of BTV-26. Reassortants were recovered and most replicated well in mammalian cells (BSR cells). However, mono-reassortants containing Seg-1 or Seg-3 of BTV-26 (encoding VP1, or VP3 respectively) and the triple reassortant failed to replicate, while a mono-reassortant containing Seg-7 of BTV-26 only replicated slowly in KC cells. PMID:26890863

  9. Culicoides Midge Bites Modulate the Host Response and Impact on Bluetongue Virus Infection in Sheep

    PubMed Central

    Pages, Nonito; Talavera, Sandra; Viarouge, Cyril; Lorca-Oro, Cristina; Jouneau, Luc; Charley, Bernard; Zientara, Stéphan; Bensaid, Albert; Solanes, David; Pujols, Joan; Schwartz-Cornil, Isabelle

    2014-01-01

    Many haematophagous insects produce factors that help their blood meal and coincidently favor pathogen transmission. However nothing is known about the ability of Culicoides midges to interfere with the infectivity of the viruses they transmit. Among these, Bluetongue Virus (BTV) induces a hemorrhagic fever- type disease and its recent emergence in Europe had a major economical impact. We observed that needle inoculation of BTV8 in the site of uninfected C. nubeculosus feeding reduced viraemia and clinical disease intensity compared to plain needle inoculation. The sheep that developed the highest local inflammatory reaction had the lowest viral load, suggesting that the inflammatory response to midge bites may participate in the individual sensitivity to BTV viraemia development. Conversely compared to needle inoculation, inoculation of BTV8 by infected C. nubeculosus bites promoted viraemia and clinical symptom expression, in association with delayed IFN- induced gene expression and retarded neutralizing antibody responses. The effects of uninfected and infected midge bites on BTV viraemia and on the host response indicate that BTV transmission by infected midges is the most reliable experimental method to study the physio-pathological events relevant to a natural infection and to pertinent vaccine evaluation in the target species. It also leads the way to identify the promoting viral infectivity factors of infected Culicoides in order to possibly develop new control strategies against BTV and other Culicoides transmitted viruses. PMID:24421899

  10. Culicoides midge bites modulate the host response and impact on bluetongue virus infection in sheep.

    PubMed

    Pages, Nonito; Bréard, Emmanuel; Urien, Céline; Talavera, Sandra; Viarouge, Cyril; Lorca-Oro, Cristina; Jouneau, Luc; Charley, Bernard; Zientara, Stéphan; Bensaid, Albert; Solanes, David; Pujols, Joan; Schwartz-Cornil, Isabelle

    2014-01-01

    Many haematophagous insects produce factors that help their blood meal and coincidently favor pathogen transmission. However nothing is known about the ability of Culicoides midges to interfere with the infectivity of the viruses they transmit. Among these, Bluetongue Virus (BTV) induces a hemorrhagic fever- type disease and its recent emergence in Europe had a major economical impact. We observed that needle inoculation of BTV8 in the site of uninfected C. nubeculosus feeding reduced viraemia and clinical disease intensity compared to plain needle inoculation. The sheep that developed the highest local inflammatory reaction had the lowest viral load, suggesting that the inflammatory response to midge bites may participate in the individual sensitivity to BTV viraemia development. Conversely compared to needle inoculation, inoculation of BTV8 by infected C. nubeculosus bites promoted viraemia and clinical symptom expression, in association with delayed IFN- induced gene expression and retarded neutralizing antibody responses. The effects of uninfected and infected midge bites on BTV viraemia and on the host response indicate that BTV transmission by infected midges is the most reliable experimental method to study the physio-pathological events relevant to a natural infection and to pertinent vaccine evaluation in the target species. It also leads the way to identify the promoting viral infectivity factors of infected Culicoides in order to possibly develop new control strategies against BTV and other Culicoides transmitted viruses.

  11. Vector species of Culicoides midges implicated in the 2012‑2014 Bluetongue epidemics in Italy.

    PubMed

    Goffredo, Maria; Catalani, Monica; Federici, Valentina; Portanti, Ottavio; Marini, Valeria; Mancini, Giuseppe; Quaglia, Michela; Santilli, Adriana; Teodori, Liana; Savini, Giovanni

    2015-01-01

    In 2012, serotypes 1 and 4 of bluetongue virus (BTV) entered and co‑circulated in Sardinia. The following year, BTV‑1 spread all over Sardinia and invaded Sicily and the Italian Tyrrenian coast. In 2014, this strain spread extensively in mainland Italy, causing severe outbreaks. In late 2014, BTV‑4 was detected in Southern Italy (Apulia region). This study reports the detection of BTV in species of Culicoides (Diptera: Ceratopogonidae) collected in Italy during the epidemics between 2012 and 2014. A total of 2,925 pools (83,102 midges), sorted from 651 collections made on 339 affected farms of 12 Italian regions, were tested for the presence of BTV by real time polymerase chain reaction (RT‑PCR). The study clearly shows that Culicoides imicola and Obsoletus complex have played a crucial role in the bluetongue (BT) epidemics in Italy in 2012‑2014. Nevertheless, it also shows that other species may have played a role in transmitting BTV during these outbreaks. Culicoides dewulfi and at least 3 species of the Pulicaris complex, namely Culicoides pulicaris, Culicoides newsteadi and Culicoides punctatus, were found positive to BTV. Serotype 1 was detected in all species tested, whereas the BTV‑4 was detected in the Obsoletus complex, C. imicola, and C. newsteadi.

  12. Influence of carbon dioxide on numbers of Culicoides midges collected with suction light traps in South Africa.

    PubMed

    Venter, G J; Boikanyo, S N B; Majatladi, D M; Morey, L

    2016-03-01

    To implement risk management against diseases transmitted by species of Culicoides Latreille, 1809 (Diptera: Ceratopogonidae), it is essential to identify all potential vectors. Light traps are the most commonly used tool for the collection of Culicoides midges. Given the indiscriminate artificial attraction of light, traps will collect all night-flying insects rather than only livestock-associated Culicoides midges. Factors that may increase the efficacy of traps, especially for livestock-associated Culicoides midges, require investigation. In the present study, results obtained with Centers for Disease Control (CDC) and Onderstepoort light traps baited with carbon dioxide (CO2 ) were compared with those of unbaited controls. Comparisons were made using two replicates of a 4 × 4 randomized Latin square design. With both trap types, the mean numbers of Culicoides midges collected in 16 baited traps were higher than those caught in 16 unbaited traps. Although exceptionally low numbers were collected with the CDC traps, the increases in the numbers and frequency of collection of Culicoides imicola Kieffer, 1913 were more pronounced in the CDC traps compared with the Onderstepoort traps. These results indicate that the addition of CO2 may increase the efficiency of these traps for the collection of C. imicola and other livestock-associated Culicoides species. PMID:26522279

  13. Sugar-feeding behaviour and longevity of European Culicoides biting midges.

    PubMed

    Kaufmann, C; Mathis, A; Vorburger, C

    2015-03-01

    Most haematophagous insect vectors can also use sugar as an energy source; thus their sugar-feeding behaviour influences their longevity and blood-feeding rate and hence their vectorial capacity. Scant information is available on the sugar-feeding behaviour of Culicoides Latreille biting midges (Diptera: Ceratopogonidae), which are vectors of bluetongue and Schmallenberg viruses. The longevity of laboratory-reared Culicoides nubeculosus (Meigen) under fluctuating temperatures (16 and 28 °C) and with access to water or water and blood was on average 6.4 days and 8.9 days, respectively, which was around one third of the lifespan of siblings with access to sugar or sugar and blood (22.2 days and 27.1 days, respectively). Access to honeydew significantly increased the midge's longevity, whereas the provision of extrafloral nectaries had no impact. Females with access to sugar produced a significantly higher number of eggs (65.5 ± 5.2) than their starved sisters (45.4 ± 8.4). More than 80% of field-caught female Culicoides from the two most abundant European groups, Obsoletus (n = 2243) and Pulicaris (n = 805), were fructose-positive. Fructose-positivity was high in all physiological stages and no seasonal variability was noted. The high rate of natural sugar feeding of Culicoides offers opportunities for the development of novel control strategies using toxic sugar baits and for the monitoring of vector-borne diseases using sugar-treated FTA (nucleic acid preservation) cards in the field.

  14. Sugar-feeding status alters biting midge photoattraction.

    PubMed

    Snyder, D; Cernicchiaro, N; Cohnstaedt, L W

    2016-03-01

    The biting midge Culicoides sonorensis Wirth and Jones (Diptera: Ceratopogonidae) transmits pathogens to both livestock and wildlife. Biting midge surveillance relies heavily on light traps for collection; however, little is known about the light spectra preferences of C. sonorensis midges. A light assay arena was constructed and light-emitting diodes (LEDs) of various light spectra were used as light sources to evaluate midge photoattraction. A comparison of responses to light spectra indicated the highest proportions of C. sonorensis were attracted to ultraviolet (UV) light and that midges differentiated 10-nm differences in wavelength. Stronger intensities of UV light resulted in greater attraction. Midges exhibited both sugar-seeking and escape behaviours under different conditions of sugar supplementation before and during the experiment. These behaviours occurred with lights of 355 nm and 365 nm in wavelength. Based on the results of this study, the attraction of C. sonorensis to light traps can be improved through the use of bright LEDs at 355 nm or 365 nm. PMID:26555011

  15. Investigating incursions of bluetongue virus using a model of long-distance Culicoides biting midge dispersal.

    PubMed

    Burgin, L E; Gloster, J; Sanders, C; Mellor, P S; Gubbins, S; Carpenter, S

    2013-06-01

    Bluetongue virus (BTV) is an economically important pathogen of ruminants that is the aetiological agent of the haemorrhagic disease bluetongue. Bluetongue virus is biologically transmitted by Culicoides biting midges (Diptera: Ceratopogonidae), and long-range dispersal of infected vector species contributes substantially to the rapid spread of the virus. The range of semi-passive flights of infected Culicoides on prevailing winds has been inferred to reach several hundred kilometres in a single night over water bodies. In this study, an atmospheric dispersion model was parameterized to simulate Culicoides flight activity based on dedicated entomological data sets collected in the UK. Five outbreaks of BTV in Europe were used to evaluate the model for use as an early warning tool and for retrospective analyses of BTV incursions. In each case, the generated predictions were consistent with epidemiological observations confirming its reliability for use in disease outbreak management. Furthermore, the model aided policy makers to predict, contain and eradicate BTV outbreaks in the UK during 2007 and 2008.

  16. Efficacy of alphacypermethrin-treated high density polyethylene mesh applied to jet stalls housing horses against Culicoides biting midges in South Africa.

    PubMed

    Page, P C; Labuschagne, K; Venter, G J; Schoeman, J P; Guthrie, A J

    2015-05-30

    The efficacy of alphacypermethrin-treated high density polyethylene (HDPE) mesh applied to jet stalls against Culicoides biting midges (Diptera: Ceratopogonidae) was determined by mechanical aspiration of midges from horses and using Onderstepoort 220 V downdraught black light traps in four blocks of a 3 × 2 randomised design under South African field conditions. The alphacypermethrin-treated HDPE mesh applied to the stall significantly (P = 0.008) reduced the number of Culicoides midges, predominantly Culicoides (Avaritia) imicola Kieffer, mechanically aspirated from horses housed in the stall. The mesh reduced the Culicoides midge attack rate in the treated stall compared to the untreated stall and a sentinel horse by 6 times and 14 times, respectively. The number of Culicoides midges and C. imicola collected in light traps from the untreated and alphacypermethrin HDPE mesh-treated stalls did not differ significantly (P = 0.82). Alphacypermethrin-treated HDPE mesh could be used to reduce exposure of horses in jet stalls to Culicoides midges, specifically C. imicola, and the risk of midge-borne Orbivirus transmission. PMID:25794942

  17. Efficacy of alphacypermethrin-treated high density polyethylene mesh applied to jet stalls housing horses against Culicoides biting midges in South Africa.

    PubMed

    Page, P C; Labuschagne, K; Venter, G J; Schoeman, J P; Guthrie, A J

    2015-05-30

    The efficacy of alphacypermethrin-treated high density polyethylene (HDPE) mesh applied to jet stalls against Culicoides biting midges (Diptera: Ceratopogonidae) was determined by mechanical aspiration of midges from horses and using Onderstepoort 220 V downdraught black light traps in four blocks of a 3 × 2 randomised design under South African field conditions. The alphacypermethrin-treated HDPE mesh applied to the stall significantly (P = 0.008) reduced the number of Culicoides midges, predominantly Culicoides (Avaritia) imicola Kieffer, mechanically aspirated from horses housed in the stall. The mesh reduced the Culicoides midge attack rate in the treated stall compared to the untreated stall and a sentinel horse by 6 times and 14 times, respectively. The number of Culicoides midges and C. imicola collected in light traps from the untreated and alphacypermethrin HDPE mesh-treated stalls did not differ significantly (P = 0.82). Alphacypermethrin-treated HDPE mesh could be used to reduce exposure of horses in jet stalls to Culicoides midges, specifically C. imicola, and the risk of midge-borne Orbivirus transmission.

  18. Mosquitoes and Culicoides biting midges: vector range and the influence of climate change.

    PubMed

    Elbers, A R W; Koenraadt, C J M; Meiswinkel, R

    2015-04-01

    Vector-borne animal diseases pose a continuous and substantial threat to livestock economies around the globe. Increasing international travel, the globalisation of trade, and climate change are likely to play a progressively more important role in the introduction, establishment and spread of arthropod-borne pathogens worldwide. A review of the literature reveals that many climatic variables, functioning singly or in combination, exert varying effects on the distribution and range of Culicoides vector midges and mosquitoes. For example, higher temperatures may be associated with increased insect abundance--thereby amplifying the risk of disease transmission--but there are no indications yet of dramatic shifts occurring in the geographic range of Culicoides midges. However, the same cannot be said for mosquitoes: over the last few decades, multiple Asian species have established themselves in Europe, spread and are unlikely to ever be eradicated. Research on how insects respond to changes in climate is still in its infancy. The authors argue that we need to grasp how other annectant changes, such as extremes in precipitation (drought and flooding), may affect the dispersal capability of mosquitoes. Models are useful for assessing the interplay between mosquito vectors expanding their range and the native flora and fauna; however, ecological studies employing classical mark-release-recapture techniques remain essential for addressing fundamental questions about the survival and dispersal of mosquito species, with the resulting parameters fed directly into new-generation disease transmission models. Studies on the eventual impact of mosquitoes on animal and human health should be tackled through large-scale integrated research programmes. Such an approach calls for more collaborative efforts, along the lines of the One Health Initiative. PMID:26470453

  19. Mosquitoes and Culicoides biting midges: vector range and the influence of climate change.

    PubMed

    Elbers, A R W; Koenraadt, C J M; Meiswinkel, R

    2015-04-01

    Vector-borne animal diseases pose a continuous and substantial threat to livestock economies around the globe. Increasing international travel, the globalisation of trade, and climate change are likely to play a progressively more important role in the introduction, establishment and spread of arthropod-borne pathogens worldwide. A review of the literature reveals that many climatic variables, functioning singly or in combination, exert varying effects on the distribution and range of Culicoides vector midges and mosquitoes. For example, higher temperatures may be associated with increased insect abundance--thereby amplifying the risk of disease transmission--but there are no indications yet of dramatic shifts occurring in the geographic range of Culicoides midges. However, the same cannot be said for mosquitoes: over the last few decades, multiple Asian species have established themselves in Europe, spread and are unlikely to ever be eradicated. Research on how insects respond to changes in climate is still in its infancy. The authors argue that we need to grasp how other annectant changes, such as extremes in precipitation (drought and flooding), may affect the dispersal capability of mosquitoes. Models are useful for assessing the interplay between mosquito vectors expanding their range and the native flora and fauna; however, ecological studies employing classical mark-release-recapture techniques remain essential for addressing fundamental questions about the survival and dispersal of mosquito species, with the resulting parameters fed directly into new-generation disease transmission models. Studies on the eventual impact of mosquitoes on animal and human health should be tackled through large-scale integrated research programmes. Such an approach calls for more collaborative efforts, along the lines of the One Health Initiative.

  20. Biting rates of Culicoides midges (Diptera: Ceratopogonidae) on sheep in northeastern Spain in relation to midge capture using UV light and carbon dioxide-baited traps.

    PubMed

    Gerry, Alec C; Sarto i Monteys, V; Moreno Vidal, J O; Francino, O; Mullens, Bradley A

    2009-05-01

    Biting midges in the genus Culicoides (Diptera: Ceratopogonidae) were collected near sunset by direct aspiration from sheep in northeastern Spain to determine species-specific biting rates and crepuscular activity. Midges were also collected by UV-baited light traps and CO2-baited traps over the same period to compare species diversity and abundance using these common surveillance methods to actual sheep attack rates. Culicoides aspirated from sheep included C. obsoletus, C. parroti, C. scoticus, C. punctatus, and C. imicola. Peak host-seeking activity during the time period examined for the two most commonly collected species (C. obsoletus and C. parroti) occurred just before sunset and activity ceased within 1 h after sunset. Host attack rates near sunset averaged 0.9 midges/min for both species with maximum attack rates of 3/min for C. obsoletus and 4/min for C. parroti. For both species, approximately 35% of midges collected from the sheep were engorged, giving a maximum biting rate of 1.1/min for C. obsoletus and 1.5/min for C. parroti. Traps baited with CO2 collected fewer midges of each species relative to other collection methods. Traps baited with UV light provided a good indication of species richness but significantly underestimated the host attack rate of C. obsoletus and C. parroti while overestimating the host attack rate of C. imicola. Animal-baited collecting is critical to interpret the epidemiological significance of light trap collections used for surveillance of the midge vectors of bluetongue virus and African horse sickness virus.

  1. Entomopathogenic Fungus as a Biological Control for an Important Vector of Livestock Disease: The Culicoides Biting Midge

    PubMed Central

    Ansari, Minshad Ali; Pope, Edward C.; Carpenter, Simon; Scholte, Ernst-Jan; Butt, Tariq M.

    2011-01-01

    Background The recent outbreak of bluetongue virus in northern Europe has led to an urgent need to identify control measures for the Culicoides (Diptera: Ceratopogonidae) biting midges that transmit it. Following successful use of the entomopathogenic fungus Metarhizium anisopliae against larval stages of biting midge Culicoides nubeculosus Meigen, we investigated the efficacy of this strain and other fungi (Beauveria bassiana, Isaria fumosorosea and Lecanicillium longisporum) as biocontrol agents against adult C. nubeculosus in laboratory and greenhouse studies. Methodology/Findings Exposure of midges to ‘dry’ conidia of all fungal isolates caused significant reductions in survival compared to untreated controls. Metarhizium anisopliae strain V275 was the most virulent, causing a significantly decrease in midge survival compared to all other fungal strains tested. The LT50 value for strain V275 was 1.42 days compared to 2.21–3.22 days for the other isolates. The virulence of this strain was then further evaluated by exposing C. nubeculosus to varying doses (108–1011 conidia m−2) using different substrates (horse manure, damp peat, leaf litter) as a resting site. All exposed adults were found to be infected with the strain V275 four days after exposure. A further study exposed C. nubeculosus adults to ‘dry’ conidia and ‘wet’ conidia (conidia suspended in 0.03% aq. Tween 80) of strain V275 applied to damp peat and leaf litter in cages within a greenhouse. ‘Dry’ conidia were more effective than ‘wet’ conidia, causing 100% mortality after 5 days. Conclusion/Significance This is the first study to demonstrate that entomopathogenic fungi are potential biocontrol agents against adult Culicoides, through the application of ‘dry’ conidia on surfaces (e.g., manure, leaf litter, livestock) where the midges tend to rest. Subsequent conidial transmission between males and females may cause an increased level of fungi-induced mortality in midges

  2. Infrared absorption characteristics of Culicoides sonorensis in relation to insect age

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biting midges can transmit diseases that significantly impact livestock in many parts of the world. The age structure of an insect vector population determines its likelihood of transmitting pathogens because the older insects are more likely to be infected than younger ones. Understanding the insec...

  3. Laboratory and field evaluations of chemical and plant-derived potential repellents against Culicoides biting midges in northern Spain.

    PubMed

    González, M; Venter, G J; López, S; Iturrondobeitia, J C; Goldarazena, A

    2014-12-01

    The efficacy of 23 compounds in repelling Culicoides biting midges (Diptera: Ceratopogonidae), particularly Culicoides obsoletus (Meigen) females, was determined by means of a Y-tube olfactometer. The 10 most effective compounds were further evaluated in landing bioassays. The six most promising compounds (including chemical and plant-derived repellents) were evaluated at 10% and 25% concentrations in field assays using Centers for Disease Control (CDC) light traps. At least three compounds showed promising results against Culicoides biting midges with the methodologies used. Whereas olfactometer assays indicated DEET at 1 µg/µL to be the most effective repellent, filter paper landing bioassays showed plant-derived oils to be better. Light traps fitted with polyester mesh impregnated with a mixture of octanoic, decanoic and nonanoic fatty acids at 10% and 25% concentrations collected 2.2 and 3.6 times fewer midges than control traps and were as effective as DEET, which is presently considered the reference standard insect repellent. The best plant-derived product was lemon eucalyptus oil. Although these have been reported as safe potential repellents, the present results indicate DEET and the mixture of organic fatty acids to be superior and longer lasting. PMID:25079042

  4. Update on the Culicoides sonorensis transcriptome project: a peek into the molecular biology of the midge

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Next Generation Sequencing is transforming the way scientists collect and measure an organism’s genetic background and gene dynamics, while bioinformatics and super-computing are merging to facilitate parallel sample computation and interpretation at unprecedented speeds. Analyzing the complete gene...

  5. Foraging range of arthropods with veterinary interest: New insights for Afrotropical Culicoides biting midges (Diptera: Ceratopogonidae) using the ring method.

    PubMed

    Bakhoum, M T; Fall, M; Seck, M T; Gardès, L; Fall, A G; Diop, M; Mall, I; Balenghien, T; Baldet, T; Gimonneau, G; Garros, C; Bouyer, J

    2016-05-01

    The identification of blood meal source of arthropod vector species contributes to the understanding of host-vector-pathogen interactions. The aim of the current work was to identify blood meal source in Culicoides biting midge species, biological vectors of internationally important arboviruses of livestock and equids, using a new ecological approach. We examined the correlation between blood meal source identified in engorged Culicoides females collected in a suction light trap and the available vertebrate hosts along four rings (200, 500, 1000 and 2000 m) centered at the trap site and described the foraging range of the three main vector species of veterinary interest present in the study area, Culicoides imicola, Culicoides kingi and Culicoides oxystoma. The study was performed in four sites localized in the Niayes region of Senegal (West Africa) where recent outbreaks of African horse sickness occurred. Blood meal source identification was carried out by species-specific multiplex PCRs with genomic DNA extracted from the abdomen of engorged females collected during nine night collections for twenty-six collections. The four most abundant hosts present in the studied area (horse, cattle, goat and sheep) were surveyed in each ring zone. The blood meal source varied according to Culicoides species and host availability in each site. C. oxystoma and C. imicola females mainly fed on horses readily available at 200 m maximum from the trap location whereas females of C. kingi fed mainly on cattle, at variable distances from the traps (200 to 2000 m). C. oxystoma may also feed on other vertebrates. We discuss the results in relation with the transmission of Culicoides-borne arboviruses and the species dispersion capacities. PMID:26826391

  6. Field and in vitro insecticidal efficacy of alphacypermethrin-treated high density polyethylene mesh against Culicoides biting midges in South Africa.

    PubMed

    Page, P C; Labuschagne, K; Venter, G J; Schoeman, J P; Guthrie, A J

    2014-06-16

    The efficacy of untreated and alphacypermethrin-treated high density polyethylene (HDPE) mesh against Culicoides biting midges (Diptera: Ceratopogonidae) was determined using Onderstepoort downdraught black light traps and a contact bioassay. Three traps were operated overnight in four replicates of a 3×3 randomised Latin square design near horses under South African field conditions. Both the untreated and alphacypermethrin-treated HDPE mesh significantly (P<0.05) reduced the numbers of Culicoides midges, predominantly Culicoides (Avaritia) imicola Kieffer, collected in the light traps by 4.2 and 7.2 times, respectively. A repellent effect of the alphacypermethrin-treated mesh was not confirmed because the number of midges collected in the light traps with untreated and alphacypermethrin-treated HDPE mesh was not significantly different (P=0.656). Bioassay of the insecticidal contact efficacy indicated median C. imicola mortality of 100% from 30 and 10 min following exposure to the alphacypermethrin-treated HDPE mesh for 1 or 3 min, respectively. In the bioassay, mortality was significantly higher (P=0.016) at 5 min post exposure in the midges exposed to the alphacypermethrin-treated mesh for 3 min (74.8%) compared to the 1 min exposure group (59.5%). The HDPE mesh could be used to reduce exposure of housed animals to Culicoides midges, specifically C. imicola, and viruses transmitted by these midges. Mesh treated with alphacypermethrin had the additional benefit of a rapid insecticidal effect on C. imicola. PMID:24655725

  7. Identification of Cattle-Derived Volatiles that Modulate the Behavioral Response of the Biting Midge Culicoides nubeculosus.

    PubMed

    Isberg, Elin; Bray, Daniel Peter; Birgersson, Göran; Hillbur, Ylva; Ignell, Rickard

    2016-01-01

    Identification of host-derived volatiles is an important step towards the development of novel surveillance and control tools for Culicoides biting midges. In this study, we identified compounds from headspace collections of cattle hair and urine that modulate the behavioral response of Culicoides nubeculosus, a research model species with a similar host-range as the vectors of Bluetongue disease and Schmallenberg disease in Europe. Combined gas chromatography and electroantennographic detection (GC-EAD) analysis revealed 23 bioactive compounds, of which 17, together with octanal, were evaluated in a two-choice behavioral assay in the presence of CO2. Decanal, 2-phenylethanal, 1-octen-3-ol, 2-ethylhexanol, 3-methylindole, phenol, and 3-ethylphenol elicited attraction of host seeking C. nubeculosus, whereas heptanal, octanal, nonanal, 3-propylphenol, and 4-propylphenol inhibited the insects' attraction to CO2, when compared to CO2 alone. 6-Methyl-5-hepten-2-one, 3-methylphenol, 4-methylphenol, and 4-ethylphenol elicited both attraction and inhibition. The behavioral responses were dependent on the concentration tested. Our results show that cattle-derived odors have the potential to be used for the manipulation of the behavior of Culicoides biting midges. PMID:26687092

  8. Comparison of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry and Molecular Biology Techniques for Identification of Culicoides (Diptera: Ceratopogonidae) Biting Midges in Senegal

    PubMed Central

    Sambou, Masse; Aubadie-Ladrix, Maxence; Fenollar, Florence; Fall, Becaye; Bassene, Hubert; Almeras, Lionel; Sambe-Ba, Bissoume; Perrot, Nadine; Chatellier, Sonia; Faye, Ngor; Parola, Philippe; Wade, Boubacar; Raoult, Didier

    2014-01-01

    Biting midges of the genus Culicoides are implicated as vectors for a wide variety of pathogens. The morphological identification of these arthropods may be difficult because of a lack of detailed investigation of taxonomy for this species in Africa. However, matrix-assisted laser desorption ionization−time of flight mass spectrometry (MALDI-TOF MS) profiling is efficient for arthropod identification at the species level. This study established a spectrum database of Culicoides spp. from Senegal using MALDI-TOF. Identification of Culicoides insects to the species level before mass spectrometry was performed on the basis of morphological characters. MALDI-TOF MS reference spectra were determined for 437 field-caught Culicoides of 10 species. The protein profiles of all tested Culicoides revealed several peaks with mass ranges of 2 to 20 kDa. In a validation study, 72 Culicoides specimens in the target species were correctly identified at the species level with a similarity of 95 to 99.9%. Four Culicoides protein profiles were misidentified. Nevertheless, six SuperSpectra (C. imicola, C. enderleini, C. oxystoma, C. kingi, C. magnus, and C. fulvithorax) were created. Abdomens of midges were used to amplify and sequence a portion of the mitochondrial cytochrome oxidase I gene (COI). The results obtained using the MALDI-TOF MS method were consistent with the morphological identification and similar to the genetic identification. Protein profiling using MALDI-TOF is an efficient approach for the identification of Culicoides spp., and it is economically advantageous for approaches that require detailed and quantitative information of vector species that are collected in field. The database of African Culicoides MS spectra created is the first database in Africa. The COI sequences of five Culicoides species that were previously noncharacterized using molecular methods were deposited in GenBank. PMID:25411169

  9. Colonization of the Mediterranean basin by the vector biting midge species Culicoides imicola: an old story.

    PubMed

    Jacquet, S; Garros, C; Lombaert, E; Walton, C; Restrepo, J; Allene, X; Baldet, T; Cetre-Sossah, C; Chaskopoulou, A; Delecolle, J-C; Desvars, A; Djerbal, M; Fall, M; Gardes, L; de Garine-Wichatitsky, M; Goffredo, M; Gottlieb, Y; Gueye Fall, A; Kasina, M; Labuschagne, K; Lhor, Y; Lucientes, J; Martin, T; Mathieu, B; Miranda, M; Pages, N; Pereira da Fonseca, I; Ramilo, D W; Segard, A; Setier-Rio, M-L; Stachurski, F; Tabbabi, A; Talla Seck, M; Venter, G; Zimba, M; Balenghien, T; Guis, H; Chevillon, C; Bouyer, J; Huber, K

    2015-11-01

    Understanding the demographic history and genetic make-up of colonizing species is critical for inferring population sources and colonization routes. This is of main interest for designing accurate control measures in areas newly colonized by vector species of economically important pathogens. The biting midge Culicoides imicola is a major vector of orbiviruses to livestock. Historically, the distribution of this species was limited to the Afrotropical region. Entomological surveys first revealed the presence of C. imicola in the south of the Mediterranean basin by the 1970s. Following recurrent reports of massive bluetongue outbreaks since the 1990s, the presence of the species was confirmed in northern areas. In this study, we addressed the chronology and processes of C. imicola colonization in the Mediterranean basin. We characterized the genetic structure of its populations across Mediterranean and African regions using both mitochondrial and nuclear markers, and combined phylogeographical analyses with population genetics and approximate Bayesian computation. We found a west/east genetic differentiation between populations, occurring both within Africa and within the Mediterranean basin. We demonstrated that three of these groups had experienced demographic expansions in the Pleistocene, probably because of climate changes during this period. Finally, we showed that C. imicola could have colonized the Mediterranean basin in the Late Pleistocene or Early Holocene through a single event of introduction; however, we cannot exclude the hypothesis involving two routes of colonization. Thus, the recent bluetongue outbreaks are not linked to C. imicola colonization event, but rather to biological changes in the vector or the virus.

  10. Comparison of single- and multi-scale models for the prediction of the Culicoides biting midge distribution in Germany.

    PubMed

    Lühken, Renke; Gethmann, Jörn Martin; Kranz, Petra; Steffenhagen, Pia; Staubach, Christoph; Conraths, Franz J; Kiel, Ellen

    2016-01-01

    This study analysed Culicoides presence-absence data from 46 sampling sites in Germany, where monitoring was carried out from April 2007 until May 2008. Culicoides presence-absence data were analysed in relation to land cover data, in order to study whether the prevalence of biting midges is correlated to land cover data with respect to the trapping sites. We differentiated eight scales, i.e. buffer zones with radii of 0.5, 1, 2, 3, 4, 5, 7.5 and 10 km, around each site, and chose several land cover variables. For each species, we built eight single-scale models (i.e. predictor variables from one of the eight scales for each model) based on averaged, generalised linear models and two multiscale models (i.e. predictor variables from all of the eight scales) based on averaged, generalised linear models and generalised linear models with random forest variable selection. There were no significant differences between performance indicators of models built with land cover data from different buffer zones around the trapping sites. However, the overall performance of multi-scale models was higher than the alternatives. Furthermore, these models mostly achieved the best performance for the different species using the index area under the receiver operating characteristic curve. However, as also presented in this study, the relevance of the different variables could significantly differ between various scales, including the number of species affected and the positive or negative direction. This is an even more severe problem if multi-scale models are concerned, in which one model can have the same variable at different scales but with different directions, i.e. negative and positive direction of the same variable at different scales. However, multi-scale modelling is a promising approach to model the distribution of Culicoides species, accounting much more for the ecology of biting midges, which uses different resources (breeding sites, hosts, etc.) at different scales

  11. Farms, pastures and woodlands: the fine-scale distribution of Palearctic Culicoides spp. biting midges along an agro-ecological gradient.

    PubMed

    Rigot, T; Drubbel, M Vercauteren; Delécolle, J-C; Gilbert, M

    2013-03-01

    The spatial epidemiology of Bluetongue virus (BTV) at the landscape level relates to the fine-scale distribution and dispersal capacities of its vectors, midges belonging to the genus Culicoides Latreille (Diptera: Ceratopogonidae). Although many previous researches have carried out Culicoides sampling on farms, little is known of the fine-scale distribution of Culicoides in the landscape immediately surrounding farms. The aim of this study was to gain a better understanding of Culicoides populations at increasing distances from typical dairy farms in north-west Europe, through the use of eight Onderstepoort-type black-light traps positioned along linear transects departing from farms, going through pastures and entering woodlands. A total of 16 902 Culicoides were collected in autumn 2008 and spring 2009. The majority were females, of which more than 97% were recognized as potential vectors. In pastures, we found decreasing numbers of female Culicoides as a function of the distance to the farm. This pattern was modelled by leptokurtic models, with parameters depending on season and species. By contrast, the low number of male Culicoides caught were homogeneously distributed along the transects. When transects entered woodlands, we found a higher abundance of Culicoides than expected considering the distance of the sampling sites to the farm, although this varied according to species.

  12. Farms, pastures and woodlands: the fine-scale distribution of Palearctic Culicoides spp. biting midges along an agro-ecological gradient.

    PubMed

    Rigot, T; Drubbel, M Vercauteren; Delécolle, J-C; Gilbert, M

    2013-03-01

    The spatial epidemiology of Bluetongue virus (BTV) at the landscape level relates to the fine-scale distribution and dispersal capacities of its vectors, midges belonging to the genus Culicoides Latreille (Diptera: Ceratopogonidae). Although many previous researches have carried out Culicoides sampling on farms, little is known of the fine-scale distribution of Culicoides in the landscape immediately surrounding farms. The aim of this study was to gain a better understanding of Culicoides populations at increasing distances from typical dairy farms in north-west Europe, through the use of eight Onderstepoort-type black-light traps positioned along linear transects departing from farms, going through pastures and entering woodlands. A total of 16 902 Culicoides were collected in autumn 2008 and spring 2009. The majority were females, of which more than 97% were recognized as potential vectors. In pastures, we found decreasing numbers of female Culicoides as a function of the distance to the farm. This pattern was modelled by leptokurtic models, with parameters depending on season and species. By contrast, the low number of male Culicoides caught were homogeneously distributed along the transects. When transects entered woodlands, we found a higher abundance of Culicoides than expected considering the distance of the sampling sites to the farm, although this varied according to species. PMID:22897885

  13. Collection and analysis of salivary proteins from the biting midge Culicoides nubeculosus (Diptera: Ceratopogonidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salivary proteins of hematophagous Culicoides spp. are thought to play an important role in pathogen transmission and skin hypersensitivity. Analysis of these proteins, however, has been problematic due to the difficulty in obtaining adequate amounts of secreted Culicoides saliva. In the current stu...

  14. Protection of horses against Culicoides biting midges in different housing systems in Switzerland.

    PubMed

    Lincoln, V J; Page, P C; Kopp, C; Mathis, A; von Niederhäusern, R; Burger, D; Herholz, C

    2015-06-15

    Species belonging to the Culicoides complexes (Diptera, Ceratopogonidae), obsoletus and pulicaris, in Switzerland, are potential vectors of both bluetongue virus (BTV) and African horse sickness virus (AHSV). The epidemic of BTV in 2006 and 2007 in Europe has highlighted the risk of introduction and spread of vector-borne diseases in previously non-endemic areas. As a measure of prevention, as part of an integrated control programme in the event of an outbreak of African horse sickness (AHS), it is of utmost importance to prevent, or substantially reduce, contact between horses and Culicoides. The aim of the present study was to compare the effect of three protection systems, net, fan, repellent, or combinations thereof, with regard to their potential to reduce contact between horses and Culicoides. Three different equine housing systems, including individual boxes (BX), group housing systems (GR), and individual boxes with permanently accessible paddock (BP) were used. The efficacy of the protection systems were evaluated by comparing the total number counts of collected female Culicoides, of non-blood-fed and blood-fed Culicoides, respectively, with UV black light traps. The study was conducted over 3 summer months during 2012 and 2013 each and focused on the efficacy and practicality of the protection systems. The repellent was tested in 2012 only and not further investigated in 2013, as it showed no significant effect in reducing Culicoides collected in the light traps. Net protection system provided the best overall protection for the total number of female Culicoides, non-blood-fed and blood-fed Culicoides in all tested housing systems. The net, with a pore size of 0.1825 mm(2), reduced the total number of Culicoides collected in the housing systems BP, GR and BX by 98%, 85% and 67%, respectively. However, in the GR housing system, no significant difference between the effectiveness of the fan and the net were determined for any of the three Culicoides

  15. Response of Culicoides sonorensis (Diptera: Ceratopogonidae) to 1-octen-3-ol and three plant-derived repellent formulations in the field.

    PubMed

    Braverman, Y; Wegis, M C; Mullens, B A

    2000-06-01

    The potential attractant 1-octen-3-ol and 3 potential repellents were assayed for activity for Culicoides sonorensis, the primary vector of bluetongue virus in North America. Collections using octenol were low, but numbers in suction traps were greater in the high-octenol treatment (11.5 mg/h) than in the low-octenol treatment (1.2 mg/h) or unbaited control for both sexes. Collections using high octenol, CO2 (approximately 1,000 ml/min), or both showed octenol alone to be significantly less attractive than either of the CO2 treatments and that octenol did not act synergistically with this level of CO2. A plant-derived (Meliaceae) extract with 4.5% of active ingredient (AI) (Ag1000), heptanone solvent, Lice free (2% AI from plant extracts in water), Mosi-guard with 50% Eucalyptus maculata var. citriodora Hook extract, and N,N-diethyl-m-toluamide (deet) were applied to polyester-cotton coarse mesh nets and deployed in conjunction with suction light traps plus CO2. Collections in the trap with deet were 66% lower (P < 0.05) than the heptanone and 56% (P > 0.05) less than the untreated (negative) control. Relative to deet, collections in the traps with the lice repellent, Ag1000, and Mosi-guard were reduced by 15, 34, and 39%, respectively (P > 0.05). The method has promise for field screening of potential repellents before on-animal testing. PMID:10901641

  16. Principal climatic and edaphic determinants of Culicoides biting midge abundance during the 2007-2008 bluetongue epidemic in the Netherlands, based on OVI light trap data.

    PubMed

    Scolamacchia, F; VAN DEN Broek, J; Meiswinkel, R; Heesterbeek, J A P; Elbers, A R W

    2014-06-01

    Palaearctic Culicoides midges (Diptera: Ceratopogonidae) represent a vital link in the northward advance of certain arboviral pathogens of livestock such as that caused by bluetongue virus. The effects of relevant ecological factors on weekly Culicoides vector abundances during the bluetongue virus serotype 8 epidemics in the Netherlands in 2007 and 2008 were quantified within a hurdle modelling framework. The relative role of meteorological parameters showed a broadly consistent association across species, with larger catches linked to temperature-related variables and lower wind speed. Moreover, vector abundance was found to be influenced by edaphic factors, likely related to species-specific breeding habitat preferences that differed markedly amongst some species. This is the first study on Culicoides vector species in the Netherlands identified during an entomological surveillance programme, in which an attempt is made to pinpoint the factors that influence midge abundance levels. In addition to providing key inputs into risk-mitigating tools for midge-borne pathogens and disease transmission models, the adoption of methods that explicitly address certain features of abundance datasets (frequent zero-count observations and over-dispersion) helped enhance the robustness of the ecological analysis. PMID:24148154

  17. Seasonal dynamics of Culicoides (Diptera: Ceratopogonidae) biting midges, potential vectors of African horse sickness and bluetongue viruses in the Niayes area of Senegal

    PubMed Central

    2014-01-01

    Background The African horse sickness epizootic in Senegal in 2007 caused considerable mortality in the equine population and hence major economic losses. The vectors involved in the transmission of this arbovirus have never been studied specifically in Senegal. This first study of the spatial and temporal dynamics of the Culicoides (Diptera: Ceratopogonidae) species, potential vectors of African horse sickness in Senegal, was conducted at five sites (Mbao, Parc Hann, Niague, Pout and Thies) in the Niayes area, which was affected by the outbreak. Methods Two Onderstepoort light traps were used at each site for three nights of consecutive collection per month over one year to measure the apparent abundance of the Culicoides midges. Results In total, 224,665 specimens belonging to at least 24 different species (distributed among 11 groups of species) of the Culicoides genus were captured in 354 individual collections. Culicoides oxystoma, Culicoides kingi, Culicoides imicola, Culicoides enderleini and Culicoides nivosus were the most abundant and most frequent species at the collection sites. Peaks of abundance coincide with the rainy season in September and October. Conclusions In addition to C. imicola, considered a major vector for the African horse sickness virus, C. oxystoma may also be involved in the transmission of this virus in Senegal given its abundance in the vicinity of horses and its suspected competence for other arboviruses including bluetongue virus. This study depicted a site-dependent spatial variability in the dynamics of the populations of the five major species in relation to the eco-climatic conditions at each site. PMID:24690198

  18. Effect of Culicoides sonorensis salivary proteins on clinical disease outcome in experimental bluetongue virus serotype 8 infection of Dorset sheep.

    PubMed

    Drolet, Barbara S; Reister, Lindsey M; Lehiy, Christopher J; Van Rijn, Piet A; Bowen, Richard A

    2015-01-01

    The severity of bluetongue clinical disease in ruminants varies greatly depending on the outbreak serotype/strain, animal species/breed, and immune status of the herd. To predict disease risk from any of the 26 bluetongue virus (BTV) serotypes identified to date, experimental animal susceptibility studies are often conducted. Although sheep are the most susceptible livestock species in the US, infection of domestic breeds by injection of field isolates rarely produces the level of clinical disease observed in natural Culicoides midge‑transmitted outbreaks. Thus, outbreak risk assessments based on experimental animal infections can underestimate the severity posed by a potential outbreak with a given virus serotype or strain. The aim of this study was to determine whether secreted Culicoides salivary proteins injected simultaneously with virus, to more closely mimic midge‑delivered virus, would affect clinical disease outcome in a BTV‑8 sheep susceptibility study. Eight sheep were intradermally inoculated with BTV‑8; 4 received virus mixed with secreted Culicoides salivary proteins (BTV‑8 + Cu SP), 4 received virus alone. Clinical signs were monitored daily for type, severity and duration. In sheep receiving the BTV‑8 + Cu SP inoculum, clinical signs were more varied, more severe, and duration was three times longer compared to sheep receiving virus alone. These results suggest that Culicoides salivary proteins may play a contributing role in BTV pathology and that use of these proteins in experimental animal infections may allow development of a more robust target‑host animal model. PMID:26741250

  19. Long-distance aerial dispersal modelling of Culicoides biting midges: case studies of incursions into Australia

    PubMed Central

    2014-01-01

    Background Previous studies investigating long-distance, wind-borne dispersal of Culicoides have utilised outbreaks of clinical disease (passive surveillance) to assess the relationship between incursion and dispersal event. In this study, species of exotic Culicoides and isolates of novel bluetongue viruses, collected as part of an active arbovirus surveillance program, were used for the first time to assess dispersal into an endemic region. Results A plausible dispersal event was determined for five of the six cases examined. These include exotic Culicoides specimens for which a possible dispersal event was identified within the range of two days – three weeks prior to their collection and novel bluetongue viruses for which a dispersal event was identified between one week and two months prior to their detection in cattle. The source location varied, but ranged from Lombok, in eastern Indonesia, to Timor-Leste and southern Papua New Guinea. Conclusions Where bluetongue virus is endemic, the concurrent use of an atmospheric dispersal model alongside existing arbovirus and Culicoides surveillance may help guide the strategic use of limited surveillance resources as well as contribute to continued model validation and refinement. Further, the value of active surveillance systems in evaluating models for long-distance dispersal is highlighted, particularly in endemic regions where knowledge of background virus and vector status is beneficial. PMID:24943652

  20. Two new species and new records of biting midges of the genus Culicoides from northwestern Argentina (Diptera: Ceratopogonidae)

    PubMed Central

    Spinelli, Gustavo Ricardo; Aybar, Cecilia Veggiani; Juri, María Julia Dantur; de Grosso, Mercedes Lizarralde; Marino, Pablo Ignacio

    2013-01-01

    The following two new species of Culicoides from the Argentinean Yungas are described, illustrated and placed to subgenus or species group and compared with related congeners: Culicoides calchaqui Spinelli & Veggiani Aybar and Culicoides willinki Spinelli & Veggiani Aybar. Culicoides daedaloides Wirth & Blanton is recorded for the first time for Argentina and Culicoides pseudoheliconiae Felippe-Bauer is firstly mentioned from the northwestern region of the country. PMID:23903973

  1. Insecticidal sugar baits for adult biting midges.

    PubMed

    Snyder, D; Cernicchiaro, N; Allan, S A; Cohnstaedt, L W

    2016-06-01

    The mixing of an insecticide with sugar solution creates an oral toxin or insecticidal sugar bait (ISB) useful for reducing adult insect populations. The ability of ISBs to kill the biting midge Culicoides sonorensis Wirth and Jones (Diptera: Ceratopogonidae), a vector of bluetongue virus, epizootic hemorrhagic disease and vesicular stomatitis viruses, was tested. The commercial insecticide formulations (percentage active ingredient) tested included bifenthrin, cyfluthrin, deltamethrin, permethrin, dinotefuran, imidacloprid, thiamethoxam and spinosad. Mortality rates were determined for various concentrations of commercial formulations (0.01, 0.05, 0.1, 1, 2 and 3%) and observed at 1, 4, 10 and 24 h post-exposure to the ISB. In the first set of assays, laboratory-reared midges were fed sugar ad libitum and then exposed to insecticide-treated sugar solutions to measure mortality. The second assay assessed competitive feeding: midges were provided with a control sugar solution (10% sucrose) in one vial, and a sugar and insecticide solution in another. Pyrethroid treatments resulted in the greatest mortality in the first hour at the lowest concentrations and spinosad consumption resulted in the least mortality. Biting midges were not deterred from feeding on the 1% ISB solutions despite the presence of an insecticide-free alternative source of sugar. PMID:26789534

  2. In situ immune infrared fluorescent staining for detection and quantitation of bluetongue virus in Culicoides insect cell culture.

    PubMed

    Mecham, James O; Brown, Philip L; McHolland, Linda E

    2009-06-01

    Bluetongue virus (BTV) is transmitted to sheep, cattle and other ruminants by Culicoides spp. of biting midges. Cell lines have been developed from Culicoides sonorensis; however, techniques to detect and quantitate viable virus directly in these insect cells are lacking. In situ immune infrared fluorescent staining techniques were developed to visualize and quantitate BTV infection in Culicoides cell culture by both an endpoint titration and an agarose overlay fluorescent focus assay. Insect cell cultures infected with BTV were fixed, permeabilized and reacted with virus-specific monoclonal antibody and fluorescent-labeled secondary antibody. Virus replication in the infected cells was visualized and quantitated by measuring fluorescence with an infrared imager. The sensitivity of virus detection in insect cell culture using these techniques was comparable to or better than detection by standard techniques in vertebrate cell culture.

  3. Occurrence of genetic drift and founder effect during quasispecies evolution of the VP2 and NS3/NS3A genes of bluetongue virus upon passage between sheep, cattle, and Culicoides sonorensis.

    PubMed

    Bonneau, K R; Mullens, B A; MacLachlan, N J

    2001-09-01

    Bluetongue virus (BTV) is the cause of an insect-transmitted virus infection of ruminants that occurs throughout much of the world. Individual gene segments differ between field strains of BTV; thus, we hypothesized that key viral genes undergo genetic drift during alternating passage of BTV in its ruminant and insect hosts. To test this hypothesis, variation in the consensus sequence and quasispecies heterogeneity of the VP2 and NS3/NS3A genes of a plaque-purified strain of BTV serotype 10 was determined during alternating infection of vector Culicoides sonorensis and a sheep and calf. Consensus sequences were determined after reverse transcriptase-nested PCR amplification of viral RNA directly from ruminant blood and homogenized insects, and quasispecies heterogeneity was determined by the sequencing of clones derived from directly amplified viral RNA. Comparison of these sequences to those of the original BTV inoculum used to initiate the cycle of BTV infection demonstrated, for the first time, that individual BTV gene segments evolve independently of one another by genetic drift in a host-specific fashion, generating quasispecies populations in both ruminant and insect hosts. Furthermore, a unique viral variant was randomly ingested by C. sonorensis insects that fed on a sheep with low-titer viremia, thereby fixing a novel genotype by founder effect. Thus, we conclude that genetic drift and founder effect contribute to diversification of individual gene segments of field strains of BTV.

  4. The Spatio-Temporal Distribution Patterns of Biting Midges of the Genus Culicoides in Salta Province, Argentina

    PubMed Central

    Aybar, Cecilia A. Veggiani; Juri, María J. Dantur; Santana, Mirta; de Grosso, Mercedes S. Lizarralde; Spinelli, Gustavo R.

    2012-01-01

    The goal of this survey was to analyze the spatio-temporal distribution patterns of Culicoides Latreille species (Diptera: Ceratopogonidae) and their relationship with environmental variables in Salta, northwestern Argentina. Culicoides were collected monthly from January 2003 through December 2005. The influence of the climatic variables on population abundance was analyzed with a multilevel Poisson regression. A total of 918 specimens belonging to five species were collected. The most abundant species was Culicoides paraensis Goeldi (65.5%), followed by Culicoides lahillei Iches (14.6%) and Culicoides debilipalpis Lutz (7.6%). The highest seasonal abundance for C. paraensis, C. debilipalpis and C. lahillei occurred during the spring and summer. A Poisson regression analysis showed that the mean maximum and minimum temperature and the mean maximum and minimum humidity were the variables with the greatest influence on the population abundance of Culicoides species. PMID:23461794

  5. An improved, high-throughput method for detection of bluetongue virus RNA in Culicoides midges utilizing infrared-dye-labeled primers for reverse transcriptase PCR.

    PubMed

    Kato, Cecilia Y; Mayer, Richard T

    2007-03-01

    A new rapid (less than 6h from insect-to-results) high-throughput assay that is sensitive and specific for detecting BTV RNA in Culicoides biting midges is reported. Homogenization and extraction of nucleic acids from individual Culicoides specimens were performed in a 96-well plate format using specialized beads in a homogenization buffer compatible with cell culture and RNA extraction. A portion of homogenate (10%) from each specimen was retained for confirmatory infectious virus isolation, while the remaining 90% was used for RNA extraction. The RNA was used in a single step reverse transcriptase PCR (RT-PCR) reaction with infrared (IR)-dye-labeled primers. The RT-PCR products were visualized in agarose gels with an infrared scanner. The adaptation of IR-dye-labeled primers in combination with a one step RT-PCR resulted in a detection limit of 0.5 pfu of purified BTV RNA. All 24 serotypes of BTV prototype strains and none of the 8 serotypes of the closely related epizootic hemorrhagic disease virus (EHDV) prototype strains were detected.

  6. Haemoproteus minutus and Haemoproteus belopolskyi (Haemoproteidae): complete sporogony in the biting midge Culicoides impunctatus (Ceratopogonidae), with implications on epidemiology of haemoproteosis.

    PubMed

    Ziegytė, Rita; Palinauskas, Vaidas; Bernotienė, Rasa; Iezhova, Tatjana A; Valkiūnas, Gediminas

    2014-10-01

    Species of Haemoproteus (Haemoproteidae) are cosmopolitan haemosporidian parasites, some of which cause severe diseases in birds. Numerous recent studies address molecular characterization, distribution and genetic diversity of haemoproteids. However, the information about their vectors is scarce. We investigated sporogonic development of two widespread species of Haemoproteus (Haemoproteus minutus and Haemoproteus belopolskyi) in the experimentally infected biting midge Culicoides impunctatus. Wild-caught flies were allowed to take blood meals on naturally infected common blackbirds Turdus merula and icterine warblers Hippolais icterina harboring mature gametocytes of H. minutus (lineage hTURDUS2) and H. belopolskyi (hHIICT1), respectively. The engorged flies were collected, transported to the laboratory, held at 15-18°C, and dissected daily in order to obtain ookinetes, oocysts and sporozoites. Mature ookinetes of H. minutus developed blisteringly rapidly; they were numerous in the midgut content between 1 and 4 h post exposure. Ookinetes of H. belopolskyi developed slower and were reported 1 day post exposure (dpe). Oocysts of both parasites were seen in the midgut wall 3-4 dpe. Sporozoites of H. minutus and H. belopolskyi were first observed in the salivary glands preparations 7 dpe. The percentage of experimentally infected flies with sporozoites of H. minutus was 82.1% and 91.7% with H. belopolskyi. In accordance with microscopy data, polymerase chain reaction amplification and sequencing confirmed presence of the corresponding parasite lineages in experimentally infected biting midges. Sporogonic stages of these parasites were described and illustrated. This study indicates that C. impunctatus is involved in the transmission of deadly H. minutus, which kills captive parrots in Europe. This biting midge is an important vector of avian haemoproteids and worth more attention in epidemiology research of avian haemoproteosis. PMID:25102434

  7. RNA interference targets arbovirus replication in Culicoides cells.

    PubMed

    Schnettler, Esther; Ratinier, Maxime; Watson, Mick; Shaw, Andrew E; McFarlane, Melanie; Varela, Mariana; Elliott, Richard M; Palmarini, Massimo; Kohl, Alain

    2013-03-01

    Arboviruses are transmitted to vertebrate hosts by biting arthropod vectors such as mosquitoes, ticks, and midges. These viruses replicate in both arthropods and vertebrates and are thus exposed to different antiviral responses in these organisms. RNA interference (RNAi) is a sequence-specific RNA degradation mechanism that has been shown to play a major role in the antiviral response against arboviruses in mosquitoes. Culicoides midges are important vectors of arboviruses, known to transmit pathogens of humans and livestock such as bluetongue virus (BTV) (Reoviridae), Oropouche virus (Bunyaviridae), and likely the recently discovered Schmallenberg virus (Bunyaviridae). In this study, we investigated whether Culicoides cells possess an antiviral RNAi response and whether this is effective against arboviruses, including those with double-stranded RNA (dsRNA) genomes, such as BTV. Using reporter gene-based assays, we established the presence of a functional RNAi response in Culicoides sonorensis-derived KC cells which is effective in inhibiting BTV infection. Sequencing of small RNAs from KC and Aedes aegypti-derived Aag2 cells infected with BTV or the unrelated Schmallenberg virus resulted in the production of virus-derived small interfering RNAs (viRNAs) of 21 nucleotides, similar to the viRNAs produced during arbovirus infections of mosquitoes. In addition, viRNA profiles strongly suggest that the BTV dsRNA genome is accessible to a Dicer-type nuclease. Thus, we show for the first time that midge cells target arbovirus replication by mounting an antiviral RNAi response mainly resembling that of other insect vectors of arboviruses.

  8. RNA Interference Targets Arbovirus Replication in Culicoides Cells

    PubMed Central

    Schnettler, Esther; Ratinier, Maxime; Watson, Mick; Shaw, Andrew E.; McFarlane, Melanie; Varela, Mariana; Elliott, Richard M.; Palmarini, Massimo

    2013-01-01

    Arboviruses are transmitted to vertebrate hosts by biting arthropod vectors such as mosquitoes, ticks, and midges. These viruses replicate in both arthropods and vertebrates and are thus exposed to different antiviral responses in these organisms. RNA interference (RNAi) is a sequence-specific RNA degradation mechanism that has been shown to play a major role in the antiviral response against arboviruses in mosquitoes. Culicoides midges are important vectors of arboviruses, known to transmit pathogens of humans and livestock such as bluetongue virus (BTV) (Reoviridae), Oropouche virus (Bunyaviridae), and likely the recently discovered Schmallenberg virus (Bunyaviridae). In this study, we investigated whether Culicoides cells possess an antiviral RNAi response and whether this is effective against arboviruses, including those with double-stranded RNA (dsRNA) genomes, such as BTV. Using reporter gene-based assays, we established the presence of a functional RNAi response in Culicoides sonorensis-derived KC cells which is effective in inhibiting BTV infection. Sequencing of small RNAs from KC and Aedes aegypti-derived Aag2 cells infected with BTV or the unrelated Schmallenberg virus resulted in the production of virus-derived small interfering RNAs (viRNAs) of 21 nucleotides, similar to the viRNAs produced during arbovirus infections of mosquitoes. In addition, viRNA profiles strongly suggest that the BTV dsRNA genome is accessible to a Dicer-type nuclease. Thus, we show for the first time that midge cells target arbovirus replication by mounting an antiviral RNAi response mainly resembling that of other insect vectors of arboviruses. PMID:23269795

  9. Sympatry in the Culicoides variipennis complex (Diptera: Ceratopogonidae): a taxonomic reassessment.

    PubMed

    Holbrook, F R; Tabachnick, W J; Schmidtmann, E T; McKinnon, C N; Bobian, R J; Grogan, W L

    2000-01-01

    We report sympatry among larval populations of the Culicoides variipennis complex in widespread and diverse aquatic habitats throughout the United States. Six sites in California, Nevada, New Mexico, and Texas were co-inhabited by C. v. occidentalis and C. v. sonorensis, whereas 8 sites in Florida, Georgia, Louisiana, Maryland, and Texas were co-occupied by C. v. sonorensis and C. v. variipennis. No intermediate forms were identified either electrophoretically or morphologically in adults reared from field-collected larvae and pupae. The absence of intergrades in zones of sympatry represents sufficient evidence to confirm species status for Culicoides variipennis (Coquillett) and Culicoides occidentalis Wirth & Jones, and to elevate Culicoides sonorensis to species rank (NEW STATUS). Culicoides v. albertensis Wirth & Jones is a synonym of C. sonorensis (NEW SYNONYMY); C. v. australis Wirth & Jones also is confirmed as a synonym of C. sonorensis. We also demonstrated a correlation between population taxonomic status as determined by electrophoresis and adult morphology.

  10. Vector competence of Culicoides for arboviruses: three major periods of research, their influence on current studies and future directions.

    PubMed

    Carpenter, S; Veronesi, E; Mullens, B; Venter, G

    2015-04-01

    The spectacular and unprecedented outbreaks of bluetongue virus (BTV) that have occurred in Europe since 1998 have led to increased interest in those factors that determine competence of Culicoides biting midges (Diptera: Ceratopogonidae) for arboviruses. In this review the authors critically examine three major periods of research into the biological transmission by Culicoides of two economically important arboviruses ofthefamily Reoviridae: African horse sicknessvirus (AHSV) and BTV. First they examine early studies, largely conducted in southern Africa, that played a key role in initially implicating Culicoides as agents of AHSV and BTV transmission. Then they examine advances in understanding made following the establishment of colonies of the BTV vector species Culicoides sonorensis, which have largely shaped our current understanding of BTV and AHSV transmission. They then consider attempts in recent years to implicate vectors of BTV in the European Union during what has become the most economically damaging series of outbreaks in recorded history. In some cases the origin of these outbreaks was uncertain and unexpected, particularly in northern Europe, where BTV had not previously occurred. Limitations imposed on studies of vector competence by the biology of Culicoides are then discussed, along with advances in the technologies now available and the logistics of working upon agents requiring biosecure containment outside their endemic range. Finally, the authors suggest areas that have either been poorly addressed to date or entirely ignored and ways in which studies could be conducted to provide standardised data for comparison worldwide.

  11. Detection and titration of bluetongue virus in Culicoides insect cell culture by an antigen-capture enzyme-linked immunosorbent assay.

    PubMed

    Mecham, James O

    2006-08-01

    Bluetongue virus (BTV) infects sheep, cattle and other ruminants and is transmitted by Culicoides spp. of biting midges. Virus is typically isolated and characterized by infection of susceptible vertebrate cells that undergo detectable and measurable cytopathic effects. Cell lines derived from C. sonorensis may be useful for virus isolation and studies to better understand BTV replication in the insect vector. However, their use is hampered because BTV infection does not produce significant cytopathic effects in these insect cell cultures. Detection of virus replication in these cells typically requires co-cultivation with susceptible vertebrate cell culture. This report describes the use of an antigen-capture enzyme-linked immunosorbent assay (Ag-Cap ELISA) for direct detection and titration of BTV in cultures of a Culicoides cell line. This assay should facilitate use of this cell line for virus isolation, titration and studies of BTV replication.

  12. On the study of the transmission networks of blood parasites from SW Spain: diversity of avian haemosporidians in the biting midge Culicoides circumscriptus and wild birds

    PubMed Central

    2013-01-01

    Background Blood-sucking flying insects play a key role in the transmission of pathogens of vector-borne diseases. However, at least for the case of avian malaria parasites, the vast majority of studies focus on the interaction between parasites and vertebrate hosts, but there is a lack of information regarding the interaction between the parasites and the insect vectors. Here, we identified the presence of malaria and malaria-like parasite lineages harbored by the potential vector Culicoides circumscriptus (Kieffer). Also, we identified some nodes of the transmission network connecting parasite lineages, potential insect vectors and avian hosts by comparing Haemoproteus and Plasmodium lineages isolated from insects with those infecting wild birds in this and previous studies. Methods Using a molecular approach, we analysed the presence of blood parasites in a total of 97 biting midges trapped in the Doñana National Park (SW Spain) and surrounding areas. Also, 123 blood samples from 11 bird species were analyzed for the presence of blood parasite infections. Blood parasites Haemoproteus and Plasmodium were identified by amplification of a 478 bp fragment of the mitochondrial cytochrome b gen. Results Thirteen biting midges harboured blood parasites including six Haemoproteus and two Plasmodium lineages, supporting the potential role of these insects on parasite transmission. Moreover, ten (8.1%) birds carried blood parasites. Seven Plasmodium and one Haemoproteus lineages were isolated from birds. Overall, six new Haemoproteus lineages were described in this study. Also, we identified the transmission networks of some blood parasites. Two Haemoproteus lineages, hCIRCUM03 and GAGLA03, were identical to those isolated from Corvus monedula in southern Spain and Garrulus glandarius in Bulgaria, respectively. Furthermore, the new Haemoproteus lineage hCIRCUM05 showed a 99% similarity with a lineage found infecting captive penguins in Japan. Conclusions The comparison

  13. Assessment of vector/host contact: comparison of animal-baited traps and UV-light/suction trap for collecting Culicoides biting midges (Diptera: Ceratopogonidae), vectors of Orbiviruses

    PubMed Central

    2011-01-01

    Background The emergence and massive spread of bluetongue in Western Europe during 2006-2008 had disastrous consequences for sheep and cattle production and confirmed the ability of Palaearctic Culicoides (Diptera: Ceratopogonidae) to transmit the virus. Some aspects of Culicoides ecology, especially host-seeking and feeding behaviors, remain insufficiently described due to the difficulty of collecting them directly on a bait animal, the most reliable method to evaluate biting rates. Our aim was to compare typical animal-baited traps (drop trap and direct aspiration) to both a new sticky cover trap and a UV-light/suction trap (the most commonly used method to collect Culicoides). Methods/results Collections were made from 1.45 hours before sunset to 1.45 hours after sunset in June/July 2009 at an experimental sheep farm (INRA, Nouzilly, Western France), with 3 replicates of a 4 sites × 4 traps randomized Latin square using one sheep per site. Collected Culicoides individuals were sorted morphologically to species, sex and physiological stages for females. Sibling species were identified using a molecular assay. A total of 534 Culicoides belonging to 17 species was collected. Abundance was maximal in the drop trap (232 females and 4 males from 10 species) whereas the diversity was the highest in the UV-light/suction trap (136 females and 5 males from 15 species). Significant between-trap differences abundance and parity rates were observed. Conclusions Only the direct aspiration collected exclusively host-seeking females, despite a concern that human manipulation may influence estimation of the biting rate. The sticky cover trap assessed accurately the biting rate of abundant species even if it might act as an interception trap. The drop trap collected the highest abundance of Culicoides and may have caught individuals not attracted by sheep but by its structure. Finally, abundances obtained using the UV-light/suction trap did not estimate accurately Culicoides

  14. Culicoides monitoring in Belgium in 2011: analysis of spatiotemporal abundance, species diversity and Schmallenberg virus detection.

    PubMed

    DE Regge, N; DE Deken, R; Fassotte, C; Losson, B; Deblauwe, I; Madder, M; Vantieghem, P; Tomme, M; Smeets, F; Cay, A B

    2015-09-01

    In 2011, Culicoides (Diptera: Ceratopogonidae) were collected at 16 locations covering four regions of Belgium with Onderstepoort Veterinary Institute (OVI) traps and at two locations with Rothamsted suction traps (RSTs). Quantification of the collections and morphological identification showed important variations in abundance and species diversity between individual collection sites, even for sites located in the same region. However, consistently higher numbers of Culicoides midges were collected at some sites compared with others. When species abundance and diversity were analysed at regional level, between-site variation disappeared. Overall, species belonging to the subgenus Avaritia together with Culicoides pulicaris (subgenus Culicoides) were the most abundant, accounting for 80% and 96% of all midges collected with RSTs and OVI traps, respectively. Culicoides were present during most of the year, with Culicoides obsoletus complex midges found from 9 February until 27 December. Real-time reverse-transcription polymerase chain reaction screening for Schmallenberg virus in the heads of collected midges resulted in the first detection of the virus in August 2011 and identified C. obsoletus complex, Culicoides chiopterus and Culicoides dewulfi midges as putative vector species. At Libramont in the south of Belgium, no positive pools were identified. PMID:25761054

  15. Contribution to the knowledge of Culicoides (Diptera: Ceratopogonidae) host preferences in France.

    PubMed

    Ninio, Camille; Augot, Denis; Delecolle, Jean-Claude; Dufour, Barbara; Depaquit, Jerome

    2011-03-01

    Knowledge on host-feeding pattern of blood-sucking insects helps to understand the epidemiology of a vector-born disease. We determined blood meal origin from blood-fed Culicoides thanks to molecular techniques. A set of primers was used to selectively amplify segment of vertebrates' prepronociceptin gene from abdomen of engorged Culicoides (Diptera: Ceratopogonidae). Vertebrate DNA was successfully amplified in 91% of blood-fed Culicoides assayed. Direct sequencing and comparison of resultant sequences with sequences in GenBank, using BLAST, lead to the specific identification of the host in 100% of the cases. A total of 157 blood-fed females belonging to 13 different Culicoides' species were captured thanks to light traps in different areas of France between 2008 and 2009. Blood meal origin was determined for 143 blood-fed midges: 59 Culicoides obsoletus, 18 Culicoides dewulfi, 16 Culicoides scoticus, 11 Culicoides chiopterus, 10 Culicoides lupicaris, 1 Culicoides pulicaris, 8 Culicoides punctatus, 10 Culicoides pallidicornis, 3 Culicoides achrayi, 2 Culicoides furcillatus, 3 Culicoides brunnicans, 1 Culicoides picturatus and 1 Culicoides poperinghensis. The predominant species in our study belong to the C. obsoletus complex; they are considered as putative vectors of Bluetongue virus in the north of Europe. C. chiopterus sampled fed only on cattle, while blood meal origin of C. dewulfi, C. obsoletus and C. scoticus was diversified. In our sampling, we found that midges were fed mainly on cattle (54%), rabbits (20%), horses (17%), sheep (4%), pigs or wild boars (4%) and human (1%). Cattle DNA was found in at least 11 different species of Culicoides assayed.

  16. The effect of high frequency sound on Culicoides numbers collected with suction light traps.

    PubMed

    Venter, Gert J; Labuschagne, Karien; Boikanyo, Solomon N B; Morey, Liesl

    2012-11-07

    Culicoides midges (Diptera: Ceratopogonidae), are involved in the transmission of various pathogens that cause important diseases of livestock worldwide. The use of insect repellents to reduce the attack rate of these insects on livestock could play an important role as part of an integrated control programme against diseases transmitted by these midges. The objective of this study was to determine whether high frequency sound has any repellent effect on Culicoides midges. The number of midges collected with 220 V Onderstepoort white light traps fitted with electronic mosquito repellents (EMRs), emitting 5-20 KHz multi-frequency sound waves, was compared with that of two untreated traps. Treatments were rotated in two replicates of a 4 x 4 randomised Latin square design. Although fewer midges were collected in the two traps fitted with EMRs, the average number collected over eight consecutive nights was not significantly different. The EMRs also had no influence on any of the physiological groups of Culicoides imicola Kieffer or the species composition of the Culicoides population as determined with light traps. The results indicate that high frequency sound has no repellent effect on Culicoides midges. There is therefore no evidence to support their promotion or use in the protection of animals against pathogens transmitted by Culicoides midges.

  17. An Improved, high-throughput method for detection of bluetongue virus RNA in Culicodes midges

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new rapid (less than 6 h from insect-to-results) high-throughput assay is reported that is sensitive and specific for detecting BTV RNA in Culicoides biting midges. Homogenization and extraction of nucleic acids from individual Culicoides specimens were performed in a 96-well plate format using sp...

  18. Differential emergence of Culicoides (Diptera: Ceratopogonidae) from on-farm breeding substrates in Northern Ireland.

    PubMed

    Thompson, Geoffrey M; Jess, Stephen; Murchie, Archie K

    2013-05-01

    Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) are vectors of a number of viral diseases worldwide. Following the unforeseen outbreak of bluetongue in northern Europe (2006–2009) there was a need to clarify on-farm breeding substrates utilized by temperate Culicoides spp. Six substrates (cow dung, cow slurry, horse dung, sheep dung, maize silage and soil) were investigated for Culicoides spp. emergence over a 31-week period. Overall, most Obsoletus group Culicoides emerged from the cow dung and the most Pulicaris group Culicoides emerged from the sheep dung. Furthermore, Culicoides of the Obsoletus group were found to be abundant in cow slurry and sheep dung. Temperature played a significant role in the emergence times of adult Culicoides. The Obsoletus group appear to have undergone 3 generations during the experimental period. The sex ratio of emergent Obsoletus group Culicoides was affected by substrate type, with a greater proportion of males emerging from cow dung and slurry compared with the other substrates.

  19. A New Species of Culicoides (Selfia) (Diptera: Ceratopogonidae) from Southeastern Utah.

    PubMed

    Phillips, Robert A

    2015-09-01

    A new species of biting midge, Culicoides (Selfia) moabensis, is described and illustrated from southeastern Utah. Its relationship to Culicoides (Selfia) multipunctatus Malloch and Culicoides (Selfia) brookmani Wirth is discussed, and modifications to existing keys to adult males and females of C. (Selfia) species are provided. Its abundance, seasonal distribution, and aspects of its reproductive and feeding biology and potential as an arbovirus vector are discussed. PMID:26336237

  20. The occurrence of Culicoides species, the vectors of arboviruses, at selected trap sites in Zimbabwe.

    PubMed

    Gordon, Stuart J G; Bolwell, Charlotte; Rogers, Chris; Musuka, Godfrey; Kelly, Patrick; Labuschagne, Karien; Guthrie, Alan J; Denison, Eric; Mellor, Philip S; Hamblin, Chris

    2015-05-29

    A study of the distribution of Culicoides species was conducted by establishing 12 light trap sites over five rainy seasons between 1998 and 2003 covering all the geo-climatic natural regions of Zimbabwe. In total, 279 919 specimens of Culicoides were trapped over a total of 163 trapping nights. The highest median counts of Culicoides per trapping night were recorded in natural region III, which has climatic conditions conducive to the successful development of the larvae. Culicoides imicola, the major vector of bluetongue and African horse sickness viruses in Africa, was found to be the most abundant species (80.4%), followed by Culicoides enderleini (5.9%) and Culicoides milnei (5.2%). This study identified 10 species of Culicoides that had not been previously described in Zimbabwe, including Culicoides loxodontis and Culicoides miombo, which are members of the C. imicola complex. A total of 23 994 Culicoides midges were collected from five trap sites in Harare, Zimbabwe, with the dominant species, C. imicola, representing 91.6% of the total collection. Seventeen arboviruses were isolated from these midges, 15 of which were bluetongue virus. The predominant bluetongue virus serotype was serotype 11, followed by serotypes 1, 8, 12 and 15. Bluetongue virus serotypes 1, 2, 8, 10, 12, 15, 16 and 18, detected in this study, had not been previously reported in Zimbabwe.

  1. Field trials assessing deltamethrin (Butox®) treatments of sheep against Culicoides species.

    PubMed

    Weiher, Wiebke; Bauer, Burkhard; Mehlitz, Dieter; Nijhof, Ard M; Clausen, Peter-Henning

    2014-07-01

    Culicoides (Diptera: Ceratopogonidae) biting midges may transmit various diseases of economic importance, including bluetongue virus (BTV) and Schmallenberg (SV) virus, which affect ruminants. During the outbreak of BTV in central and northern Europe in 2006, and in the absence of BTV vaccines, many national veterinary services recommended the treatment of susceptible livestock with pyrethroids as a first-line defense against biting midges, although these insecticides were officially not registered and authorized for use against Culicoides midges. The efficacy of Butox® pour on (7.5 mg deltamethrin/mL) against biting midges was therefore evaluated in a double-blinded GCP field trial performed in Brandenburg, Germany. Forty female Merino sheep with an average body weight of 38 kg (±7 kg) were used for the study. Twenty randomly selected sheep were treated with 10 mL Butox® pour on. The remaining 20 sheep were left untreated and served as a control group. Midge collections took place in two separate drop traps covering two crush pens with three confined treated/untreated sheep standing inside, on weekdays at 1, 7, 14, 21, 28, and 35 days post treatment. A total of 19,057 midges were collected during this period. Midges were identified as belonging to the subgenus Avaritia, Fox (84.6%) and subgenus Culicoides, Latreille (15.4%). A total of 12,031 midges were collected inside the drop trap containing untreated sheep, in comparison to 7,026 midges collected from the vicinity of the treated sheep. Significantly, more midges had fed on control compared to treated sheep with 757 and 103 engorged midges, respectively. The results indicate that treatment of sheep with Butox® pour on provided a significant decrease in Culicoides feeding rates under field conditions for at least 35 days.

  2. Ten species of Culicoides Latreille (Diptera: Ceratopogonidae) newly recorded from Thailand.

    PubMed

    Thepparat, Arunrat; Bellis, Glenn; Ketavan, Chitapa; Ruangsittichai, Jiraporn; Sumruayphol, Suchada; Apiwathnasorn, Chamnarn

    2015-01-01

    A survey of biting midges in animal sheds, mangroves and beaches along the Andaman coastal region in southern Thailand between April 2012 and May 2013 collected 10 species of Culicoides which were not previously known from Thailand. These new records are C. arenicola, C. flavipunctatus, C. hui, C. kinari, C. kusaiensis, C. parabubalus, C. quatei, C. spiculae, C. pseudocordiger and C. tamada. An updated checklist of species of Culicoides reported from Thailand is provided.

  3. Ten species of Culicoides Latreille (Diptera: Ceratopogonidae) newly recorded from Thailand.

    PubMed

    Thepparat, Arunrat; Bellis, Glenn; Ketavan, Chitapa; Ruangsittichai, Jiraporn; Sumruayphol, Suchada; Apiwathnasorn, Chamnarn

    2015-01-01

    A survey of biting midges in animal sheds, mangroves and beaches along the Andaman coastal region in southern Thailand between April 2012 and May 2013 collected 10 species of Culicoides which were not previously known from Thailand. These new records are C. arenicola, C. flavipunctatus, C. hui, C. kinari, C. kusaiensis, C. parabubalus, C. quatei, C. spiculae, C. pseudocordiger and C. tamada. An updated checklist of species of Culicoides reported from Thailand is provided. PMID:26624391

  4. Assessment of the repellent effect of citronella and lemon eucalyptus oil against South African Culicoides species.

    PubMed

    Venter, Gert J; Labuschagne, Karien; Boikanyo, Solomon N B; Morey, Liesl

    2014-01-01

    The use of insect repellents to reduce the attack rate of Culicoides species (Diptera:Ceratopogonidae) should form part of an integrated control programme to combat African horse sickness and other diseases transmitted by these blood-feeding midges. In the present study the repellent effects of a commercially available mosquito repellent, a combination of citronella and lemon eucalyptus oils, on Culicoides midges was determined. The number of midges collected with two 220 V Onderstepoort traps fitted with 8 W 23 cm white light tubes and baited with peel-stick patches, each containing 40 mg of active ingredient, was compared with that of two unbaited traps. Two trials were conducted and in each trial the four traps were rotated in two replicates of a 4 x 4 randomised Latin square design. Although more midges were collected in the baited traps, the mean number in the baited and unbaited traps was not significantly different. This mosquito repellent did not influence either the species composition or the physiological groups of Culicoides imicola Kieffer. The higher mean numbers in the baited traps, although not statistically significant, may indicate that this mosquito repellent might even attract Culicoides midges under certain conditions.

  5. Assessment of the repellent effect of citronella and lemon eucalyptus oil against South African Culicoides species.

    PubMed

    Venter, Gert J; Labuschagne, Karien; Boikanyo, Solomon N B; Morey, Liesl

    2014-01-01

    The use of insect repellents to reduce the attack rate of Culicoides species (Diptera:Ceratopogonidae) should form part of an integrated control programme to combat African horse sickness and other diseases transmitted by these blood-feeding midges. In the present study the repellent effects of a commercially available mosquito repellent, a combination of citronella and lemon eucalyptus oils, on Culicoides midges was determined. The number of midges collected with two 220 V Onderstepoort traps fitted with 8 W 23 cm white light tubes and baited with peel-stick patches, each containing 40 mg of active ingredient, was compared with that of two unbaited traps. Two trials were conducted and in each trial the four traps were rotated in two replicates of a 4 x 4 randomised Latin square design. Although more midges were collected in the baited traps, the mean number in the baited and unbaited traps was not significantly different. This mosquito repellent did not influence either the species composition or the physiological groups of Culicoides imicola Kieffer. The higher mean numbers in the baited traps, although not statistically significant, may indicate that this mosquito repellent might even attract Culicoides midges under certain conditions. PMID:25686204

  6. Impact of flooding on the immature stages of dung-breeding Culicoides in Northern Europe.

    PubMed

    Lühken, Renke; Steinke, Sonja; Wittmann, Anna; Kiel, Ellen

    2014-09-15

    In Northern Europe, dung-breeding Culicoides (e.g., Culicoides chiopterus (Meigen 1830) and Culicoides dewulfi (Goetghebuer 1936)) are considered to be important vectors of the Bluetongue virus and Schmallenberg virus. The interpretation of their distribution is difficult due to the lack of knowledge about their ecology. Previously, soil moisture and especially flooding were identified as important factors that influence the development of several biting-midge species. Therefore, this experimental study addressed the question whether flooding has a negative impact on the development of immature stages of Obsoletus group species. Ten cowpats were collected, and each was divided into four quarters and kept at different moisture regimes in a greenhouse: (1) "dry" (no water added), (2) "control" (regularly moistened), (3) "alternately flooded" and (4) "permanently flooded", to compare Culicoides emergence. Flooding had a significant negative impact on the emergence of Culicoides. No individuals emerged from the "permanently flooded" treatment and only two individuals were sampled from the "alternately flooded" treatment. In contrast, the total emergence from the non-flooded samples in the "dry" (96 individuals, 38.6% of all Culicoides) and "control" (151 individuals, 60.6% of all biting midges) treatments was considerably higher. Biting midges were predominantly identified as C. dewulfi (161 individuals, 64.7% of all Culicoides) and C. chiopterus (63 individuals, 25.3% of all Culicoides). There were no significant differences in emergence between the "dry" and "control" treatments. Our results highlight the importance of soil moisture on the distribution of C. chiopterus and C. dewulfi. Regarding physiological and behavioural adaptations of other Culicoides species, we argue that pupae of C. chiopterus and C. dewulfi are in danger of drowning when breeding sites are flooded as they cannot float. On the contrary, our results indicate that desiccation might not be

  7. Does covering of farm-associated Culicoides larval habitat reduce adult populations in the United Kingdom?☆

    PubMed Central

    Harrup, L.E.; Gubbins, S.; Barber, J.; Denison, E.; Mellor, P.S.; Purse, B.V.; Carpenter, S.

    2014-01-01

    Culicoides biting midges (Diptera: Ceratopogonidae) are the biological vectors of a range of internationally important arboviruses of livestock, including bluetongue virus (BTV) and the recently emerging Schmallenberg virus (SBV). Culicoides species in the subgenus Avaritia (in the UK: Culicoides obsoletus Meigen, Culicoides scoticus Downes & Kettle, Culicoides dewulfi Goetghebuer and Culicoides chiopterus Meigen) have been implicated in BTV transmission in northern Europe and to a varying degree utilise cattle dung as a larval development substrate. The collection of cattle dung into heaps on farms provides a localised source of Culicoides emergence in close proximity to livestock. This study assesses the impact of covering dung heaps prior to the onset of adult Culicoides activity with the aim of reducing recruitment to the local adult populations at four livestock farms in England. Light suction trap catches of adult Culicoides from these farms were compared with those from four untreated control farms from a wide geographic range across the UK. It was demonstrated that implementing control of emergence from dung heaps did not have a significant impact upon the local adult subgenus Avaritia abundance at the treated farm holdings and that the onset of Culicoides activity was similarly unaffected. Use of this method in isolation is unlikely to have an effect in reducing the risk of BTV and SBV transmission. The implications of these results for control of farm-associated Culicoides in Europe are discussed. PMID:24472769

  8. Evaluation of in vitro methods for assessment of infection of Australian Culicoides spp. with bluetongue viruses.

    PubMed

    Van der Saag, Matthew; Nicholas, Adrian; Ward, Michael; Kirkland, Peter

    2015-01-01

    Biting midges from the genus Culicoides (Diptera: Ceratopogonidae) are the vectors of several globally important arboviruses that affect livestock. These include orbiviruses from the bluetongue virus (BTV) and African horse sickness virus (AHSV) groups and members of the Simbu serogroup of orthobunyaviruses, such as the recently emerged Schmallenberg virus. In this article, the authors evaluate several methods for feeding wild‑caught Australian Culicoides on BTV infected preparations of blood and sucrose. Feeding Culicoides on the membrane of embryonated chicken eggs was identified as the preferred feeding method. Although, cotton wool pads soaked in either virus‑infected blood or virus‑sucrose mixtures were also successful. A non‑destructive nucleic acid extraction technique for the detection of viral RNA in Culicoides was also evaluated as it allows for readily differentiating infected from non‑infected Culicoides. PMID:26741248

  9. Culicoides spp. (Diptera: Ceratopogonidae) as vectors of bluetongue virus in South Africa - a review.

    PubMed

    Venter, Gert Johannes

    2015-01-01

    The aim of this paper is to consolidate vector competence studies on Culicoides midges (Diptera: Ceratopogonidae) as vectors of bluetongue virus (BTV) done over a period 25 years at the ARC‑Onderstepoort Veterinary Institute in South Africa. In 1944, it was demonstrated for the first time in South Africa that Culicoides midges transmit BTV. In 1991, field‑collected Culicoides imicola were fed on blood containing BTV‑3 or ‑6 and the infection rates were established as being 31% and 24%, respectively. In 1998, Culicoides bolitinos was shown to have a higher infection prevalence and virus titre/midge than C. imicola. This species was then shown to have a higher transmission potential for BTV‑1 over a range of incubation temperatures wider than the one showed by C. imicola. Attenuation of BTV also does not reduce its ability to infect competent Culicoides species. Oral susceptibility studies, involving 29 BTV isolates of various serotypes, indicated differences between various geographic virus isolates and Culicoides populations evaluated. While low recovery rates of European BTV strains from South African Culicoides species suggest co‑adaptation between orbiviruses and vectors in a given locality, co‑adaption was shown not to be essential for virus transmission. Cumulative results since 1991 provide evidence that at least 13 livestock‑associated Culicoides species are susceptible to BTV. Susceptibility results are supported by field isolations from 5 of these species. This implies that multi‑vector potential for the transmission of BTV will complicate the epidemiology of BT. It must be emphasised that neither oral susceptibility nor virus isolation/detection from field‑collected specimens is proof that a species is a confirmed field vector. PMID:26741247

  10. Seasonal abundance of livestock-associated Culicoides species in northeastern Brazil.

    PubMed

    Carvalho, L P C; Silva, F S

    2014-06-01

    Culicoides biting midges (Diptera: Ceratopogonidae) are of great medical and veterinary importance because the haematophagous females of some species can transmit diseases to humans and animals. In order to determine the presence and seasonal abundance of the bluetongue virus (BTV) vector Culicoides insignis Lutz at domestic animal sheds in northeastern Brazil, insects were collected once a month between January and December 2010. Light traps were set from 18.00 to 06.00 hours at a pigsty, chicken coop and bovine corral. Culicoides insignis accounted for 81% of the 22,316 specimens collected. Other well-represented species were: Culicoides paucienfuscatus Barbosa (3246 individuals), Culicoides diabolicus Hoffman (308), Culicoides leopoldoi Ortiz (224) and Culicoides duartei Tavares and Luna Dias (221). The remainder accounted for 4% of the total sample. Culicoides insignis occurred mostly at the cattle corral, 98.2% in the rainy season. This study confirms the presence and close association of C. insignis with cattle in Maranhão state, northeastern Brazil and emphasizes the risk of bluetongue infections spreading in the area. PMID:24382216

  11. Seasonal Dynamics, Parity Rate, and Composition of Culicoides (Diptera: Ceratopogonidae) Occurring in the Vicinity of Wild and Domestic Ruminants in the Czech Republic.

    PubMed

    Rádrová, Jana; Mračková, Marie; Galková, Zdenka; Lamka, Jírí; Račka, Karol; Barták, Pavel; Votýpka, Jan

    2016-03-01

    In the light of the emergence of bluetongue and Schmallenberg viruses in northern and central Europe, an extensive entomological survey within the framework of a bluetongue control program was undertaken from 2008 to 2013 in the Czech Republic to investigate Culicoides biting midges (Diptera: Ceratopogonidae) collected in close proximity of domestic livestock and semiwild ruminants. Insects were sampled using CDC black-light suction traps placed overnight near ruminants in farms or in forest game preserves to provide data on Culicoides fauna collected near these two groups of hosts inhabiting different environments. From almost a half million biting midge specimens collected at 41 sampling sites, 34 species were identified including three species newly recorded for the Czech Republic: Culicoides (Oecacta) clastrieri Callot, Kremer & Deduit, Culicoides (Oecacta) odiatus Austen, and Culicoides (Pontoculicoides) saevus Kieffer. The Culicoides obsoletus species group, incriminated as a bluetongue virus vector, was predominant in both domestic livestock (91%) and semiwild game (52%). A relatively high proportion (around 30%) of C. obsoletus Meigen females with pigmented abdomen (= more likely parous) was observed from spring till autumn. In contrast, adult biting midges were found to be largely absent during at least three winter months, approximately December till March, which could be considered as the biting midge vector-free period.

  12. Seasonal Dynamics, Parity Rate, and Composition of Culicoides (Diptera: Ceratopogonidae) Occurring in the Vicinity of Wild and Domestic Ruminants in the Czech Republic.

    PubMed

    Rádrová, Jana; Mračková, Marie; Galková, Zdenka; Lamka, Jírí; Račka, Karol; Barták, Pavel; Votýpka, Jan

    2016-03-01

    In the light of the emergence of bluetongue and Schmallenberg viruses in northern and central Europe, an extensive entomological survey within the framework of a bluetongue control program was undertaken from 2008 to 2013 in the Czech Republic to investigate Culicoides biting midges (Diptera: Ceratopogonidae) collected in close proximity of domestic livestock and semiwild ruminants. Insects were sampled using CDC black-light suction traps placed overnight near ruminants in farms or in forest game preserves to provide data on Culicoides fauna collected near these two groups of hosts inhabiting different environments. From almost a half million biting midge specimens collected at 41 sampling sites, 34 species were identified including three species newly recorded for the Czech Republic: Culicoides (Oecacta) clastrieri Callot, Kremer & Deduit, Culicoides (Oecacta) odiatus Austen, and Culicoides (Pontoculicoides) saevus Kieffer. The Culicoides obsoletus species group, incriminated as a bluetongue virus vector, was predominant in both domestic livestock (91%) and semiwild game (52%). A relatively high proportion (around 30%) of C. obsoletus Meigen females with pigmented abdomen (= more likely parous) was observed from spring till autumn. In contrast, adult biting midges were found to be largely absent during at least three winter months, approximately December till March, which could be considered as the biting midge vector-free period. PMID:26701798

  13. Environmental drivers of Culicoides phenology: how important is species-specific variation when determining disease policy?

    PubMed

    Searle, Kate R; Barber, James; Stubbins, Francesca; Labuschagne, Karien; Carpenter, Simon; Butler, Adam; Denison, Eric; Sanders, Christopher; Mellor, Philip S; Wilson, Anthony; Nelson, Noel; Gubbins, Simon; Purse, Bethan V

    2014-01-01

    Since 2006, arboviruses transmitted by Culicoides biting midges (Diptera: Ceratopogonidae) have caused significant disruption to ruminant production in northern Europe. The most serious incursions involved strains of bluetongue virus (BTV), which cause bluetongue (BT) disease. To control spread of BTV, movement of susceptible livestock is restricted with economic and animal welfare impacts. The timing of BTV transmission in temperate regions is partly determined by the seasonal presence of adult Culicoides females. Legislative measures therefore allow for the relaxation of ruminant movement restrictions during winter, when nightly light-suction trap catches of Culicoides fall below a threshold (the 'seasonally vector free period': SVFP). We analysed five years of time-series surveillance data from light-suction trapping in the UK to investigate whether significant inter-specific and yearly variation in adult phenology exists, and whether the SVFP is predictable from environmental factors. Because female vector Culicoides are not easily morphologically separated, inter-specific comparisons in phenology were drawn from male populations. We demonstrate significant inter-specific differences in Culicoides adult phenology with the season of Culicoides scoticus approximately eight weeks shorter than Culicoides obsoletus. Species-specific differences in the length of the SVFP were related to host density and local variation in landscape habitat. When the Avaritia Culicoides females were modelled as a group (as utilised in the SFVP), we were unable to detect links between environmental drivers and phenological metrics. We conclude that the current treatment of Avaritia Culicoides as a single group inhibits understanding of environmentally-driven spatial variation in species phenology and hinders the development of models for predicting the SVFP from environmental factors. Culicoides surveillance methods should be adapted to focus on concentrated assessments of species

  14. Environmental Drivers of Culicoides Phenology: How Important Is Species-Specific Variation When Determining Disease Policy?

    PubMed Central

    Searle, Kate R.; Barber, James; Stubbins, Francesca; Labuschagne, Karien; Carpenter, Simon; Butler, Adam; Denison, Eric; Sanders, Christopher; Mellor, Philip S.; Wilson, Anthony; Nelson, Noel; Gubbins, Simon; Purse, Bethan V.

    2014-01-01

    Since 2006, arboviruses transmitted by Culicoides biting midges (Diptera: Ceratopogonidae) have caused significant disruption to ruminant production in northern Europe. The most serious incursions involved strains of bluetongue virus (BTV), which cause bluetongue (BT) disease. To control spread of BTV, movement of susceptible livestock is restricted with economic and animal welfare impacts. The timing of BTV transmission in temperate regions is partly determined by the seasonal presence of adult Culicoides females. Legislative measures therefore allow for the relaxation of ruminant movement restrictions during winter, when nightly light-suction trap catches of Culicoides fall below a threshold (the ‘seasonally vector free period’: SVFP). We analysed five years of time-series surveillance data from light-suction trapping in the UK to investigate whether significant inter-specific and yearly variation in adult phenology exists, and whether the SVFP is predictable from environmental factors. Because female vector Culicoides are not easily morphologically separated, inter-specific comparisons in phenology were drawn from male populations. We demonstrate significant inter-specific differences in Culicoides adult phenology with the season of Culicoides scoticus approximately eight weeks shorter than Culicoides obsoletus. Species-specific differences in the length of the SVFP were related to host density and local variation in landscape habitat. When the Avaritia Culicoides females were modelled as a group (as utilised in the SFVP), we were unable to detect links between environmental drivers and phenological metrics. We conclude that the current treatment of Avaritia Culicoides as a single group inhibits understanding of environmentally-driven spatial variation in species phenology and hinders the development of models for predicting the SVFP from environmental factors. Culicoides surveillance methods should be adapted to focus on concentrated assessments of species

  15. Culicoides Latreille (Diptera: Ceratopogonidae) taxonomy: Current challenges and future directions

    PubMed Central

    Harrup, L.E.; Bellis, G.A.; Balenghien, T.; Garros, C.

    2015-01-01

    Culicoides Latreille biting midges (Diptera: Ceratopogonidae) cause a significant biting nuisance to humans, livestock and equines, and are the biological vectors of a range of internationally important pathogens of both veterinary and medical importance. Despite their economic significance, the delimitation and identification of species and evolutionary relationships between species within this genus remains at best problematic. To date no phylogenetic study has attempted to validate the subgeneric classification of the genus and the monophyly of many of the subgenera remains doubtful. Many informal species groupings are also known to exist but few are adequately described, further complicating accurate identification. Recent contributions to Culicoides taxonomy at the species level have revealed a high correlation between morphological and molecular analyses although molecular analyses are revealing the existence of cryptic species. This review considers the methods for studying the systematics of Culicoides using both morphological and genetic techniques, with a view to understanding the factors limiting our current understanding of Culicoides biology and hence arbovirus epidemiology. In addition, we examine the global status of Culicoides identification, highlighting areas that are poorly addressed, including the potential implementation of emerging technologies. PMID:25535946

  16. Endophily in Culicoides associated with BTV-infected cattle in the province of Limburg, south-eastern Netherlands, 2006.

    PubMed

    Meiswinkel, R; Goffredo, M; Dijkstra, E G M; van der Ven, I J K; Baldet, T; Elbers, A

    2008-10-15

    Culicoides were captured at a BTV-infected dairy near Gulpen in the province of Limburg (south-east Netherlands) between 14 September and 4 October 2006. Onderstepoort-type blacklight traps were used to sample Culicoides both inside and outside a partially open shed housing 11 cattle. A total of 28 light trap collections were made at the shed and yielded: 9371 Culicoides representing 11 species; >90% comprised five potential vectors of BTV and in order of abundance were Culicoides obsoletus and Culicoides scoticus (of the Obsoletus Complex), Culicoides dewulfi, Culicoides pulicaris and Culicoides chiopterus; Culicoides imicola, the principal Mediterranean (and African) vector of BTV, was absent. 2339 Culicoides representing seven species were captured inside (endophily) the cattle shed; >95% comprised the Obsoletus Complex and C. dewulfi. Conversely, the Pulicaris Complex, represented by five species and including C. pulicaris, showed strong exophily with >97% captured outside the shed. 7032 Culicoides were captured outside the shed, approximately threefold more than inside. This trend was reversed on an overcast day, when eightfold more Culicoides were captured inside; this indicates that when the light intensity outdoors is low Culicoides will attack (i) earlier in the day while cattle are still at pasture, and (ii) might follow cattle into the sheds in the late afternoon leading to elevated numbers of biting midges being trapped inside the shed during the subsequent hours of darkness. Culicoides were captured inside the shed on all 14 sampling nights. On occasion up to 33% were freshly blood fed indicating they had avidly attacked the cattle inside (endophagy); because half the cattle had seroconverted to BTV, and because no cattle were left outdoors at night, the data indicate that (i) the housing of animals in partially open buildings does not interrupt the transmission of BTV, and/or (ii) BTV is being transmitted while cattle are grazing outdoors during the

  17. Culicoides species composition and environmental factors influencing African horse sickness distribution at three sites in Namibia.

    PubMed

    Liebenberg, Danica; Piketh, Stuart; Labuschagne, Karien; Venter, Gert; Greyling, Telane; Mienie, Charlotte; de Waal, Tania; van Hamburg, Huib

    2016-11-01

    African horse sickness (AHS) is one of the most lethal infectious, non-contagious, vector-borne disease of equids. The causative agent, African horse sickness virus (AHSV) is transmitted via Culicoides midges (Diptera: Ceratopogonidae). AHS is endemic to Namibia but detailed studies of Culicoides communities and influencing environmental parameters are limited. This study aims to determine the Culicoides species composition at three different sites and to assess environmental parameters influencing the geographical distribution of AHS in Namibia. Weekly collections of Culicoides were made during the AHS peak season from January to May for 2013 and 2014 using the Onderstepoort 220V UV-light trap. Out of 397 collections made, 124 collections (3287 Culicoides) were analysed for AHSV presence with RT-qPCR. A total of 295 collections were analysed for total Culicoides (all collected Culicoides individuals) and in 75% of these collections the Culicoides were identified to species level. C. imicola was the dominant species with proportional representation of 29.9%. C. subschultzei, C. exspectator and C. ravus each contribute more than 10% to the species composition. The lowest number of Culicoides was collected at Aus 9980, a total of 21819 at Windhoek and the highest number at Okahandja 47343. AHSV was present at all three sites during 2013 but only in Windhoek and Okahandja during 2014. Multivariate analyses of data from the two year survey indicate the environmental parameters in order of importance for the distribution of AHS in Namibia as precipitation>temperature>clay>relative humidity>NDVI. The implication of these findings is that any precipitation event increases Culicoides numbers significantly. Together with these results the high number of species found of which little is known regarding their vector competence, add to the complexity of the distribution of AHS in Namibia. PMID:27491343

  18. Culicoides species abundance and potential over-wintering of African horse sickness virus in the Onderstepoort area, Gauteng, South Africa.

    PubMed

    Venter, Gert J; Labuschagne, Karien; Majatladi, Daphney; Boikanyo, Solomon N B; Lourens, Carina; Ebersohn, Karen; Venter, Estelle H

    2014-01-01

    In South Africa, outbreaks of African horse sickness (AHS) occur in summer; no cases are reported in winter, from July to September. The AHS virus (AHSV) is transmitted almost exclusively by Culicoides midges (Diptera: Ceratopogonidae), of which Culicoides imicola is considered to be the most important vector. The over-wintering mechanism of AHSV is unknown. In this study, more than 500 000 Culicoides midges belonging to at least 26 species were collected in 88 light traps at weekly intervals between July 2010 and September 2011 near horses in the Onderstepoort area of South Africa. The dominant species was C. imicola. Despite relatively low temperatures and frost, at least 17 species, including C. imicola, were collected throughout winter (June-August). Although the mean number of midges per night fell from > 50 000 (March) to < 100 (July and August), no midge-free periods were found. This study, using virus isolation on cell cultures and a reverse transcriptase polymerase chain reaction (RT-PCR) assay, confirmed low infection prevalence in field midges and that the detection of virus correlated to high numbers. Although no virus was detected during this winter period, continuous adult activity indicated that transmission can potentially occur. The absence of AHSV in the midges during winter can be ascribed to the relatively low numbers collected coupled to low infection prevalence, low virus replication rates and low virus titres in the potentially infected midges. Cases of AHS in susceptible animals are likely to start as soon as Culicoides populations reach a critical level. PMID:25686125

  19. Impact of biting midges on residential property values in Hervey Bay, Queensland, Australia.

    PubMed

    Ratnayake, Jay; Dale, Pat E; Sipe, Neil G; Daniels, Peter

    2006-03-01

    Biting midges (Culicoides spp.) are an important environmental health issue in Hervey Bay, an area of rapid population growth in Australia. It is also the gateway to a World Heritage area (Great Sandy Strait) and a destination for tourists. The spread of housing developments into suburbs close to midge breeding habitats has led to a problem for the local government responsible for managing biting insects in its area. Suburbs with a severe biting midge problem were found to have significantly lower residential property values than less affected suburbs. The gross reduction in value in due to the midge problem was estimated to range from more than AUS dollar 25 million, based on actual sale price, to more than AUS dollar 55 million, based on the perceptions of the most severely affected residents. PMID:16646336

  20. Chemical composition of silage residues sustaining the larval development of the Culicoides obsoletus/Culicoides scoticus species (Diptera: Ceratopogonidae).

    PubMed

    Zimmer, Jean-Yves; Saegerman, Claude; Losson, Bertrand; Beckers, Yves; Haubruge, Eric; Francis, Frédéric

    2013-01-16

    Culicoides (Diptera: Ceratopogonidae) are biological vectors of bluetongue virus (BTV). Bluetongue is a viral disease that affects domestic and wild ruminants. Since its recent emergence in northern Europe, this disease has caused considerable economic losses to the sheep and cattle industry. The biotopes, and more particularly the chemical characteristics which are suitable for larval development of the main vector species, are still relatively unknown. This study shows that the larvae of biting midges belonging to the species Culicoides obsoletus and Culicoides scoticus are able to breed in different types of silage residue (maize, grass, sugar beet pulp and their combinations). The chemical composition of substrates strongly influences the presence of the immature stages of these biting midges. Higher lignin and insoluble fibre contents seem to favour their presence and could play the role of a physical support for semi-aquatic larvae. In contrast, higher concentrations of magnesium and calcium are negatively correlated with the presence of these two species. These data will help to locate and monitor the breeding sites of these species and could contribute to the control of these insects on farms.

  1. Chemical composition of silage residues sustaining the larval development of the Culicoides obsoletus/Culicoides scoticus species (Diptera: Ceratopogonidae).

    PubMed

    Zimmer, Jean-Yves; Saegerman, Claude; Losson, Bertrand; Beckers, Yves; Haubruge, Eric; Francis, Frédéric

    2013-01-16

    Culicoides (Diptera: Ceratopogonidae) are biological vectors of bluetongue virus (BTV). Bluetongue is a viral disease that affects domestic and wild ruminants. Since its recent emergence in northern Europe, this disease has caused considerable economic losses to the sheep and cattle industry. The biotopes, and more particularly the chemical characteristics which are suitable for larval development of the main vector species, are still relatively unknown. This study shows that the larvae of biting midges belonging to the species Culicoides obsoletus and Culicoides scoticus are able to breed in different types of silage residue (maize, grass, sugar beet pulp and their combinations). The chemical composition of substrates strongly influences the presence of the immature stages of these biting midges. Higher lignin and insoluble fibre contents seem to favour their presence and could play the role of a physical support for semi-aquatic larvae. In contrast, higher concentrations of magnesium and calcium are negatively correlated with the presence of these two species. These data will help to locate and monitor the breeding sites of these species and could contribute to the control of these insects on farms. PMID:22963713

  2. Studying Culicoides vectors of BTV in the post-genomic era: resources, bottlenecks to progress and future directions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Culicoides biting midges (Diptera: Ceratopogonidae) are a major vector group responsible for the biological transmission of a wide variety of globally significant arboviruses, including bluetongue virus (BTV). In this review we examine current biological resources for the study of this genus, with a...

  3. Blood meal analysis of culicoides (Diptera: ceratopogonidae) in central Tunisia.

    PubMed

    Slama, Darine; Haouas, Najoua; Mezhoud, Habib; Babba, Hamouda; Chaker, Emna

    2015-01-01

    To evaluate the host preferences of Culicoides species (Diptera: Ceratopogonidae) in Central Tunisia, we identified the source of blood meals of field collected specimens by sequencing of the cytochrome b (cyt b) mitochondrial locus and Prepronociceptine single copy nuclear gene. The study includes the most common and abundant livestock associated species of biting midges in Tunisia: C. imicola, C. jumineri, C. newsteadi, C. paolae, C. cataneii, C. circumscriptus, C. kingi, C. pseudojumineri, C. submaritimus, C. langeroni, C. jumineri var and some unidentified C. species. Analysis of cyt b PCR products from 182 field collected blood-engorged females' midges revealed that 92% of them fed solely on mammalian species, 1.6% on birds, 2.4% on insects and 0.8% on reptiles. The blast results identified the blood origin of biting midges to the species level with exact or nearly exact matches (≥98%). The results confirm the presence of several Culicoides species, including proven vectors in Central Tunisia. Blood meal analyses show that these species will indeed feed on bigger mammals, thereby highlighting the risk that these viruses will be able to spread in Tunisia.

  4. Blood Meal Analysis of Culicoides (Diptera: Ceratopogonidae) in Central Tunisia

    PubMed Central

    Slama, Darine; Haouas, Najoua; Mezhoud, Habib; Babba, Hamouda; Chaker, Emna

    2015-01-01

    To evaluate the host preferences of Culicoides species (Diptera: Ceratopogonidae) in Central Tunisia, we identified the source of blood meals of field collected specimens by sequencing of the cytochrome b (cyt b) mitochondrial locus and Prepronociceptine single copy nuclear gene. The study includes the most common and abundant livestock associated species of biting midges in Tunisia: C. imicola, C. jumineri, C. newsteadi, C. paolae, C. cataneii, C. circumscriptus, C. kingi, C. pseudojumineri, C. submaritimus, C. langeroni, C. jumineri var and some unidentified C. species. Analysis of cyt b PCR products from 182 field collected blood-engorged females’ midges revealed that 92% of them fed solely on mammalian species, 1.6% on birds, 2.4% on insects and 0.8% on reptiles. The blast results identified the blood origin of biting midges to the species level with exact or nearly exact matches (≥98%). The results confirm the presence of several Culicoides species, including proven vectors in Central Tunisia. Blood meal analyses show that these species will indeed feed on bigger mammals, thereby highlighting the risk that these viruses will be able to spread in Tunisia. PMID:25793285

  5. A Spatial Simulation Model for the Dispersal of the Bluetongue Vector Culicoides brevitarsis in Australia

    PubMed Central

    Kelso, Joel K.; Milne, George J.

    2014-01-01

    Background The spread of Bluetongue virus (BTV) among ruminants is caused by movement of infected host animals or by movement of infected Culicoides midges, the vector of BTV. Biologically plausible models of Culicoides dispersal are necessary for predicting the spread of BTV and are important for planning control and eradication strategies. Methods A spatially-explicit simulation model which captures the two underlying population mechanisms, population dynamics and movement, was developed using extensive data from a trapping program for C. brevitarsis on the east coast of Australia. A realistic midge flight sub-model was developed and the annual incursion and population establishment of C. brevitarsis was simulated. Data from the literature was used to parameterise the model. Results The model was shown to reproduce the spread of C. brevitarsis southwards along the east Australian coastline in spring, from an endemic population to the north. Such incursions were shown to be reliant on wind-dispersal; Culicoides midge active flight on its own was not capable of achieving known rates of southern spread, nor was re-emergence of southern populations due to overwintering larvae. Data from midge trapping programmes were used to qualitatively validate the resulting simulation model. Conclusions The model described in this paper is intended to form the vector component of an extended model that will also include BTV transmission. A model of midge movement and population dynamics has been developed in sufficient detail such that the extended model may be used to evaluate the timing and extent of BTV outbreaks. This extended model could then be used as a platform for addressing the effectiveness of spatially targeted vaccination strategies or animal movement bans as BTV spread mitigation measures, or the impact of climate change on the risk and extent of outbreaks. These questions involving incursive Culicoides spread cannot be simply addressed with non-spatial models. PMID

  6. Effects of Bayofly on specimens of Culicoides species when incubated in hair taken from the feet of previously treated cattle and sheep.

    PubMed

    Mehlhorn, Heinz; Schmahl, Günter; Schumacher, Bärbel; D'Haese, Jochen; Walldorf, Volker; Klimpel, Sven

    2008-02-01

    Sheep and cattle were treated with Bayofly pour-on containing 1 g cyfluthrin per 100 ml ready-to-use solution. Seven, 14, 21 and 28 days after treatment, hair was clipped off from the back and feet and mixed for 10-15 s, 30 s, 1 or 2 min with freshly caught Culicoides midges. It was found that the insecticide on hair from the legs--the predominant biting site of midges--had a significant killing effect on Culicoides for 3-4 weeks, even after a short-term contact.

  7. Mosquito repellent attracts Culicoides imicola (Diptera: Ceratopogonidae).

    PubMed

    Braverman, Y; Chizov-Ginzburg, A; Mullens, B A

    1999-01-01

    A plant-derived mosquito repellent, based on the oil of Eucalyptus maculata var. citriodora Hook, was evaluated against the biting midge Culicoides imicola Kieffer. Suction black light-traps covered with repellent-impregnated polyester mesh and deployed near horses attracted large numbers of C. imicola, which were seen near the treated net within a few minutes of the start of the experiment. Initial collections in the traps were approximately 3 times as large as those in control traps with untreated mesh. Numbers collected in treated traps were similar to untreated control traps after 4 h. Traps with mesh treated with DEET or another plant-derived (Meliaceae) proprietary product, AG1000, acted as repellents relative to the control. The differential activity of repellents against blood-feeding Diptera is discussed. PMID:10071502

  8. Factors affecting Culicoides species composition and abundance in avian nests.

    PubMed

    Martínez-de la Puente, J; Merino, S; Tomás, G; Moreno, J; Morales, J; Lobato, E; Talavera, S; Sarto I Monteys, V

    2009-08-01

    Mechanisms affecting patterns of vector distribution among host individuals may influence the population and evolutionary dynamics of vectors, hosts and the parasites transmitted. We studied the role of different factors affecting the species composition and abundance of Culicoides found in nests of the blue tit (Cyanistes caeruleus). We identified 1531 females and 2 males of 7 different Culicoides species in nests, with C. simulator being the most abundant species, followed by C. kibunensis, C. festivipennis, C. segnis, C. truncorum, C. pictipennis and C. circumscriptus. We conducted a medicationxfumigation experiment randomly assigning bird's nests to different treatments, thereby generating groups of medicated and control pairs breeding in fumigated and control nests. Medicated pairs were injected with the anti-malarial drug Primaquine diluted in saline solution while control pairs were injected with saline solution. The fumigation treatment was carried out using insecticide solution or water for fumigated and control nests respectively. Brood size was the main factor associated with the abundance of biting midges probably because more nestlings may produce higher quantities of vector attractants. In addition, birds medicated against haemoparasites breeding in non-fumigated nests supported a higher abundance of C. festivipennis than the rest of the groups. Also, we found that the fumigation treatment reduced the abundance of engorged Culicoides in both medicated and control nests, thus indicating a reduction of feeding success produced by the insecticide. These results represent the first evidence for the role of different factors in affecting the Culicoides infracommunity in wild avian nests.

  9. Are bogs reservoirs for emerging disease vectors? Evaluation of culicoides populations in the Hautes Fagnes Nature Reserve (Belgium).

    PubMed

    Zimmer, Jean-Yves; Smeets, François; Simonon, Grégory; Fagot, Jean; Haubruge, Eric; Francis, Frédéric; Losson, Bertrand

    2013-01-01

    Several species of Culicoides (Diptera: Ceratopogonidae) biting midges serve as biological vectors for the bluetongue virus (BTV) and the recently described Schmallenberg virus (SBV) in northern Europe. Since their recent emergence in this part of the continent, these diseases have caused considerable economic losses to the sheep and cattle industries. Much data is now available that describe the distribution, population dynamics, and feeding habits of these insects. However, little is known regarding the presence of Culicoides in unusual habitats such as peaty marshes, nor their potential vector capacity. This study evaluated Culicoides biting midges present in the bogs of a Belgian nature reserve compared to those residing at a nearby cattle farm. Culicoides were trapped in 2011 at four different sites (broadleaved and coniferous forested areas, open environments, and at a scientific station) located in the Hautes Fagnes Nature Reserve (Belgium). An additional light trap was operated on a nearby cattle farm. Very high numbers of biting midges were captured in the marshy area and most of them (70 to 95%) were Culicoides impunctatus, a potential vector of BTV and other pathogens. In addition, fewer numbers of C. obsoletus/C. scoticus species, C. chiopterus, and C. dewulfi were observed in the bogs compared to the farm. The wet environment and oligotrophic nature of the soil were probably responsible for these changes in the respective populations. A total of 297,808 Culicoides midges belonging to 27 species were identified during this study and 3 of these species (C. sphagnumensis, C. clintoni and C. comosioculatus) were described in Belgium for the first time.

  10. Are Bogs Reservoirs for Emerging Disease Vectors? Evaluation of Culicoides Populations in the Hautes Fagnes Nature Reserve (Belgium)

    PubMed Central

    Zimmer, Jean-Yves; Smeets, François; Simonon, Grégory; Fagot, Jean; Haubruge, Eric; Francis, Frédéric; Losson, Bertrand

    2013-01-01

    Several species of Culicoides (Diptera: Ceratopogonidae) biting midges serve as biological vectors for the bluetongue virus (BTV) and the recently described Schmallenberg virus (SBV) in northern Europe. Since their recent emergence in this part of the continent, these diseases have caused considerable economic losses to the sheep and cattle industries. Much data is now available that describe the distribution, population dynamics, and feeding habits of these insects. However, little is known regarding the presence of Culicoides in unusual habitats such as peaty marshes, nor their potential vector capacity. This study evaluated Culicoides biting midges present in the bogs of a Belgian nature reserve compared to those residing at a nearby cattle farm. Culicoides were trapped in 2011 at four different sites (broadleaved and coniferous forested areas, open environments, and at a scientific station) located in the Hautes Fagnes Nature Reserve (Belgium). An additional light trap was operated on a nearby cattle farm. Very high numbers of biting midges were captured in the marshy area and most of them (70 to 95%) were Culicoides impunctatus, a potential vector of BTV and other pathogens. In addition, fewer numbers of C. obsoletus/C. scoticus species, C. chiopterus, and C. dewulfi were observed in the bogs compared to the farm. The wet environment and oligotrophic nature of the soil were probably responsible for these changes in the respective populations. A total of 297,808 Culicoides midges belonging to 27 species were identified during this study and 3 of these species (C. sphagnumensis, C. clintoni and C. comosioculatus) were described in Belgium for the first time. PMID:23799137

  11. Repellent effect of topical deltamethrin on blood feeding by Culicoides on horses.

    PubMed

    Robin, M; Archer, D; McGowan, C; Garros, C; Gardès, L; Baylis, M

    2015-05-30

    African horse sickness (AHS) is a vectorborne disease spread by Culicoides biting midges. The UK's Department for Environment, Food and Rural Affairs currently suggests using topical deltamethrin for AHS control; however, no data are available regarding its efficacy in the horse. The aims of this study were to investigate the effect of topical deltamethrin on blood feeding by Culicoides on horses and to investigate which Culicoides species blood fed on horses. Three pairs of horses were placed in partially enclosed cages that allowed samples representing the Culicoides interacting with individual horses to be sampled. Four data collection sessions were completed before one horse from each pair was topically treated with 10 ml of 1 per cent deltamethrin solution and another four sessions were then carried out. Collected Culicoides were identified and each biting midge examined to see if it had blood fed. The most abundant species collected were C. chiopterus, C. dewulfi, C. obsoletus and C. scoticus (44.3 per cent) and either C. pulicaris or C. punctatus (34.7 per cent). These species were also more likely to have blood fed than other species, supporting their potential role as AHS vectors if the virus were to reach the UK. There was no significant effect of treatment on blood feeding by Culicoides. The results do not support the use of topical deltamethrin to prevent blood feeding by Culicoides on individual horses; however, the study does not investigate the effect that the widespread use of topical deltamethrin might have on vector numbers or disease transmission from viraemic individuals during an outbreak of AHS. PMID:25948630

  12. Culicoides vector species on three South American camelid farms seropositive for bluetongue virus serotype 8 in Germany 2008/2009.

    PubMed

    Schulz, Claudia; Ziller, Mario; Kampen, Helge; Gauly, Matthias; Beer, Martin; Grevelding, Christoph G; Hoffmann, Bernd; Bauer, Christian; Werner, Doreen

    2015-12-15

    Palearctic species of Culicoides (Diptera, Ceratopogonidae), in particular of the Obsoletus and Pulicaris complexes, were identified as putative vectors of bluetongue virus serotype 8 (BTV-8) on ruminant farms during the epizootic in Germany from 2006 to 2009. BTV may cause severe morbidity and mortality in ruminants and sporadically in South American camelids (SAC). However, the fauna of Culicoides spp. on SAC farms has not been investigated. Therefore, the ceratopogonid fauna was monitored on three farms with BTV-seropositive SAC in Germany. Black-light traps were set up on pastures and in stables from summer 2008 to autumn 2009. Additionally, ceratopogonids were caught in emergence traps mounted on llama dung and dung-free pasture from spring to autumn 2009. After morphological identification, selected Culicoides samples were analysed for BTV-RNA by real-time RT-PCR. The effects of the variables 'location', 'temperature' and 'humidity' on the number of Culicoides caught in black-light traps were modelled using multivariable Poisson regression. In total, 26 species of Culicoides and six other genera of biting midges were identified. The most abundant Culicoides spp. collected both outdoors and indoors with black-light traps belonged to the Obsoletus (77.4%) and Pulicaris (16.0%) complexes. The number of Culicoides peaked in summer, while no biting midges were caught during the winter months. Daily collections of Culicoides were mainly influenced by the location and depended on the interaction of temperature and humidity. In the emergence traps, species of the Obsoletus complex predominated the collections. In summary, the absence of BTV-RNA in any of the analysed Culicoides midges and in the BTV-seropositive SAC on the three farms together with the differences in the pathogenesis of BTV-8 in SAC compared to ruminants suggests a negligible role of SAC in the spread of the virus. Although SAC farms may provide similar suitable habitats for putative Culicoides

  13. Culicoides vector species on three South American camelid farms seropositive for bluetongue virus serotype 8 in Germany 2008/2009.

    PubMed

    Schulz, Claudia; Ziller, Mario; Kampen, Helge; Gauly, Matthias; Beer, Martin; Grevelding, Christoph G; Hoffmann, Bernd; Bauer, Christian; Werner, Doreen

    2015-12-15

    Palearctic species of Culicoides (Diptera, Ceratopogonidae), in particular of the Obsoletus and Pulicaris complexes, were identified as putative vectors of bluetongue virus serotype 8 (BTV-8) on ruminant farms during the epizootic in Germany from 2006 to 2009. BTV may cause severe morbidity and mortality in ruminants and sporadically in South American camelids (SAC). However, the fauna of Culicoides spp. on SAC farms has not been investigated. Therefore, the ceratopogonid fauna was monitored on three farms with BTV-seropositive SAC in Germany. Black-light traps were set up on pastures and in stables from summer 2008 to autumn 2009. Additionally, ceratopogonids were caught in emergence traps mounted on llama dung and dung-free pasture from spring to autumn 2009. After morphological identification, selected Culicoides samples were analysed for BTV-RNA by real-time RT-PCR. The effects of the variables 'location', 'temperature' and 'humidity' on the number of Culicoides caught in black-light traps were modelled using multivariable Poisson regression. In total, 26 species of Culicoides and six other genera of biting midges were identified. The most abundant Culicoides spp. collected both outdoors and indoors with black-light traps belonged to the Obsoletus (77.4%) and Pulicaris (16.0%) complexes. The number of Culicoides peaked in summer, while no biting midges were caught during the winter months. Daily collections of Culicoides were mainly influenced by the location and depended on the interaction of temperature and humidity. In the emergence traps, species of the Obsoletus complex predominated the collections. In summary, the absence of BTV-RNA in any of the analysed Culicoides midges and in the BTV-seropositive SAC on the three farms together with the differences in the pathogenesis of BTV-8 in SAC compared to ruminants suggests a negligible role of SAC in the spread of the virus. Although SAC farms may provide similar suitable habitats for putative Culicoides

  14. Emergence of Culicoides obsoletus group species from farm-associated habitats in Germany.

    PubMed

    Steinke, S; Lühken, R; Balczun, C; Kiel, E

    2016-06-01

    Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) may transmit several arboviruses to ruminant livestock. The species of the Obsoletus group are considered to be among the most important vectors of bluetongue virus (BTV) in northern Europe. As agricultural environments offer suitable habitats for the development of their immature stages, the emergence of adult Culicoides from potential breeding sites was investigated at 20 cattle farms throughout Germany in 2012 and 2013. In analyses of species-specific habitat preferences and relationships between Culicoides abundance in breeding substrates and their physicochemical characteristics, dungheaps emerged as the most important substrate for the development of Culicoides obsoletus sensu stricto (s.s.) (Meigen), whereas Culicoides chiopterus (Meigen) and Culicoides dewulfi Goetghebuer were generally restricted to cowpats. A decreasing pH value was associated with a higher abundance or a higher probability of observing these three species. Furthermore, the abundance of C. obsoletus s.s. was positively related to increasing moisture. Dungheaps were very productive breeding sites for this species and are therefore suggested as a target for potential control measures. PMID:26744290

  15. Effects of permethrin (Flypor) and fenvalerate (Acadrex60, Arkofly) on Culicoides species-the vector of Bluetongue virus.

    PubMed

    Schmahl, Günter; Klimpel, Sven; Walldorf, Volker; Schumacher, Bärbel; Jatzlau, Antja; Al-Quraishy, Saleh; Mehlhorn, Heinz

    2009-03-01

    Bluetongue disease struggles ruminants in Europe since summer 2006, introducing high levels of morbidity and mortality. Besides vaccination, the application of insecticides is another means to protect cattle and sheep from infections with the Bluetongue virus, which is transmitted in Europe by female specimens of Culicoides species (Culicoides obsoletus and in a few cases of Culicoides pulicaris and Culicoides dewulfi). The present study deals with the effects of permethrin (Flypor) and fenvalerate (Arkofly, Acadrex 60) on freshly caught Culicoides specimens when brought into contact for 15, 30, 60 or 120 s with hair of cattle or sheep treated topically 7,14, 21, 28 or 35 days before. The experiments clearly showed that the lege arte application of these compounds (products) onto the hair of the experimental animals succeeds in killing Culicoides specimens when brought into contact with hair from feet of animals being treated even 35 days before. This test was needed to make sure that the products do reach the feet and belly of the animals in sufficient amounts, since this region is the predominant biting site of the Culicoides midges. PMID:19015876

  16. Effects of permethrin (Flypor) and fenvalerate (Acadrex60, Arkofly) on Culicoides species-the vector of Bluetongue virus.

    PubMed

    Schmahl, Günter; Klimpel, Sven; Walldorf, Volker; Schumacher, Bärbel; Jatzlau, Antja; Al-Quraishy, Saleh; Mehlhorn, Heinz

    2009-03-01

    Bluetongue disease struggles ruminants in Europe since summer 2006, introducing high levels of morbidity and mortality. Besides vaccination, the application of insecticides is another means to protect cattle and sheep from infections with the Bluetongue virus, which is transmitted in Europe by female specimens of Culicoides species (Culicoides obsoletus and in a few cases of Culicoides pulicaris and Culicoides dewulfi). The present study deals with the effects of permethrin (Flypor) and fenvalerate (Arkofly, Acadrex 60) on freshly caught Culicoides specimens when brought into contact for 15, 30, 60 or 120 s with hair of cattle or sheep treated topically 7,14, 21, 28 or 35 days before. The experiments clearly showed that the lege arte application of these compounds (products) onto the hair of the experimental animals succeeds in killing Culicoides specimens when brought into contact with hair from feet of animals being treated even 35 days before. This test was needed to make sure that the products do reach the feet and belly of the animals in sufficient amounts, since this region is the predominant biting site of the Culicoides midges.

  17. The dying of the light: crepuscular activity in Culicoides and impact on light trap efficacy at temperate latitudes.

    PubMed

    Meiswinkel, R; Elbers, A R W

    2016-03-01

    The light trap is the tool of choice for conducting large-scale Culicoides (Diptera: Ceratopogonidae) vector surveillance programmes. Its efficacy is in doubt, however. To assess this, hourly changes in Culicoides activity over the 24-h diel were determined comparatively by way of light trapping and aerial sweeping, and correlated against light intensity. In the Netherlands, sweeping around cattle at pasture revealed that, in early summer, Culicoides are active throughout the diel, and that their abundance peaks during the crepuscular period and falls to a low during the brightest hours of the day. By contrast, the light trap was able to accumulate Culicoides only at night (i.e. after illuminance levels had dropped to 0 lux and midge activity had begun to decline). Although Culicoides chiopterus and species of the Culicoides obsoletus complex were similarly abundant around livestock, they differed critically in their hours of peak activity, being largely diurnal and nocturnal, respectively. This polarity helps to explain why, routinely, the C. obsoletus complex dominates light trap collections and C. chiopterus does not. Inability to accumulate Culicoides at light intensity levels above 0 lux means that, at ever-higher latitudes, particularly beyond 45° N, the progressive northward lengthening of the twilight period will have an increasingly adverse impact upon the efficacy of the light trap as a vector surveillance tool. PMID:26555116

  18. DEET (N,N-diethyl-meta-toluamide)/PMD (para-menthane-3,8-diol) repellent-treated mesh increases Culicoides catches in light traps.

    PubMed

    Murchie, A K; Clawson, S; Rea, I; Forsythe, I W N; Gordon, A W; Jess, S

    2016-09-01

    Biting midges (Culicoides spp.) are vectors of bluetongue and Schmallenberg viruses. Treatment of mesh barriers is a common method for preventing insect-vectored diseases and has been proposed as a means of limiting Culicoides ingression into buildings or livestock transporters. Assessments using animals are costly, logistically difficult and subject to ethical approval. Therefore, initial screening of test repellents/insecticides was made by applying treatments to mesh (2 mm) cages surrounding Onderstepoort light traps. Five commercial treatments were applied to cages as per manufacturers' application rates: control (water), bendiocarb, DEET/p-menthane-3,8-diol (PMD) repellent, Flygo (a terpenoid based repellent) and lambda-cyhalothrin. The experimental design was a 5 × 5 Latin square, replicated in time and repeated twice. Incongruously, the traps surrounded by DEET/PMD repellent-treated mesh caught three to four times more Obsoletus group Culicoides (the commonest midge group) than the other treatments. A proposed hypothesis is that Obsoletus group Culicoides are showing a dose response to DEET/PMD, being attracted at low concentrations and repelled at higher concentrations but that the strong light attraction from the Onderstepoort trap was sufficient to overcome close-range repellence. This study does not imply that DEET/PMD is an ineffective repellent for Culicoides midges in the presence of an animal but rather that caution should be applied to the interpretation of light trap bioassays. PMID:27179956

  19. Host preferences and circadian rhythm of Culicoides (Diptera: Ceratopogonidae), vectors of African horse sickness and bluetongue viruses in Senegal.

    PubMed

    Fall, Moussa; Fall, Assane G; Seck, Momar T; Bouyer, Jérémy; Diarra, Maryam; Lancelot, Renaud; Gimonneau, Geoffrey; Garros, Claire; Bakhoum, Mame T; Faye, Ousmane; Baldet, Thierry; Balenghien, Thomas

    2015-09-01

    African horse sickness- and bluetongue virus are orbiviruses transmitted by Culicoides biting midges (Diptera: Ceratopogonidae) to horses and to ruminants, respectively. Since the last epizootic outbreak of African horse sickness in 2007 in Senegal, extensive investigations have been undertaken to improve our knowledge on Culicoides species involved locally in the transmission of the virus. The purpose of this study was to compare and quantify the host preferences of potential vectors of these orbiviruses on horse and sheep and to study their circadian rhythm. We found that Culicoides oxystoma and species of the sub-genus Avaritia (Culicoides imicola, Culicoides bolitinos and Culicoides pseudopallidipennis) had a preference for horse when compared to sheep (the predicted ratio between horse and sheep was 80 for C. oxystoma and 26 for C. imicola), and were mostly crepuscular: C. oxystoma had continuous activity throughout the diel with peaks in numbers collected after sunrise and sunset, while C. imicola was mostly nocturnal with peak after sunset. Unexpectedly, species of the subgenus Lasiohelea was also collected during this study. This diurnal biting species was a nuisance pest for both animal species used as bait.

  20. Culicoides hildebrandoi, a new species of the reticulatus species group from the Brazilian Amazon Region (Diptera, Ceratopogonidae).

    PubMed

    Farias, Emanuelle de Sousa; Pereira Júnior, Antonio Marques; Felippe-Bauer, Maria Luiza; Pessoa, Felipe Arley Costa; Medeiros, Jansen Fernandes; Santarém, Maria Clara Alves

    2016-01-01

    A new species of biting midge (Diptera: Ceratopogonidae), Culicoides hildebrandoi sp. n., is described and illustrated based on female and male specimens from the states of Amazonas and Rondônia, Brazil. This new species belongs to the reticulatus species group and differs from the 24 other species of this group by the elongate slightly swollen 3(rd) palpal segment with scattered capitate sensilla but lacking a sensory pit. PMID:27110160

  1. Culicoides hildebrandoi, a new species of the reticulatus species group from the Brazilian Amazon Region (Diptera, Ceratopogonidae)

    PubMed Central

    Farias, Emanuelle de Sousa; Pereira Júnior, Antonio Marques; Felippe-Bauer, Maria Luiza; Pessoa, Felipe Arley Costa; Medeiros, Jansen Fernandes; Santarém, Maria Clara Alves

    2016-01-01

    Abstract A new species of biting midge (Diptera: Ceratopogonidae), Culicoides hildebrandoi sp. n., is described and illustrated based on female and male specimens from the states of Amazonas and Rondônia, Brazil. This new species belongs to the reticulatus species group and differs from the 24 other species of this group by the elongate slightly swollen 3rd palpal segment with scattered capitate sensilla but lacking a sensory pit. PMID:27110160

  2. Characterization of Viral Communities of Biting Midges and Identification of Novel Thogotovirus Species and Rhabdovirus Genus.

    PubMed

    Temmam, Sarah; Monteil-Bouchard, Sonia; Robert, Catherine; Baudoin, Jean-Pierre; Sambou, Masse; Aubadie-Ladrix, Maxence; Labas, Noémie; Raoult, Didier; Mediannikov, Oleg; Desnues, Christelle

    2016-03-11

    More than two thirds of emerging viruses are of zoonotic origin, and among them RNA viruses represent the majority. Ceratopogonidae (genus Culicoides) are well-known vectors of several viruses responsible for epizooties (bluetongue, epizootic haemorrhagic disease, etc.). They are also vectors of the only known virus infecting humans: the Oropouche virus. Female midges usually feed on a variety of hosts, leading to possible transmission of emerging viruses from animals to humans. In this context, we report here the analysis of RNA viral communities of Senegalese biting midges using next-generation sequencing techniques as a preliminary step toward the identification of potential viral biohazards. Sequencing of the RNA virome of three pools of Culicoides revealed the presence of a significant diversity of viruses infecting plants, insects and mammals. Several novel viruses were detected, including a novel Thogotovirus species, related but genetically distant from previously described tick-borne thogotoviruses. Novel rhabdoviruses were also detected, possibly constituting a novel Rhabdoviridae genus, and putatively restricted to insects. Sequences related to the major viruses transmitted by Culicoides, i.e., African horse sickness, bluetongue and epizootic haemorrhagic disease viruses were also detected. This study highlights the interest in monitoring the emergence and circulation of zoonoses and epizooties using their arthropod vectors.

  3. Characterization of Viral Communities of Biting Midges and Identification of Novel Thogotovirus Species and Rhabdovirus Genus

    PubMed Central

    Temmam, Sarah; Monteil-Bouchard, Sonia; Robert, Catherine; Baudoin, Jean-Pierre; Sambou, Masse; Aubadie-Ladrix, Maxence; Labas, Noémie; Raoult, Didier; Mediannikov, Oleg; Desnues, Christelle

    2016-01-01

    More than two thirds of emerging viruses are of zoonotic origin, and among them RNA viruses represent the majority. Ceratopogonidae (genus Culicoides) are well-known vectors of several viruses responsible for epizooties (bluetongue, epizootic haemorrhagic disease, etc.). They are also vectors of the only known virus infecting humans: the Oropouche virus. Female midges usually feed on a variety of hosts, leading to possible transmission of emerging viruses from animals to humans. In this context, we report here the analysis of RNA viral communities of Senegalese biting midges using next-generation sequencing techniques as a preliminary step toward the identification of potential viral biohazards. Sequencing of the RNA virome of three pools of Culicoides revealed the presence of a significant diversity of viruses infecting plants, insects and mammals. Several novel viruses were detected, including a novel Thogotovirus species, related but genetically distant from previously described tick-borne thogotoviruses. Novel rhabdoviruses were also detected, possibly constituting a novel Rhabdoviridae genus, and putatively restricted to insects. Sequences related to the major viruses transmitted by Culicoides, i.e., African horse sickness, bluetongue and epizootic haemorrhagic disease viruses were also detected. This study highlights the interest in monitoring the emergence and circulation of zoonoses and epizooties using their arthropod vectors. PMID:26978389

  4. Characterization of Viral Communities of Biting Midges and Identification of Novel Thogotovirus Species and Rhabdovirus Genus.

    PubMed

    Temmam, Sarah; Monteil-Bouchard, Sonia; Robert, Catherine; Baudoin, Jean-Pierre; Sambou, Masse; Aubadie-Ladrix, Maxence; Labas, Noémie; Raoult, Didier; Mediannikov, Oleg; Desnues, Christelle

    2016-03-01

    More than two thirds of emerging viruses are of zoonotic origin, and among them RNA viruses represent the majority. Ceratopogonidae (genus Culicoides) are well-known vectors of several viruses responsible for epizooties (bluetongue, epizootic haemorrhagic disease, etc.). They are also vectors of the only known virus infecting humans: the Oropouche virus. Female midges usually feed on a variety of hosts, leading to possible transmission of emerging viruses from animals to humans. In this context, we report here the analysis of RNA viral communities of Senegalese biting midges using next-generation sequencing techniques as a preliminary step toward the identification of potential viral biohazards. Sequencing of the RNA virome of three pools of Culicoides revealed the presence of a significant diversity of viruses infecting plants, insects and mammals. Several novel viruses were detected, including a novel Thogotovirus species, related but genetically distant from previously described tick-borne thogotoviruses. Novel rhabdoviruses were also detected, possibly constituting a novel Rhabdoviridae genus, and putatively restricted to insects. Sequences related to the major viruses transmitted by Culicoides, i.e., African horse sickness, bluetongue and epizootic haemorrhagic disease viruses were also detected. This study highlights the interest in monitoring the emergence and circulation of zoonoses and epizooties using their arthropod vectors. PMID:26978389

  5. Species Diversity and Seasonal Distribution of Culicoides spp. (Diptera: Ceratopogonidae) in Jeju-do, Republic of Korea

    PubMed Central

    Kim, Heung Chul; Bellis, Glenn A.; Kim, Myung-Soon; Klein, Terry A.; Gopurenko, David; Cai, Du-Cheng; Seo, Hyun-Ji; Cho, In-Soo; Park, Jee-Yong

    2015-01-01

    Biting midges belonging to the genus Culicoides (Diptera: Ceratopogonidae) were collected by Mosquito Magnet® and black light traps at 5 sites on Jeju-do, Republic of Korea (Korea), from May-November 2013 to determine species diversity and seasonal distribution. A total of 4,267 specimens were collected, of which 99.9% were female. The most common species was Culicoides tainanus (91.8%), followed by C. lungchiensis (7.2%) and C. punctatus (0.6%), while the remaining 4 species accounted for <0.5% of all Culicoides spp. that were collected. High numbers of C. tainanus were collected in May, followed by decreasing numbers through August, and then increasing numbers through November when surveillance was terminated. Peak numbers of C. lungchiensis were collected during September, with low numbers collected from May-August and October-November. The presence of C. lungchiensis in Korea was confirmed by morphological and molecular analyses. PMID:26323852

  6. Species Diversity and Seasonal Distribution of Culicoides spp. (Diptera: Ceratopogonidae) in Jeju-do, Republic of Korea.

    PubMed

    Kim, Heung Chul; Bellis, Glenn A; Kim, Myung-Soon; Klein, Terry A; Gopurenko, David; Cai, Du-Cheng; Seo, Hyun-Ji; Cho, In-Soo; Park, Jee-Yong

    2015-08-01

    Biting midges belonging to the genus Culicoides (Diptera: Ceratopogonidae) were collected by Mosquito Magnet(®) and black light traps at 5 sites on Jeju-do, Republic of Korea (Korea), from May-November 2013 to determine species diversity and seasonal distribution. A total of 4,267 specimens were collected, of which 99.9% were female. The most common species was Culicoides tainanus (91.8%), followed by C. lungchiensis (7.2%) and C. punctatus (0.6%), while the remaining 4 species accounted for <0.5% of all Culicoides spp. that were collected. High numbers of C. tainanus were collected in May, followed by decreasing numbers through August, and then increasing numbers through November when surveillance was terminated. Peak numbers of C. lungchiensis were collected during September, with low numbers collected from May-August and October-November. The presence of C. lungchiensis in Korea was confirmed by morphological and molecular analyses.

  7. The barriers to bluetongue virus infection, dissemination and transmission in the vector, Culicoides variipennis (Diptera: Ceratopogonidae).

    PubMed

    Fu, H; Leake, C J; Mertens, P P; Mellor, P S

    1999-01-01

    Transmission of bluetongue virus (BTV) by a vector species of Culicoides was studied using immunohistochemistry, virus titration and in vitro transmission tests. Adult female C. variipennis were used from two colonies that are either "transmission competent" or "transmission refractory" after oral infection with BTV. Intrathoracic (i.t.) injection of BTV into the haemocoel always resulted in a fully disseminated infection and transmission of virus in saliva. However, after ingestion of an infectious blood meal, only 30% (approximately) of midges from either colony became persistently infected. Although none of the orally infected insects from the "refractory" colony were able to transmit virus, 12% of those from the "competent" colony (containing > or = 10(3.0)TCID50 of virus/midge) did transmit BTV in their saliva. The most important barriers to BTV transmission in Culicoides vector species appeared to be a mesenteron infection barrier (MIB), which controls initial establishment of persistent infection, a mesenteron escape barrier (MEB) which can restrict virus to gut cells and a dissemination barrier (DB) which can prevent virus which enters the haemocoel from infecting secondary target organs. Culicoides variipennis do not appear to present either a salivary gland infection barrier (SGIB), or a salivary gland escape barrier (SGEB) to BTV.

  8. Haemoproteus tartakovskyi (Haemoproteidae): Complete sporogony in Culicoides nubeculosus (Ceratopogonidae), with implications for avian haemoproteid experimental research.

    PubMed

    Žiegytė, Rita; Bernotienė, Rasa; Palinauskas, Vaidas; Valkiūnas, Gediminas

    2016-01-01

    Numerous recent studies have addressed the molecular characterization, distribution and genetic diversity of Haemoproteus spp. (Haemoproteidae). Some species of these blood parasites cause severe disease in birds, and heavy infections are often lethal in biting midges (Ceratopogonidae) and other blood-sucking insects. However, information about the vectors of haemoproteids is scarce. This presents an obstacle for better understanding the mechanisms of host-parasite interactions and the epidemiology of haemoproteosis. Here we investigated the sporogonic development of Haemoproteus tartakovskyi, a widespread bird parasite, in experimentally infected biting midges, Culicoides nubeculosus. These biting midges are widespread in the Europe. The insects were cultivated under laboratory conditions. Unfed females were allowed to take blood meals on wild caught siskins Carduelis spinus naturally infected with H. tartakovskyi (lineage hSISKIN1). Engorged females were maintained at 22-23 °C, dissected at intervals, and examined for sporogonic stages. Mature ookinetes of H. tartakovskyi were seen in the midgut content between 6 and 48 h post infection, oocysts were observed in the midgut wall 3-4 days post infection (dpi). Sporozoites were first reported in the salivary gland preparations 7 dpi. In accordance with microscopy data, polymerase chain reaction amplification and sequencing confirmed presence of the corresponding parasite lineage in experimentally infected biting midges. This study indicates that C. nubeculosus willingly takes blood meals on birds and is a vector of H. tartakovskyi. These biting midges are readily amenable to cultivation under laboratory conditions. Culicoides nubeculosus transmits Haemoproteus parasites infecting parrots, owls and siskins, birds belonging to different families and orders. Thus, this vector provides a convenient model for experimental research with avian haemoproteids. PMID:26616347

  9. Detection of African horse sickness virus in Culicoides imicola pools using RT-qPCR.

    PubMed

    de Waal, Tania; Liebenberg, Danica; Venter, Gert J; Mienie, Charlotte Ms; van Hamburg, Huib

    2016-06-01

    African horse sickness (AHS) is an infectious, non-contagious arthropod-borne disease of equids, caused by the African horse sickness virus (AHSV), an orbivirus of the Reoviridae family. It is endemic in sub-Saharan Africa and thought to be the most lethal viral disease of horses. This study focused on detection of AHSV in Culicoides imicola (Diptera: Ceratopogonidae) pools by the application of a RT-qPCR. Midges were fed on AHSV-infected blood. A single blood-engorged female was allocated to pools of unfed nulliparous female midges. Pool sizes varied from 1 to 200. RNA was extracted and prepared for RT-qPCR. The virus was successfully detected and the optimal pool size for the limit of detection of the virus was determined at a range between 1 to 25. Results from this investigation highlight the need for a standardized protocol for AHSV investigation in Culicoides midges especially for comparison among different studies and for the determination of infection rate. PMID:27232141

  10. Repellency of two deet formulations and Avon Skin-So-Soft against biting midges (Diptera: Ceratopogonidae) in Honduras.

    PubMed

    Magnon, G J; Robert, L L; Kline, D L; Roberts, L W

    1991-03-01

    Two U.S. military issue deet repellent formulations (75% deet liquid and 33% deet lotion) and Avon Skin-So-Soft were tested against ceratopogonid midges under field conditions in Honduras. Test subjects were U.S. military personnel deployed to Honduras for training. Culicoides furens accounted for 96.3% of all midges collected. The liquid and lotion formulations of deet and Avon Skin-So-Soft provided 97.9, 95.9 and 71.4% protection, respectively, compared with the untreated control. Both deet formulations provided significantly better protection (P less than 0.05) than Avon Skin-So-Soft. The latter provided protection by trapping the midges in the oily film and not by repelling the insects as did the deet formulations.

  11. Quorum quenching Bacillus sonorensis isolated from soya sauce fermentation brine.

    PubMed

    Yin, Wai-Fong; Tung, Hun-Jiat; Sam, Choon-Kook; Koh, Chong-Lek; Chan, Kok-Gan

    2012-01-01

    An N-acylhomoserine lactone (AHL)-degrading bacterial strain, L62, was isolated from a sample of fermentation brine of Chinese soya sauce by using rich medium agar supplemented with soya sauce (10% v/v). L62, a rod-shaped Gram positive bacterium with amylolytic activity, was phylogentically related to Bacillus sonorensis by 16S ribosomal DNA and rpoB sequence analyses. B. sonorensis L62 efficiently degraded N-3-oxohexanoyl homoserine lactone and N-octanoylhomoserine lactone. However, the aiiA homologue, encoding an autoinducer inactivation enzyme catalyzing the degradation of AHLs, was not detected in L62, suggesting the presence of a different AHL-degrading gene in L62. To the best of our knowledge, this is the first report of AHL-degrading B. sonorensis from soya sauce liquid state fermentation.

  12. Quorum Quenching Bacillus sonorensis Isolated from Soya Sauce Fermentation Brine

    PubMed Central

    Yin, Wai-Fong; Tung, Hun-Jiat; Sam, Choon-Kook; Koh, Chong-Lek; Chan, Kok-Gan

    2012-01-01

    An N-acylhomoserine lactone (AHL)-degrading bacterial strain, L62, was isolated from a sample of fermentation brine of Chinese soya sauce by using rich medium agar supplemented with soya sauce (10% v/v). L62, a rod-shaped Gram positive bacterium with amylolytic activity, was phylogentically related to Bacillus sonorensis by 16S ribosomal DNA and rpoB sequence analyses. B. sonorensis L62 efficiently degraded N-3-oxohexanoyl homoserine lactone and N-octanoylhomoserine lactone. However, the aiiA homologue, encoding an autoinducer inactivation enzyme catalyzing the degradation of AHLs, was not detected in L62, suggesting the presence of a different AHL-degrading gene in L62. To the best of our knowledge, this is the first report of AHL-degrading B. sonorensis from soya sauce liquid state fermentation. PMID:22666018

  13. Habitats of Culicoides spp. in an intertidal zone of southeast Queensland, Australia.

    PubMed

    Hagan, C E; Kettle, D S

    1990-01-01

    The distribution of immature Culicoides Latreille (Diptera: Ceratopogonidae) in the intertidal zone was investigated at Redland Bay near Brisbane, southeast Queensland. The aims of this study were to determine the distribution of Culicoides immatures and to identify environmental factors influencing these distributions. Light trapping of adult midges indicated that C.subimmaculatus Lee & Reye, C.marmoratus (Skuse), C.longior Hagan & Reye, C.henryi Lee & Reye, C.cordiger Macfie, may have been breeding in the study site. Soil sampling on six transects traversing mangrove and salt-marsh revealed the breeding habitats from which immature stages of the first four species were obtained. The elevation, vegetation and soils of positive sites were recorded and analysed for each species of Culicoides. The distribution of intertidal vegetation (mangroves and salt-marsh plants) was compared to MacNae's (1966) system of mangrove zonation for eastern Australia. The distribution of immature Culicoides did not correspond with mangrove zones, but was related to the presence or absence of intertidal vegetation. C.subimmaculatus was closely associated with a particular substrate and the presence of burrowing crabs.

  14. Effect of temperature on replication of epizootic hemorrhagic disease viruses in Culicoides sonorensis (Diptera: Ceratopogonidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Replication of many arboviruses, including some orbiviruses, within the vector has been shown to be temperature-dependent. In general, cooler ambient temperatures slow virus replication in arthropod vectors, whereas viruses replicate faster and to higher titers at warmer ambient temperatures. Prev...

  15. Three new Scandinavian species of Culicoides (Culicoides): Culicoides boyi sp. nov., Culicoides selandicus sp. nov. and Culicoides kalix sp. nov. (Diptera: Ceratopogonidae)

    PubMed Central

    Kristensen, Michael; Pape, Thomas

    2015-01-01

    Abstract Background In the context of a major monitoring program of Culicoides in Denmark and Sweden due to the appearance of bluetongue disease in 2007–2008, a large number of specimens were collected by light traps and sorted morphologically, with COI barcodes generated for selected specimens. New information Three species are described as new to science based on both morphological and molecular data: Culicoides (Culicoides) boyi sp. nov. (Denmark: Jutland), C. (C.) selandicus sp. nov. (Denmark: Zealand) and C. (C.) kalix sp. nov. (Sweden: Norrbotten). All are diagnosed morphologically as well as by molecular barcoding. A key to slide-mounted females of all Scandinavian species of Culicoides (Culicoides) is presented. PMID:26696760

  16. Spatial and temporal distribution of Culicoides species in mainland Portugal (2005-2010). Results of the Portuguese Entomological Surveillance Programme.

    PubMed

    Ribeiro, Rita; Wilson, Anthony J; Nunes, Telmo; Ramilo, David W; Amador, Rita; Madeira, Sara; Baptista, Filipa M; Harrup, Lara E; Lucientes, Javier; Boinas, Fernando

    2015-01-01

    Bluetongue virus (BTV) is transmitted by Culicoides biting midges and causes an infectious, non-contagious disease of ruminants. It has been rapidly emerging in southern Europe since 1998. In mainland Portugal, strains of BTV belonging to three serotypes have been detected: BTV-10 (1956-1960), BTV-4 (2004-2006 and 2013) and BTV-1 (2007-2012). This paper describes the design, implementation and results of the Entomological Surveillance Programme covering mainland Portugal, between 2005 and 2010, including 5,650 caches. Culicoides imicola Kieffer was mostly found in central and southern regions of Portugal, although it was sporadically detected in northern latitudes. Its peak activity occurred in the autumn and it was active during the winter months in limited areas of the country. Obsoletus group was present at the highest densities in the north although they were found throughout the country in substantial numbers. Culicoides activity occurred all year round but peaked in the spring. A generalized linear mixed model was developed for the analysis of the environmental factors associated with activity of the species of Culicoides suspected vectors of BTV in the country. For C. imicola Kieffer, the most important variables were month, diurnal temperature range (DTR), the number of frost days (FRS) and median monthly temperature (TMP). For the Obsoletus group, the most important factors were month, diurnal temperature range (DTR), and linear and quadratic terms for median monthly temperature (TMP). The results reported can improve our understanding of climatic factors in Culicoides activity influencing their distribution and seasonal pattern.

  17. Evaluation of naled applied as a thermal fog against Culicoides furens (Diptera: Ceratopogonidae).

    PubMed

    Linley, J R; Parsons, R E; Winner, R A

    1987-09-01

    Naled/diesel oil (1:99), applied as a thermal fog, was tested against the biting midge Culicoides furens. The insects were confined in small cages suspended at 4 heights on poles at progressively greater distances from the fog release point. In terms of population survival 24 hr after treatment, a parabolic equation accurately described the regression of percent survival on distance from the release point. If 10% survival is considered as the maximum acceptable, then the equation predicts adequate control up to 19.6 m (64.3 ft) from the fog release point. PMID:3504923

  18. Genetic characterization and molecular identification of the bloodmeal sources of the potential bluetongue vector Culicoides obsoletus in the Canary Islands, Spain

    PubMed Central

    2012-01-01

    Background Culicoides (Diptera: Ceratopogonidae) biting midges are vectors for a diversity of pathogens including bluetongue virus (BTV) that generate important economic losses. BTV has expanded its range in recent decades, probably due to the expansion of its main vector and the presence of other autochthonous competent vectors. Although the Canary Islands are still free of bluetongue disease (BTD), Spain and Europe have had to face up to a spread of bluetongue with disastrous consequences. Therefore, it is essential to identify the distribution of biting midges and understand their feeding patterns in areas susceptible to BTD. To that end, we captured biting midges on two farms in the Canary Islands (i) to identify the midge species in question and characterize their COI barcoding region and (ii) to ascertain the source of their bloodmeals using molecular tools. Methods Biting midges were captured using CDC traps baited with a 4-W blacklight (UV) bulb on Gran Canaria and on Tenerife. Biting midges were quantified and identified according to their wing patterns. A 688 bp segment of the mitochondrial COI gene of 20 biting midges (11 from Gran Canaria and 9 from Tenerife) were PCR amplified using the primers LCO1490 and HCO2198. Moreover, after selected all available females showing any rest of blood in their abdomen, a nested-PCR approach was used to amplify a fragment of the COI gene from vertebrate DNA contained in bloodmeals. The origin of bloodmeals was identified by comparison with the nucleotide-nucleotide basic alignment search tool (BLAST). Results The morphological identification of 491 female biting midges revealed the presence of a single morphospecies belonging to the Obsoletus group. When sequencing the barcoding region of the 20 females used to check genetic variability, we identified two haplotypes differing in a single base. Comparison analysis using the nucleotide-nucleotide basic alignment search tool (BLAST) showed that both haplotypes belong to

  19. Screening of oomycete fungi for their potential role in reducing the biting midge (Diptera: Ceratopogonidae) larval populations in Hervey Bay, Queensland, Australia.

    PubMed

    Stephen, Kirsty; Kurtböke, D Ipek

    2011-05-01

    Biting midges are globally distributed pests causing significant economic losses and transmitting arbovirus diseases to both animals and humans. Current biological and chemical control strategies for biting midge target destruction of adult forms, but strategies directed at immature stages of the insect have yet to be explored in Australia. In the present study, coastal waters of Hervey Bay region in Queensland, Australia were screened to detect the habitats of biting midge at immature stages. These results were then correlated to local environmental conditions and naturally occurring entomopathogenic fungal flora, in particular the Oomycete fungi, to determine their reducing effect on insect immature stages in the search for biological control agents in the region. The dominant species of biting midge found within this study was Culicoides subimmaculatus occuring between mean high water neaps and mean high water spring tide levels. Within this intertidal zone, the presence of C. subimmaculatus larvae was found to be influenced by both sediment size and distance from shore. Halophytophthora isolates colonized both dead and alive pupae. However, the association was found to be surface colonization rather than invasion causing the death of the host. Lack of aggressive oomycete fungal antagonists towards midge larvae might correlate with increased incidences of biting midge infestations in the region.

  20. Screening of Oomycete Fungi for Their Potential Role in Reducing the Biting Midge (Diptera: Ceratopogonidae) Larval Populations in Hervey Bay, Queensland, Australia

    PubMed Central

    Stephen, Kirsty; Kurtböke, D. Ipek

    2011-01-01

    Biting midges are globally distributed pests causing significant economic losses and transmitting arbovirus diseases to both animals and humans. Current biological and chemical control strategies for biting midge target destruction of adult forms, but strategies directed at immature stages of the insect have yet to be explored in Australia. In the present study, coastal waters of Hervey Bay region in Queensland, Australia were screened to detect the habitats of biting midge at immature stages. These results were then correlated to local environmental conditions and naturally occurring entomopathogenic fungal flora, in particular the Oomycete fungi, to determine their reducing effect on insect immature stages in the search for biological control agents in the region. The dominant species of biting midge found within this study was Culicoides subimmaculatus occuring between mean high water neaps and mean high water spring tide levels. Within this intertidal zone, the presence of C. subimmaculatus larvae was found to be influenced by both sediment size and distance from shore. Halophytophthora isolates colonized both dead and alive pupae. However, the association was found to be surface colonization rather than invasion causing the death of the host. Lack of aggressive oomycete fungal antagonists towards midge larvae might correlate with increased incidences of biting midge infestations in the region. PMID:21655137

  1. Morphological description of the fourth instar larva: Culicoides cataneii and Culicoides sahariensis (Diptera: Ceratopogonidae).

    PubMed

    Slama, Darine; Khedher, Asma; Bdira, Sassi; Khayech, Fethi; Delecolle, Jean-claude; Mezhoud, Habib; Babba, Hamouda; Emna, Chaker

    2013-01-01

    This study was carried out of the region of Monastir in Central Tunisia, between July and August 2010. Larvae were collected using a floatation technique with magnesium sulfate in mud samples. The fourth instar larva of Culicoides cataneii Clastrier, 1957 and Culicoides sahariensis Callot, Kremer, Bailly-Choumara, 1970 are described, illustrated and drawn. Measurements of instars IV are also presented. This is the first record of Culicoides cataneii and Culicoides sahariensis (Diptera: Ceratopogonidae) to Tunisia.

  2. Faustovirus-Like Asfarvirus in Hematophagous Biting Midges and Their Vertebrate Hosts.

    PubMed

    Temmam, Sarah; Monteil-Bouchard, Sonia; Sambou, Masse; Aubadie-Ladrix, Maxence; Azza, Saïd; Decloquement, Philippe; Khalil, Jacques Y Bou; Baudoin, Jean-Pierre; Jardot, Priscilla; Robert, Catherine; La Scola, Bernard; Mediannikov, Oleg Y; Raoult, Didier; Desnues, Christelle

    2015-01-01

    Faustovirus, a new Asfarviridae-related giant virus, was recently isolated in Vermamoeba vermiformis, a protist found in sewage water in various geographical locations and occasionally reported in human eye infection cases. As part of a global metagenomic analysis of viral communities existing in biting midges, we report here for the first time the identification and isolation of a Faustovirus-like virus in hematophagous arthropods and its detection in their animal hosts. The DNA virome analysis of three pools of Culicoides sp., engorged female Culicoides imicola and non-engorged male/female C. imicola biting midges collected in Senegal, revealed the presence of amoeba-infecting giant viruses and, among them, a majority of sequences related to Faustovirus. Phylogenetic analyses conducted on several structural genes of Faustovirus confirmed the clustering of the arthropod-borne Faustovirus with sewage-borne Faustoviruses, with a distinct geographical clustering of Senegalese Faustovirus strains. Transmission electron microscopy identified viral particles with morphologies and diameters which were compatible with Faustovirus. The presence of infectious arthropod-borne Faustovirus was finally confirmed by successful isolation on V. vermiformis amoeba. Global proteomic analysis of biting midges identified that arthropods' blood meal originating from cattle, rodents and humans. Further screening of cattle sera and rodent tissue resulted in prevalence of Faustovirus being estimated at 38% in rodents and 14% in cattle, suggesting a possible origin of Faustovirus presence in arthropods via the ingestion of contaminated blood meal. Viral loads were the highest in rodents' urine and kidney samples, suggesting a possible excretion of viral particles into the environment. Faustovirus DNA polymerase-related sequences were also detected in more than 9 and 11% of febrile patients and healthy Senegalese human sera, respectively. Our study thus, highlights the need to investigate

  3. Faustovirus-Like Asfarvirus in Hematophagous Biting Midges and Their Vertebrate Hosts

    PubMed Central

    Temmam, Sarah; Monteil-Bouchard, Sonia; Sambou, Masse; Aubadie-Ladrix, Maxence; Azza, Saïd; Decloquement, Philippe; Khalil, Jacques Y. Bou; Baudoin, Jean-Pierre; Jardot, Priscilla; Robert, Catherine; La Scola, Bernard; Mediannikov, Oleg Y.; Raoult, Didier; Desnues, Christelle

    2015-01-01

    Faustovirus, a new Asfarviridae-related giant virus, was recently isolated in Vermamoeba vermiformis, a protist found in sewage water in various geographical locations and occasionally reported in human eye infection cases. As part of a global metagenomic analysis of viral communities existing in biting midges, we report here for the first time the identification and isolation of a Faustovirus-like virus in hematophagous arthropods and its detection in their animal hosts. The DNA virome analysis of three pools of Culicoides sp., engorged female Culicoides imicola and non-engorged male/female C. imicola biting midges collected in Senegal, revealed the presence of amoeba-infecting giant viruses and, among them, a majority of sequences related to Faustovirus. Phylogenetic analyses conducted on several structural genes of Faustovirus confirmed the clustering of the arthropod-borne Faustovirus with sewage-borne Faustoviruses, with a distinct geographical clustering of Senegalese Faustovirus strains. Transmission electron microscopy identified viral particles with morphologies and diameters which were compatible with Faustovirus. The presence of infectious arthropod-borne Faustovirus was finally confirmed by successful isolation on V. vermiformis amoeba. Global proteomic analysis of biting midges identified that arthropods' blood meal originating from cattle, rodents and humans. Further screening of cattle sera and rodent tissue resulted in prevalence of Faustovirus being estimated at 38% in rodents and 14% in cattle, suggesting a possible origin of Faustovirus presence in arthropods via the ingestion of contaminated blood meal. Viral loads were the highest in rodents' urine and kidney samples, suggesting a possible excretion of viral particles into the environment. Faustovirus DNA polymerase-related sequences were also detected in more than 9 and 11% of febrile patients and healthy Senegalese human sera, respectively. Our study thus, highlights the need to investigate

  4. Faustovirus-Like Asfarvirus in Hematophagous Biting Midges and Their Vertebrate Hosts.

    PubMed

    Temmam, Sarah; Monteil-Bouchard, Sonia; Sambou, Masse; Aubadie-Ladrix, Maxence; Azza, Saïd; Decloquement, Philippe; Khalil, Jacques Y Bou; Baudoin, Jean-Pierre; Jardot, Priscilla; Robert, Catherine; La Scola, Bernard; Mediannikov, Oleg Y; Raoult, Didier; Desnues, Christelle

    2015-01-01

    Faustovirus, a new Asfarviridae-related giant virus, was recently isolated in Vermamoeba vermiformis, a protist found in sewage water in various geographical locations and occasionally reported in human eye infection cases. As part of a global metagenomic analysis of viral communities existing in biting midges, we report here for the first time the identification and isolation of a Faustovirus-like virus in hematophagous arthropods and its detection in their animal hosts. The DNA virome analysis of three pools of Culicoides sp., engorged female Culicoides imicola and non-engorged male/female C. imicola biting midges collected in Senegal, revealed the presence of amoeba-infecting giant viruses and, among them, a majority of sequences related to Faustovirus. Phylogenetic analyses conducted on several structural genes of Faustovirus confirmed the clustering of the arthropod-borne Faustovirus with sewage-borne Faustoviruses, with a distinct geographical clustering of Senegalese Faustovirus strains. Transmission electron microscopy identified viral particles with morphologies and diameters which were compatible with Faustovirus. The presence of infectious arthropod-borne Faustovirus was finally confirmed by successful isolation on V. vermiformis amoeba. Global proteomic analysis of biting midges identified that arthropods' blood meal originating from cattle, rodents and humans. Further screening of cattle sera and rodent tissue resulted in prevalence of Faustovirus being estimated at 38% in rodents and 14% in cattle, suggesting a possible origin of Faustovirus presence in arthropods via the ingestion of contaminated blood meal. Viral loads were the highest in rodents' urine and kidney samples, suggesting a possible excretion of viral particles into the environment. Faustovirus DNA polymerase-related sequences were also detected in more than 9 and 11% of febrile patients and healthy Senegalese human sera, respectively. Our study thus, highlights the need to investigate

  5. Seasonal Abundance of Culicoides (Diptera: Ceratopogonidae) Collected by Mosquito Magnet® in Northern Gyeonggi-do (Province), Korea

    PubMed Central

    Kim, Heung Chul; Bellis, Glenn A.; Kim, Myung-Soon; Klein, Terry A.; Chong, Sung-Tae

    2014-01-01

    Biting midges (Culicoides: Ceratopogonidae) were collected by Mosquito Magnet® traps at the Neutral Nations Supervisory Commission (NNSC) camp and Daeseongdong village inside the demilitarized zone (DMZ) and near the military demarcation line (MDL) separating North and South Korea and at Warrior Base (US Army training site) and Tongilchon 3 km south of the DMZ in northern Gyeonggi Province, Republic of Korea (ROK), from May-October 2010-2012, to determine their seasonal distributions. A total of 18,647 Culicoides females (18,399; 98.7%) and males (248; 1.3%) comprising 16 species were collected. Overall, the most commonly collected species was Culicoides nipponensis (42.9%), followed by C. erairai (29.2%), C. punctatus (20.3%), C. arakawae (3.3%), C. pallidulus (1.8%), and C. circumscriptus (1.4%), while the remaining 10 species accounted for only 1.1% of all Culicoides spp. collected. The seasonal distribution of C. nipponensis was bimodal, with high numbers collected during May-June and again during September. C. erairai was more frequently collected during June-July, followed by sharply decreased populations from August-October. C. punctatus was collected in low numbers from May-September with high numbers collected during October. C. erairai was predominantly collected from the NNSC camp (85.1% of all C. erairai collected) located adjacent to the MDL at Panmunjeom in the northernmost part of Gyeonggi-do (Province), while other sites yielded low numbers of specimens. PMID:24623883

  6. Seasonal abundance of Culicoides (Diptera: Ceratopogonidae) collected by mosquito Magnet® in Northern Gyeonggi-do (Province), Korea.

    PubMed

    Kim, Heung Chul; Bellis, Glenn A; Kim, Myung-Soon; Klein, Terry A; Chong, Sung-Tae; Park, Jee-Yong

    2014-02-01

    Biting midges (Culicoides: Ceratopogonidae) were collected by Mosquito Magnet® traps at the Neutral Nations Supervisory Commission (NNSC) camp and Daeseongdong village inside the demilitarized zone (DMZ) and near the military demarcation line (MDL) separating North and South Korea and at Warrior Base (US Army training site) and Tongilchon 3 km south of the DMZ in northern Gyeonggi Province, Republic of Korea (ROK), from May-October 2010-2012, to determine their seasonal distributions. A total of 18,647 Culicoides females (18,399; 98.7%) and males (248; 1.3%) comprising 16 species were collected. Overall, the most commonly collected species was Culicoides nipponensis (42.9%), followed by C. erairai (29.2%), C. punctatus (20.3%), C. arakawae (3.3%), C. pallidulus (1.8%), and C. circumscriptus (1.4%), while the remaining 10 species accounted for only 1.1% of all Culicoides spp. collected. The seasonal distribution of C. nipponensis was bimodal, with high numbers collected during May-June and again during September. C. erairai was more frequently collected during June-July, followed by sharply decreased populations from August-October. C. punctatus was collected in low numbers from May-September with high numbers collected during October. C. erairai was predominantly collected from the NNSC camp (85.1% of all C. erairai collected) located adjacent to the MDL at Panmunjeom in the northernmost part of Gyeonggi-do (Province), while other sites yielded low numbers of specimens.

  7. Range expansion of the Bluetongue vector, Culicoides imicola, in continental France likely due to rare wind-transport events.

    PubMed

    Jacquet, Stéphanie; Huber, Karine; Pagès, Nonito; Talavera, Sandra; Burgin, Laura E; Carpenter, Simon; Sanders, Christopher; Dicko, Ahmadou H; Djerbal, Mouloud; Goffredo, Maria; Lhor, Youssef; Lucientes, Javier; Miranda-Chueca, Miguel A; Pereira Da Fonseca, Isabel; Ramilo, David W; Setier-Rio, Marie-Laure; Bouyer, Jérémy; Chevillon, Christine; Balenghien, Thomas; Guis, Hélène; Garros, Claire

    2016-01-01

    The role of the northward expansion of Culicoides imicola Kieffer in recent and unprecedented outbreaks of Culicoides-borne arboviruses in southern Europe has been a significant point of contention. We combined entomological surveys, movement simulations of air-borne particles, and population genetics to reconstruct the chain of events that led to a newly colonized French area nestled at the northern foot of the Pyrenees. Simulating the movement of air-borne particles evidenced frequent wind-transport events allowing, within at most 36 hours, the immigration of midges from north-eastern Spain and Balearic Islands, and, as rare events, their immigration from Corsica. Completing the puzzle, population genetic analyses discriminated Corsica as the origin of the new population and identified two successive colonization events within west-Mediterranean basin. Our findings are of considerable importance when trying to understand the invasion of new territories by expanding species. PMID:27263862

  8. Range expansion of the Bluetongue vector, Culicoides imicola, in continental France likely due to rare wind-transport events

    PubMed Central

    Jacquet, Stéphanie; Huber, Karine; Pagès, Nonito; Talavera, Sandra; Burgin, Laura E.; Carpenter, Simon; Sanders, Christopher; Dicko, Ahmadou H.; Djerbal, Mouloud; Goffredo, Maria; Lhor, Youssef; Lucientes, Javier; Miranda-Chueca, Miguel A.; Pereira Da Fonseca, Isabel; Ramilo, David W.; Setier-Rio, Marie-Laure; Bouyer, Jérémy; Chevillon, Christine; Balenghien, Thomas; Guis, Hélène; Garros, Claire

    2016-01-01

    The role of the northward expansion of Culicoides imicola Kieffer in recent and unprecedented outbreaks of Culicoides-borne arboviruses in southern Europe has been a significant point of contention. We combined entomological surveys, movement simulations of air-borne particles, and population genetics to reconstruct the chain of events that led to a newly colonized French area nestled at the northern foot of the Pyrenees. Simulating the movement of air-borne particles evidenced frequent wind-transport events allowing, within at most 36 hours, the immigration of midges from north-eastern Spain and Balearic Islands, and, as rare events, their immigration from Corsica. Completing the puzzle, population genetic analyses discriminated Corsica as the origin of the new population and identified two successive colonization events within west-Mediterranean basin. Our findings are of considerable importance when trying to understand the invasion of new territories by expanding species. PMID:27263862

  9. Bioscouring of cotton using lipase from marine bacteria Bacillus sonorensis.

    PubMed

    Nerurkar, Madhura; Joshi, Manasi; Adivarekar, Ravindra

    2015-01-01

    Bioscouring refers to the enzymatic removal of impurities from cotton fabric, which imparts it with improved hydrophilicity for further wet processes. In the present study, the efficacy of lipase from newly isolated marine bacteria Bacillus sonorensis isolated from marine clams Paphia malabarica collected from Kalbadevi estuary, Mumbai, India, has been evaluated for scouring of cotton fabric and compared with conventional alkaline scouring of cotton. As a scouring agent for cotton fabrics, the lipase from B. sonorensis was capable of removing substantial amount of wax from the cotton surface and hydrolyzing it into fatty acids. Bioscouring carried out with lipase at a concentration of 8 % on the weight of the fabric (owf) at pH 9, temperature 60 °C for 120 min showed maximum weight loss and hydrophilicity. The Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) studies revealed that the lipase-scoured fabric showed smooth surface indicating no damage to the fabric whereas the surface of the alkaline-scoured fabric appeared rough causing damage to the fabric. Evaluation of fabric properties such as wettability, whiteness, dyeing behaviour, tensile strength and bending rigidity revealed that the bioscouring using lipase from B. sonorensis is as effective as conventional alkaline treatment. PMID:25256798

  10. Feltiella acarisuga (predatory gall midge)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The predatory gall midge, Feltiella acarisuga is one of the most effective and widespread natural enemies of spider mites. Because of their flying and prey detecting capabilities, and high feeding potential, it is considered an important natural enemy of the two-spotted spider mite in a number of cr...

  11. Orientation behaviour of Culicoides obsoletus (Diptera: Ceratopogonidae), a relevant virus vector in northern Europe, toward host-associated odorant cues.

    PubMed

    Zimmer, Jean-Yves; Verheggen, François J; Haubruge, Eric; Francis, Frédéric

    2015-07-30

    Some Culicoides biting midge species (Diptera: Ceratopogonidae) are biological virus vectors worldwide and have recently been associated with outbreaks of important epizootic diseases such as bluetongue and Schmallenberg in northern Europe. These diseases, which affect domestic and wild ruminants, have caused considerable economic losses. Knowledge of host preferences of these biting midges - especially of the relevant vectors of arboviruses near farms, such as Culicoides obsoletus in northern Europe - is essential to understand pathogen transmission cycles and the epidemiology of associated diseases. This study aimed to determine host preferences of C. obsoletus using an in-field flight tunnel containing pairs of calf, sheep, chicken, and human hosts (and controls) and a laboratory two-choice bioassay containing volatile extracts of host skin (and controls). Behavioural responses of nulliparous C. obsoletus females in the in-field flight tunnel showed a preference for human (but also calf and sheep) hosts, probably due to their exhalation of greater quantities of carbon dioxide. The laboratory experiment revealed that volatile organic compounds released from the skin of chicken and sheep seemed to attract this species. Culicoides obsoletus, thus, seems to have a wide host range and to be particularly attracted by humans under field conditions. A better understanding of vector-host interaction could enable the development of control strategies against adult biting midges, by exploiting insect-repelling or -attractive semiochemicals. Volatile extracts of chicken and/or sheep skin could be used to identify volatile compounds attractive to C. obsoletus, which in turn could be used in baited traps.

  12. To bite or not to bite! A questionnaire-based survey assessing why some people are bitten more than others by midges

    PubMed Central

    2010-01-01

    Background The Scottish biting midge, Culicoides impunctatus, responsible for more than 90% of biting attacks on human beings in Scotland, is known to demonstrate a preference for certain human hosts over others. Methods In this study we used a questionnaire-based survey to assess the association between people's perception of how badly they get bitten by midges and their demographic, lifestyle and health related characteristics. Results Most people (85.8%) reported being bitten sometimes, often or always with only 14.2% reporting never being bitten by midges when in Scotland. There was no association between level of bites received and age, smoking, diet, exercise, medication, eating strongly flavoured foods or alcohol consumption. However, there was a strong association between the probability of being bitten and increasing height (in men) and BMI (in women). A large proportion of participants (33.8%) reported experiencing a bad/severe reaction to midge bites while 53.1% reported a minor reaction and 13.1% no reaction at all. Also, women tend to react more than men to midge bites. Additionally, the results indicated that the susceptibility to being bitten by midges is hereditary. Conclusions This study suggests that midges prefer to bite men that are tall and women that have a large BMI, and that the tendency for a child to be bitten or not could be inherited from their parent. The study is questionnaire-based; therefore, the interpretation of the results may be limited by the subjectivity of the answers given by the respondents. Although the results are relevant only to the Scottish biting midge, the approach used here could be useful for investigating human-insect interactions for other insects, particularly those which transmit pathogens that cause disease. PMID:20500852

  13. Spatial and Temporal Distribution of Culicoides Species in Mainland Portugal (2005–2010). Results of the Portuguese Entomological Surveillance Programme

    PubMed Central

    Ramilo, David W.; Amador, Rita; Madeira, Sara; Baptista, Filipa M.; Harrup, Lara E.; Lucientes, Javier; Boinas, Fernando

    2015-01-01

    Bluetongue virus (BTV) is transmitted by Culicoides biting midges and causes an infectious, non-contagious disease of ruminants. It has been rapidly emerging in southern Europe since 1998. In mainland Portugal, strains of BTV belonging to three serotypes have been detected: BTV-10 (1956-1960), BTV-4 (2004-2006 and 2013) and BTV-1 (2007-2012). This paper describes the design, implementation and results of the Entomological Surveillance Programme covering mainland Portugal, between 2005 and 2010, including 5,650 caches. Culicoides imicola Kieffer was mostly found in central and southern regions of Portugal, although it was sporadically detected in northern latitudes. Its peak activity occurred in the autumn and it was active during the winter months in limited areas of the country. Obsoletus group was present at the highest densities in the north although they were found throughout the country in substantial numbers. Culicoides activity occurred all year round but peaked in the spring. A generalized linear mixed model was developed for the analysis of the environmental factors associated with activity of the species of Culicoides suspected vectors of BTV in the country. For C. imicola Kieffer, the most important variables were month, diurnal temperature range (DTR), the number of frost days (FRS) and median monthly temperature (TMP). For the Obsoletus group, the most important factors were month, diurnal temperature range (DTR), and linear and quadratic terms for median monthly temperature (TMP). The results reported can improve our understanding of climatic factors in Culicoides activity influencing their distribution and seasonal pattern. PMID:25906151

  14. Protection of livestock against bluetongue virus vector Culicoides imicola using insecticide-treated netting in open areas.

    PubMed

    Calvete, C; Estrada, R; Miranda, M A; Del Rio, R; Borrás, D; Beldron, F J; Martínez, A; Calvo, A J; Lucientes, J

    2010-06-01

    The protection of livestock against Culicoides species (Diptera: Ceratopogonidae) using physical barriers or chemically treated barriers is difficult owing to the small size of these biting midges and animal welfare concerns associated with the reduction of air flow. Culicoides imicola Kieffer is the main bluetongue virus vector in the Mediterranean basin, including the southern Iberian peninsula, where livestock is mainly housed in open pens or sheds which offer no physical protection against C. imicola. In this study we assessed the efficacy of surrounding yearling ewe pens with a canvas barrier or a cypermethrin-treated canvas barrier in reducing the entry of Culicoides spp. and C. imicola. Analyses were based on comparisons of Culicoides catches in traps in pens with and without barriers, and in traps located outside pens. Although there was no clear reduction in the abundance of Culicoides other than C. imicola in pens with either barrier, the C. imicola presence was markedly reduced by the insecticide-treated barrier compared with the untreated barrier; the latter did not reduce the abundance of this species in pens. Estimates of the protection conferred against C. imicola by the treated barrier differed depending on whether catch comparisons were based on outside traps or on traps located inside no-barrier pens. The results suggest that the use of insecticide-treated barriers may reduce contact between livestock and C. imicola in open areas or sheds. More research is necessary to assess the degree of protection as a function of barrier height, C. imicola abundance, and the size of the area to be protected.

  15. Culicoides (Diptera: Ceratopogonidae) and livestock in the Netherlands: comparing host preference and attack rates on a Shetland pony, a dairy cow, and a sheep.

    PubMed

    Elbers, A R W; Meiswinkel, R

    2015-12-01

    Culicoides (Diptera: Ceratopogonidae) host preferences and attack rates were quantified in early summer at a dairy farm in the Netherlands using livestock tethered at pasture. Midges were aspirated hourly over seven consecutive hours (17:00-23:00) from a dairy cow, a Shetland pony, and a sheep and correspondingly yielded seventeen, thirteen, and nine species. Of the 14,181 midges obtained, approximately 95% belonged to the C. obsoletus complex, C. dewulfi, C. chiopterus, and C. punctatus that together include all proven or potential vectors for arboviral diseases in livestock in northwestern Europe. On average, 7.6 and 3.5 times more Culicoides were collected, respectively, from the cow and the Shetland pony than from the sheep. In descending order of abundance, the C. obsoletus complex, C. dewulfi, and C. chiopterus dominated attacks on all three hosts, whereas C. punctatus and C. pulicaris favored only the two larger hosts. Irrespective of the host species involved, the three body regions attracted the same component species, C. chiopterus favoring the legs, C. punctatus and C. achrayi the belly, and the C. obsoletus complex, C. dewulfi, and C. pulicaris the head, back, and flanks. That known and potential vectors for animal diseases feed indiscriminately on a broad range of mammal hosts means that all major livestock species, including equines, are rendered susceptible to one or more Culicoides-borne pathogens. PMID:26611966

  16. A new algorithm quantifies the roles of wind and midge flight activity in the bluetongue epizootic in northwest Europe.

    PubMed

    Sedda, Luigi; Brown, Heidi E; Purse, Bethan V; Burgin, Laura; Gloster, John; Rogers, David J

    2012-06-22

    The 2006 bluetongue (BT) outbreak in northwestern Europe had devastating effects on cattle and sheep in that intensively farmed area. The role of wind in disease spread, through its effect on Culicoides dispersal, is still uncertain, and remains unquantified. We examine here the relationship between farm-level infection dates and wind speed and direction within the framework of a novel model involving both mechanistic and stochastic steps. We consider wind as both a carrier of host semio-chemicals, to which midges might respond by upwind flight, and as a transporter of the midges themselves, in a more or less downwind direction. For completeness, we also consider midge movement independent of wind and various combinations of upwind, downwind and random movements. Using stochastic simulation, we are able to explain infection onset at 94 per cent of the 2025 affected farms. We conclude that 54 per cent of outbreaks occurred through (presumably midge) movement of infections over distances of no more than 5 km, 92 per cent over distances of no more than 31 km and only 2 per cent over any greater distances. The modal value for all infections combined is less than 1 km. Our analysis suggests that previous claims for a higher frequency of long-distance infections are unfounded. We suggest that many apparent long-distance infections resulted from sequences of shorter-range infections; a 'stepping stone' effect. Our analysis also found that downwind movement (the only sort so far considered in explanations of BT epidemics) is responsible for only 39 per cent of all infections, and highlights the effective contribution to disease spread of upwind midge movement, which accounted for 38 per cent of all infections. The importance of midge flight speed is also investigated. Within the same model framework, lower midge active flight speed (of 0.13 rather than 0.5 m s(-1)) reduced virtually to zero the role of upwind movement, mainly because modelled wind speeds in the area

  17. Experimental infection of Culicoides lahillei (Diptera: Ceratopogonidae) with epizootic hemorrhagic disease virus serotype 2 (Orbivirus: Reoviridae).

    PubMed

    Smith, K E; Stallknecht, D E; Nettles, V F

    1996-01-01

    To evaluate the vector competence of Culicoides lahillei Lutz for epizootic hemorrhagic disease (EHD) viruses, wild-caught females were allowed to feed on 4 viremic white-tailed deer, Odocoileus virginianus Zimmermann, experimentally infected with EHD virus serotype 2 (EHDV-2). Colonized C. variipennis sonorensis (Coquillett) were included as a positive control. Virus was not isolated from 13 C. lahillei tested 4-15 d after feeding on deer with viremias of 3.0 or <2.1 log10 tissue culture infectious dose50 (TCID50) virus per milliliter of blood. Virus was isolated from 6 of 69 (8.7%) C. lahillei tested 4-15 d after feeding on deer with viremias of 5.3 or 6.0 TCID50 virus per milliliter of blood. The average amount of EHDV-2 ingested in the blood meal ranged from

  18. Experimental infection of Culicoides lahillei (Diptera: Ceratopogonidae) with epizootic hemorrhagic disease virus serotype 2 (Orbivirus: Reoviridae).

    PubMed

    Smith, K E; Stallknecht, D E; Nettles, V F

    1996-01-01

    To evaluate the vector competence of Culicoides lahillei Lutz for epizootic hemorrhagic disease (EHD) viruses, wild-caught females were allowed to feed on 4 viremic white-tailed deer, Odocoileus virginianus Zimmermann, experimentally infected with EHD virus serotype 2 (EHDV-2). Colonized C. variipennis sonorensis (Coquillett) were included as a positive control. Virus was not isolated from 13 C. lahillei tested 4-15 d after feeding on deer with viremias of 3.0 or <2.1 log10 tissue culture infectious dose50 (TCID50) virus per milliliter of blood. Virus was isolated from 6 of 69 (8.7%) C. lahillei tested 4-15 d after feeding on deer with viremias of 5.3 or 6.0 TCID50 virus per milliliter of blood. The average amount of EHDV-2 ingested in the blood meal ranged from

  19. Virus recovery rates for wild-type and live-attenuated vaccine strains of African horse sickness virus serotype 7 in orally infected South African Culicoides species.

    PubMed

    Venter, G J; Paweska, J T

    2007-12-01

    Previously reported virus recovery rates from Culicoides (Avaritia) imicola Kieffer and Culicoides (Avaritia) bolitinos Meiswinkel (Diptera, Ceratopogonidae) orally infected with vaccine strain of African horse sickness virus serotype 7 (AHSV-7) were compared with results obtained from concurrently conducted oral infections with five recent AHSV-7 isolates from naturally infected horses from various localities in South Africa. Culicoides were fed sheep bloods spiked with 10(7.6) TCID(50)/mL of a live-attenuated vaccine strain AHSV-7, and with five field isolates in which virus titre in the bloodmeals ranged from 10(7.1) to 10(8.2) TCID(50)/mL). After an extrinsic incubation of 10 days at 23.5 degrees C, virus recovery rates were significantly higher in C. imicola (13.3%) and C. bolitinos (4.2%) infected with the live-attenuated virus than in midges infected with any of the field isolates. The virus recovery rates for the latter groups ranged from 0% to 9.5% for C. imicola and from 0% to 1.5% for C. bolitinos. The C. imicola population at Onderstepoort was significantly more susceptible to infection with AHSV-7 isolated at Onderstepoort than to the virus strains isolated from other localities. Results of this study suggest that tissue culture attenuation of AHSV-7 does not reduce its ability to orally infect competent Culicoides species and may even lead to enhanced replication in the vector. Furthermore, oral susceptibility in a midge population appears to vary for geographically distinct isolates of AHSV-7.

  20. Prevalence of different species of Culicoides in Bangalore rural and urban districts of South India.

    PubMed

    Archana, M; D'Souza, Placid E; Renuka Prasad, C; Byregowda, S M

    2016-09-01

    A study was conducted to observe the prevalence of Culicoides a biting midge, important pest and prime vector for various viruses, protozoa and filarid worms. In the vicinity of 11 different farms of cattle, buffalo, sheep and goats in Bangalore rural and urban districts the flies were collected by using UV traps (Onderstepoort Veterinary Institute. ARC. LNR) connected with suction fan for the period of 1 year (2012-2013). Around 83,629 Culicoides were collected of which 77,906 (93.16 %) were female and 5,723 (6.84 %) were males and 40,120 (47.97 %) of C. imicola, 39,366 (47.07 %) C. oxystoma, 2,504 (2.99 %) C. actoni, 1,145 (1.37 %) C. peregrinus, 145 (0.17 %) C. huffi, 120 (0.16 %) C. innoxius, 90 (0.11 %) C. palpifer, 67 (0.08 %) C. anopheles, 37 (0.04 %) C. circumscriptus and 25 (0.03 %) were C. arakawae. It was observed that C. imicola and C. oxystoma were the most predominant species prevalent in Bangalore rural and urban districts of Karnataka.

  1. Prevalence of different species of Culicoides in Bangalore rural and urban districts of South India.

    PubMed

    Archana, M; D'Souza, Placid E; Renuka Prasad, C; Byregowda, S M

    2016-09-01

    A study was conducted to observe the prevalence of Culicoides a biting midge, important pest and prime vector for various viruses, protozoa and filarid worms. In the vicinity of 11 different farms of cattle, buffalo, sheep and goats in Bangalore rural and urban districts the flies were collected by using UV traps (Onderstepoort Veterinary Institute. ARC. LNR) connected with suction fan for the period of 1 year (2012-2013). Around 83,629 Culicoides were collected of which 77,906 (93.16 %) were female and 5,723 (6.84 %) were males and 40,120 (47.97 %) of C. imicola, 39,366 (47.07 %) C. oxystoma, 2,504 (2.99 %) C. actoni, 1,145 (1.37 %) C. peregrinus, 145 (0.17 %) C. huffi, 120 (0.16 %) C. innoxius, 90 (0.11 %) C. palpifer, 67 (0.08 %) C. anopheles, 37 (0.04 %) C. circumscriptus and 25 (0.03 %) were C. arakawae. It was observed that C. imicola and C. oxystoma were the most predominant species prevalent in Bangalore rural and urban districts of Karnataka. PMID:27605753

  2. Impact of experimental flooding on larvae and pupae of dung-breeding Culicoides.

    PubMed

    Steinke, S; Lühken, R; Kiel, E

    2016-10-01

    Culicoides biting midges (Diptera: Ceratopogonidae) spend the greatest part of their life in the larval stage. However, knowledge on the immature stages and the impact of abiotic factors on their development is still poor. Therefore, we investigated the effect of flooding on the larvae and pupae of Culicoides chiopterus (Meigen, 1830) and C. dewulfi Goetghebuer, 1936. In water, the larvae of both species showed head-to-tail flexions and sinuous flexions, at slow rates, but were not able to swim. Flooding of larvae for 24 h did not affect the number of emerging adults; flooding of pupae significantly reduced the emergence rate of C. chiopterus, compared to the control group, while C. dewulfi was not affected. Pupae were not able to float and no pupae survived flooding for 10 days. After flooding of larvae for 10 days, 50 % of C. chiopterus and 4 % of C. dewulfi completed the pre-adult development. During this treatment, 84 % of C. chiopterus and 48 % of C. dewulfi larvae pupated in water.

  3. Larval development sites of the main Culicoides species (Diptera: Ceratopogonidae) in northern Europe and distribution of coprophilic species larvae in Belgian pastures.

    PubMed

    Zimmer, Jean-Yves; Brostaux, Yves; Haubruge, Eric; Francis, Frédéric

    2014-10-15

    Some Culicoides species of biting midges (Diptera: Ceratopogonidae) are biological virus vectors worldwide and have indeed been associated with outbreaks of important epizoonoses in recent years, such as bluetongue and Schmallenberg disease in northern Europe. These diseases, which affect domestic and wild ruminants, have caused considerable economic losses. Knowledge of substrates suitable for Culicoides larval development is important, particularly for the main vector temperate species. This study, realized during two years, aimed to highlight the larval development sites of these biting midge species in the immediate surroundings of ten Belgian cattle farms. Moreover, spatial distribution of the coprophilic Culicoides larvae (C. chiopterus and C. dewulfi) within pastures was studied with increasing distance from farms along linear transects (farm-pasture-woodland). A total of 4347 adult specimens belonging to 13 Culicoides species were obtained by incubation of 2131 soil samples belonging to 102 different substrates; 18 of these substrates were suitable for larval development. The Obsoletus complex (formed by two species) was observed in a wide range of substrates, including silage residues, components of a chicken coop, dung adhering to walls inside stables, leftover feed along the feed bunk, a compost pile of sugar beet residues, soil of a livestock trampling area, and decaying wood, while the following served as substrates for the other specimens: C. chiopterus, mainly cow dung; C. dewulfi, cow dung and molehill soil; C. circumscriptus, algae; C. festivipennis, algae and soil in stagnant water; C. nubeculosus, algae and silt specifically from the edge of a pond; C. punctatus, mainly wet soil between silage reserves; C. salinarius, algae; and C. stigma, algae and wet soil between silage reserves. We also recorded significantly higher densities of coprophilic larvae within pastures in cow dung located near forests, which is likely due to the localization of

  4. Description of the Pupa of Culicoides crucifer Clastrier (Diptera: Ceratopogonidae).

    PubMed

    Ronderos, M M; Spinelli, G R; Keppler, R L F

    2013-10-01

    The pupa of Culicoides crucifer Clastrier is described, illustrated and photomicrographed by using binocular microscope and phase-contrast microscopy from material collected in an artificial container in Manaus, Brazil. The pupa shows features typical of pupae occurring in calm and clean waters, and it is compared with its similar congeners of the subgenus Haematomyiidium, Culicoides annuliductus Wirth and Culicoides debilipalpis Lutz.

  5. Effect of Culicoides Sonorensis Salivary Proteins on Clinical Disease Outcome in Experimental Bluetongue Virus Serotype 8 Infection of Dorset Sheep

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bluetongue is an insect-transmitted disease of domestic and wild ruminants. In the U.S., sheep are the most susceptible livestock species. Severity and form of clinical disease varies greatly depending on the outbreak serotype or specific strain within a serotype. To predict disease risk from any of...

  6. Colonization of the Mediterranean Basin by the vector biting midge species Culicoides imicola: an old story

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding the demographic history and genetic make-up of colonizing species is critical for inferring population sources and colonization routes. This is of main interest for designing accurate control measures in areas newly colonized by vector species of economically important pathogens. The b...

  7. New Neotropical Culicoides and redescription of Culicoides reticulatus Lutz (Diptera: Ceratopogonidae).

    PubMed

    Santarém, Maria Clara Alves; Da Trindade, Rosimeire Lopes; Da Silva, Tiago Do Nascimento; Castellón, Eloy Guillermo; Patiu, Cátia Antunes De Mello; Felippe-Bauer, Maria Luiza

    2014-01-01

    Seven new species of the Culicoides reticulatus species group are described and illustrated based on specimens from Colombia, Panama and Brazilian states of northern (Amazonas, Pará and Roraima) and southeast region (Rio de Janeiro). The new species are compared with their similar congener, Culicoides reticulatus Lutz, and a systematic key, table with numerical characters to the females of the species are provided. Redescription of Culicoides reticulatus Lutz is given based on type series deposited in the Ceratopogonidae Collection of the Oswaldo Cruz Foundation, Brazil. The distribution of these species is presented in figure 9.

  8. Molecular differentiation of the Old World Culicoides imicola species complex (Diptera, Ceratopogonidae), inferred using random amplified polymorphic DNA markers.

    PubMed

    Sebastiani, F; Meiswinkel, R; Gomulski, L M; Guglielmino, C R; Mellor, P S; Malacrida, A R; Gasperi, G

    2001-07-01

    Samples of seven of the 10 morphological species of midges of the Culicoides imicola complex were considered. The importance of this species complex is connected to its vectorial capacity for African horse sickness virus (AHSV) and bluetongue virus (BTV). Consequently, the risk of transmission may vary dramatically, depending upon the particular cryptic species present in a given area. The species complex is confined to the Old World and our samples were collected in Southern Africa, Madagascar and the Ivory Coast. Genomic DNA of 350 randomly sampled individual midges from 19 populations was amplified using four 20-mer primers by the random amplified polymorphic DNA (RAPD) technique. One hundred and ninety-six interpretable polymorphic bands were obtained. Species-specific RAPD profiles were defined and for five species diagnostic RAPD fragments were identified. A high degree of polymorphism was detected in the species complex, most of which was observed within populations (from 64 to 76%). Principal coordinate analysis (PCO) and cluster analysis provided an estimate of the degree of variation between and within populations and species. There was substantial concordance between the taxonomies derived from morphological and molecular data. The amount and the different distributions of genetic (RAPD) variation among the taxa can be associated to their life histories, i.e. the abundance and distribution of the larval breeding sites and their seasonality.

  9. Culicoides bottimeri as a vector of Haemoproteus lophortyx to quail in California, USA.

    PubMed

    Mullens, B A; Cardona, C J; McClellan, L; Szijj, C E; Owen, J P

    2006-08-31

    Arthropod sampling via periodic direct bird examination and regular light trapping was conducted between June 2000 and October 2002 to survey for potential vectors of Haemoproteus lophortyx to nonnative, captive-raised bobwhite quail (Colinus virginianus) in northern California, USA. Examination of individual bobwhite quail (from 5 weeks of age through adult, total n=76) was conducted on several dates during the transmission period (June-October). No ectoparasites, including hippoboscid flies (reported as Haemoproteus vectors to wild quail in early literature), were collected from the birds. Trapping with ultraviolet light suction traps near the quail revealed nine species of biting midges (Culicoides spp.). Of these, 94% were C. bottimeri, which was abundant near the birds, and 65% of collected C. bottimeri were engorged with blood. C. bottimeri adult activity began in late-April, slightly before the onset of disease in the quail. Activity peaked between July and late-September, coincident with maximum reported transmission, and adult activity ceased by early-November. Nonengorged C. bottimeri had a parity rate of 43.6% overall, suggesting excellent survival for biological transmission of a pathogen like H. lophortyx. A controlled study was done injecting a macerated slurry of pooled, nonengorged, wild-caught C. bottimeri into the peritoneum of 1-day-old bobwhite quail hatchlings held in insect-proof containers. Blood smears 13-19 days later confirmed H. lophortyx infection in zero controls but all insect-injected quail. Biting midges, especially C. bottimeri, transmit H. lophortyx to captive quail and probably are the dominant vector to native California quail (Callipepla californica) as well. PMID:16716520

  10. Biting midges (Diptera: Ceratopogonidae) from Martín García Island, Argentina.

    PubMed

    Ronderos, María M; Marino, Pablo I; Díaz, Florentina; Estévez, Ana L

    2011-09-01

    Nearly 230 species of biting midges have been recorded or described from Argentina; 38 of them are known from the Buenos Aires province and only one is cited from Martín García Island. This paper presents the results raised from six collecting trips which took place on the island during spring 2005, summer 2006 and autumn 2009. Diverse sampling sites including permanent and temporary aquatic environments were chosen, most of the ten sampling sites were ponds of diverse origin, some of these environments were covered with floating vegetation as Lemna gibba, Lemna minuscule, Salvinia biloba, Salvinia minima, Azolla filiculoides, Limnobium laevigatum, Pistia stratiotes, Spirodela intermedia, Wolffiella oblonga and Wolffia columbiana. Other sites were placed in urban and suburban areas. Adults were collected with sweep nets at sunrise and sunset and with light traps at intervals of four to five hours at night, depending on electricity availability on the island. Larvae and pupae were collected with different implements depending on characteristics of each surveyed aquatic habitat. In free standing water, they were captured with small sieves or hand pipettes and micropipettes, flotation techniques were utilized for sampling vegetated areas, free and rooted floating hydrophytes were extracted for removing insects among them. Thirteen species of Ceratopogonidae were collected, three of Atrichopogon Kieffer, three of Forcipomyia Meigen, two of Dasyhelea Kieffer, four of Culicoides Latreille, and one of Bezzia Kieffer, all representing new records from the island. PMID:22017124

  11. Midge Diversity and Bioassessment in the Everglades

    NASA Astrophysics Data System (ADS)

    Jacobsen, R. E.

    2005-05-01

    Everglades midge community composition is strongly dependent upon hydroperiod (HP) and water quality. Longer HPs are generally associated with higher alpha diversity, species density, and total species richness. However, the development of extensive calcareous periphyton growth in marshes with 4-10 month HPs strongly influences community structure, and diversity and richness measures show no change along marl prairie HP gradients. Increases in species density with hydroperiod represent increases in habitat volume and productivity, not changes in community structure. Beta diversity is greatest when transitioning from marshes with 7-10 month HPs to those with >10 month HPs. At these HP lengths / water depths, plant communities that permit extensive periphyton growth are replaced by plant communities that inhibit periphyton growth, enable more organic soil development, and provide habitat for more specialized species. Point-source nutrient enrichment produces strong shifts in Everglades midge community composition, thereby increasing gamma diversity along nutrient gradients. Biologists studying invertebrate communities have reported either little structural change, or increases in species density, diversity and richness near sources of enrichment. I will report on midge community structural responses along a variety of nutrient gradients in the Everglades, and discuss important differences between pupal exuviae sampling and conventional larvae sampling.

  12. Culicoides Species Communities Associated with Wild Ruminant Ecosystems in Spain: Tracking the Way to Determine Potential Bridge Vectors for Arboviruses

    PubMed Central

    Talavera, Sandra; Muñoz-Muñoz, Francesc; Durán, Mauricio; Verdún, Marta; Soler-Membrives, Anna; Oleaga, Álvaro; Arenas, Antonio; Ruiz-Fons, Francisco; Estrada, Rosa; Pagès, Nitu

    2015-01-01

    The genus Culicoides Latreille 1809 is a well-known vector for protozoa, filarial worms and, above all, numerous viruses. The Bluetongue virus (BTV) and the recently emerged Schmallenberg virus (SBV) are responsible for important infectious, non-contagious, insect-borne viral diseases found in domestic ruminants and transmitted by Culicoides spp. Both of these diseases have been detected in wild ruminants, but their role as reservoirs during the vector-free season still remains relatively unknown. In fact, we tend to ignore the possibility of wild ruminants acting as a source of disease (BTV, SBV) and permitting its reintroduction to domestic ruminants during the following vector season. In this context, a knowledge of the composition of the Culicoides species communities that inhabit areas where there are wild ruminants is of major importance as the presence of a vector species is a prerequisite for disease transmission. In this study, samplings were conducted in areas inhabited by different wild ruminant species; samples were taken in both 2009 and 2010, on a monthly basis, during the peak season for midge activity (in summer and autumn). A total of 102,693 specimens of 40 different species of the genus Culicoides were trapped; these included major BTV and SBV vector species. The most abundant vector species were C. imicola and species of the Obsoletus group, which represented 15% and 11% of total numbers of specimens, respectively. At the local scale, the presence of major BTV and SBV vector species in areas with wild ruminants coincided with that of the nearest sentinel farms included in the Spanish Bluetongue Entomological Surveillance Programme, although their relative abundance varied. The data suggest that such species do not exhibit strong host specificity towards either domestic or wild ruminants and that they could consequently play a prominent role as bridge vectors for different pathogens between both types of ruminants. This finding would support the

  13. Culicoides Species Communities Associated with Wild Ruminant Ecosystems in Spain: Tracking the Way to Determine Potential Bridge Vectors for Arboviruses.

    PubMed

    Talavera, Sandra; Muñoz-Muñoz, Francesc; Durán, Mauricio; Verdún, Marta; Soler-Membrives, Anna; Oleaga, Álvaro; Arenas, Antonio; Ruiz-Fons, Francisco; Estrada, Rosa; Pagès, Nitu

    2015-01-01

    The genus Culicoides Latreille 1809 is a well-known vector for protozoa, filarial worms and, above all, numerous viruses. The Bluetongue virus (BTV) and the recently emerged Schmallenberg virus (SBV) are responsible for important infectious, non-contagious, insect-borne viral diseases found in domestic ruminants and transmitted by Culicoides spp. Both of these diseases have been detected in wild ruminants, but their role as reservoirs during the vector-free season still remains relatively unknown. In fact, we tend to ignore the possibility of wild ruminants acting as a source of disease (BTV, SBV) and permitting its reintroduction to domestic ruminants during the following vector season. In this context, a knowledge of the composition of the Culicoides species communities that inhabit areas where there are wild ruminants is of major importance as the presence of a vector species is a prerequisite for disease transmission. In this study, samplings were conducted in areas inhabited by different wild ruminant species; samples were taken in both 2009 and 2010, on a monthly basis, during the peak season for midge activity (in summer and autumn). A total of 102,693 specimens of 40 different species of the genus Culicoides were trapped; these included major BTV and SBV vector species. The most abundant vector species were C. imicola and species of the Obsoletus group, which represented 15% and 11% of total numbers of specimens, respectively. At the local scale, the presence of major BTV and SBV vector species in areas with wild ruminants coincided with that of the nearest sentinel farms included in the Spanish Bluetongue Entomological Surveillance Programme, although their relative abundance varied. The data suggest that such species do not exhibit strong host specificity towards either domestic or wild ruminants and that they could consequently play a prominent role as bridge vectors for different pathogens between both types of ruminants. This finding would support the

  14. Culicoides Species Communities Associated with Wild Ruminant Ecosystems in Spain: Tracking the Way to Determine Potential Bridge Vectors for Arboviruses.

    PubMed

    Talavera, Sandra; Muñoz-Muñoz, Francesc; Durán, Mauricio; Verdún, Marta; Soler-Membrives, Anna; Oleaga, Álvaro; Arenas, Antonio; Ruiz-Fons, Francisco; Estrada, Rosa; Pagès, Nitu

    2015-01-01

    The genus Culicoides Latreille 1809 is a well-known vector for protozoa, filarial worms and, above all, numerous viruses. The Bluetongue virus (BTV) and the recently emerged Schmallenberg virus (SBV) are responsible for important infectious, non-contagious, insect-borne viral diseases found in domestic ruminants and transmitted by Culicoides spp. Both of these diseases have been detected in wild ruminants, but their role as reservoirs during the vector-free season still remains relatively unknown. In fact, we tend to ignore the possibility of wild ruminants acting as a source of disease (BTV, SBV) and permitting its reintroduction to domestic ruminants during the following vector season. In this context, a knowledge of the composition of the Culicoides species communities that inhabit areas where there are wild ruminants is of major importance as the presence of a vector species is a prerequisite for disease transmission. In this study, samplings were conducted in areas inhabited by different wild ruminant species; samples were taken in both 2009 and 2010, on a monthly basis, during the peak season for midge activity (in summer and autumn). A total of 102,693 specimens of 40 different species of the genus Culicoides were trapped; these included major BTV and SBV vector species. The most abundant vector species were C. imicola and species of the Obsoletus group, which represented 15% and 11% of total numbers of specimens, respectively. At the local scale, the presence of major BTV and SBV vector species in areas with wild ruminants coincided with that of the nearest sentinel farms included in the Spanish Bluetongue Entomological Surveillance Programme, although their relative abundance varied. The data suggest that such species do not exhibit strong host specificity towards either domestic or wild ruminants and that they could consequently play a prominent role as bridge vectors for different pathogens between both types of ruminants. This finding would support the

  15. Climate change and the spread of vector-borne diseases: using approximate Bayesian computation to compare invasion scenarios for the bluetongue virus vector Culicoides imicola in Italy.

    PubMed

    Mardulyn, Patrick; Goffredo, Maria; Conte, Annamaria; Hendrickx, Guy; Meiswinkel, Rudolf; Balenghien, Thomas; Sghaier, Soufien; Lohr, Youssef; Gilbert, Marius

    2013-05-01

    Bluetongue (BT) is a commonly cited example of a disease with a distribution believed to have recently expanded in response to global warming. The BT virus is transmitted to ruminants by biting midges of the genus Culicoides, and it has been hypothesized that the emergence of BT in Mediterranean Europe during the last two decades is a consequence of the recent colonization of the region by Culicoides imicola and linked to climate change. To better understand the mechanism responsible for the northward spread of BT, we tested the hypothesis of a recent colonization of Italy by C. imicola, by obtaining samples from more than 60 localities across Italy, Corsica, Southern France, and Northern Africa (the hypothesized source point for the recent invasion of C. imicola), and by genotyping them with 10 newly identified microsatellite loci. The patterns of genetic variation within and among the sampled populations were characterized and used in a rigorous approximate Bayesian computation framework to compare three competing historical hypotheses related to the arrival and establishment of C. imicola in Italy. The hypothesis of an ancient presence of the insect vector was strongly favoured by this analysis, with an associated P ≥ 99%, suggesting that causes other than the northward range expansion of C. imicola may have supported the emergence of BT in southern Europe. Overall, this study illustrates the potential of molecular genetic markers for exploring the assumed link between climate change and the spread of diseases.

  16. Evaluation of an IgE ELISA with Culicoides spp. extracts and recombinant salivary antigens for diagnosis of insect bite hypersensitivity in Warmblood horses.

    PubMed

    Peeters, L M; Janssens, S; Goddeeris, B M; De Keyser, K; Wilson, A D; Kaufmann, C; Schaffartzik, A; Marti, E; Buys, N

    2013-10-01

    Insect bite hypersensitivity (IBH) in horses represents an immunoglobulin E (IgE)-mediated hypersensitivity to salivary antigens from biting midges (Culicoides spp.). The aim of this study was to evaluate and compare the performances of IgE ELISAs using recombinant Culicoides spp. Obsoletus group salivary gland antigens or crude whole body extracts ('ObsWBE'), C. nubeculosus recombinant proteins (Culn1, 3, 4, 5, 7, 8 and 10) and Obsoletus group recombinant proteins (Culo1 and 2). IgE levels were measured in plasma of 343 Warmblood horses classified as IBH-affected (n=167) and IBH-unaffected (n=176) according to the owners' descriptions. IBH-affected horses were subdivided based on the severity of their clinical signs at sampling and whether or not their IBH history was considered to be classical. The accuracies of the tests increased when clinical signs at sampling were more pronounced or when the IBH history could be considered as classical. A combination of IgE levels against the three best performing Culicoides spp. recombinant proteins (Culn4, Culo1 and Culo2) and ObsWBE resulted in the best performing test. When IBH-affected horses showing a classical history of the disease and severe clinical signs were compared with IBH-unaffected horses, the Youden's index at the optimal cut-off for the three tests in combination was 0.67. This optimal cut-off had a sensitivity of 70%, a specificity of 97% and a total accuracy of 92%. The performance of the IgE ELISA was affected by the severity of IBH clinical signs at sampling and was improved when IgE levels against several recombinant proteins were combined.

  17. Identification of human-derived volatile chemicals that interfere with attraction of the Scottish biting midge and their potential use as repellents.

    PubMed

    Logan, James G; Seal, Nicola J; Cook, James I; Stanczyk, Nina M; Birkett, Michael A; Clark, Suzanne J; Gezan, Salvador A; Wadhams, Lester J; Pickett, John A; Mordue, A Jennifer

    2009-03-01

    The Scottish biting midge, Culicoides impunctatus (Diptera: Ceratopogonidae), is a major pest in Scotland, causing a significant impact to the Scottish tourist and forestry industries. C. impunctatus is a generalist feeder, preferring to feed on large mammals, and is notorious for its attacks on humans. Until now, there was anecdotal evidence for differential attraction of female host-seeking C. impunctatus to individual human hosts, and the mechanism for this phenomenon was unknown. Using extracts of human odor collected by air entrainment, electroantennogram recordings to identify the physiologically active components, followed by behavioral assays, we show, for the first time, the differential attraction of female C. impunctatus to human odors and the chemical basis for this phenomenon. Certain chemicals, found in greater amounts in extracts that cause low attractiveness to midges, elicit a repellent effect in laboratory assays and repellency trials in the field. Differences in the production of these natural human-derived compounds could help to explain differential "attractiveness" between different human hosts. A mixture of two compounds in particular, 6-methyl-5-hepten-2-one and geranylacetone [(E)-6,10-dimethylundeca-5,9-dien-2-one], showed significant repellency (87, 77.4, 74.2, and 31.6% at hours 0, 1, 2, and 3, respectively) in the field and have the potential to be developed as novel repellents. PMID:19351071

  18. Factors associated with Culicoides Obsoletus complex spp.-specific IgE reactivity in Icelandic horses and Shetland ponies.

    PubMed

    Schurink, Anouk; van der Meide, Nathalie M A; Savelkoul, Huub F J; Ducro, Bart J; Tijhaar, Edwin

    2014-09-01

    Insect bite hypersensitivity (IBH) is a common allergic skin disease in horses, caused by biting insects of the Culicoides spp. In The Netherlands, Culicoides spp. of the Obsoletus complex are the most important midges involved in IBH. The aim of the present study was to identify and quantify associations between several endogenous (host) and exogenous (environmental) factors and immunoglobulin E (IgE) reactivity against Obsoletus complex-derived whole body extract or seven recombinant allergens, measured by ELISA. Data from 143 Icelandic horses and 177 Shetland ponies were analysed using multivariable models. In addition, the relationship between IgE reactivity and severity of clinical signs in IBH-affected horses was examined. Positive correlations were found between Obsoletus complex-specific IgE and severity of clinical signs. Disease status (IBH affected or control), breed and the interaction between IBH status and breed were significantly associated with IgE reactivity against several Obsoletus complex allergens. Significantly greater IgE reactivity was seen in IBH-affected horses compared to controls. The differences in IgE values between cases and controls were most pronounced in Icelandic horses. Shetland pony controls had significantly greater IgE reactivity compared to Icelandic horse controls, while differences in IgE values comparing Shetland pony cases and Icelandic horse cases were not significant. Severity of clinical signs and IgE reactivity in IBH-affected horses against several Obsoletus complex allergens appeared to be related. Consideration of the factors associated with Obsoletus complex-specific IgE in horses might further improve interpretation and accuracy of IgE ELISA test results within these breeds, although further research is required.

  19. Culicoides and the Tartar Steppe: Il Deserto dei Tartari Culicoides and the spread of blue tongue virus.

    PubMed

    Houin, R

    2008-12-01

    Culicoides were described for the first time in England in 1713, but named by Latreille in 1809 only. Even so, they were better known as Ceratopogon until Kieffer reintroduced the name Culicoides. The family name became Ceratopogonidae, the description by Meigen (1803) being better adapted to that systematic level. Culicoides were considered simply as biting insects until it was found that they can carry filaria and viruses. In 1944, du Toit in Transvaal described their role in the transmission of blue-tongue virus. Blue-tongue disease has since extended progressively northward from South Africa, disseminated by Culicoides imicola. At the end of the 20th century, it reached the southern shores of the Mediterranean sea, and has since threatened the southern Europe. Surveillance and prevention procedures were put in place, but fortress Europe was taken breached when a different strain of the virus entered through Belgium in 2006. Transmitted by local Culicoides species that were aggressive and abundant, the disease spread quickly, in a disastrous epizootic southward through more than half of France. Westward, infected insects have been carried by wind over the Channel, introducing the disease to England. PMID:20055234

  20. Worldwide niche and future potential distribution of Culicoides imicola, a major vector of bluetongue and African horse sickness viruses.

    PubMed

    Guichard, Sylvain; Guis, Hélène; Tran, Annelise; Garros, Claire; Balenghien, Thomas; Kriticos, Darren J

    2014-01-01

    We modelled the ecoclimatic niche of Culicoides imicola, a major arthropod vector of midge-borne viral pathogens affecting ruminants and equids, at fine scale and on a global extent, so as to provide insight into current and future risks of disease epizootics, and increase current knowledge of the species' ecology. Based on the known distribution and ecology of C. imicola, the species' response to monthly climatic conditions was characterised using CLIMEX with 10' spatial resolution climatic datasets. The species' climatic niche was projected worldwide and under future climatic scenarios. The validated model highlights the role of irrigation in supporting the occurrence of C. imicola in arid regions. In Europe, the modelled potential distribution of C. imicola extended further West than its reported distribution, raising questions regarding ongoing process of colonization and non-climatic habitat factors. The CLIMEX model highlighted similar ecological niches for C. imicola and the Australasian C. brevitarsis raising questions on biogeography and biosecurity. Under the climate change scenarios considered, its' modelled potential distribution could expand northward in the Northern hemisphere, whereas in Africa its range may contract in the future. The biosecurity risks from bluetongue and African horse sickness viruses need to be re-evaluated in regions where the vector's niche is suitable. Under a warmer climate, the risk of vector-borne epizootic pathogens such as bluetongue and African horse sickness viruses are likely to increase as the climate suitability for C. imicola shifts poleward, especially in Western Europe.

  1. Host plant susceptibility to the swede midge (Diptera: Cecidomyiidae).

    PubMed

    Hallett, Rebecca H

    2007-08-01

    The relative resistance and susceptibility of various cruciferous plants to swede midge, Contarinia nasturtii (Kieffer) (Diptera: Cecidomyiidae), damage was investigated to provide growers with planting recommendations and to identify potential sources of resistance to the swede midge. Broccoli cultivars experienced more severe damage than cabbage, cauliflower, and Brussels sprouts. The broccoli 'Paragon', 'Eureka', and 'Packman' are highly susceptible to the swede midge, whereas 'Triathlon' and 'Regal' showed reduced susceptibility to damage and slower development of damage symptoms. No differences were found between normal and red cultivars of cabbage and cauliflower in damage severity and progression of damage symptoms. Four new plant species (Brassica juncea Integlifolia group, Erucastrum gallicum (Willd.) O. E. Shulz., Lepidium campestre (L.) R.Br., and Capsella bursa-pastoris (L.) Medic.) are reported as hosts of the swede midge. The weed species Descurainia sophia (L.) Webb, Camelina microcarpa Andrz. ex Dc., and Erysimum cheiranthoides L. exhibited no damage symptoms, and they seem to be nonhost crucifers for the swede midge. PMID:17849887

  2. Characterization and phylogenetic relationships of Photorhabdus luminescens subsp. sonorensis (γ-Proteobacteria: Enterobacteriaceae), the bacterial symbiont of the entomopathogenic nematode Heterorhabditis sonorensis (Nematoda: Heterorhabditidae).

    PubMed

    Orozco, Rousel A; Hill, Tara; Stock, S Patricia

    2013-01-01

    Photorhabdus are motile Gram-negative bacteria that have a mutualistic association with Heterorhabditis nematodes (Heterorhabditidae). These bacteria possess peculiar biochemical characteristics such as inability to reduce nitrates, and the capacity to ferment only a limited number of carbohydrates. Heterorhabditis nematodes vector the bacteria from one insect host to another and also provide shelter to the bacteria from soil stressors and antagonists. Once inside the insect host, the bacterial symbionts are released and produce toxins and secondary metabolites and broad-spectrum antibiotics, which kill the host by septicemia within 48 h. At present, three Photorhabdus spp. have been identified: P. luminescens, P. temperata, and P. asymbiotica, and many subspecies have also been described. Characterization of new species and subspecies has been based on sequence data, mostly of the 16S rDNA, and also of a selection of protein coding genes. In addition to this, phenotypic traits including temperature growth, colony morphology, color, light production, carbohydrate response, and assimilation, among others, have been considered. In this study, we characterize the bacterial symbiont of Heterorbabditis sonorensis, a recently discovered entomopathogenic nematode species form the Sonoran desert in Arizona, USA. A selection of classic biochemical and molecular methods including sequence data of six genes: 16s rDNA, and four protein coding genes: gyrB, recA, gltX, and dnaN were considered. Evolutionary relationships of this new Photorhabdus subsp. were inferred considering maximum parsimony and Bayesian analyses. PMID:23053483

  3. Comparison of emergence traps of different shape and translucency in the trapping of Culicoides (Diptera: Ceratopogonidae).

    PubMed

    Steinke, S; Lühken, R; Kroischke, F; Timmermann, E; Kiel, E

    2016-06-15

    Various types of emergence traps are available for investigations of the breeding habitats of Culicoides (Diptera: Ceratopogonidae). In order to assess the potential impact of the trap design on the trapping success, we compared the efficiency of opaque and white (more translucent) emergence traps and two trap shapes (cone-shaped and quadratic), to sample Culicoides emerging from cowpats. Significantly higher numbers of Culicoides chiopterus and Culicoides dewulfi were trapped with opaque traps, while there was no obvious effect of the trap shape. There were no distinct differences in the microclimate among different trap types. PMID:27198792

  4. Oviposition cues of the blueberry gall midge, dasineura oxycoccana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The blueberry gall midge oviposits into blueberry flower buds and leaf buds, reducing yield up to 80%. We developed an efficient rearing method with a low level of direct handling, and high levels of survival and chance of mating. We also collected and identified volatiles from blueberry flower bu...

  5. Collective Behaviour without Collective Order in Wild Swarms of Midges

    PubMed Central

    Attanasi, Alessandro; Cavagna, Andrea; Del Castello, Lorenzo; Giardina, Irene; Melillo, Stefania; Parisi, Leonardo; Pohl, Oliver; Rossaro, Bruno; Shen, Edward; Silvestri, Edmondo; Viale, Massimiliano

    2014-01-01

    Collective behaviour is a widespread phenomenon in biology, cutting through a huge span of scales, from cell colonies up to bird flocks and fish schools. The most prominent trait of collective behaviour is the emergence of global order: individuals synchronize their states, giving the stunning impression that the group behaves as one. In many biological systems, though, it is unclear whether global order is present. A paradigmatic case is that of insect swarms, whose erratic movements seem to suggest that group formation is a mere epiphenomenon of the independent interaction of each individual with an external landmark. In these cases, whether or not the group behaves truly collectively is debated. Here, we experimentally study swarms of midges in the field and measure how much the change of direction of one midge affects that of other individuals. We discover that, despite the lack of collective order, swarms display very strong correlations, totally incompatible with models of non-interacting particles. We find that correlation increases sharply with the swarm's density, indicating that the interaction between midges is based on a metric perception mechanism. By means of numerical simulations we demonstrate that such growing correlation is typical of a system close to an ordering transition. Our findings suggest that correlation, rather than order, is the true hallmark of collective behaviour in biological systems. PMID:25057853

  6. Christopher Columbus and Culicoides: was C. jamaicensis Edwards, 1922 introduced into the Mediterranean 500 years ago and later re-named C. paolae Boorman 1996?

    PubMed

    Meiswinkel, R; Labuschagne, K; Goffredo, M

    2004-01-01

    The biting midge, Culicoides paolae Boorman, described from specimens collected in the extreme south of Italy in 1996, belongs in the subgenus Drymodesmyia. This subgenus was erected by Vargas in 1960 for the so-called Copiosus species group, an assemblage of 22 species endemic to the tropical regions of the New World and, where known, breed in vegetative materials including the decaying leaves (cladodes) and fruits of Central American cacti. The Mexican peoples have utilised these cacti for over 9,000 years; one of these, Opuntia ficus-indica Linnaeus, was brought to Europe by Christopher Columbus following his voyages of discovery. As a taxon C. paolae is very similar to the Central American C. jamaicensis Edwards, 1922 raising the possibility that it (or a closely related species of Drymodesmyia) was introduced into the Mediterranean Region at the time of Columbus, but was (perplexingly) discovered only 500 years later and named C. paolae. The comparison of Sardinian specimens of C. paolae with Panamanian material of C. jamaicensis (housed in the Natural History Museum in London) confirmed the two species to be very similar but unusual differences were noted around the precise distribution of the sensilla coeloconica on the female flagellum. Until it is understood whether these differences represent either intra- or interspecific variation, the question of the possible synonymy of C. paolae must be held in abeyance.

  7. First overview of the Culicoides Latreille (Diptera: Ceratopogonidae) livestock associated species of Reunion Island, Indian Ocean.

    PubMed

    Desvars, A; Grimaud, Y; Guis, H; Esnault, O; Allène, X; Gardès, L; Balenghien, T; Baldet, T; Delécolle, J C; Garros, C

    2015-02-01

    This study establishes the first faunistic inventory of livestock associated Culicoides (Diptera: Ceratopogonidae) species of Reunion Island (Indian Ocean), where bluetongue and epizootic hemorrhagic disease are regularly recorded. Single night-catches were performed at 41 sites using light suction traps at altitudes ranging from 0 to 1525 m, from March to April 2005. Five species were recorded: Culicoides imicola, Culicoides bolitinos, Culicoides enderleini, Culicoides grahamii, and Culicoides kibatiensis, among which at least the first three species are known to be involved in virus transmission to ruminants and equids. This is the first record of C. bolitinos, C. kibatiensis, and C. enderleini on the island. C. imicola was the most abundant species along the sea coast. C. bolitinos was more abundant inland and on two sites on the east coast. C. kibatiensis and C. grahamii were less abundant than the other three species and limited to two foci. Spatial distribution analysis of the different species showed that C. bolitinos, C. enderleini and C. imicola were collected at low altitudes, while the other two species were found at higher altitude. A morphological identification key for adult females and males is given, as well as cytochrome oxydase subunit I sequences. Phylogenetic reconstructions showed a clear divergence between C. bolitinos from Reunion Island and mainland Africa. This monograph will help to identify the Culicoides species in the poorly known entomological fauna of the south-western Indian Ocean region.

  8. Isolation and identification of allelochemicals produced by B. sonorensis for suppression of charcoal rot of Arachis hypogaea L.

    PubMed

    Pandya, Urja; Saraf, Meenu

    2015-05-01

    Bacillus sonorensis MBCU2 isolated from vermicompost-amended soil from Gujarat, India showed most antagonistic activity against Macrophomina phaseolina by dual culture screening. The culture supernatant of MBCU2 completely suppressed the mycelia growth of pathogen, indicating that suppression was due to the presence of allelochemicals in the culture filtrate. Results of scanning electron microscopy revealed that MBCU2 caused morphological alteration in mycelia of M. phaseolina as evident by hyphal lysis and perforation. Lipopeptides (iturin A and surfactin) produced by MBCU2 were detected and identified by MALDI-TOF-MS as well as liquid chromatography coupled with ESI-MS/MS. Pot trial studies conducted by seed bacterization with MBCU2 resulted in statistically significant increase in Arachis hypogaea L. vegetative growth parameters such as root length (91%), shoot length (252%), fresh weight (71%), dry weight (57%), number of pod (128%), and number of seed (290%) in M. phaseolina infested soil over control as well as decreased M. phaseolina disease severity. We suggest that allelochemicals production can be linked to the mechanism of protection of A. hypogaea L. from M. phaseolina by B. sonorensis MBCU2. PMID:25346523

  9. Tripius gyraloura n. sp. (Aphelenchoidea: Sphaerulariidae) parasitic in the gall midge Lasioptera donacis Coutin (Diptera: Cecidomyiidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new nematode, Tripius gyraloura sp. n., is described from the arundo gall midge, Lasioptera donacis Coutin (Diptera: Cecidomyiidae). This gall midge is being considered as a biological control agent for use in North America against the introduced giant reed, Arundo donax (L.) (Poaceae: Cyperales)....

  10. Method refinements for the midge life-cycle, Chironomus dilutus test

    EPA Science Inventory

    Larval stages of non-biting midges can be found in almost any freshwater ecosystem, and one of the commonly tested midges is Chironomus dilutus (Chironomidae, Diptera) which is used for toxicity testing and ecological risk assessment of freshwater contaminants. USEPA, ASTM, Envir...

  11. Characterization of a Hyperthermostable Alkaline Lipase from Bacillus sonorensis 4R

    PubMed Central

    Bhosale, Hemlata; Shaheen, Uzma

    2016-01-01

    Hyperthermostable alkaline lipase from Bacillus sonorensis 4R was purified and characterized. The enzyme production was carried out at 80°C and 9.0 pH in glucose-tween inorganic salt broth under static conditions for 96 h. Lipase was purified by anion exchange chromatography by 12.15 fold with a yield of 1.98%. The molecular weight of lipase was found to be 21.87 KDa by SDS-PAGE. The enzyme activity was optimal at 80°C with t1/2 of 150 min and at 90°C, 100°C, 110°C, and 120°C; the respective values were 121.59 min, 90.01 min, 70.01 min, and 50 min. The enzyme was highly activated by Mg and t1/2 values at 80°C were increased from 150 min to 180 min when magnesium and mannitol were added in combination. The activation energy calculated from Arrhenius plot was 31.102 KJ/mol. At 80–120°C, values of ΔH and ΔG were in the range of 28.16–27.83 KJ/mol and 102.79 KJ/mol to 111.66 KJ/mol, respectively. Lipase activity was highest at 9.0 pH and stable for 2 hours at this pH at 80°C. Pretreatment of lipase with MgSO4 and CaSO4 stimulated enzyme activity by 249.94% and 30.2%, respectively. The enzyme activity was greatly reduced by CoCl2, CdCl2, HgCl2, CuCl2, Pb(NO3)2, PMSF, orlistat, oleic acid, iodine, EDTA, and urea. PMID:26904276

  12. Bioprocess development for the production of sonorensin by Bacillus sonorensis MT93 and its application as a food preservative.

    PubMed

    Chopra, Lipsy; Singh, Gurdeep; Jena, Kautilya Kumar; Verma, Himanshu; Sahoo, Debendra K

    2015-01-01

    Media composition and environmental conditions were optimized using statistical tools, Plackett Burman design and response surface methodology, to maximize the yield of a bacteriocin, named as sonorensin, from a new marine isolate Bacillus sonorensis MT93 showing broad spectrum of antimicrobial activity. Under optimized conditions, MT93 produced 15-fold higher yield of sonorensin compared to that under initial fermentation conditions. As oxygen supply is a critical parameter controlling growth and product formation in aerobic bioprocesses and used as a parameter for bioprocess scale up, the effects of oxygen transfer, in terms of volumetric oxygen transfer coefficient (kLa), on production of sonorensin was investigated using optimized medium composition in a bioreactor. Studies on effectiveness of sonorensin against Staphylococcus aureus and Listeria monocytogenes in fruit juice and as a preservative in pasteurized milk demonstrated its potential as a biopreservative in fruit products and shelf life extender of the pasteurized milk.

  13. Redescription of Campoletis sonorensis (Cameron, 1886) (Hymenoptera, Ichneumonidae, Campopleginae), parasitoid of Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera, Noctuidae) in Brazil.

    PubMed

    Camargo, L F; Brito, R A; Penteado-Dias, A M

    2015-11-01

    The fall armyworm Spodoptera frugiperda (Lepidoptera; Noctuidae) is a voracious pest of numerous crops of economic importance throughout the New World. In Brazil, its larvae are attacked by several species of parasitoid wasps, making them potential candidate as biological control agents against this pest. A survey of the parasitoid fauna on S. frugiperda in maize crops throughout Brazil reveals two species of Campoletis, which are morphologicaly very similar species. In this paper we combine these data with pictures from the type material of C. sonorensis and C. flavicincta, as well as their descriptions to provide a redescription to Campoletis sonorensis (Cameron, 1886) using for this both morphological characters and DNA Barcoding (Hebert et al., 2003) information, in an attempt to help with the correct identification of the taxa to improve biological control studies. PMID:26675917

  14. Redescription of Campoletis sonorensis (Cameron, 1886) (Hymenoptera, Ichneumonidae, Campopleginae), parasitoid of Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera, Noctuidae) in Brazil.

    PubMed

    Camargo, L F; Brito, R A; Penteado-Dias, A M

    2015-11-01

    The fall armyworm Spodoptera frugiperda (Lepidoptera; Noctuidae) is a voracious pest of numerous crops of economic importance throughout the New World. In Brazil, its larvae are attacked by several species of parasitoid wasps, making them potential candidate as biological control agents against this pest. A survey of the parasitoid fauna on S. frugiperda in maize crops throughout Brazil reveals two species of Campoletis, which are morphologicaly very similar species. In this paper we combine these data with pictures from the type material of C. sonorensis and C. flavicincta, as well as their descriptions to provide a redescription to Campoletis sonorensis (Cameron, 1886) using for this both morphological characters and DNA Barcoding (Hebert et al., 2003) information, in an attempt to help with the correct identification of the taxa to improve biological control studies.

  15. Sonorensin: an Antimicrobial Peptide, Belonging to the Heterocycloanthracin Subfamily of Bacteriocins, from a New Marine Isolate, Bacillus sonorensis MT93

    PubMed Central

    Chopra, Lipsy; Singh, Gurdeep; Choudhary, Vikas

    2014-01-01

    Marine environments are the greatest fronts of biodiversity, representing a resource of unexploited or unknown microorganisms and new substances having potential applications. Among microbial products, antimicrobial peptides (AMPs) have received great attention recently due to their applications as food preservatives and therapeutic agents. A new marine soil isolate producing an AMP was identified as Bacillus sonorensis based on 16S rRNA gene sequence analysis. It produced an AMP that showed a broad spectrum of activity against both Gram-positive and Gram-negative bacteria. The peptide, named sonorensin, was purified to homogeneity using a combination of chromatographic techniques. The intact molecular mass of the purified peptide, 6,274 Da, as revealed by matrix-assisted laser desorption ionization–time of flight (MALDI-TOF), was in agreement with Tricine-SDS-PAGE analysis. A PCR array of primers was used to identify AMP structural genes, which allowed the successful amplification of the related genes from strain MT93. The putative open reading frame of sonorensin was amplified, cloned into the pET-32a(+) vector, expressed as a thioredoxin (Trx) fusion protein in Escherichia coli, and then purified. Sequence alignment analysis revealed that the bacteriocin being reported could belong to new subfamily of bacteriocins, heterocycloanthracin. The peptide indicated its potential as a biocontrol agent or food antimicrobial agent, due to its antimicrobial activity against bacteria such as Listeria monocytogenes and Staphylococcus aureus. This is the first report of the production, purification, and characterization of wild-type and recombinant bacteriocin by B. sonorensis and the first bacteriocin of the heterocycloanthracin subfamily to be characterized. PMID:24610839

  16. CHRONIC EFFECTS OF THE HERBICIDE DIURON ON FRESHWATER CLADOCERANS,AMPHIPODS,MIDGES,MINNOWS,WORMS, AND SNAILS

    EPA Science Inventory

    The chronic effects of the herbicide diuron on survival and reproduction of Daphnia pulex, and survival and growth of the amphipod Hyalella azteca, the midge Chironomus tentans, juvenile and embro/larval fathead minnows, Pimephales promelas, annelid worms, Lumbriculus variegatus,...

  17. Sex pheromone of orange wheat blossom midge, Sitodiplosis mosellana

    NASA Astrophysics Data System (ADS)

    Gries, Regine; Gries, G.; Khaskin, Grigori; King, Skip; Olfert, Owen; Kaminski, Lori-Ann; Lamb, Robert; Bennett, Robb

    Pheromone extract of the female orange wheat blossom midge, Sitodiplosis mosellana (Géhin) (SM) (Diptera: Cecidomyiidae), was analyzed by coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometry (MS), employing fused silica columns coated with DB-5, DB-210, DB-23 or SP-1000. These analyses revealed a single, EAD-active candidate pheromone which was identified as 2,7-nonanediyl dibutyrate. In experiments in wheat fields in Saskatchewan, traps baited with (2S,7S)-2,7-nonanediyl dibutyrate attracted significant numbers of male SM. The presence of other stereoisomers did not adversely affect trap captures. Facile synthesis of stereoisomeric 2,7-nonanediyl dibutyrate will facilitate the development of pheromone-based monitoring or even control of SM populations.

  18. Evidence for transmission of bluetongue virus serotype 26 through direct contact.

    PubMed

    Batten, Carrie; Darpel, Karin; Henstock, Mark; Fay, Petra; Veronesi, Eva; Gubbins, Simon; Graves, Samantha; Frost, Lorraine; Oura, Christopher

    2014-01-01

    The aim of this study was to assess the mechanisms of transmission of bluetongue virus serotype 26 (BTV-26) in goats. A previous study, which investigated the pathogenicity and infection kinetics of BTV-26 in goats, unexpectedly revealed that one control goat may have been infected through a direct contact transmission route. To investigate the transmission mechanisms of BTV-26 in more detail an experimental infection study was carried out in which three goats were infected with BTV-26, three goats were kept uninfected, but were housed in direct contact with the infected goats, and an additional four goats were kept in indirect contact separated from infected goats by metal gates. This barrier allowed the goats to have occasional face-to-face contact in the same airspace, but feeding, watering, sampling and environmental cleaning was carried out separately. The three experimentally infected goats did not show clinical signs of BTV, however high levels of viral RNA were detected and virus was isolated from their blood. At 21 dpi viral RNA was detected in, and virus was isolated from the blood of the three direct contact goats, which also seroconverted. The four indirect barrier contact goats remained uninfected throughout the duration of the experiment. In order to assess replication in a laboratory model species of Culicoides biting midge, more than 300 Culicoides sonorensis were fed a BTV-26 spiked blood meal and incubated for 7 days. The dissemination of BTV-26 in individual C. sonorensis was inferred from the quantity of virus RNA and indicated that none of the insects processed at day 7 possessed transmissible infections. This study shows that BTV-26 is easily transmitted through direct contact transmission between goats, and the strain does not seem to replicate in C. sonorensis midges using standard incubation conditions.

  19. Responses of the aquatic midge Chironomus riparius to DEET exposure.

    PubMed

    Campos, Diana; Gravato, Carlos; Quintaneiro, Carla; Soares, Amadeu M V M; Pestana, João L T

    2016-03-01

    N,N-diethyl-3-methylbenzamide (DEET) is the active ingredient of many commercial insect repellents. Despite being detected worldwide in effluents, surface water and groundwater, there is still limited information on DEET's toxicity toward non-target aquatic invertebrates. Thus, our main objective was to assess the effects of DEET in the life cycle of Chironomus riparius and assess its biochemical effects. Laboratory assays showed that DEET reduced developmental rates (reduced larval growth, delayed emergence) of C. riparius larvae and also caused a decrease in the size of adult midges. Concerning the biochemical responses, a short exposure to DEET caused no effects in lipid peroxidation, despite the significant inhibition of catalase and glutathione-S-transferase activities and of total glutathione contents. Moreover, inhibition of acetylcholinesterase activity was also observed showing neurotoxic effects. Environmental risk assessment of insect repellents is needed. Our results showed moderate toxicity of DEET toward C. riparius, however, due to their mode of action, indirect ecological effects of DEET and of other insect repellents cannot be excluded and should be evaluated. PMID:26773354

  20. Chronic effects of Cd on the reproduction of the guppy (Poecilia reticulata) through Cd-accumulated midge larvae (Chironomus yoshimatsui)

    SciTech Connect

    Hatakeyama, S.; Yasuno, M.

    1987-12-01

    Chronic effects of Cd on the growth and reproduction of the guppy (Poecilia reticulata) were studied using a food chain model, midge larvae as prey and guppy as predator. The transfer rate of Cd from the midge to the guppy was between 0.5 and 1% during the 30-day experiment. Growth rate of the guppy fed Cd-accumulated midge larvae (270 micrograms/g dry wt) for 30 days was not impaired. Cumulative numbers of fry produced by the guppy fed Cd-accumulated midge larvae (210 micrograms/g) for 2 months decreased to ca. 80% of the control. Guppies had been fed the Cd-accumulated midges from 30 days old for 7 months. Cumulative numbers of fry produced by the guppy fed midge larvae-accumulated 500, 800, and 1300 micrograms Cd/g for 6 months decreased to 79, 65, and 55% of the control, respectively. Similar effects of Cd on the reproduction of guppy were shown between the guppies fed the Cd-accumulated midge larvae (500 micrograms Cd/g) and exposed to 10 or 20 micrograms Cd/liter for the 6 months. The Cd concentrations of the digestive tract, liver, and kidney increased strongly, indicating that such Cd accumulation was brought on mainly through the Cd-accumulated midges. Mortality of the female guppies fed larvae-accumulated 1300 micrograms Cd/g increased abruptly from the 6 months of the experiment, whereas no male guppy died during the experiment.

  1. Effects of temperature and photoperiod on the development of overwintering immature Culicoides chiopterus and C. dewulfi.

    PubMed

    Lühken, Renke; Steinke, Sonja; Hoppe, Nikolai; Kiel, Ellen

    2015-11-30

    In areas with harsh winters, several studies have recorded low numbers - or even zero - adult Culicoides during the winter period followed by a population peak in the subsequent spring. This experimental study determined whether temperature, photoperiod, or the combination thereof affect the development of overwintering immature dung breeding Culicoides, resulting in this peak. Temperature had a significant impact on the development period of Culicoides chiopterus (Meigen), 1830 and C. dewulfi Goetghebuer, 1936. In treatments with constant high temperature, emergence occurred shortly after the beginning of the experiment (mean=day 9). In contrast, no individuals emerged from the other two treatments, as long as the temperatures were below 10°C. In these treatments, the emergence of Culicoides started when the temperature exceeded 20°C for some days (mean=day 33). There was no significant difference between the two photoperiods (February or April day length; 9 h:15 h [light:dark] vs. 13 h:11 h). Our results highlight the importance of temperature on the spring emergence of C. chiopterus and C. dewulfi, but the response to the four temperature-photoperiod treatments did not differ between the two species.

  2. Complete mitochondrial genome of the Antarctic midge Parochlus steinenii (Diptera: Chironomidae).

    PubMed

    Kim, Sanghee; Kim, Hanna; Shin, Seung Chul

    2016-09-01

    Parochlus steinenii is a winged midge found in the Antarctic Peninsula and its offshore islands. We determined the complete mitochondrial genome sequence of P. steinenii, which is comprised of 16 803 nucleotides and contains 13 protein-coding genes (PCGs), 22 tRNA genes, and the large (rrnL) and small (rrnS) rRNA genes. Its total A + T content is 72.5%. The PCG arrangement of P. steinenii is identical to that of the ancestral Diptera ground pattern. This is the first report on the mitogenome sequence of an Antarctic midge, and provides insights into the evolution of dipterans in Antarctica. PMID:26642812

  3. Complete mitochondrial genome of the Antarctic midge Parochlus steinenii (Diptera: Chironomidae).

    PubMed

    Kim, Sanghee; Kim, Hanna; Shin, Seung Chul

    2016-09-01

    Parochlus steinenii is a winged midge found in the Antarctic Peninsula and its offshore islands. We determined the complete mitochondrial genome sequence of P. steinenii, which is comprised of 16 803 nucleotides and contains 13 protein-coding genes (PCGs), 22 tRNA genes, and the large (rrnL) and small (rrnS) rRNA genes. Its total A + T content is 72.5%. The PCG arrangement of P. steinenii is identical to that of the ancestral Diptera ground pattern. This is the first report on the mitogenome sequence of an Antarctic midge, and provides insights into the evolution of dipterans in Antarctica.

  4. The North American gall midges (Diptera: Cecidomyiidae) of hackberries (Cannabaceae: Celtis spp.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twenty-three species of gall midges occur exclusively on hackberries in North America north of Mexico. Twenty-one of them belong to Celticecis and form complex, dehiscent galls on leaves and the current year’s twigs. Celticecis are definitely known only from the typical subgenus of Celtis that is di...

  5. Artocarpus (Moraceae)-gall midge pollination mutualism mediated by a male-flower parasitic fungus.

    PubMed

    Sakai, S; Kato, M; Nagamasu, H

    2000-03-01

    A previously undescribed pollination system involving a monoecious tree species, Artocarpus integer (Moraceae), pollinator gall midges, and fungi is reported from a mixed dipterocarp forest in Sarawak, Borneo. The fungus Choanephora sp. (Choanephoraceae, Mucorales, Zygomycetes) infects male inflorescences of A. integer, and gall midges (Contarinia spp., Cecidomyiinae, Diptera) feed on the fungal mycelia and oviposit on the inflorescence. Their larvae also feed on the mycelia and pupate in the inflorescence. The gall midges are also attracted by female inflorescences lacking mycelia, probably due to a floral fragrance similar to that of male inflorescences. Because of the sticky pollen, dominance of Contarinia spp. in flower visitors, and pollen load observed on Contarinia spp. collected on both male and female inflorescences, Artocarpus integer is thought to be pollinated by the gall midges. Although several pathogenic fungi have been reported to have interactions with pollinators, this is the first report on a pollination mutualism in which a fungus plays an indispensable role. The pollination system described here suggests that we should be more aware of the roles fungi can play in pollinations.

  6. Massive shift in gene expression during transitions between developmental stages of the Gall Midge, Mayetiola destructor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The gall midge Mayetiola destructor is a destructive pest of wheat worldwide and a model organism for studying plant – insect interactions. The insect has six different developmental stages including eggs, three instars of larvae, pupae, and adults. Molecular mechanisms controlling the transition ...

  7. Analysis of SSH library of rice variety Aganni reveals candidate gall midge resistance genes.

    PubMed

    Divya, Dhanasekar; Singh, Y Tunginba; Nair, Suresh; Bentur, J S

    2016-03-01

    The Asian rice gall midge, Orseolia oryzae, is a serious insect pest causing extensive yield loss. Interaction between the gall midge and rice genotypes is known to be on a gene-for-gene basis. Here, we report molecular basis of HR- (hypersensitive reaction-negative) type of resistance in Aganni (an indica rice variety possessing gall midge resistance gene Gm8) through the construction and analysis of a suppressive subtraction hybridization (SSH) cDNA library. In all, 2,800 positive clones were sequenced and analyzed. The high-quality ESTs were assembled into 448 non-redundant gene sequences. Homology search with the NCBI databases, using BlastX and BlastN, revealed that 73% of the clones showed homology to genes with known function and majority of ESTs belonged to the gene ontology category 'biological process'. Validation of 27 putative candidate gall midge resistance genes through real-time PCR, following gall midge infestation, in contrasting parents and their derived pre-NILs (near isogenic lines) revealed induction of specific genes related to defense and metabolism. Interestingly, four genes, belonging to families of leucine-rich repeat (LRR), heat shock protein (HSP), pathogenesis related protein (PR), and NAC domain-containing protein, implicated in conferring HR+ type of resistance, were found to be up-regulated in Aganni. Two of the reactive oxygen intermediates (ROI)-scavenging-enzyme-coding genes Cytosolic Ascorbate Peroxidase1, 2 (OsAPx1 and OsAPx2) were found up-regulated in Aganni in incompatible interaction possibly suppressing HR. We suggest that Aganni has a deviant form of inducible, salicylic acid (SA)-mediated resistance but without HR. PMID:26801786

  8. Analysis of SSH library of rice variety Aganni reveals candidate gall midge resistance genes.

    PubMed

    Divya, Dhanasekar; Singh, Y Tunginba; Nair, Suresh; Bentur, J S

    2016-03-01

    The Asian rice gall midge, Orseolia oryzae, is a serious insect pest causing extensive yield loss. Interaction between the gall midge and rice genotypes is known to be on a gene-for-gene basis. Here, we report molecular basis of HR- (hypersensitive reaction-negative) type of resistance in Aganni (an indica rice variety possessing gall midge resistance gene Gm8) through the construction and analysis of a suppressive subtraction hybridization (SSH) cDNA library. In all, 2,800 positive clones were sequenced and analyzed. The high-quality ESTs were assembled into 448 non-redundant gene sequences. Homology search with the NCBI databases, using BlastX and BlastN, revealed that 73% of the clones showed homology to genes with known function and majority of ESTs belonged to the gene ontology category 'biological process'. Validation of 27 putative candidate gall midge resistance genes through real-time PCR, following gall midge infestation, in contrasting parents and their derived pre-NILs (near isogenic lines) revealed induction of specific genes related to defense and metabolism. Interestingly, four genes, belonging to families of leucine-rich repeat (LRR), heat shock protein (HSP), pathogenesis related protein (PR), and NAC domain-containing protein, implicated in conferring HR+ type of resistance, were found to be up-regulated in Aganni. Two of the reactive oxygen intermediates (ROI)-scavenging-enzyme-coding genes Cytosolic Ascorbate Peroxidase1, 2 (OsAPx1 and OsAPx2) were found up-regulated in Aganni in incompatible interaction possibly suppressing HR. We suggest that Aganni has a deviant form of inducible, salicylic acid (SA)-mediated resistance but without HR.

  9. Is the morphology of Culicoides intersexes parasitized by mermithid nematodes a parasite adaptation? A morphometric approach to Culicoides circumscriptus (Diptera: Ceratopogonidae).

    PubMed

    Muñoz-Muñoz, Francesc; Ramoneda, Josep; Pagès, Nonito; Pujol, Nuria; Talavera, Sandra

    2016-03-01

    Mermithidae is a family of endoparasitic nematodes known to cause intersexuality in arthropods. Intersexes of the genus Culicoides parasitized by mermithids have been the object of several studies aiming to describe their particular morphology. Culicoides intersexes are specimens with male genitalia and feminized sexually dimorphic structures, i.e. antennae, mouthparts and wings. To date, these specimens have only been described qualitatively and a quantitative approach supported by statistical analysis is lacking. Here we conduct morphometric analyses of sexually dimorphic structures in a sample of Culicoides circumscriptus that includes 34 intersexes with the aim of describing precisely the intersexual morphology. The morphology of antennae and the mouthparts was studied by multivariate statistical analysis of linear measures, and wing form by implementing geometric morphometrics techniques. While intersex wings proved to have a similar size to male wings, their shape was intermediate between males and females. However, when allometric shape variation was removed, the wing shape of intersexes was almost identical to that of females. The intersex antennae were morphometrically of the female type, especially when size variation was considered. In contrast, the measured mouthparts (the labrum and the third palpal segment) were halfway between males and females, even when body size was considered. Overall, the antennae and the wings showed a higher degree of feminization than the mouthparts. These findings indicate that the degree of feminization depends both on the morphological structure and on body size. Moreover, we propose that the feminization of the wings and antennae has an adaptive meaning for the parasite, which would favor female-like traits in order to access more easily its breeding sites, where the parasite has plenty of new hosts to infect. Female-like antennae would be beneficial to detect these sites, while having female-like wings would favor the

  10. [Studies on the massive flights of chironomid midges (Diptera: Chironomidae) as nuisance insects and plans for their control in the Lake Suwa area, central Japan. 2. Quantitative evaluations of the nuisance of chironomid midges].

    PubMed

    Hirabayashi, K

    1991-06-01

    In order to make clear the present "nuisance" caused by chironomid midges around a eutrophic lake, a questionnaire survey of 249 leaders of the Hygiene Self-governing Association of the cities of Suwa and Okaya and the town of Shimosuwa near Lake Suwa was conducted. The results are as follows: 1. More than 90% of the respondents had specific knowledge about the chironomid midge, but 40% of them didn't know about its role as a purifier in the lake. 2. More than 10% of respondents answered that they were "can not able to stand any more" massive flights of chironomid midges, and about half of them lived within 500 m of the lake shore. The damages "nuisances" were "running laundry or defacing walls (67.1%) and "contamination of food (15.3%)", suggesting that chironomid midges influenced the daily life of the residents. 3. The selected causes of massive flights of chironomid midges were "pollution in Lake Suwa" and "decreases in the numbers of birds and dragonflies" as well as others. This means that the deterioration of the environmental situation around the lake may cause the "nuisance" of chironomid midges. 4. The respondents were more strongly interested in counterplans for the control of the chironomid midges made by administrative authorities than in plans made by each family. 5. "The distance from the lake shore" was the major factor contributing to the impression of chironomid damage. "The occupation of the respondent" was the second important factor. To redirect the insect flights away from the residential area, and to decrease the number of adult midges coming from the lake, are thought to be the most important measures for the resolution of this problem. PMID:1890774

  11. [Two filariae of the genus Eufilaria in Turdus merula; development in Culicoides nubeculosus (author's transl)].

    PubMed

    Bain, O

    1980-01-01

    Turdus merula from Nevers (France) is infected by two species of microfilariae which both evolve in eight days (26 degrees C) in Culicoides nubeculosus. We determine as Eufilaria delicata Supperer, 1958, the females with the longest microfilariae, the male with slightly unequal spicules and the largest infective larvae. We consider the species with the shorter microfilariae, males with more markedly unequal spicules and a relatively short infective larva as E. bartlettae n. sp. The female of this species is unknown. The identification of the infective larvae is provisional since it is based on the relative frequency of the two species. The infective larvae of Onchocercidae in birds which have been described as developing in Culicoides and simuliids (genera Splendidofilaria, Chandlerella and Eufilaria) and morphological similar but the caudal extremities of the first and third stages differ between the genera.

  12. Modelling spatio-temporal patterns of long-distance Culicoides dispersal into northern Australia.

    PubMed

    Eagles, D; Walker, P J; Zalucki, M P; Durr, P A

    2013-07-01

    Novel arboviruses, including new serotypes of bluetongue virus, are isolated intermittently from cattle and insects in northern Australia. These viruses are thought to be introduced via windborne dispersal of Culicoides from neighbouring land masses to the north. We used the HYSPLIT particle dispersal model to simulate the spatio-temporal patterns of Culicoides dispersal into northern Australia from nine putative source sites across Indonesia, Timor-Leste and Papua New Guinea. Simulated dispersal was found to be possible from each site, with the islands of Timor and Sumba highlighted as the likely principal sources and February the predominant month of dispersal. The results of this study define the likely spatial extent of the source and arrival regions, the relative frequency of dispersal from the putative sources and the temporal nature of seasonal winds from source sites into arrival regions. Importantly, the methodology and results may be applicable to other insect and pathogen incursions into northern Australia.

  13. Evaluation of a eucalyptus-based repellent against Culicoides impunctatus (Diptera:Ceratopogonidae) in Scotland.

    PubMed

    Trigg, J K

    1996-06-01

    A eucalyptus-based insect repellent (PMD) was evaluated against Culicoides impunctatus in Scotland in comparison with deet. In human landing catches, both repellents still afforded 98% protection from biting 8 h after application of 0.5 ml to the forearm. A second trial looking at protection between 8 and 10 h after repellent application showed 99.5% protection for PMD and 97% for deet as compared with controls. PMID:8827615

  14. Isolation of Tibet orbivirus, TIBOV, from Culicoides Collected in Yunnan, China

    PubMed Central

    Feng, Yun; Nie, Kai; Song, Jingdong; Li, Yang; Ma, Xuejun; Liang, Guodong; Zhou, Hongning

    2015-01-01

    We isolated a novel virus strain (YN12246) from Culicoides spp. specimens collected at the China-Laos-Myanmar border in southern Yunnan Province. This virus had a cytopathic effect (CPE) on both insect cells (C6/36) and mammalian cells (BHK-21). Electron microscopy revealed the structure of the virions to be spherical with a diameter of 75 nm. Polyacrylamide gel analysis demonstrated that the viral genome consisted of 10 segments of double-stranded RNA (dsRNA), with a distribution pattern of 3-3-3-1. The coding sequences of 9 genome segments of YN12246 (Seg1, Seg3-Seg10) were obtained by high-throughput sequencing and Sanger sequencing. Comparisons of conserved genome segments 1 and 3 (Seg1 and Seg3), encoding the polymerase-VP1 and sub-core T2 protein, respectively, showed that YN12246 groups with the Culicoides-borne orbiviruses. The highest levels of sequence identity were detected between YN12246 and Tibet orbivirus (TIBOV), indicating that they belong to the same virus species (with amino acid identity of 98.8% and 96.4% for the polymerase and T2 protein, respectively). The data presented here confirm that YN12246 is a member of the TIBOV species, which was first isolated from mosquitoes in 2009. This is the first report of the isolation of TIBOV from Culicoides. PMID:26295700

  15. Host and Potential Vector Susceptibility to an Emerging Orbivirus in the United States: Epizootic Hemorrhagic Disease Virus Serotype 6.

    PubMed

    Ruder, M G; Stallknecht, D E; Allison, A B; Mead, D G; Carter, D L; Howerth, E W

    2016-05-01

    Epizootic hemorrhagic disease viruses (EHDVs) are orbiviruses transmitted by Culicoides biting midges to domestic and wild ruminants. EHDV-1 and EHDV-2 are endemic in the United States, where epizootic hemorrhagic disease is the most significant viral disease of white-tailed deer (WTD;Odocoileus virginianus) and reports of epizootic hemorrhagic disease in cattle are increasing. In 2006, a reassortant EHDV-6 was isolated from dead WTD in Indiana and has been detected each subsequent year over a wide geographic region. Since EHDV-6 is not a historically endemic serotype in the United States, it is important to understand infection outcome in potential hosts. Specifically, we aimed to evaluate the pathogenicity of the virus in 2 primary US ruminant hosts (WTD and cattle) and the susceptibility of a confirmed US vector (Culicoides sonorensis). Five WTD and 4 cattle were inoculated with >10(6)TCID50EHDV-6 by intradermal and subcutaneous injection. All 5 WTD exhibited moderate to severe disease, and 3 died. Viremia was first detected 3 to 5 days postinfection (dpi) with surviving animals seroconverting by 10 dpi. Two of 4 inoculated cattle had detectable viremia, 5 to 10 dpi and 7 to 24 dpi, respectively. No clinical, hematologic, or pathologic abnormalities were observed. Antibodies were detected by 10 dpi in 3 of 4 cows.C. sonorensis were fed on WTD blood spiked with EHDV-6 and held for 4 to 14 days postfeeding at 25°C. From 4 to 14 days postfeeding, 19 of 171 midges were virus isolation positive and 6 of 171 had ≥10(2.7)TCID50EHDV-6. Although outcomes varied, these studies demonstrate the susceptibility of ruminant and vector hosts in the United States for this recently emerged EHDV serotype. PMID:26459518

  16. Modelling the Abundances of Two Major Culicoides (Diptera: Ceratopogonidae) Species in the Niayes Area of Senegal

    PubMed Central

    Diarra, Maryam; Fall, Moussa; Lancelot, Renaud; Diop, Aliou; Fall, Assane G.; Dicko, Ahmadou; Seck, Momar Talla; Garros, Claire; Allène, Xavier; Rakotoarivony, Ignace; Bakhoum, Mame Thierno; Bouyer, Jérémy; Guis, Hélène

    2015-01-01

    In Senegal, considerable mortality in the equine population and hence major economic losses were caused by the African horse sickness (AHS) epizootic in 2007. Culicoides oxystoma and Culicoides imicola, known or suspected of being vectors of bluetongue and AHS viruses are two predominant species in the vicinity of horses and are present all year-round in Niayes area, Senegal. The aim of this study was to better understand the environmental and climatic drivers of the dynamics of these two species. Culicoides collections were obtained using OVI (Onderstepoort Veterinary Institute) light traps at each of the 5 sites for three nights of consecutive collection per month over one year. Cross Correlation Map analysis was performed to determine the time-lags for which environmental variables and abundance data were the most correlated. C. oxystoma and C. imicola count data were highly variable and overdispersed. Despite modelling large Culicoides counts (over 220,000 Culicoides captured in 354 night-traps), using on-site climate measures, overdispersion persisted in Poisson, negative binomial, Poisson regression mixed-effect with random effect at the site of capture models. The only model able to take into account overdispersion was the Poisson regression mixed-effect model with nested random effects at the site and date of capture levels. According to this model, meteorological variables that contribute to explaining the dynamics of C. oxystoma and C. imicola abundances were: mean temperature and relative humidity of the capture day, mean humidity between 21 and 19 days prior a capture event, density of ruminants, percentage cover of water bodies within a 2 km radius and interaction between temperature and humidity for C. oxystoma; mean rainfall and NDVI of the capture day and percentage cover of water bodies for C. imicola. Other variables such as soil moisture, wind speed, degree days, land cover or landscape metrics could be tested to improve the models. Further work

  17. Compact genome of the Antarctic midge is likely an adaptation to an extreme environment

    PubMed Central

    Kelley, Joanna L.; Peyton, Justin T.; Fiston-Lavier, Anna-Sophie; Teets, Nicholas M.; Yee, Muh-Ching; Johnston, J. Spencer; Bustamante, Carlos D.; Lee, Richard E.; Denlinger, David L.

    2014-01-01

    The midge, Belgica antarctica, is the only insect endemic to Antarctica, and thus it offers a powerful model for probing responses to extreme temperatures, freeze tolerance, dehydration, osmotic stress, ultraviolet radiation and other forms of environmental stress. Here we present the first genome assembly of an extremophile, the first dipteran in the family Chironomidae, and the first Antarctic eukaryote to be sequenced. At 99 megabases, B. antarctica has the smallest insect genome sequenced thus far. Although it has a similar number of genes as other Diptera, the midge genome has very low repeat density and a reduction in intron length. Environmental extremes appear to constrain genome architecture, not gene content. The few transposable elements present are mainly ancient, inactive retroelements. An abundance of genes associated with development, regulation of metabolism and responses to external stimuli may reflect adaptations for surviving in this harsh environment. PMID:25118180

  18. Edaphic environment, gall midges, and goldenrod clonal expansion in a mid-successional old-field

    NASA Astrophysics Data System (ADS)

    Wise, Michael J.; Abrahamson, Warren G.; Landis, Kelly

    2006-11-01

    During the middle stage of old-field succession, genets of clonal plants vie to take over space from annual and short-lived perennial plants. We studied factors that may influence the relative rates of expansion of Solidago altissima genets in an old-field population attacked by the gall midge Rhopalomyia solidaginis. Genets growing in more clayey soil expanded more slowly, as evidenced by differences in rhizome growth. Edaphic conditions also affected galling frequencies, with genets in more sandy soil having twice as many galls. Gall midges reduced goldenrod stem growth, and stem height was positively correlated with rhizome growth. For a given stem height, galled ramets allocated relatively more biomass to rhizome growth than ungalled ramets. The end result was that galled ramets produced the same number and sizes of rhizomes as ungalled ramets.

  19. A fossil biting midge (Diptera: Ceratopogonidae) from early Eocene Indian amber with a complex pheromone evaporator

    PubMed Central

    Stebner, Frauke; Szadziewski, Ryszard; Rühr, Peter T.; Singh, Hukam; Hammel, Jörg U.; Kvifte, Gunnar Mikalsen; Rust, Jes

    2016-01-01

    The life-like fidelity of organisms captured in amber is unique among all kinds of fossilization and represents an invaluable source for different fields of palaeontological and biological research. One of the most challenging aspects in amber research is the study of traits related to behaviour. Here, indirect evidence for pheromone-mediated mating behaviour is recorded from a biting midge (Ceratopogonidae) in 54 million-year-old Indian amber. Camptopterohelea odora n. sp. exhibits a complex, pocket shaped structure on the wings, which resembles the wing folds of certain moth flies (Diptera: Psychodidae) and scent organs that are only known from butterflies and moths (Lepidoptera) so far. Our studies suggests that pheromone releasing structures on the wings have evolved independently in biting midges and might be much more widespread in fossil as well as modern insects than known so far. PMID:27698490

  20. New records and new species of gall midges (Diptera: Cecidomyiidae) developing on Chenopodiaceae in Egypt.

    PubMed

    Elsayed, Ayman Khamis; Skuhravá, Marcela; Karam, Hedaya Hamza; Elminshawy, Abdelaziz; Al-Eryan, Mohamed Awad

    2015-01-05

    The Cecidomyiidae (Diptera: Bibionomorpha) fauna of Egypt is poorly known. Investigations in northern Egypt in 2013 revealed the presence of seven species of gall midges on three host plant species: Atriplex halimus L., Arthrocnemum macrostachyum (Moric.) and Suaeda pruniosa Lange (all Chenopodiaceae). Among the gall midges, Baldratia salicorniae  Kieffer and Stefaniella trinacriae De Stefani are reconfirmed records in Egypt; Houardiella gracilis Dorchin & Freidberg and Asphondylia punica Marchal are new records; and Baldratia karamae Elsayed & Skuhraván. sp. , Primofavilla aegyptiaca Elsayed n. sp. and Stefaniella skuhravae Elsayed n. sp. are new to science. Adult morphology of the latter three new species is described and illustrated, and their biology and geographic distribution are given. 

  1. Evidence incriminating midges (Diptera: Ceratopogonidae) as potential vectors of Leishmania in Australia.

    PubMed

    Dougall, Annette M; Alexander, Bruce; Holt, Deborah C; Harris, Tegan; Sultan, Amal H; Bates, Paul A; Rose, Karrie; Walton, Shelley F

    2011-04-01

    The first autochthonous Leishmania infection in Australia was reported by Rose et al. (2004) and the parasite was characterised as a unique species. The host was the red kangaroo (Macropus rufus) but the transmitting vector was unknown. To incriminate the biological vector, insect trapping by a variety of methods was undertaken at two field sites of known Leishmania transmission. Collected sand flies were identified to species level and were screened for Leishmania DNA using a semi-quantitative real-time PCR. Collections revealed four species of sand fly, with a predominance of the reptile biter Sergentomyia queenslandi (Hill). However, no Leishmania-positive flies were detected. Therefore, alternative vectors were investigated for infection, giving startling results. Screening revealed that an undescribed species of day-feeding midge, subgenus Forcipomyia (Lasiohelea) Kieffer, had a prevalence of up to 15% for Leishmania DNA, with high parasitemia in some individuals. Manual gut dissections confirmed the presence of promastigotes and in some midges material similar to promastigote secretory gel, including parasites with metacyclic-like morphology. Parasites were cultured from infected midges and sequence analysis of the Leishmania RNA polymerase subunit II gene confirmed infections were identical to the original isolated Leishmania sp. Phylogenetic analysis revealed the closest known species to be Leishmania enriettii, with this and the Australian species confirmed as members of Leishmania sensu stricto. Collectively the results strongly suggest that the day-feeding midge (F. (Lasiohelea) sp. 1) is a potential biological vector of Leishmania in northern Australia, which is to our knowledge the first evidence of a vector other than a phlebotomine sand fly anywhere in the world. These findings have considerable implications in the understanding of the Leishmania life cycle worldwide.

  2. Characterization of volatiles of necrotic Stenocereus thurberi and Opuntia littoralis and toxicity and olfactory preference of Drosophila melanogster, D. mojavensis wrigleyi, and D. mojavensis sonorensis to necrotic cactus volatiles.

    PubMed

    Wright, Cynthia R; Setzer, William N

    2014-08-01

    Drosophila mojavensis wrigleyi and D. mojavensis sonorensis are geographically separated races of cactophilic fruit flies. D. mojavensis sonorensis inhabits the Sonoran Desert and utilizes necrotic rots of Stenocereus thurberi Engelm. as a food source and to oviposit while D. mojavensis wrigleyi inhabits Santa Catalina Island, California and utilizes the necrotic rots of Opuntia littoralis (Engelm.) Cockerell. The objectives of this study were to determine the volatile compositions of the necrotic cacti and to determine if the volatile components show either selective toxicity or attraction toward the fruit flies. The volatile chemical compositions of field-rot specimens of both necrotic cacti were obtained by dynamic headspace (purge-and-trap) and hydrodistillation techniques and analyzed by gas chromatography - mass spectrometry. The volatile fraction of necrotic S. thurberi early rot was dominated by carboxylic acids (84.8%) and the late rot by p-cresol (32.6% in the dynamic headspace sample and 55.9% in the hydrodistilled sample). O. littoralis volatiles were dominated by carboxylic acids (86% in the dynamic headspace sample and 89.1% in the hydrodistilled sample). Fifteen compounds that were identified in the necrotic rot volatiles were used to test insecticidal activity and olfactory preference on the cactophilic Drosophila species, as well as D. melanogaster. Differences in toxicity and olfactory preference were observed between the different taxa. Both races of D. mojavensis exhibited toxicity to benzaldehyde and 2-nonanone, while butanoic acid and palmitic acid were tolerated at high concentrations. D. m. wrigleyi demonstrated a greater olfactory preference for anisole, butanoic acid, 2-heptanone, and palmitic acid than did D. m. sonorensis, while D. m. sonorensis demonstrated a greater preference for hexadecane, octanoic acid, and oleic acid than did D. m. wrigleyi.

  3. [Construction of PPENK-MIDGE-NLS gene vector and the expression in rat].

    PubMed

    Chen, Xi; Xu, Xuemin; Peng, Xijuan; Jiang, Wei; Yao, Linong

    2015-02-01

    Increasing the production and secretion of endogenous opioid peptide by immune cell can significantly induce myocardial protective effects against ischemia-reperfusion injury. Gene therapy is promising to increase endogenous enkephalin (ENK). However, classical viral and plasmid vectors for gene delivery are hampered by immunogenicity, gene recombination, oncogene activation, the production of antibacterial antibody and changes in physiological gene expression. Minimalistic immunologically defined gene expression (MIDGE) can overcome all the deficients of viral and plasmid vectors. The exon of rat's preproenkephalin (PPENK) gene was amplified by PCR and the fragments were cloned into pEGFP-N1 plasmids. The recombined plasmids were digested with enzymes to obtain a linear vector contained promoter, preproenkephalin gene, RNA stable sequences and oligodesoxy nucleotides (ODNs) added to both ends of the gene vector to protect gene vector from exonuclease degradation. A nuclear localization sequence (NLS) was attached to an ODN to ensure the effective transport to the nucleus and transgene expression. Flow cytometry, laser confocal microscopy and Western blotting demonstrated that PPENK-MIDGE-NLS can transfect leukocyte of rat in vivo, increase the expression of proenkephalin (PENK) in tissue, and the transfection efficiency depends on gene vector's dosage. These results indicate that PPENK-MIDGE-NLS could be an innovative method to protect and treatment of myocardial ischemia-reperfusion injury.

  4. Does gall midge larvae cause pre-dispersal seed mortality and limit cornflower population growth?

    NASA Astrophysics Data System (ADS)

    Koprdova, Stanislava; Bellanger, Solène; Skuhrovec, Jiří; Darmency, Henri

    2015-11-01

    Many kinds of pests can reduce seed production. Some directly attack seeds before they are released, and some are hosted by the fruit and impact seed ripening and viability indirectly. Pre-dispersal seed mortality may have strong effects on plant population dynamics and evolution. Our goals were to determine to what extent insect-mediated pre-dispersal seed mortality contributes to population-level declines of cornflower, Centaurea cyanus L. We recorded occurrence and abundance of seed-feeding insects on flower heads in twelve cornflower populations. We measured flower head size, number of disc florets, seed production, and seed viability and germination. Larger flower heads had proportionally fewer healthy seeds. Although we observed no visible damage to the C. cyanus seed, the presence of gall midge (Cecidomyiidae) larvae inside the flower head correlated with four times fewer viable seeds. It seems that gall midges could have a significant impact on ovule fertilization, seed abortion and viability of fully developed cornflower seeds. The higher rate of aborted seeds in the presence of gall midge larvae could have been because the larvae extracted resources from the seeds, or because the larvae repelled pollinators. The viability of apparently healthy seeds was 40% lower in flower heads that contained larvae and/or aborted seed. Insect-mediated pre-dispersal mortality could select against evolution toward larger flower head, and have detrimental consequences on seed number, viability and germination, all of which could limit the spread of C. cyanus populations.

  5. Comparison of Vertebrate Cytochrome b and Prepronociceptin for Blood Meal Analyses in Culicoides

    PubMed Central

    Hadj-Henni, Leila; De Meulemeester, Thibaut; Depaquit, Jérôme; Noël, Philippe; Germain, Adeline; Helder, Remi; Augot, Denis

    2015-01-01

    To date, studies on host preferences and blood meal identification have been conducted for Culicoides species using molecular-based methods such as PCR techniques to amplify only a fragment from universal vertebrate mitochondrial genes such as cytochrome c oxidase subunit I or cytochrome b (Cyt b). The vertebrate prepronociceptin gene (PNOC) was also tested in this field. However, the choice of molecular marker to identify blood meal is critical. The objective of our study is to compare the ability of Cyt b and PNOC as molecular markers for blood meal identification depending on the stage of blood meal digestion. In order to determine whether these Cyt b and PNOC could provide a positive result, 565 blood-fed females of Culicoides spp were collected and morphologically identified. The samples were collected between 2012 and 2014, in two localities in France. The collection localities were near either livestock or a forest. To catch the specimens, we used UV CDC miniature light traps. PNOC sequence of donkeys (Equus asinus) was sequenced and submitted because it was missing in GenBank. Our findings emphasize that the PNOC marker is not suitable to separate closely related Equid species such as horses and donkeys. The Cyt b marker was able to identify 204 more samples when compared to PNOC (99.55% of specimens). Cyt b appears to be better able to detect the origin of blood meals from females with digested blood in their abdomens. We conclude that Cyt b is a good marker as it increases the accuracy of blood meal identification of engorged females containing digested blood in their abdomens. The host opportunist behavior of Culicoides, especially that of C. obsoletus and C. scoticus, the main vectors of BTV in Europe was also highlighted. PMID:26664944

  6. Comparison of Vertebrate Cytochrome b and Prepronociceptin for Blood Meal Analyses in Culicoides.

    PubMed

    Hadj-Henni, Leila; De Meulemeester, Thibaut; Depaquit, Jérôme; Noël, Philippe; Germain, Adeline; Helder, Remi; Augot, Denis

    2015-01-01

    To date, studies on host preferences and blood meal identification have been conducted for Culicoides species using molecular-based methods such as PCR techniques to amplify only a fragment from universal vertebrate mitochondrial genes such as cytochrome c oxidase subunit I or cytochrome b (Cyt b). The vertebrate prepronociceptin gene (PNOC) was also tested in this field. However, the choice of molecular marker to identify blood meal is critical. The objective of our study is to compare the ability of Cyt b and PNOC as molecular markers for blood meal identification depending on the stage of blood meal digestion. In order to determine whether these Cyt b and PNOC could provide a positive result, 565 blood-fed females of Culicoides spp were collected and morphologically identified. The samples were collected between 2012 and 2014, in two localities in France. The collection localities were near either livestock or a forest. To catch the specimens, we used UV CDC miniature light traps. PNOC sequence of donkeys (Equus asinus) was sequenced and submitted because it was missing in GenBank. Our findings emphasize that the PNOC marker is not suitable to separate closely related Equid species such as horses and donkeys. The Cyt b marker was able to identify 204 more samples when compared to PNOC (99.55% of specimens). Cyt b appears to be better able to detect the origin of blood meals from females with digested blood in their abdomens. We conclude that Cyt b is a good marker as it increases the accuracy of blood meal identification of engorged females containing digested blood in their abdomens. The host opportunist behavior of Culicoides, especially that of C. obsoletus and C. scoticus, the main vectors of BTV in Europe was also highlighted. PMID:26664944

  7. Culicoides, the vector of epizootic hemorrhagic disease in white-tailed deer in Kentucky in 1971.

    PubMed

    Jones, R H; Roughton, R D; Foster, N M; Bando, B M

    1977-01-01

    The biting gnat, Culicoides variipennis (Coquillett), was shown to be a vector of epizootic hemorrhagic disease (EHD) in white-tailed deer, Odocoileus virginianus, in Kentucky because of virus isolations from parous females. Epidemiological evidence showed a close relationship of this vector to the animal host during an outbreak of EHD in penned deer. Larval breeding sites of C. variipennis were found and C. variipennis was the most abundant biting fly present during the outbreak. Females of C. variipennis were commonly observed biting deer, swine, cattle and, occasionally, man.

  8. Biology and efficacy of Aprostocetus (Eulophidae: hymenoptera) as a parasitoid of the blueberry gall midge complex: Dasineura oxycoccana Johnson and Prodiplosis vaccinii (Felt) (Diptera: cecidomyiidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the southeastern US, bud-infesting larvae of two gall midge species, Dasineura oxycoccana (Johnson) and Prodiplosis vaccinii (Felt), destroy from 20% to 80% of the rabbiteye blueberry crop, Vaccinium virgatum Aiton. Fortunately, these midge larvae fall prey to five species of endoparasitic wasps....

  9. Bioconcentration of 5,5',6-trichlorobiphenyl and pentachlorophenol in the midge, Chironomus riparius, as measured by a pharmacokinetic model

    USGS Publications Warehouse

    Lydy, M.J.; Hayton, W.L.; Staubus, A.E.; Fisher, S.W.

    1994-01-01

    A two compartment pharmacokinetic model was developed which describes the uptake and elimination of 5,5',6-trichlorobiphenyl (TCB) and pentachlorophenol (PCP) in the midge, Chironomus riparius. C. riparius were exposed to nominal TCB (2 ??g L-1) and PCP (9 ??g L-1) concentrations during a 16 h static uptake phase. Depuration was determined over approximately 45 h using a flowthrough system without feeding. The uptake clearance (P) was 330 ?? 61 ml g-1 midge h-1 for TCB and 55 ?? 4 ml g-1 midge h-1 for PCP, while measured bioconcentration factors (BCF) were 35,900 and 458 for TCB and PCP, respectively. Overall, the clearance-volume- based pharmacokinetic model predicted BCF values that were consistent with published values as well as with BCF values obtained from the octanol-water partition coefficient (K(ow)).

  10. A redescription of Culicoides griseidorsum Kieffer, 1918, with comments on subgeneric position of some European taxa (Diptera: Ceratopogonidae).

    PubMed

    Szadziewski, Ryszard; Filatov, Serhii; Dominiak, Patrycja

    2016-01-01

    Culicoides griseidorsum Kieffer, 1918 is formally redescribed, and the male described and illustrated for the first time. The species is placed within Sensiculicoides Shevchenko, 1977 the subgenus restored from the synonymy with Oecacta Poey, 1853. A checklist of European species placed in subgenera Sensiculicoides and Oecacta is provided. PMID:27394830

  11. Critical body residues for lethal and sublethal effects of membrane narcotics in the midge, Chironomus riparius

    SciTech Connect

    Fisher, S.W.; Hwang, H.; Landrum, P.F.

    1995-12-31

    The concept of the critical body residue (CBR) offers a compelling new way to evaluate hazard posed by persistent contaminants such as PCBs. The authors tested the utility of using CBRs for PCBs in an invertebrate species, Chironomus riparius. Acute toxicity (< 10 d) tests were performed with 2nd instar larvae by adding trace amounts of {sup 14}C-labeled PCBs to unlabeled PCBs in amounts sufficient to generate a dose-responsive mortality curve. Because of the limited water solubility of the PCBs tested, it was not possible to produce a toxic tissue concentration via aqueous exposure. This difficulty was overcome by allowing the midges to feed upon contaminated algae (Chlorella vulgaris) which could be loaded with much higher levels of PCBs than would dissolve in water. CBRs for acute toxicity were measured for 3 PCBs; an average CBR of about 1 mmol/kg was determined. If the midge CBRs are lipid normalized, they fall into the range of values that have previously been determined for vertebrates. The authors also evaluated CBRs in midges for a variety of sublethal impairments including development time within a stadium, larval weight and fecundity. A CBR of 1.09 {micro}mol/kg resulted in a significant increase in larval development time and decrease in larval weight for second instar larvae. Tissue residues declined in the third and fourth instars, despite continuing exposure suggesting that the animals developed attenuating mechanisms or that contaminant loss at ecdysis is significant. Despite declining tissue residues throughout the larval instars, fecundity was reduced from 284 eggs/female in controls to 244 eggs/female in animals exposed to the highest sublethal concentration.

  12. Identification of female-produced sex pheromone of the honey locust gall midge, Dasineura gleditchiae.

    PubMed

    Molnár, Béla; Kárpáti, Zsolt; Szocs, Gábor; Hall, David R

    2009-06-01

    The honey locust gall midge, Dasineura gleditchiae Osten Sacken 1866 (Diptera: Cecidomyiidae) is the main pest of ornamental varieties of the honey locust tree, Gleditsia triacanthos L., in North America, and is now becoming a pest of concern in Europe. Female midges were observed to emerge in the early morning with their ovipositor extended until they mated. Volatiles were collected from virgin females in a closed-loop stripping apparatus and analyzed by gas chromatography (GC) coupled to electroantennographic (EAG) recording from the antenna of a male midge. A single EAG response was observed, which was assumed to be to the major component of the female sex pheromone. This was identified as (Z)-2-acetoxy-8-heptadecene by comparison of its mass spectrum and GC retention times on different columns with those of synthetic standards and by micro-analytical reactions. This compound was synthesized, and the individual enantiomers were produced by kinetic resolution with lipase from Candida antarctica. Analysis of the naturally-produced compound on a cyclodextrin GC column indicated it was the (R)-enantiomer. In EAG dose-response measurements, the (R)-enantiomer alone or in the racemic mixture evoked significant responses from the antennae of male D. gleditchiae, whereas the (S)-enantiomer did not. In field trapping tests, the (R)-enantiomer attracted male D. gleditchiae. The racemic compound was equally attractive, but the (S)-enantiomer was not attractive. Both the pure (R)-enantiomer or racemic (Z)-2-acetoxy-8-heptadecene, applied to red rubber septa in a dose range of 3-30 microg, constitute a strongly attractive bait in sticky traps for monitoring the flight of D. gleditchiae. PMID:19459010

  13. A novel mechanism of gall midge resistance in the rice variety Kavya revealed by microarray analysis.

    PubMed

    Rawat, Nidhi; Chiruvuri Naga, Neeraja; Raman Meenakshi, Sundaram; Nair, Suresh; Bentur, Jagadish S

    2012-06-01

    The Asian rice gall midge [Orseolia oryzae (Wood-Mason)] is an important rice pest causing an annual average yield loss of about US $80 million in India. Rice varieties possess several discrete resistance (R) genes conferring resistance against the pest in two distinct ways, i.e., with (HR+ type) or without (HR- type) the expression of hypersensitive reaction (HR). The aim of the present work is to understand the molecular basis of compatible and incompatible (HR- type) rice gall midge interactions between the rice variety Kavya and the two gall midge biotypes: the virulent GMB4M and the avirulent GMB1 using transcriptional microarray gene expression analysis. A large number of differentially expressed genes (602genes in incompatible interaction and 1,330 genes in compatible interaction with at least twofold changes, p value <0.05) was obtained from the microarray analysis that could be grouped into six clusters based on their induction during both or either of the interactions. MapMan software was used for functional characterization of these genes into 13 categories (BINs). Real-time polymerase chain reaction validation of 26 genes selected through the analysis revealed four genes viz. NADPH oxidase, AtrbohF, cinnamoyl-CoA reductase, and von Willebrand factor type A domain containing protein coding genes to be significantly upregulated during the incompatible interaction. But most of the signature genes related to HR+ type resistance like salicylic acid pathway-related genes and disease resistance protein coding genes were downregulated. On the other hand, during the compatible interaction, genes related to primary metabolism and nutrient transport were upregulated and genes for defense and signaling were downregulated. We propose a hypothesis that HR- type of resistance in the rice variety Kavya against gall midge could be due to the constitutive expression of an R gene and a case of extreme resistance which is devoid of cell death. Compatible interaction

  14. Acute toxicity of selected herbicides and surfactants to larvae of the midge Chironomus riparius

    USGS Publications Warehouse

    Buhl, Kevin J.; Faerber, Neil L.

    1989-01-01

    The acute toxicities of eight commercial herbicides and two surfactants to early fourth instar larvae of the midgeChironomus riparius were determined under static conditions. The formulated herbicides tested were Eradicane® (EPTC), Fargo® (triallate), Lasso® (alachlor), ME4 Brominal® (bromoxynil), Ramrod® (propachlor), Rodeo® (glyphosate), Sencor®(metribuzin), and Sutan (+)® (butylate); the two surfactants were Activator N.F.® and Ortho X-77®. In addition, technical grade alachlor, metribuzin, propachlor, and triallate were tested for comparison with the formulated herbicides. The relative toxicity of the commercial formulations, based on percent active ingredient, varied considerably. The EC50 values ranged from 1.23 mg/L for Fargo® to 5,600 mg/L for Rodeo®. Fargo®, ME4 Brominal®, and Ramrod®were moderately toxic to midge larvae; Lasso®, Sutan (+)®, and Eradicane® were slightly toxic; and Sencor® and Rodeo® were practically non-toxic. The 48-hr EC50 values of the two surfactants were nearly identical and were considered moderately toxic to midges. For two of the herbicides in which the technical grade material was tested, the inert ingredients in the formulations had a significant effect on the toxicity of the active ingredients. Fargo® was twice as toxic as technical grade triallate, whereas Sencor® was considerably less toxic than technical grade metribuzin. A comparison of the slope function values indicated that the toxic action of all the compounds occurred within a relatively narrow range. Published acute toxicity data on these compounds for other freshwater biota were tabulated and compared with our results. In general, the relative order of toxicity toC. riparius was similar to those for other freshwater invertebrates and fish. Maximum concentrations of each herbicide in bulk runoff during a projected “critical” runoff event were calculated as a percentage of the application rate lost in a given volume of runoff. A comparison

  15. Field test of a lemon eucalyptus repellent against Leptoconops biting midges.

    PubMed

    Carroll, Scott P; Loye, Jenella

    2006-09-01

    We tested a lemon eucalyptus-based repellent against the biting midge Leptoconops carteri Hoffman in the Central Valley of California. This relatively new active ingredient has demonstrated high efficacy in a number of studies with mosquitoes. Ten subjects tested spray and lotion formulations on 2 consecutive days, along with a deet-positive control and an untreated control, with 6 h of continuous exposure per treatment. Half of the eucalyptus subjects received no bites, and the true median protection time probably exceeded the test duration. PMID:17067050

  16. Field test of a lemon eucalyptus repellent against Leptoconops biting midges.

    PubMed

    Carroll, Scott P; Loye, Jenella

    2006-09-01

    We tested a lemon eucalyptus-based repellent against the biting midge Leptoconops carteri Hoffman in the Central Valley of California. This relatively new active ingredient has demonstrated high efficacy in a number of studies with mosquitoes. Ten subjects tested spray and lotion formulations on 2 consecutive days, along with a deet-positive control and an untreated control, with 6 h of continuous exposure per treatment. Half of the eucalyptus subjects received no bites, and the true median protection time probably exceeded the test duration.

  17. All stages of the Palaearctic predaceous midge Palpomyia schmidti Goetghebuer, 1934 (Diptera: Ceratopogonidae).

    PubMed

    Szadziewski, Ryszard; Golovatyuk, Larisa V; Sontag, Elżbieta; Urbanek, Aleksandra; Zinchenko, Tatiana D

    2016-01-01

    All stages and the ecology of the Southern Palaearctic Palpomyia schmidti collected from the vicinity of the saline Lake Elton in Russia are described and illustrated. The morphology of larvae and pupae as well as the detailed ecology of the larvae are described for the first time. P. schmidti is a halobiontic biting midge, widely distributed in the steppes and deserts of the Palaearctic region. It is proposed that the Palpomyia schmidti group should include five Holarctic species. P. downesi Grogan & Wirth, 1979 from north-western North America is recognized as a new junior synonym of the Eastern Palaearctic P. tuvae Remm, 1972. New synonymy. PMID:27395743

  18. Effects of pH on the toxicity and uptake of (14C)lindane in the midge, Chironomus riparius

    SciTech Connect

    Fisher, S.W.

    1985-10-01

    The toxicity of the insecticide, lindane, was measured in the midge, Chironomus riparius, at pH 4, 6, and 8 with the finding that lindane is significantly more toxic at pH 6 than at pH 4 and 8. The higher toxicity of lindane at pH 6 is a product of two factors. First the penetration of the compound into the midge is lower at pH 4 than at pH 6 and 8. Second, a greater percentage of total radioactivity is contributed by parent compound at pH 6.

  19. Integrative taxonomy to investigate species boundaries within Culicoides (Diptera: Ceratopogonidae): a case study using subgenus Avaritia from Australasia and Eastern Asia.

    PubMed

    Gopurenko, David; Bellis, Glenn Adam; Yanase, Tohru; Wardhana, April Hari; Thepparat, Arunrat; Wang, Jinglin; Cai, Ducheng; Mitchell, Andrew

    2015-01-01

    In this study, species boundaries were examined for 15 described and 2 undescribed species within the economically important Culicoides subg. Avaritia Fox from Australasia and Eastern Asia. We used an integrative taxonomic approach incorporating DNA barcoding, nuclear gene sequencing, and retrospective morphological analyses. Some arbovirus vector species such as Culicoides fulvus Sen and Das Gupta and Culicoides wadai Kitaoka were genetically and morphologically uniform across sampled distributions, but others including Culicoides actoni Smith and Culicoides brevipalpis Delfinado contained 2 or more genetically independent populations of 'cryptic species' that in some cases were sympatric. Some of these 'cryptic species' exhibited consistent morphological differences, while differences are yet to be found for others species. Additionally, an undescribed species, C. Avaritia sp. No. 3, was found to be synonymous with C. fulvus. These results refine our understanding of the distribution of individual species of C. subg. Avaritia and demonstrate that species descriptions and distribution records need revision for part of the Culicoides fauna. Furthermore, because vector competence studies for most of these species are based entirely on Australian populations, the competence of the putative cryptic species identified elsewhere will require independent assessment. Finally, integrative taxonomic assessment requires genetic and morphological assessment of material from the type localities in order to clarify the status and distribution of species, especially for clades containing cryptic species. International collaboration is needed to facilitate this research. PMID:26741249

  20. Bioavailability of sediment-sorbed chlorobenzenes to larvae of the midge, Chironomus decorus

    SciTech Connect

    Knezovich, J.P.; Harrison, F.L.

    1988-04-01

    Larval stages of the midge, Chironomus decorus, were used to define the bioaccumulation of sediment-sorbed mono-, di-, tri-, and hexachlorobenzene. Larvae were exposed to high- and low-organic-content sediments that had been equilibrated with individual radiolabeled chlorobenzenes prior to testing. Equilibrium or nonequilibrium aqueous concentrations of the volatile test chemicals were flowed through sealed chambers in a sediment-water exposure system. The uptake of chlorobenzenes by midge larvae was rapid for all compounds tested, and apparent steady-state conditions were reached within 48 hr of exposure. Bioconcentration factors for the accumulation of chlorobenzenes from sediments and from interstitial and overlying waters were related to the octanol/water partition coefficients of the compounds. Because the diffusion of chlorobenzenes to overlying water during nonequilibrium flow through conditions was very slow, bioaccumulation was dependent on the concentration of the chemicals in interstitial water. These results show how benthic organisms may be able to accumulate significant levels of chlorinated aromatic compounds from ecosystems where their concentrations in the water column are relatively low.

  1. Rampant host- and defensive phenotype-associated diversification in a goldenrod gall midge.

    PubMed

    Stireman, J O; Devlin, H; Abbot, P

    2012-10-01

    Natural selection can play an important role in the genetic divergence of populations and their subsequent speciation. Such adaptive diversification, or ecological speciation, might underlie the enormous diversity of plant-feeding insects that frequently experience strong selection pressures associated with host plant use as well as from natural enemies. This view is supported by increasing documentation of host-associated (genetic) differentiation in populations of plant-feeding insects using alternate hosts. Here, we examine evolutionary diversification in a single nominal taxon, the gall midge Asteromyia carbonifera (O.S.), with respect to host plant use and gall phenotype. Because galls can be viewed as extended defensive phenotypes of the midges, gall morphology is likely to be a reflection of selective pressures by enemies. Using phylogenetic and comparative analyses of mtDNA and nuclear sequence data, we find evidence that A. carbonifera populations are rapidly diversifying along host plant and gall morphological lines. At a broad scale, geography explains surprisingly little genetic variation, and there is little evidence of strict co-cladogenesis with their Solidago hosts. Gall morphology is relatively labile, distinct gall morphs have evolved repeatedly and colonized multiple hosts, and multiple genetically and morphologically distinct morphs frequently coexist on a single host plant species. These results suggest that Asteromyia carbonifera is in the midst of an adaptive radiation driven by multitrophic selective pressures. Similar complex community pressures are likely to play a role in the diversification of other herbivorous insect groups.

  2. Aquaporins in the antarctic midge, an extremophile that relies on dehydration for cold survival.

    PubMed

    Goto, Shin G; Lee, Richard E; Denlinger, David L

    2015-08-01

    The terrestrial midge Belgica antarctica relies extensively on dehydration to survive the low temperatures and desiccation stress that prevail in its Antarctic habitat. The loss of body water is thus a critical adaptive mechanism employed at the onset of winter to prevent injury from internal ice formation; a rapid mechanism for rehydration is equally essential when summer returns and the larva resumes the brief active phase of its life. This important role for water movement suggests a critical role for aquaporins (AQPs). Recent completion of the genome project on this species revealed the presence of AQPs in B. antarctica representing the DRIP, PRIP, BIB, RPIP, and LHIP families. Treatment with mercuric chloride to block AQPs also blocks water loss, thereby decreasing cell survival at low temperatures. Antibodies directed against mammalian or Drosophila AQPs suggest a wide tissue distribution of AQPs in the midge and changes in protein abundance in response to dehydration, rehydration, and freezing. Thus far, functional studies have been completed only for PRIP1. It appears to be a water-specific AQP, but expression levels are not altered by dehydration or rehydration. Functional assays remain to be completed for the additional AQPs. PMID:26338869

  3. Proteomic evaluation of cadmium toxicity on the midge Chironomus riparius Meigen larvae.

    PubMed

    Lee, Sung-Eun; Yoo, Dong-hun; Son, Jino; Cho, Kijong

    2006-02-01

    Heavy-metal pollution of aquatic ecosystems is a widespread phenomenon after industrial consumption. Whether aquatic organisms are adapted to the heavy-metal pollutants or not, such environmental stress causes changes in physiological responses. In this study, the aquatic midge, Chironomus riparius Meigen, was used to find changes of expression of proteins in relation to cadmium exposure. Dose-response relationships between cadmium concentrations and mortality of 3rd instar midge larvae were observed and the protein levels were compared using PD-Quest after 2-DE. Comparing the intensity of protein spots, 21 proteins decreased and 18 proteins increased in response to cadmium treatment. With increased proteins, three enzymes such as S-adenosylmethionine decarboxylase, O-methyltransferase, and aspartokinase were involved in the glutathione biosynthesis and a key enzyme regulating fatty acid biosynthesis, oleyl-acyl carrier protein thioesterase was also identified. According to the functional classification of decreased levels of proteins, they were involved in energy production, protein fate, nucleotide biosynthesis, cell division, transport and binding, signal transduction, and fatty acid and phospholipid metabolism in the cell. In addition, phenol hydroxylase, thioesterase, zinc metalloprotease, and aspartate kinase were newly expressed after cadmium exposure at the concentration of the LC(10 )value. Therefore, these proteins seem to be potential biomarkers for cadmium exposure in the aquatic ecosystems. PMID:16372273

  4. Aquaporins in the antarctic midge, an extremophile that relies on dehydration for cold survival.

    PubMed

    Goto, Shin G; Lee, Richard E; Denlinger, David L

    2015-08-01

    The terrestrial midge Belgica antarctica relies extensively on dehydration to survive the low temperatures and desiccation stress that prevail in its Antarctic habitat. The loss of body water is thus a critical adaptive mechanism employed at the onset of winter to prevent injury from internal ice formation; a rapid mechanism for rehydration is equally essential when summer returns and the larva resumes the brief active phase of its life. This important role for water movement suggests a critical role for aquaporins (AQPs). Recent completion of the genome project on this species revealed the presence of AQPs in B. antarctica representing the DRIP, PRIP, BIB, RPIP, and LHIP families. Treatment with mercuric chloride to block AQPs also blocks water loss, thereby decreasing cell survival at low temperatures. Antibodies directed against mammalian or Drosophila AQPs suggest a wide tissue distribution of AQPs in the midge and changes in protein abundance in response to dehydration, rehydration, and freezing. Thus far, functional studies have been completed only for PRIP1. It appears to be a water-specific AQP, but expression levels are not altered by dehydration or rehydration. Functional assays remain to be completed for the additional AQPs.

  5. Continuous activity and no cycling of clock genes in the Antarctic midge during the polar summer.

    PubMed

    Kobelkova, Alena; Goto, Shin G; Peyton, Justin T; Ikeno, Tomoko; Lee, Richard E; Denlinger, David L

    2015-10-01

    The extreme seasonal shifts of day length in polar regions, ranging from constant light in the summer to constant darkness in the winter, pose an intriguing environment for probing activity rhythms and the functioning of circadian clocks. Here, we monitor locomotor activity during the summer on the Antarctic Peninsula and under laboratory conditions, as well as the accompanying patterns of clock gene expression in the Antarctic midge, the only insect endemic to Antarctica. Larvae and adults are most active during the warmest portion of the day, but at a constant temperature they remain continuously active regardless of the photoregime, and activity also persists in constant darkness. The canonical clock genes period, timeless, Clock, and vrille are expressed in the head but we detected no cycling of expression in either the field or under diverse photoregimes in the laboratory. The timekeeping function of the clock has possibly been lost, enabling the midge to opportunistically exploit the unpredictable availability of permissive thermal conditions for growth, development, and reproduction during the short summer in Antarctica.

  6. Wild swarms of midges linger at the edge of an ordering phase transition

    NASA Astrophysics Data System (ADS)

    Giardina, Irene

    2014-03-01

    The most notable hallmark of collective behavior in biological systems is the emergence of order: individuals synchronize their state, giving the stunning impression that the group behaves as one. Birds flocks, fish schools and mammal herds are just a few common examples of polarized animal groups. Mating swarms of mosquitoes and midges, on the other hand, do not display global order and it is therefore unclear whether swarms are a true instance of collective behavior or a mere epiphenomenon of the independent response of each insect to an environmental stimulus. The crucial task for a group, however, is not simply to achieve an ordered state, but to respond collectively to the environmental stimuli. For this to happen, correlation must be large, namely individuals must be able to influence each other's behavioral changes on a group scale. In this work, we experimentally study wild swarms of midges and find that, despite the lack of collective order, swarms display strong correlation, comparable to that found in highly ordered groups of vertebrates. Correlation is orders of magnitude larger in natural swarms than in random systems, indicating the existence of large clusters of insects responding together. We also find that the total amount of correlation, i.e. the susceptibility, increases sharply with the swarm density, a distinctive mark of an incipient ordering phase transition. Swarms, however, live at the near-critical edge of this transition, never plunging in the ordered phase, suggesting that their size and density are tuned to maximize collective response.

  7. Analysis of single nucleotide polymorphism via genotyping-by-sequencing in the gall midge Mayetiola Destructor (Hessian Fly)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genotyping-by-sequencing (GBS) is a recently developed technology that has been used to identify DNA markers and map genes for specific traits in many organisms. The gall midge Mayetiola destructor, commonly known as Hessian fly, is a global destructive pest of wheat. In this study, we identified ...

  8. Aprostocetus xiphopunctus Sampson nov. sp. (Hymenoptera: Eulophidea): A new natural ememy of a gall midge complex (Diptera: Cecidomyiidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new endoparasitoid kills 40 – 100% of Dasineura oxycoccana and Prodiplosis vaccinii larvae, pest midges that seriously reduce blueberry yield. Female wasps methodically probe leaf buds for host larvae and their parasitism can be more effective than chemical control. With each successive molt, host...

  9. Estimation of survival and gonotrophic cycle length of Culicoides variipennis (Diptera: Ceratopogonidae) in California.

    PubMed

    Work, T M; Mullens, B A; Jessup, D A

    1991-06-01

    The use of a time series analysis to estimate the survival rate and gonotrophic cycle length of Culicoides variipennis at 2 California sites is described. Collections were made daily for 28 days in Yolo County (northern California) and for 25 days in Riverside County (southern California) in July and August of 1989, respectively, using CO2-baited suction traps. The time series analysis of these collections yielded a gonotrophic cycle length estimate of 3 days. Stage-specific and daily survivorship estimates 0.242 and 0.623, respectively, were determined for the northern California site. The time series method was found unsuitable for estimating the gonotrophic cycle length or daily survivorship at the southern California site. PMID:1895081

  10. Bivens arm virus: a new rhabdovirus isolated from Culicoides insignis in Florida and related to Tibrogargan virus of Australia.

    PubMed

    Gibbs, E P; Calisher, C H; Tesh, R B; Lazuick, J S; Bowen, R; Greiner, E C

    1989-02-01

    During field studies in 1981 on the transmission of bluetongue viruses in ruminants in Florida, a virus was isolated from Culicoides insignis collected near water buffalo (Bubalus bubalis) recently imported from Trinidad. Electron microscopy showed that this isolate, for which the name Bivens Arm virus is proposed, has rhabdovirus morphology. Serologic comparisons were made with recognized rhabdoviruses from terrestrial vertebrates and hematophagous arthropods. Indirect fluorescent antibody, complement fixation and neutralization tests indicated antigenic reactivity between Bivens Arm virus and two rhabdoviruses found only in Australia, Tibrogargan and Coastal Plains viruses. The Australian isolates cause subclinical infections in cattle and water buffalo and are believed to be transmitted by Culicoides. Initially, it was thought that Bivens Arm virus may have been introduced to Florida with the water buffalo from Trinidad, but a serologic survey of cattle serum, collected before the importation of the buffalo revealed antibody to the virus in cattle on farms located in diverse areas of Florida.

  11. Refining methods for conducting long-term sediment and water toxicity tests with Chironomus dilutus: Formation of a midge chronic testing work group

    EPA Science Inventory

    Standard methods have been established by USEPA, ASTM International, Environment Canada and Organization for Economic Cooperation and Development for conducting sediment toxicity tests with various species of midges including Chironomus dilutus. Short-term 10-day exposures are ty...

  12. A Key to the Pupal Exuviae of the Midges (Diptera: Chironomidae) of Everglades National Park, Florida

    USGS Publications Warehouse

    Jacobsen, Richard E.

    2008-01-01

    A key has been developed for identifying the pupal exuviae of 132 taxa of chironomid midges collected in Everglades National Park, as well as 18 additional species from freshwater habitats adjacent to the Park. Descriptions and illustrations are based upon voucher specimens from extensive collections of chironomid pupal exuviae for faunal surveys and biomonitoring research conducted in ENP and surrounding freshwater areas from 1998 to 2007. The key includes taxonomic comments for confirming identifications, as well as brief summaries of the distribution and ecology of each species in southern Florida waters. Information is also provided on the morphology of chironomid pupal exuviae, recommended references for identifying pupal exuviae, techniques for making slides, and methods to confirm proper identification.

  13. A cysteine-clamp gene drives embryo polarity in the midge Chironomus*

    PubMed Central

    Klomp, Jeff; Athy, Derek; Kwan, Chun Wai; Bloch, Natasha I.; Sandmann, Thomas; Lemke, Steffen; Schmidt-Ott, Urs

    2015-01-01

    In the common fruit fly Drosophila, head formation is driven by a single gene, bicoid, which generates head-to-tail polarity of the main embryonic axis. Bicoid deficiency results in embryos with tail-to-tail polarity and no head. However, most insects lack bicoid, and the molecular mechanism for establishing head-to-tail polarity is poorly understood. We have identified a gene that establishes head-to-tail polarity of the mosquito-like midge, Chironomus riparius. This gene, named panish, encodes a cysteine-clamp DNA binding domain and operates through a different mechanism than bicoid. This finding, combined with the observation that the phylogenetic distributions of panish and bicoid are limited to specific families of flies, reveals frequent evolutionary changes of body axis determinants and a remarkable opportunity to study gene regulatory network evolution. PMID:25953821

  14. Sensitivity of midge larvae of Chironomus tentans Fabricius (Diptera Chironomidae) to heavy metals

    SciTech Connect

    Khangarot, B.S.; Ray, P.K.

    1989-03-01

    The discharge of heavy metals into the natural waters has numerous obvious impacts on physical, chemical and biological parameters of aquatic ecosystem. Bioassay tests are important steps in establishing appropriate water quality criteria and standards for diverse use of ponds, lakes, streams and river waters. Therefore, the acute toxicities of various heavy metals to water flea Daphnia magna, and snail Lymnaea acuminata, and toad tadpoles Bufo mentanostictus have been reported from the authors' laboratory. Chironomid larvae might be particularly useful as indicators of water quality because they are widely distributed in freshwater systems and often from diverse communities within particular habitat. The aim of this study was to determine the acute toxicity of ten heavy metals to the midge larvae Chironomus tentans Fabricius, which forms an important link in aquatic food chain(s).

  15. First Report of 13 Species of Culicoides (Diptera: Ceratopogonidae) in Mainland Portugal and Azores by Morphological and Molecular Characterization

    PubMed Central

    Pereira da Fonseca, Isabel; Delécolle, Jean-Claude; Wilson, Anthony; Meireles, José; Lucientes, Javier; Ribeiro, Rita; Boinas, Fernando

    2012-01-01

    The genus Culicoides (Diptera: Ceratopogonidae) contains important vectors of animal and human diseases, including bluetongue, African horse sickness and filariosis. A major outbreak of bluetongue occurred in mainland Portugal in 2004, forty eight years after the last recorded case. A national Entomological Surveillance Plan was initiated in mainland Portugal, Azores and the Madeira archipelagos in 2005 in order to better understand the disease and facilitate policy decisions. During the survey, the most prevalent Culicoides species in mainland Portugal was C. imicola (75.3%) and species belonging to the Obsoletus group (6.5%). The latter were the most prevalent in Azores archipelago, accounting for 96.7% of the total species identified. The Obsoletus group was further characterized by multiplex Polymerase Chain Reaction to species level showing that only two species of this group were present: C. obsoletus sensu strictu (69.6%) and C. scoticus (30.4%). Nine species of Culicoides were detected for the first time in mainland Portugal: C. alazanicus, C. bahrainensis, C. deltus, C. lupicaris, C. picturatus, C. santonicus, C. semimaculatus, C. simulator and C. subfagineus. In the Azores, C. newsteadi and C. circumscriptus were identified for the first time from some islands, and bluetongue vectors belonging to the Obsoletus group (C. obsoletus and C. scoticus) were found to be widespread. PMID:22536340

  16. Moonlight receptor of the "1-h-midge" Clunio marinus studied by micro-XRF

    NASA Astrophysics Data System (ADS)

    Falkenberg, G.; Fleissner, Ge; Neumann, D.; Wellenreuther, G.; Alraun, P.; Fleissner, Gue

    2013-10-01

    Melanin is a pigment widely occurring in animals, plants, fungi and algae. It does not only colour skin, hair and eyes but serves mainly as photoprotectant and prevents overload with minerals induced by inflammations, infections and degenerative diseases. Therefore, the mechanisms underlying melanisation gained increasing interest in the field of biomedical research and clinic. So far, the processes of melanogenesis are only partly analysed, nearly nothing is known on a putative switch between melanins of different types. Here we offer a model organism to study these mechanisms as part of a naturally cycling change of transparency of the retinal shielding pigment. A marine midge, Clunio marinus, living in coastal regions, underlies a complex timing of its development by solar and lunar climatic periodicities, which synchronise biological clocks. The question was how the animals can discriminate changing sunlight from moonlight intensities. For the first time, we could show a "moonlight window" in the larval ocelli of this midge, and propose a hypothesis on the underlying mechanisms. Driven by a lunar clock the image forming ocelli become transparent and convert during moonlit nights to a sensitive photometer, which can record the dynamics of environmental light. High resolution X-ray fluorescence (XRF) measurements of the distribution of trace minerals in single melanosomes combined with their fine structural details in various states of the lunar cycle provide a first insight into the enzymatic pathways for the generation of a dark melanin (like eumelanin) and a light coloured melanin (like phaeomelanin). Essential advantage of this approach is the spatial and temporal resolution of the metals associated with melanisation processes, which could never before be demonstrated in these details. The data may stimulate further research projects in biomedicine.

  17. Effect of sediment contact and uptake mechanisms on accumulation of three chlorinated hydrocarbons in the midge, Chironomus riparius

    SciTech Connect

    Fry, D.M.; Fisher, S.W. )

    1990-05-01

    Chlorinated hydrocarbons (CHCs) are major contaminants of bottom sediments in many freshwater systems. The behavior and availability of sediment-sorbed compounds arouse much controversy due to the potential impact these contaminants could have on the ecosystem if they were to get into the food chain. Benthic organisms are at great risk from sediment-sorbed contaminants since they inhabit bottom sediments. In this investigation, uptake of sediment-sorbed 5,5{prime},6-trichlorobiphenyl (PCB), p,p{prime}-DDE and PCP by the midge (Chironomus riparius) was examined under 3 conditions. Uptake from direct contact with contaminated sediment (sediment + water) was compared to uptake levels by the midge when it was screened from contaminated sediment contact (screened sediment) and to uptake in dead organisms exposed to contaminated sediment (passive).

  18. An inducible HSP70 gene from the midge Chironomus dilutus: Characterization and transcription profile under environmental stress

    USGS Publications Warehouse

    Karouna-Renier, N. K.; Rao, K.R.

    2009-01-01

    In the present study, we identified and characterized an inducible heat shock protein 70 (HSP70) from the midge Chironomus dilutus and investigated the transcriptional profile of the gene under baseline and environmentally stressful conditions. Using real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR), we observed increased expression of CD-HSP70-1 in response to both heat shock and copper stress. We also investigated the expression of this gene during midge development. All C. dilutus developmental stages expressed CD-HSP70-1 under normal conditions, although at extremely low levels. Phylogenetic analysis of the amino acid sequence demonstrated distinct clustering of this gene with inducible HSP70s from other insect species. ?? 2008 The Authors.

  19. From Midges to Spiders: Mercury Biotransport in Riparian Zones Near the Buffalo River Area of Concern (AOC), USA.

    PubMed

    Pennuto, C M; Smith, M

    2015-12-01

    Riparian communities can receive environmental contaminants from adjacent aquatic 'donor' habitats. We investigated mercury biotransport from aquatic to terrestrial habitats via aquatic insect emergence and uptake by riparian spiders at sites within and upstream of the Buffalo River Area of Concern (AOC), a site with known sediment Hg contamination. Mercury concentration in emerging midges was roughly 10× less than contaminated sediment levels with the AOC, but biomagnification factors from midges to spiders ranged from 2.0 to 2.65 between sites. There was a significantly negative body mass:total mercury relationship in spiders (p < 0.001), indicating that mercury depuration is rapid or tissue dilution occurs in these riparian predators. Spiders contained significantly more mercury than their midge prey and spiders upstream of the AOC had higher mercury concentrations than spiders from within the AOC. Collectively, these data indicate that riparian spiders can be good mercury sentinels in urban environments, and that riparian communities upstream from the AOC may be at greater risk to mercury than has been previously considered. PMID:26387024

  20. From Midges to Spiders: Mercury Biotransport in Riparian Zones Near the Buffalo River Area of Concern (AOC), USA.

    PubMed

    Pennuto, C M; Smith, M

    2015-12-01

    Riparian communities can receive environmental contaminants from adjacent aquatic 'donor' habitats. We investigated mercury biotransport from aquatic to terrestrial habitats via aquatic insect emergence and uptake by riparian spiders at sites within and upstream of the Buffalo River Area of Concern (AOC), a site with known sediment Hg contamination. Mercury concentration in emerging midges was roughly 10× less than contaminated sediment levels with the AOC, but biomagnification factors from midges to spiders ranged from 2.0 to 2.65 between sites. There was a significantly negative body mass:total mercury relationship in spiders (p < 0.001), indicating that mercury depuration is rapid or tissue dilution occurs in these riparian predators. Spiders contained significantly more mercury than their midge prey and spiders upstream of the AOC had higher mercury concentrations than spiders from within the AOC. Collectively, these data indicate that riparian spiders can be good mercury sentinels in urban environments, and that riparian communities upstream from the AOC may be at greater risk to mercury than has been previously considered.

  1. Efficient shedding of accumulated metals during metamorphosis in metal-adapted populations of the midge Chironomus riparius

    SciTech Connect

    Groenendijk, D.; Kraak, M.H.S.; Admiraal, W. . Dept. of Aquatic Ecology and Ecotoxicology)

    1999-06-01

    Metal accumulation and loss during metamorphosis were investigated in Chironomus riparius populations in a metal contaminated lowland river. Cadmium and zinc levels were measured in imagoes and larvae at reference and metal-exposed sites. It was hypothesized that the relationship between metal concentrations in biota and environmental compartments would be influenced by the presence of metal-adapted chironomids. In contrast to the large interpopulation differences in larval body burdens of cadmium, body burdens in imagoes vanished to background levels for all midge populations. This indicated that any cadmium accumulated in larval stages was lost during metamorphosis. This nearly 100% efficiency in shedding of cadmium is most likely caused by an increased metal handling capacity present in exposed midges. In agreement with the cadmium measurements, larval body burdens of zinc showed also highly significant interpopulation differences. In contrast with the cadmium values, however, body burdens of zinc in imagoes showed highly significant interpopulation differences and differences were even recorded between the two exposed sites, indicating interpopulation differences in shedding capacity for zinc. It is concluded that the highly efficient shedding of accumulated metals reflected the metal adaptation recorded in earlier studies of metal-exposed C. riparius populations from the River Dommel. Based on the differences in metal accumulation and the differences found in shedding of metals between the two exposed midge populations, it was concluded that population differentiation due to metal stress is a gradual process rather than an all-or-nothing situation.

  2. Interrelationship between the raspberry cane midge, Resseliella theobaldi (Diptera: Cecidomyiidae) and its parasitoid, Aprostocetus epicharmus (Hymenoptera: Eulophidae).

    PubMed

    Vétek, G; Thuróczy, C; Pénzes, B

    2006-08-01

    The raspberry cane midge Resseliella theobaldi (Barnes) is one of the most important pests of cultivated red raspberry Rubus idaeus L. throughout Europe. For the last 50 years several studies have been made on the biology, life cycle and control of the pest. Some data can also be found on its natural enemies, but among these species only the chalcidoid Tetrastichus inunctus Nees turned out to be important in controlling raspberry cane midge populations. However, this species name is now ambiguous as the type is lost. In the present study, Aprostocetus epicharmus Walker was the chalcidoid species that parasitized the larvae of the raspberry cane midge, and its biology seems to be very similar to that of T. inunctus. It is therefore probable that the eulophid species earlier referred to as T. inunctus in the literature is A. epicharmus. Besides discussing this problem, particular consideration and detailed data are given on the biology and life cycle of A. epicharmus in relation to R. theobaldi. Different factors having effect on the population dynamics of both species are also discussed as results of a survey on several red raspberry cultivars, carried out in Hungary between 2002 and 2005.

  3. Butox 7.5 pour on: a deltamethrin treatment of sheep and cattle: pilot study of killing effects on Culicoides species (Ceratopogonidae).

    PubMed

    Mehlhorn, Heinz; Schmahl, Günter; D'Haese, Jochen; Schumacher, Bärbel

    2008-02-01

    Topical treatment (at the neck and along the vertebral column) with deltamethrin (Butox 7.5 pour on) of cattle (30 ml/400-kg body weight) and sheep (10 ml/60-kg body weight) was done to find out, whether the insecticide may reach in a sufficient dosage the legs, which are known to be the main biting site of Culicoides specimens that are the vectors of the recently introduced Bluetongue virus in central Europe. At days 7, 14, 21, 28, and 35 after treatment, some hair was cut off from the legs--close to the claws. Freshly (the night before) caught Culicoides obsoletus specimens were then exposed for 15, 30, 60, or 120 s to such hair and afterwards transferred to a filter paper within plastic Petri dishes to observe their fate. It turned out that even a short contact of 15 s of the Culicoides specimens with deltamethrin-treated hair of cattle or sheep was sufficient to paralyze and kill Culicoides specimens within a reasonable short time even when the hair were cut off at day 28 after treatment. While the results obtained in cattle and sheep were rather similar for days 7 and 14 after treatment, the speed of the killing effect of treated hair of cattle on Culicoides considerably slowed down beginning from day 21 after treatment. However, all the experiments clearly showed that the insecticide deltamethrin may reach the feet of cattle and may kill Culicoides specimens when the product is poured along the vertebral column. Such a treatment may considerably reduce the risk of transmission of the agents of disease. However, in the case of the thick fleece of sheep, the insecticide must be poured directly into the skin to reach full activity.

  4. Using climate data to map the potential distribution of Culicoides imicola (Diptera: Ceratopogonidae) in Europe.

    PubMed

    Wittmann, E J; Mellor, P S; Baylis, M

    2001-12-01

    Culicoides imicola, a vector of bluetongue virus and African horse sickness virus, is principally Afro-Asian in distribution, but has recently been found in parts of Europe. A logistic regression model based on climate data (temperature, saturation deficit, rainfall and altitude) and the published distribution of C. imicola in Iberia was developed and then applied to other countries in Europe, to identify locations where C. imicola could become established. The model identified three temperature variables as significant determinants of the distribution of C. imicola in Iberia (minimum of the monthly minimum temperatures, maximum of the monthly maximum temperatures and number of months per year with a mean temperature > or = 12.5 degrees C). The model indicated that under current conditions, the distribution of C. imicola in Spain, Greece and Italy could be extended and the vector could potentially invade parts of Albania, Yugoslavia, Bosnia and Croatia. To simulate the effect of global warming, temperature values in the model were increased by 2 degrees C. Under these conditions, the potential spread of C. imicola in Europe would be even more extensive.

  5. Evaluation of ULV naled applied simultaneously against caged adult Aedes taeniorhynchus and Culicoides furens.

    PubMed

    Linley, J R; Parsons, R E; Winner, R A

    1988-09-01

    Two experiments were conducted to test application of ULV naled against adult Aedes taeniorhynchus and Culicoides furens exposed simultaneously in cages hung on poles at selected heights and distances from the spray source. ULV spray was released at 0.14 oz active ingredient/acre, droplet size 13.5 micron mmd. In both experiments, insecticide largely carried over the first poles. The greatest mortality occurred at the second pole position, 18.3 and 25.7 m, respectively, from the spray origin, and diminished progressively with increasing distance. Cages at the highest elevation (183 cm) showed the greatest mortality, while those near the ground (15 cm) were substantially less affected. Regression analysis showed that 70% control or better was attained up to a distance (beyond a line 10 m from the release point) of 23 m in the case of Ae. taeniorhynchus and 18 m in the case of C. furens. ULV naled, applied as described, was not particularly effective for control of Ae. taeniorhynchus and C. furens, and was poor for insects exposed in low vegetation. PMID:3199122

  6. Comparative genome sequencing reveals genomic signature of extreme desiccation tolerance in the anhydrobiotic midge

    PubMed Central

    Gusev, Oleg; Suetsugu, Yoshitaka; Cornette, Richard; Kawashima, Takeshi; Logacheva, Maria D.; Kondrashov, Alexey S.; Penin, Aleksey A.; Hatanaka, Rie; Kikuta, Shingo; Shimura, Sachiko; Kanamori, Hiroyuki; Katayose, Yuichi; Matsumoto, Takashi; Shagimardanova, Elena; Alexeev, Dmitry; Govorun, Vadim; Wisecaver, Jennifer; Mikheyev, Alexander; Koyanagi, Ryo; Fujie, Manabu; Nishiyama, Tomoaki; Shigenobu, Shuji; Shibata, Tomoko F.; Golygina, Veronika; Hasebe, Mitsuyasu; Okuda, Takashi; Satoh, Nori; Kikawada, Takahiro

    2014-01-01

    Anhydrobiosis represents an extreme example of tolerance adaptation to water loss, where an organism can survive in an ametabolic state until water returns. Here we report the first comparative analysis examining the genomic background of extreme desiccation tolerance, which is exclusively found in larvae of the only anhydrobiotic insect, Polypedilum vanderplanki. We compare the genomes of P. vanderplanki and a congeneric desiccation-sensitive midge P. nubifer. We determine that the genome of the anhydrobiotic species specifically contains clusters of multi-copy genes with products that act as molecular shields. In addition, the genome possesses several groups of genes with high similarity to known protective proteins. However, these genes are located in distinct paralogous clusters in the genome apart from the classical orthologues of the corresponding genes shared by both chironomids and other insects. The transcripts of these clustered paralogues contribute to a large majority of the mRNA pool in the desiccating larvae and most likely define successful anhydrobiosis. Comparison of expression patterns of orthologues between two chironomid species provides evidence for the existence of desiccation-specific gene expression systems in P. vanderplanki. PMID:25216354

  7. Increased cadmium excretion in metal-adapted populations of the midge Chironomus riparius (Diptera)

    SciTech Connect

    Postma, J.F.; Nugteren, P. van; Buckert-De Jong, M.B.

    1996-03-01

    Cadmium kinetics were studied in cadmium-adapted and nonadapted field populations of the midge Chironomus riparius. Accumulation and elimination experiments were carried out using first-generation laboratory-reared animals. Differences between populations were, therefore, assumed to have a genetic basis. Larvae were dissected to analyze the guts and the remainder of the larvae separately. First-order one-compartment models were not always successful in describing accumulation processes, probably due to acclimation. No interpopulation differences were observed in larval development based on dry weights, whereas some differences existed based on pupation rate. In most cases more than 80% of the total amount of cadmium was found in the guts of all populations. Larvae from cadmium-adapted populations showed a decreased net accumulation rate as well as higher equilibrium values (15--20%) compared to nonadapted populations. In addition, cadmium excretion efficiency was increased for cadmium-adapted larvae, which was due to an increased elimination rate from the guts. It was concluded that exposure to high cadmium concentrations in the field resulted in populations of C. riparius with an increased storage capability and an increased excretion efficiency, especially regarding the guts.

  8. Efficacy of Biopesticides for Management of the Swede Midge (Diptera: Cecidomyiidae).

    PubMed

    Evans, Braden G; Hallett, Rebecca H

    2016-10-01

    Management of the swede midge, Contarinia nasturtii Kieffer, in North American crucifer production relies on crop rotation and the timely application of synthetic insecticides, based on pheromone trap monitoring of local adult populations. Organically acceptable formulations of azadirachtin, pyrethrin, and spinosad, and a commercial biopesticide containing the entomopathogenic fungus, Beauveria bassiana, were evaluated for their effects on larval mortality and oviposition deterrence in the greenhouse, and on damage symptoms in the field. In greenhouse trials, pyrethrin and spinosad treatments applied up to 24 h prior to C. nasturtii exposure resulted in significant reductions in oviposition on host plants, whereas azadirachtin and B. bassiana only deterred oviposition when applied 2 h prior to exposure. Spinosad caused the highest larval reduction (∼96%) on cauliflower meristems, while azadirachtin, B. bassiana, and pyrethrin caused significant larval reduction when applied preoviposition and significant mortality when applied postoviposition. Field trials conducted with these insecticides on broccoli in 2011 produced no significant reductions in overall damage levels; however, B. bassiana treatments produced more marketable plants than did the control. In 2013, all treatments significantly reduced overall damage levels and all treatments, except B. bassiana, produced more uninfested and marketable plants than the control. Field applications of these alternative insecticides may be effective in protecting yields of broccoli and cauliflower, when combined with other tactics in an integrated pest management program. PMID:27567223

  9. A staging scheme for the development of the moth midge Clogmia albipunctata.

    PubMed

    Jiménez-Guri, Eva; Wotton, Karl R; Gavilán, Brenda; Jaeger, Johannes

    2014-01-01

    Model organisms, such as Drosophila melanogaster, allow us to address a wide range of biological questions with experimental rigour. However, studies in model species need to be complemented by comparative studies if we are to fully understand the functional properties and evolutionary history of developmental processes. The establishment of new model organisms is crucial for this purpose. One of the first essential steps to establish a species as an experimental model is to carefully describe its life cycle and development. The resulting staging scheme serves as a framework for molecular studies, and allows us to homologise developmental processes between species. In this paper, we have characterised the life cycle and development of an emerging non-drosophilid dipteran model system: the moth midge Clogmia albipunctata. In particular, we focus on early embryogenesis (cleavage and blastoderm cycles before gastrulation), on formation and retraction of extraembryonic tissues, and on formation of the germ line. Considering the large evolutionary distance between the two species (approximately 250 million years), we find that the development of C. albipunctata is remarkably conserved compared to D. melanogaster. On the other hand, we detect significant differences in morphology and timing affecting the development of extraembryonic tissues and the germ line. Moreover, C. albipunctata shows several heterochronic shifts, and lacks head involution and associated processes during late stages of development. PMID:24409296

  10. Massive Shift in Gene Expression during Transitions between Developmental Stages of the Gall Midge, Mayetiola Destructor

    PubMed Central

    Chen, Ming-Shun; Liu, Sanzhen; Wang, Haiyan; Cheng, Xiaoyan; El Bouhssini, Mustapha; Whitworth, R. Jeff

    2016-01-01

    Mayetiola destructor is a destructive pest of wheat and has six developmental stages. Molecular mechanisms controlling the transition between developmental stages remain unknown. Here we analyzed genes that were expressed differentially between two successive developmental stages, including larvae at 1, 3, 5, and 7 days, pupae, and adults. A total of 17,344 genes were expressed during one or more of these studied stages. Among the expressed genes, 38–68% were differently expressed between two successive stages, with roughly equal percentages of up- and down-regulated genes. Analysis of the functions of the differentially expressed genes revealed that each developmental stage had some unique types of expressed genes that are characteristic of the physiology at that stage. This is the first genome-wide analysis of genes differentially expressed in different stages in a gall midge. The large dataset of up- and down-regulated genes in each stage of the insect shall be very useful for future research to elucidate mechanisms regulating insect development and other biological processes. PMID:27224654

  11. Factors affecting methylmercury biomagnification by a widespread aquatic invertebrate predator, the phantom midge larvae Chaoborus.

    PubMed

    Le Jeune, Anne-Hélène; Bourdiol, Floriane; Aldamman, Lama; Perron, Tania; Amyot, Marc; Pinel-Alloul, Bernadette

    2012-06-01

    MeHg biomagnification by the phantom midge Chaoborus in relation to MeHg concentrations in their prey and its migratory behavior was investigated in two Canadian Precambrian Shield lakes. Three Chaoborus species with contrasted migratory behavior were collected in a fishless and a fish-inhabited lake. All species accumulated MeHg through their ontogenic development. In the lake inhabited by fish, all instars of Chaoborus punctipennis displayed a marked migratory behavior and were unable to biomagnify MeHg, whereas in the fishless lake, Chaoborus americanus and Chaoborus trivittatus biomagnified MeHg. Reduced biomagnification capacity of C. trivittatus, the coexisting species living with C. americanus, was also ascribed to a progressive vertical segregation with age. Growth dilution, amount and type of prey items or trophic position could not explain the different patterns of biomagnification. Our findings demonstrate that the most common invertebrate predator of temperate planktonic food webs can biomagnify mercury, contrarily to previous reports. PMID:22420993

  12. Factors affecting methylmercury biomagnification by a widespread aquatic invertebrate predator, the phantom midge larvae Chaoborus.

    PubMed

    Le Jeune, Anne-Hélène; Bourdiol, Floriane; Aldamman, Lama; Perron, Tania; Amyot, Marc; Pinel-Alloul, Bernadette

    2012-06-01

    MeHg biomagnification by the phantom midge Chaoborus in relation to MeHg concentrations in their prey and its migratory behavior was investigated in two Canadian Precambrian Shield lakes. Three Chaoborus species with contrasted migratory behavior were collected in a fishless and a fish-inhabited lake. All species accumulated MeHg through their ontogenic development. In the lake inhabited by fish, all instars of Chaoborus punctipennis displayed a marked migratory behavior and were unable to biomagnify MeHg, whereas in the fishless lake, Chaoborus americanus and Chaoborus trivittatus biomagnified MeHg. Reduced biomagnification capacity of C. trivittatus, the coexisting species living with C. americanus, was also ascribed to a progressive vertical segregation with age. Growth dilution, amount and type of prey items or trophic position could not explain the different patterns of biomagnification. Our findings demonstrate that the most common invertebrate predator of temperate planktonic food webs can biomagnify mercury, contrarily to previous reports.

  13. Life-cycle effects of sediment-associated 2,4,5-trichlorophenol on two groups of the midge Chironomus riparius with different exposure histories.

    PubMed

    Ristola, T; Parker, D; Kukkonen, J V

    2001-08-01

    Effects of 2,4,5-trichlorophenol (TCP) on life-cycle traits of the midge Chironomus riparius and the ability of the midge to evolve tolerance to TCP were assessed using a reference group and a group preexposed to TCP during three generations, both originating from the same laboratory culture. F1 larvae of these groups were then exposed to nominal TCP concentrations of 51, 177, 355, and 532 micromol TCP/kg dry sediment and a control sediment in a life-cycle experiment. Most studied life-cycle traits (mortality, egg production, life span, male dry wt) were fairly insensitive to TCP, and significant effects were observed only at high (> or = 355 micromol/kg) concentrations. Larval development rate was variable, and in some cases it responded more readily to low TCP concentrations than other life-cycle parameters. Some of the observed responses were attributed to changes in food availability. No clear evidence of tolerance to 2,4,5-trichlorophenol was found, but the preexposed midges produced more eggs than the reference group. They also emerged earlier and at a smaller size than the reference midges. These differences between the midge groups suggest that some changes toward tolerance induction had occurred during the preexposure.

  14. Mode of existence and seasonality of midge larvae (Diptera: Chironomidae) in man-made lakes in the Coachella Valley, southern California.

    PubMed

    Lothrop, B B; Mulla, M S

    1995-03-01

    Over the past 2 decades, numerous man-made ponds and lakes constructed in country clubs and on golf courses in the Coachella Valley have become ideal habitats for various chironomid species. Large numbers of adult midges emerging from these water bodies pose nuisance and economic problems. During 1992 and 1993 we initiated comprehensive studies on the nature and scope of the nuisance midge problem in the valley. We sampled on a biweekly basis 2 lakes supplied with well water, 2 supplied with tertiary effluent water, and one supplied with a mixture of these 2 sources, to determine the midge larval fauna and the mode of existence, seasonal abundance, and population trends of these midges. Climbers, clingers, portable sand tube builders, and tube builders on plants predominated in well-water habitats with submerged vegetation and detritus bottoms. Tube builders and burrowers predominated in the tertiary water, which characteristically had a detritus bottom, devoid of vegetation. Habitats holding a mixture of the 2 water types with sandy bottoms supported midge larvae known to be sprawlers.

  15. [Ceratopogonidae (Diptera) of the Congolese Mayombe. I. Daily pattern of the biting activity of female Culicoides grahamii Austen, 1909].

    PubMed

    Vattier-Bernard, G; Itoua, A; Trouillet, J; Lallemant, M

    1986-01-01

    Owing to appropriate sampling methods, the study of the daily pattern of biting of female "Culicoides grahamii Austen, 1909" was achieved in the Congolese Mayombe. It was discovered that this pattern was rhythmical in close connection with the sunrise and sunset. Many climatic parameters were simultaneously studied (temperature, hygrometry, brightness). This starting factor of this rhythmical pattern seems to be a brightness which agrees to a total shortwave radiation on the ground, equal or inferior to 25 cal x m-2 x h-1. It seems that the temperature does not play any role.

  16. A comparison of a new centrifuge sugar flotation technique with the agar method for the extraction of immature Culicoides (Diptera: Ceratopogonidae) life stages from salt marsh soils.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two sampling techniques, agar extraction (AE) and centrifuge sugar flotation extraction (CSFE) were compared to determine their relative efficacy to recover immature stages of Culicoides spp from salt marsh substrates. Three types of samples (seeded with known numbers of larvae, homogenized field s...

  17. Effects of pH on the acute toxicity and uptake of (14C)pentachlorophenol in the midge, Chironomus riparius

    SciTech Connect

    Fisher, S.W.; Wadleigh, R.W.

    1986-02-01

    The acute toxicity of pentachlorophenol (PCP) was determined at pH levels 4, 6, 9 to the midge, Chironomus riparius, with the findings that PCP is of greatest toxicity at pH 4 and of least toxicity at pH 9. This differential toxicity is attributable to variations in uptake levels at the respective pH levels. At pH 4, PCP is fully protonated and therefore highly lipophilic. The amount of (14C)PCP present in the midges at 24 hr is thus highest at pH 4. Conversely, at pH 9, the compound is completely ionized. The reduction in lipophilicity at pH 9 decreases the ability of the compound to penetrate into the midge, thereby decreasing the observed toxicity of the compound.

  18. Interactive effects of acidity and aluminum exposure on the life cycle of the midge Chironomus riparius (Diptera)

    SciTech Connect

    Palawski, D.U.; Hunn, J.B.; Chester, D.N.; Wiedneyer, R.H. )

    1989-12-01

    The chronic toxicity of acidic pH and the toxicity of aluminum at pH 5.6 and pH 5.0 to the midge Chironomus riparius were determined in 30-day flow-through exposures. Larvae were exposed to water pHs of 7.2, 6.2, 5.8, 5.3, and 4.5; total aluminum concentrations were 14.6, 34.8, 61.4, 128.7, and 259.2 microgram/L at a water pH of 5.6 and to aluminum concentrations of 15.6, 32.5, 56.9, 111.4, and 235.2 microgram/L at a water pH of 5.0. The survival of midges was only 11% at pH 4.5 and 52.3% at pH 5.8. In soft water (12 mg/L as CaCO3) at pH 5.6, survival declined significantly at aluminum concentrations of 61 to 259 microgram/L, but significantly increased at 14.6 microgram/L. In soft water at pH 5.0, survival increased at concentrations of 14.6 to 111.4 microgram/L but decreased significantly at 235.2 microgram/L. At both pH 5.6 and pH 5.0, the toxicological response of midges to aluminum was thus bimodal, in that acid stress was slightly ameliorated by relatively low aluminum concentrations, but exacerbated by higher concentrations. 25 refs., 55 tabs.

  19. Effects of acid-volatile sulfide on metal bioavailability and toxicity to midge (Chironomus tentans) larvae in black shale sediments.

    PubMed

    Ogendi, George M; Brumbaugh, William G; Hannigan, Robyn E; Farris, Jerry L

    2007-02-01

    Metal bioavailability and toxicity to aquatic organisms are greatly affected by variables such as pH, hardness, organic matter, and sediment acid-volatile sulfide (AVS). Sediment AVS, which reduces metal bioavailability and toxicity by binding and immobilizing metals as insoluble sulfides, has been studied intensely in recent years. Few studies, however, have determined the spatial variability of AVS and its interaction with simultaneously extracted metals (SEM) in sediments containing elevated concentrations of metals resulting from natural geochemical processes, such as weathering of black shales. We collected four sediment samples from each of four headwater bedrock streams in northcentral Arkansa (USA; three black shale-draining streams and one limestone-draining stream). We conducted 10-d acute whole-sediment toxicity tests using the midge Chironomus tentans and performed analyses for AVS, total metals, SEMs, and organic carbon. Most of the sediments from shale-draining streams had similar total metal and SEM concentrations but considerable differences in organic carbon and AVS. Zinc was the leading contributor to the SEM molar sum, averaging between 68 and 74%, whereas lead and cadmium contributed less than 3%. The AVS concentration was very low in all but two samples from one of the shale streams, and the sum of the SEM concentrations was in molar excess of AVS for all shale stream sediments. No significant differences in mean AVS concentrations between sediments collected from shale-draining or limestone-draining sites were noted (p > 0.05). Midge survival and growth in black shale-derived sediments were significantly less (p < 0.001) than that of limestone-derived sediments. On the whole, either SEM alone or SEM-AVS explained the total variation in midge survival and growth about equally well. However, survival and growth were significantly greater (p < 0.05) in the two sediment samples that contained measurable AVS compared with the two sediments from the

  20. Efficacy of aerial spray applications using fuselage booms on Air Force C-130H aircraft against mosquitoes and biting midges.

    PubMed

    Breidenbaugh, Mark S; Haagsma, Karl A; Wojcik, George M; De Szalay, Ferenc A

    2009-12-01

    The effectiveness of a novel fuselage boom configuration was tested with flat-fan nozzles on U.S. Air Force C-130H aircraft to create ultra-low volume sprays to control mosquitoes (Culicidae) and biting midges (Ceratopogonidae). The mortality of mosquitoes and biting midges in bioassay cages and natural populations, using the organophosphate adulticide, naled, was measured. Mosquitoes in bioassay cages had 100% mortality at 639 m downwind in all single-pass spray trials, and most trials had >90% mortality up to 1491 m downwind. Mosquito mortality was negatively correlated with distance from the spray release point (r2 = 0.38, P < 0.001). The volume median diam of droplets collected was 44 tm at 213 m and decreased to 11 microm at 2130 m downwind of the release point. Droplet density decreased from an average of 18.4 drops/cm2 at 213 m to 2 drops/cm2 at 2130 m. Droplet densities of 10-18 droplets/cm2 were recorded at sampling stations with high mosquito mortality rates (>90%). In wide-area operational applications, numbers of mosquitoes from natural populations 1 wk postspray were 83% (range 55%-95%), lower than prespray numbers (P < 0.05). Biting midge numbers were reduced by 86% (range 53%-97%) on average (P = 0.051) after 7 days. The results of these field trials indicate that the fuselage boom configuration on C-130H aircraft are an effective method to conduct large-scale aerial sprays during military operations and public health emergencies. PMID:20099594

  1. Effects of acid-volatile sulfide on metal bioavailability and toxicity to midge (Chironomus tentans) larvae in black shale sediments

    USGS Publications Warehouse

    Ogendi, G.M.; Brumbaugh, W.G.; Hannigan, R.E.; Farris, J.L.

    2007-01-01

    Metal bioavailability and toxicity to aquatic organisms are greatly affected by variables such as pH, hardness, organic matter, and sediment acid-volatile sulfide (AVS). Sediment AVS, which reduces metal bioavailability and toxicity by binding and immobilizing metals as insoluble sulfides, has been studied intensely in recent years. Few studies, however, have determined the spatial variability of AVS and its interaction with simultaneously extracted metals (SEM) in sediments containing elevated concentrations of metals resulting from natural geochemical processes, such as weathering of black shales. We collected four sediment samples from each of four headwater bedrock streams in northcentral Arkansa (USA; three black shale-draining streams and one limestone-draining stream). We conducted 10-d acute whole-sediment toxicity tests using the midge Chironomus tentans and performed analyses for AVS, total metals, SEMs, and organic carbon. Most of the sediments from shale-draining streams had similar total metal and SEM concentrations but considerable differences in organic carbon and AVS. Zinc was the leading contributor to the SEM molar sum, averaging between 68 and 74%, whereas lead and cadmium contributed less than 3%. The AVS concentration was very low in all but two samples from one of the shale streams, and the sum of the SEM concentrations was in molar excess of AVS for all shale stream sediments. No significant differences in mean AVS concentrations between sediments collected from shale-draining or limestone-draining sites were noted (p > 0.05). Midge survival and growth in black shale-derived sediments were significantly less (p < 0.001) than that of limestone-derived sediments. On the whole, either SEM alone or SEM-AVS explained the total variation in midge survival and growth about equally well. However, survival and growth were significantly greater (p < 0.05) in the two sediment samples that contained measurable AVS compared with the two sediments from the

  2. Allergen-Specific Cytokine Polarization Protects Shetland Ponies against Culicoides obsoletus-Induced Insect Bite Hypersensitivity

    PubMed Central

    Meulenbroeks, Chantal; van der Lugt, Jaco J.; van der Meide, Nathalie M. A.; Willemse, Ton; Rutten, Victor P. M. G.; Zaiss, Dietmar M. W.

    2015-01-01

    The immunological mechanisms explaining development of an allergy in some individuals and not in others remain incompletely understood. Insect bite hypersensitivity (IBH) is a common, seasonal, IgE-mediated, pruritic skin disorder that affects considerable proportions of horses of different breeds, which is caused by bites of the insect Culicoides obsoletus (C. obsoletus). We investigated the allergen-specific immune status of individual horses that had either been diagnosed to be healthy or to suffer of IBH. Following intradermal allergen injection, skin biopsies were taken of IBH-affected and healthy ponies and cytokine expression was determined by RT-PCR. In addition, allergen-specific antibody titers were measured and cytokine expression of in vitro stimulated, allergen-specific CD4 T-cells was determined. 24 hrs after allergen injection, a significant increase in mRNA expression of the type-2 cytokine IL-4 was observed in the skin of IBH-affected Shetland ponies. In the skin of healthy ponies, however, an increase in IFNγ mRNA expression was found. Analysis of allergen-specific antibody titers revealed that all animals produced allergen-specific antibodies, and allergen-specific stimulation of CD4 T-cells revealed a significant higher percentage of IFNγ-expressing CD4 T-cells in healthy ponies compared to IBH-affected ponies. These data indicate that horses not affected by IBH, in contrast to the so far established dogma, are not immunologically ignorant but have a Th1-skewed allergen-specific immune response that appears to protect against IBH-associated symptoms. To our knowledge this is the first demonstration of a natural situation, in which an allergen-specific immune skewing is protective in an allergic disorder. PMID:25901733

  3. New records of predaceous midges from the Middle East, with the description of two new species (Diptera: Ceratopogonidae).

    PubMed

    Dominiak, Patrycja; Alwin, Alicja; Giłka, Wojciech

    2014-01-01

    Two new distinctive species of predaceous biting midges of the tribe Ceratopogonini are described and illustrated from the Middle East. Brachypogon freidbergi sp. nov., with a unique Y-shaped gonostylus, is recorded from Israel. We also provide the first records of Brachypogon vitiosus (Winnertz) and B. aethiopicus (Clastrier, Rioux & Descous) from this country, and a key to the adult males of the genus Brachypogon Kieffer from the Middle East. Ceratopogon azari sp. nov., described from Lebanon, shows a distinctive structure of the male genital apparatus, and is the southernmost species of that genus in the Western Palaearctic. PMID:24872285

  4. Why oviposit there? Fitness consequences of a gall midge choosing the plant's youngest leaf.

    PubMed

    Ganehiarachchi, G A S M; Anderson, Kirk M; Harmon, Jason; Harris, Marion O

    2013-02-01

    For animals that lay eggs, a longstanding question is, why do females choose particular oviposition sites? For insects that lay eggs on plants there are three hypotheses: maximizing suitable habitat for juveniles, maximizing female lifespan, and maximizing egg survival. We investigated the function of the oviposition-site choice behavior of a gall midge, the Hessian fly, Mayetiola destructor (Say). In spite of living less than a day and having hundreds of eggs, the ovipositing female is choosy about the placement of eggs. Choosiness makes sense. The tiny gall-making neonate larva has limited movement and strict requirements for colonization. We examined whether offspring benefit from the Hessian fly female's preference for the plant's youngest leaf. To do this we restricted the female's access to the first, second, or third leaf of a seedling (wheat Triticum aestivum L.) plant. Being placed on older leaves did not impact egg survival or larval survival during migration to attack sites at the base of the plant, but did have negative impacts on egg-to-adult survival (reduced by 48%) and reproductive potential (reduced by 30-45%). These negative impacts appear to come from larvae having to search harder to find the limited number of reactive plant cells that can be reprogrammed to form the gall nutritive tissue. We propose that the ability of larvae to find these reactive cells in spite of being placed on an older leaf is important because it creates leeway for female behavior to evolve in the face of other selection pressures, e.g., attack by egg parasitoids.

  5. Diversity of Non-Biting Midge Larvae Assemblages in the Jacuí River Basin, Brazil

    PubMed Central

    Floss, Elzira Cecília Serafini; Kotzian, Carla Bender; Spies, Márcia Regina; Secretti, Elisangela

    2012-01-01

    The richness and composition of a mountain-river chironomid larvae assemblage in the Jacuí River basin, Brazil were studied, and compared with other riverine non-biting midge larvae assemblages previously studied in the country. Additionally, the influence of some regional-scale environmental characteristics on the spatial distribution of these assemblages was tested. The specimens were collected at 12 sites in the middle course of the Jacuí River basin (in the state of Rio Grande do Sul) between April 2000 and May 2002. Around 100 taxa were recorded. The dominant taxa belonged to the genera Rheotanytarsus, Cricotopus, Polypedilum, and Pseudochironomus. Twenty-two rare taxa were found, representing 22% of the total of taxa inventoried. Fourteen genera (Aedokritus, Axarus, Endotribelos, Kiefferulus, Manoa, Oukuriella, Phaenopsectra, Stenochironomus, Xenochironomus, Xestochironomus, Cardiocladius, Metriocnemus, Paracladius, and Rheocricotopus) represent new occurrences in Rio Grande do Sul. The similarity analysis of the chironomid larvae assemblages inventoried in 32 regions of Brazil indicated five groups with similarity higher than 50%. The groups, when the effects of spatial autocorrelation were removed, displayed a weak positive correlation between the assemblage composition and the aquatic system or hydraulic conditions and the hydrographic basin, and a weak negative correlation in relation to the biome. The altitude showed no correlation with the composition of the assemblage. The relatively high richness of the region surveyed in relation to other Brazilian regions corroborates some tendencies already noted in other parts of the world, such as: i) lotic systems may constitute an exception to the rule that diversity is greater in tropical regions, ii) regions of transitional relief may contain the greatest richness of Chironomidae, and iii) in rivers, the group might have its spatial distribution influenced to a greater extent by local environmental

  6. Hazard evaluation of ten organophosphorous insecticides against the midge, Chironomus riparius via QSAR

    USGS Publications Warehouse

    Landrum, Peter F.; Fisher, Susan W.; Hwang, Haejo; Hickey, James P.

    1999-01-01

    Toxicities of ten organophosphorus (OP) insecticides were measured against midge larvae (Chironomus riparius) under varying temperature (11, 18, and 25°C) and pH (6, 7, and 8) conditions and with and without sediment. Toxicity usually increased with increasing temperature and was greater in the absence of sediment. No trend was found with varying pH. A series of unidimensional parameters and multidimensional models were used to describe the changes in toxicity. Log Kow was able to explain about 40–60% of the variability in response data for aqueous exposures while molecular volume and aqueous solubility were less predictive. Likewise, the linear solvation energy relationship (LSER) model only explained 40–70% of the response variability, suggesting that factors other than solubility were most important for producing the observed response. Molecular connectivity was the most useful for describing the variability in the response. In the absence of sediment, 1χv and 3κ were best able to describe the variation in response among all compounds at each pH (70–90%). In the presence of sediment, even molecular connectivity could not describe the variability until the partitioning potential to sediment was accounted for by assuming equilibrium partitioning. After correcting for partitioning, the same molecular connectivity terms as in the aqueous exposures described most of the variability, 61–87%, except for the 11°C data where correlations were not significant. Molecular connectivity was a better tool than LSER or the unidimensional variables to explain the steric fitness of OP insecticides which was crucial to the toxicity.

  7. Diversity of non-biting midge larvae assemblages in the Jacuí River basin, Brazil.

    PubMed

    Floss, Elzira Cecília Serafini; Kotzian, Carla Bender; Spies, Márcia Regina; Secretti, Elisangela

    2012-01-01

    The richness and composition of a mountain-river chironomid larvae assemblage in the Jacuí River basin, Brazil were studied, and compared with other riverine non-biting midge larvae assemblages previously studied in the country. Additionally, the influence of some regional-scale environmental characteristics on the spatial distribution of these assemblages was tested. The specimens were collected at 12 sites in the middle course of the Jacuí River basin (in the state of Rio Grande do Sul) between April 2000 and May 2002. Around 100 taxa were recorded. The dominant taxa belonged to the genera Rheotanytarsus, Cricotopus, Polypedilum, and Pseudochironomus. Twenty-two rare taxa were found, representing 22% of the total of taxa inventoried. Fourteen genera (Aedokritus, Axarus, Endotribelos, Kiefferulus, Manoa, Oukuriella, Phaenopsectra, Stenochironomus, Xenochironomus, Xestochironomus, Cardiocladius, Metriocnemus, Paracladius, and Rheocricotopus) represent new occurrences in Rio Grande do Sul. The similarity analysis of the chironomid larvae assemblages inventoried in 32 regions of Brazil indicated five groups with similarity higher than 50%. The groups, when the effects of spatial autocorrelation were removed, displayed a weak positive correlation between the assemblage composition and the aquatic system or hydraulic conditions and the hydrographic basin, and a weak negative correlation in relation to the biome. The altitude showed no correlation with the composition of the assemblage. The relatively high richness of the region surveyed in relation to other Brazilian regions corroborates some tendencies already noted in other parts of the world, such as: i) lotic systems may constitute an exception to the rule that diversity is greater in tropical regions, ii) regions of transitional relief may contain the greatest richness of Chironomidae, and iii) in rivers, the group might have its spatial distribution influenced to a greater extent by local environmental

  8. The Asian Rice Gall Midge (Orseolia oryzae) Mitogenome Has Evolved Novel Gene Boundaries and Tandem Repeats That Distinguish Its Biotypes

    PubMed Central

    Atray, Isha; Bentur, Jagadish Sanmallappa; Nair, Suresh

    2015-01-01

    The complete mitochondrial genome of the Asian rice gall midge, Orseolia oryzae (Diptera; Cecidomyiidae) was sequenced, annotated and analysed in the present study. The circular genome is 15,286 bp with 13 protein-coding genes, 22 tRNAs and 2 ribosomal RNA genes, and a 578 bp non-coding control region. All protein coding genes used conventional start codons and terminated with a complete stop codon. The genome presented many unusual features: (1) rearrangement in the order of tRNAs as well as protein coding genes; (2) truncation and unusual secondary structures of tRNAs; (3) presence of two different repeat elements in separate non-coding regions; (4) presence of one pseudo-tRNA gene; (5) inversion of the rRNA genes; (6) higher percentage of non-coding regions when compared with other insect mitogenomes. Rearrangements of the tRNAs and protein coding genes are explained on the basis of tandem duplication and random loss model and why intramitochondrial recombination is a better model for explaining rearrangements in the O. oryzae mitochondrial genome is discussed. Furthermore, we evaluated the number of iterations of the tandem repeat elements found in the mitogenome. This led to the identification of genetic markers capable of differentiating rice gall midge biotypes and the two Orseolia species investigated. PMID:26226163

  9. Exploring the utility of DNA barcoding in species delimitation of Polypedilum (Tripodura) non-biting midges (Diptera: Chironomidae).

    PubMed

    Song, Chao; Wang, Qian; Zhang, Ruilei; Sun, Bingjiao; Wang, Xinhua

    2016-01-01

    In this study, we tested the utility of the mitochondrial gene cytochrome c oxidase subunit 1 (CO1) as the barcode region to deal with taxonomical problems of Polypedilum (Tripodura) non-biting midges (Diptera: Chironomidae). The 114 DNA barcodes representing 27 morphospecies are divided into 33 well separated clusters based on both Neighbor Joining and Maximum Likelihood methods. DNA barcodes revealed an 82% success rate in matching with morphospecies. The selected DNA barcode data support 37-64 operational taxonomic units (OTUs) based on the methods of Automatic Barcode Gap Discovery (ABGD) and Poisson Tree Process (PTP). Furthermore, a priori species based on consistent phenotypic variations were attested by molecular analysis, and a taxonomical misidentification of barcode sequences from GenBank was found. We could not observe a distinct barcode gap but an overlap ranged from 9-12%. Our results supported DNA barcoding as an ideal method to detect cryptic species, delimit sibling species, and associate different life stages in non-biting midges. PMID:27394207

  10. Effects of exposure to azaarenes on emergence and mouthpart development in the midge Chironomus riparius (Diptera: Chironomidae)

    SciTech Connect

    Bleeker, E.A.J.; Leslie, H.A.; Groenendijk, D.; Plans, M.; Admiraal, W.

    1999-08-01

    Adverse effects of azaarenes on emergence and mouthpart development of the midge Chironomus riparius were analyzed using six closely related three-ringed isomers and metabolites. Effects on growth rate were examined by comparing the average day of emergence of exposed midges with that of controls. Fluctuating asymmetry (FA) in the pecten epipharyngis was examined as a measure of developmental abnormality. Delayed emergence was found at concentrations as low as 2% of the acute LC50, so emergence day appears to be a useful sensitive parameter to quantity life cycle effects. No differences in FA were found between exposed and control larvae, although, in other studies, all compounds have been proven to be genotoxic. The differences in FA were found between exposed and control larvae, although, in other studies, all compounds have been proven to be genotoxic. The differences in the genotoxic and FA-inducing properties of these compounds indicate that different mechanisms are involved in expressing these adverse effects. This study also illustrates that the choice of the morphological parameter strongly influences the results of developmental disturbance analyses and thus the risk qualification of a potentially hazardous compound.

  11. Bringing gay and lesbian activism to the White House: Midge Costanza and the National Gay Task Force Meeting.

    PubMed

    Mattingly, Doreen J; Boyd, Ashley

    2013-01-01

    In March 1977, President Carter's Assistant Margaret "Midge" Costanza made history by meeting with representatives from the National Gay Task Force (NGTF) to hear their grievances about discriminatory federal policies. The effects of the meeting were many, including changes in policies of the Bureau of Prisons and the Public Health Service. It also initiated policy discussions that would continue for decades and contributed to the incorporation of gay rights within the Democratic Party. Midge Costanza was fundamental to the process. It was her decision to hold the meeting and to advocate on behalf of the NGTF, and she bore many of the meeting's political costs. In this article we make use of Costanza's own papers and multiple interviews with her to closely analyze Costanza's role in the historic meeting. In addition to adding detail to its politics and policy impacts of the meeting, we also look at her complex motivations for holding such a controversial meeting. Costanza maintained until her death in 2010 that she was motivated by her feminism and overall commitment to social justice, rather than her own identity or experiences. PMID:23855947

  12. Life-cycle changes and zinc shortage in cadmium-tolerant midges, Chironomus riparius (Diptera), reared in the absence of cadmium

    SciTech Connect

    Postma, J.F.; Mol, S.; Larsen, H.; Admiraal, W. . Section of Aquatic Ecotoxicology)

    1995-01-01

    Adaptation to selected metals is known to modify life-cycle characteristics of some invertebrates and can modify the response to other metals. The reverse process, i.e., adaptation to nonpolluted conditions in a metal-tolerant strain, was studied here for a cadmium-tolerant population of the midge Chironomus riparius to detect whether this backward adaptation followed the same lines. It appeared that cadmium-tolerant populations, reared in the absence of cadmium, continued to suffer from high mortality rates and lowered larval growth rates and reproductive success. Also, some cadmium-tolerant populations accumulated more zinc than did nontolerant populations. Successive experiments in which both cadmium-tolerant and nontolerant populations were exposed to zinc indicated that the reduced growth rate and reproduction were a direct consequence of zinc shortage in tolerant midges reared in the absence of cadmium. Mortality among cadmium-tolerant midges was, however, not lowered by zinc exposure and, judged by their high mortality rates, these midges were even more sensitive to zinc than were nontolerant chironomids. It was concluded that cadmium-tolerant chironomid populations recovering from prolonged exposure are affected by an increased need for zinc as well as by an increased mortality rate as a direct consequence of their earlier adaptation process.

  13. Functional responses and prey-stage preferences of a predatory gall midge and two predacious mites wtih twospotted spider mites, Tetranychus urticae as host

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The twospotted spider mite, Tetranychus urticae (Acari: Tetranychidae), is an important pest of vegetables and other crops. This study was conducted to evaluate and compare the potential role of three commercially available predators, predatory gall midge, Feltiella acarisuga (Vallot) (Diptera: Ceci...

  14. Pyrosequencing Reveals the Predominance of Pseudomonadaceae in Gut Microbiome of a Gall Midge

    PubMed Central

    Bansal, Raman; Hulbert, Scot H.; Reese, John C.; Whitworth, Robert J.; Stuart, Jeffrey J.; Chen, Ming-Shun

    2014-01-01

    Gut microbes are known to play various roles in insects such as digestion of inaccessible nutrients, synthesis of deficient amino acids, and interaction with ecological environments, including host plants. Here, we analyzed the gut microbiome in Hessian fly, a serious pest of wheat. A total of 3,654 high quality sequences of the V3 hypervariable region of the 16S rRNA gene were obtained through 454-pyrosequencing. From these sequences, 311 operational taxonomic units (OTUs) were obtained at the ≥97% similarity cutoff. In the gut of 1st instar, otu01, a member of Pseudomonas, was predominant, representing 90.2% of total sequences. otu13, an unidentified genus in the Pseudomonadaceae family, represented 1.9% of total sequences. The remaining OTUs were each less than 1%. In the gut of the 2nd instar, otu01 and otu13 decreased to 85.5% and 1.5%, respectively. otu04, a member of Buttiauxella, represented 9.7% of total sequences. The remaining OTUs were each less than 1%. In the gut of the 3rd instar, otu01 and otu13 further decreased to 29.0% and 0%, respectively. otu06, otu08, and otu16, also three members of the Pseudomonadaceae family were 13.2%, 8.6%, and 2.3%, respectively. In addition, otu04 and otu14, two members of the Enterobacteriaceae family, were 4.7% and 2.5%; otu18 and otu20, two members of the Xanthomonadaceae family, were 1.3% and 1.2%, respectively; otu12, a member of Achromobacter, was 4.2%; otu19, a member of Undibacterium, was 1.4%; and otu9, otu10, and otu15, members of various families, were 6.1%, 6.3%, and 1.9%, respectively. The investigation into dynamics of Pseudomonas, the most abundant genera, revealed that its population level was at peak in freshly hatched or 1 day larvae as well as in later developmental stages, thus suggesting a prominent role for this bacterium in Hessian fly development and in its interaction with host plants. This study is the first comprehensive survey on bacteria associated with the gut of a gall midge, and

  15. A systematic analysis of the gap gene system in the moth midge Clogmia albipunctata.

    PubMed

    García-Solache, Mónica; Jaeger, Johannes; Akam, Michael

    2010-08-01

    The segmentation gene hierarchy of Drosophila melanogaster represents one of the best understood of the gene networks that generate pattern during embryogenesis. Some components of this network are ancient, while other parts of the network have evolved within the higher Diptera. To further understand the evolution of this gene network, we are studying the role of gap genes in a representative of a basally diverging dipteran lineage, the moth midge Clogmia albipunctata. We have isolated orthologues of all of the Drosophila trunk gap genes from Clogmia, and determined their domains of expression during the blastoderm stage of development, in relation to one another, and in relation to the expression of even-skipped (Calb-eve), a component of the pair-rule system that is directly regulated by the gap genes in Drosophila. We find that hunchback (Calb-hb), Krüppel (Calb-Kr), knirps (Calb-knl), giant (Calb-gt) and tailless (Calb-tll) are all expressed in patterns consistent with a gap segmentation role during blastoderm formation, but huckebein (Calb-hkb) is not. In the anterior half of the embryo, the relative positions of the gap gene expression domains in relation to one another, and in relation to the eve stripes, are rather well conserved. In the posterior half of the embryo, there are significant differences. Posteriorly, Calb-gt is expressed only transiently and very weakly, in a domain that overlaps entirely with that of Calb-knl. At late blastoderm stages, none of the candidate genes we have tested is expressed in the region between the posterior Calb-knl domain and Calb-tll. It is likely that the regulation of Calb-eve expression in this posterior region depends on combinations of gap gene factors that differ from those utilised for the same stripes in Drosophila. Both the gap and the pair-rule patterns of gene expression are dynamic in Clogmia, as they are in Drosophila, shifting anteriorly as blastoderm development proceeds. PMID:20433825

  16. An equal sex ratio followed by differential sex mortality causes overestimation of females in gall midges: no evidence for sex ratio regulation.

    PubMed

    Tabadkani, Seyed Mohammad; Ashouri, Ahmad; Qolizadeh, Majid

    2012-06-01

    Monogeny, the production of unisexual broods by individual females, has been recognized for nearly 80 years. The genetic nature of gall midges' sex determination predicts an equal numbers of male-producing and female-producing females in the populations such that the overall sex ratio is expected to be nearly 1:1. However, observations of some strictly monogenous populations with biased sex ratio, mainly toward females, have raised the question of whether gall midges are able to adjust their offspring sex ratio in response to changes in environmental conditions, and some authors have even considered sex ratio regulation as a strong force in the course of the evolution of monogeny. In this paper, first, by studying the sex ratio variations of the predatory gall midge, Aphidoletes aphidimyza within a generation, we showed that adult males emerge up to 1 day earlier and have shorter life span than females (less than 4 days and up to 6 days, respectively). Although, the sex ratio of A. aphidimyza at the time of emergence was nearly 1:1 (52.41% males), a simple population simulation indicated that the differential mortality of sexes can lead to a female-biased sex ratio estimation (57.88% females) under random sampling in the natural environments. Our results imply that the primary sex ratio of monogenous gall midges is nearly 1:1 and that the arrhenogenic/thelygenic gall midges are not able to alter the number of their male/female progenies in response to changes in environmental conditions. PMID:22643882

  17. An equal sex ratio followed by differential sex mortality causes overestimation of females in gall midges: no evidence for sex ratio regulation

    NASA Astrophysics Data System (ADS)

    Tabadkani, Seyed Mohammad; Ashouri, Ahmad; Qolizadeh, Majid

    2012-06-01

    Monogeny, the production of unisexual broods by individual females, has been recognized for nearly 80 years. The genetic nature of gall midges' sex determination predicts an equal numbers of male-producing and female-producing females in the populations such that the overall sex ratio is expected to be nearly 1:1. However, observations of some strictly monogenous populations with biased sex ratio, mainly toward females, have raised the question of whether gall midges are able to adjust their offspring sex ratio in response to changes in environmental conditions, and some authors have even considered sex ratio regulation as a strong force in the course of the evolution of monogeny. In this paper, first, by studying the sex ratio variations of the predatory gall midge, Aphidoletes aphidimyza within a generation, we showed that adult males emerge up to 1 day earlier and have shorter life span than females (less than 4 days and up to 6 days, respectively). Although, the sex ratio of A. aphidimyza at the time of emergence was nearly 1:1 (52.41 % males), a simple population simulation indicated that the differential mortality of sexes can lead to a female-biased sex ratio estimation (57.88 % females) under random sampling in the natural environments. Our results imply that the primary sex ratio of monogenous gall midges is nearly 1:1 and that the arrhenogenic/thelygenic gall midges are not able to alter the number of their male/female progenies in response to changes in environmental conditions.

  18. Discovery and Evolution of Bunyavirids in Arctic Phantom Midges and Ancient Bunyavirid-Like Sequences in Insect Genomes

    PubMed Central

    Bruenn, Jeremy A.; Hay, John; Czechowski, Donna; Taylor, Derek J.

    2014-01-01

    ABSTRACT Bunyaviridae is a large family of RNA viruses chiefly comprised of vertebrate and plant pathogens. We discovered novel bunyavirids that are approximately equally divergent from each of the five known genera. We characterized novel genome sequences for two bunyavirids, namely, Kigluaik phantom virus (KIGV), from tundra-native phantom midges (Chaoborus), and Nome phantom virus (NOMV), from tundra-invading phantom midges, and demonstrated that these bunyavirid-like sequences belong to an infectious virus by passaging KIGV in mosquito cell culture, although the infection does not seem to be well sustained beyond a few passages. Virus and host gene sequences from individuals collected on opposite ends of North America, a region spanning 4,000 km, support a long-term, vertically transmitted infection of KIGV in Chaoborus trivittatus. KIGV-like sequences ranging from single genes to full genomes are present in transcriptomes and genomes of insects belonging to six taxonomic orders, suggesting an ancient association of this clade with insect hosts. In Drosophila, endogenous virus genes have been coopted, forming an orthologous tandem gene family that has been maintained by selection during the radiation of the host genus. Our findings indicate that bunyavirid-host interactions in nonbloodsucking arthropods have been much more extensive than previously thought. IMPORTANCE Very little is known about the viral diversity in polar freshwater ponds, and perhaps less is known about the effects that climate-induced habitat changes in these regions will have on virus-host interactions in the coming years. Our results show that at the tundra-boreal boundary, a hidden viral landscape is being altered as infected boreal phantom midges colonize tundra ponds. Likewise, relatively little is known of the deeper evolutionary history of bunyavirids that has led to the stark lifestyle contrasts between some genera. The discovery of this novel bunyavirid group suggests that ancient

  19. Experimental infection of Holstein cows and calves with EHDV‑7 and preliminary evaluation of different inoculation methods.

    PubMed

    Ruder, Mark G; Mead, Daniel G; Stallknecht, David E; Kedmi, Maor; Klement, Eyal; Brown, Justin D; Carter, Deborah L; Howerth, Elizabeth W

    2015-01-01

    Infection of cattle with epizootic haemorrhagic disease (EHD) virus (EHDV) is frequently subclinical, yet reports of disease have increased in recent years. In 2006, a widespread EHDV‑7 epidemic caused disease and economic loss in the Israeli dairy industry. In this study, the main objective was to infect cattle with EHDV‑7 and replicate disease observed in Israel during 2006. Two infection studies were performed. Experiment 1, 4 cows inoculated with intradermal (ID) and subcutaneous (SC) injections with an EHDV‑7 blood inoculum. Experiment 2, 6 calves inoculated using 1 of the following 3 methods (2 calves/method): (1) mammalian cell culture supernatant by ID and SC injection; (2) culture supernatant by ID, SC, and intravenous injection; and (3) bite transmission from Culicoides sonorensis. Further, during experiment 2, C. sonorensis were fed on 4 infected calves (18 days post-inoculation) and processed for virus isolation 10 days later in order to evaluate infectivity of low‑titer viraemia. Three cows had detectable viraemia and all 4 seroconverted. No clinical signs were observed. All 6 calves developed viraemia, peaking 7‑10 dpi and all calves seroconverted. No differences in virus kinetics were observed between the inoculation groups. Calves in group 2 had transiently elevated rectal temperatures but no other clinical abnormalities were observed. The 124 midge pools processed after feeding on calves with low‑titer viraemia were virus isolation negative. Detectable viraemia was more consistent in calves than adult cows. This study demonstrates US‑origin cattle are susceptible to EHDV‑7 infection by multiple inoculation methods; however, as reported in other studies, the disease was not replicated experimentally. PMID:26741239

  20. Behavioural, ecological and genetic evidence confirm the occurrence of host-associated differentiation in goldenrod gall-midges.

    PubMed

    Dorchin, N; Scott, E R; Clarkin, C E; Luongo, M P; Jordan, S; Abrahamson, W G

    2009-04-01

    Host-associated differentiation (HAD) is considered a step towards ecological speciation and an important mechanism promoting diversification in phytophagous insects. Although the number of documented cases of HAD is increasing, these still represent only a small fraction of species and feeding guilds among phytophagous insects, and most reports are based on a single type of evidence. Here we employ a comprehensive approach to present behavioural, morphological, ecological and genetic evidence for the occurrence of HAD in the gall midge Dasineura folliculi (Diptera: Cecidomyiidae) on two sympatric species of goldenrods (Solidago rugosa and S. gigantea). Controlled experiments revealed assortative mating and strong oviposition fidelity for the natal-host species. Analysis of mitochondrial DNA showed an amount of genetic divergence between the two host-associated populations compatible with cryptic species rather than host races. Lower levels of within-host genetic divergence, gall development and natural-enemy attack in the S. gigantea population suggest this is the derived host.

  1. A simulation approach to assessing sampling strategies for insect pests: an example with the balsam gall midge.

    PubMed

    Carleton, R Drew; Heard, Stephen B; Silk, Peter J

    2013-01-01

    Estimation of pest density is a basic requirement for integrated pest management in agriculture and forestry, and efficiency in density estimation is a common goal. Sequential sampling techniques promise efficient sampling, but their application can involve cumbersome mathematics and/or intensive warm-up sampling when pests have complex within- or between-site distributions. We provide tools for assessing the efficiency of sequential sampling and of alternative, simpler sampling plans, using computer simulation with "pre-sampling" data. We illustrate our approach using data for balsam gall midge (Paradiplosis tumifex) attack in Christmas tree farms. Paradiplosis tumifex proved recalcitrant to sequential sampling techniques. Midge distributions could not be fit by a common negative binomial distribution across sites. Local parameterization, using warm-up samples to estimate the clumping parameter k for each site, performed poorly: k estimates were unreliable even for samples of n ∼ 100 trees. These methods were further confounded by significant within-site spatial autocorrelation. Much simpler sampling schemes, involving random or belt-transect sampling to preset sample sizes, were effective and efficient for P. tumifex. Sampling via belt transects (through the longest dimension of a stand) was the most efficient, with sample means converging on true mean density for sample sizes of n ∼ 25-40 trees. Pre-sampling and simulation techniques provide a simple method for assessing sampling strategies for estimating insect infestation. We suspect that many pests will resemble P. tumifex in challenging the assumptions of sequential sampling methods. Our software will allow practitioners to optimize sampling strategies before they are brought to real-world applications, while potentially avoiding the need for the cumbersome calculations required for sequential sampling methods.

  2. Osmoregulation and salinity tolerance in the Antarctic midge, Belgica antarctica: seawater exposure confers enhanced tolerance to freezing and dehydration.

    PubMed

    Elnitsky, Michael A; Benoit, Joshua B; Lopez-Martinez, Giancarlo; Denlinger, David L; Lee, Richard E

    2009-09-01

    Summer storms along the Antarctic Peninsula can cause microhabitats of the terrestrial midge Belgica antarctica to become periodically inundated with seawater from tidal spray. As microhabitats dry, larvae may be exposed to increasing concentrations of seawater. Alternatively, as a result of melting snow or following rain, larvae may be immersed in freshwater for extended periods. The present study assessed the tolerance and physiological response of B. antarctica larvae to salinity exposure, and examined the effect of seawater acclimation on their subsequent tolerance of freezing, dehydration and heat shock. Midge larvae tolerated extended exposure to hyperosmotic seawater; nearly 50% of larvae survived a 10-day exposure to 1000 mOsm kg(-1) seawater and approximately 25% of larvae survived 6 days in 2000 mOsm kg(-1) seawater. Exposure to seawater drastically reduced larval body water content and increased hemolymph osmolality. By contrast, immersion in freshwater did not affect water content or hemolymph osmolality. Hyperosmotic seawater exposure, and the accompanying osmotic dehydration, resulted in a significant correlation between the rate of oxygen consumption and larval water content and induced the de novo synthesis and accumulation of several organic osmolytes. A 3-day exposure of larvae to hyperosmotic seawater increased freezing tolerance relative to freshwater-acclimated larvae. Even after rehydration, the freezing survival of larvae acclimated to seawater was greater than freshwater-acclimated larvae. Additionally, seawater exposure increased the subsequent tolerance of larvae to dehydration. Our results further illustrate the similarities between these related, yet distinct, forms of osmotic stress and add to the suite of physiological responses used by larvae to enhance survival in the harsh and unpredictable Antarctic environment. PMID:19684222

  3. Pheromone-based action thresholds for control of the swede midge, Contarinia nasturtii (Diptera: Cecidomyiidae), and residual insecticide efficacy in cole crops.

    PubMed

    Hallett, Rebecca H; Sears, Mark K

    2013-02-01

    The swede midge, Contarinia nasturtii (Kieffer), is an invasive gall midge causing economic damage to cole crops (Brassica oleracea L.) and other crucifers in eastern Canada and United States. An effective decision-making tool for timing insecticide applications is a critical part of an integrated pest management program against C. nasturtii. Experiments were undertaken over 2 yr and at three locations in southern Ontario to develop pheromone-based action thresholds for C. nasturtii in cabbage and broccoli. An economic comparison between action threshold and calendar insecticide regimes was undertaken. The threshold approach was both economically viable and successful at minimizing swede midge damage for cabbage, and an action threshold of five males per trap per day with a minimum 7 d retreatment interval successfully reduced damage to acceptable levels. However, this approach was not successful with broccoli, which, unlike cabbage, is susceptible to damage by C. nasturtii through all plant stages, including heading. Acetamiprid and lambda-cyhalothrin both demonstrated approximately 7 d residual activity against C. nasturtii. Registration labels for both insecticides specify a minimum 7 d retreatment interval, which is supported by residual efficacy results. More effective insecticidal products may have longer residual efficacy and improve efficacy of the action threshold approach for broccoli and cabbage. PMID:23448040

  4. Changing the content of phenolic compounds as the response of blackcurrant (Ribes nigrum L.) leaves after blackcurrant leaf midge (Dasineura tetensi Rübs.) infestation.

    PubMed

    Piotrowski, Wojciech; Oszmiański, Jan; Wojdyło, Aneta; Łabanowska, Barbara H

    2016-09-01

    Blackcurrant leaf midge (Dasineura tetensi) is one of the most common pests of blackcurrant (Ribes nigrum). The aim of this study was to investigate changes in the content of phenolic compounds in the leaves damaged by the larvae of this pest. Additionally, susceptibility of different blackcurrant cultivars to the midge attack was investigated. Qualitative and quantitative analyses of control and pest-infested blackcurrant leaves were performed using LC-PDA-QTOF/MS and UPLC-PDA-FL systems. A total of 39 types of phenolic compounds were identified in blackcurrant leaf extracts and they included 3 flavan-3-ols, 14 hydroxycinnamic acid derivatives, and 22 flavonols. Feeding of blackcurrant leaf midge on blackcurrant leaves lowered the content of leaf polyphenolic compounds. The greatest differences in polyphenolics between control and infected leaves were observed in 'Ruben', 'Fariegh', 'Foxendown', 'Ores', 'Ben Hope', 'Ben Connan' and 'Tisel' cultivars that were probably highly susceptible to the pest attack. In the other cultivars: 'Ben Finlay', 'Polares', 'Tiben', and 'Gofert' the differences in phenolics content were less pronounced, so they were probably less susceptible to D. tetensi attack. Plant polyphenolic compounds was strongly involved in pathogen-plant interaction, and their accumulation significantly decreased as a result of the pathogen attack. PMID:27161581

  5. Full genome characterization of the culicoides-borne marsupial orbiviruses: Wallal virus, Mudjinbarry virus and Warrego viruses.

    PubMed

    Belaganahalli, Manjunatha N; Maan, Sushila; Maan, Narender S; Pritchard, Ian; Kirkland, Peter D; Brownlie, Joe; Attoui, Houssam; Mertens, Peter P C

    2014-01-01

    Viruses belonging to the species Wallal virus and Warrego virus of the genus Orbivirus were identified as causative agents of blindness in marsupials in Australia during 1994/5. Recent comparisons of nucleotide (nt) and amino acid (aa) sequences have provided a basis for the grouping and classification of orbivirus isolates. However, full-genome sequence data are not available for representatives of all Orbivirus species. We report full-genome sequence data for three additional orbiviruses: Wallal virus (WALV); Mudjinabarry virus (MUDV) and Warrego virus (WARV). Comparisons of conserved polymerase (Pol), sub-core-shell 'T2' and core-surface 'T13' proteins show that these viruses group with other Culicoides borne orbiviruses, clustering with Eubenangee virus (EUBV), another orbivirus infecting marsupials. WARV shares <70% aa identity in all three conserved proteins (Pol, T2 and T13) with other orbiviruses, consistent with its classification within a distinct Orbivirus species. Although WALV and MUDV share <72.86%/67.93% aa/nt identity with other orbiviruses in Pol, T2 and T13, they share >99%/90% aa/nt identities with each other (consistent with membership of the same virus species - Wallal virus). However, WALV and MUDV share <68% aa identity in their larger outer capsid protein VP2(OC1), consistent with membership of different serotypes within the species - WALV-1 and WALV-2 respectively. PMID:25299687

  6. Full genome characterization of the culicoides-borne marsupial orbiviruses: Wallal virus, Mudjinbarry virus and Warrego viruses.

    PubMed

    Belaganahalli, Manjunatha N; Maan, Sushila; Maan, Narender S; Pritchard, Ian; Kirkland, Peter D; Brownlie, Joe; Attoui, Houssam; Mertens, Peter P C

    2014-01-01

    Viruses belonging to the species Wallal virus and Warrego virus of the genus Orbivirus were identified as causative agents of blindness in marsupials in Australia during 1994/5. Recent comparisons of nucleotide (nt) and amino acid (aa) sequences have provided a basis for the grouping and classification of orbivirus isolates. However, full-genome sequence data are not available for representatives of all Orbivirus species. We report full-genome sequence data for three additional orbiviruses: Wallal virus (WALV); Mudjinabarry virus (MUDV) and Warrego virus (WARV). Comparisons of conserved polymerase (Pol), sub-core-shell 'T2' and core-surface 'T13' proteins show that these viruses group with other Culicoides borne orbiviruses, clustering with Eubenangee virus (EUBV), another orbivirus infecting marsupials. WARV shares <70% aa identity in all three conserved proteins (Pol, T2 and T13) with other orbiviruses, consistent with its classification within a distinct Orbivirus species. Although WALV and MUDV share <72.86%/67.93% aa/nt identity with other orbiviruses in Pol, T2 and T13, they share >99%/90% aa/nt identities with each other (consistent with membership of the same virus species - Wallal virus). However, WALV and MUDV share <68% aa identity in their larger outer capsid protein VP2(OC1), consistent with membership of different serotypes within the species - WALV-1 and WALV-2 respectively.

  7. Unbalanced activation of glutathione metabolic pathways suggests potential involvement in plant defense against the gall midge Mayetiola destructor in wheat.

    PubMed

    Liu, Xuming; Zhang, Shize; Whitworth, R Jeff; Stuart, Jeffrey J; Chen, Ming-Shun

    2015-01-01

    Glutathione, γ-glutamylcysteinylglycine, exists abundantly in nearly all organisms. Glutathione participates in various physiological processes involved in redox reactions by serving as an electron donor/acceptor. We found that the abundance of total glutathione increased up to 60% in resistant wheat plants within 72 hours following attack by the gall midge Mayetiola destructor, the Hessian fly. The increase in total glutathione abundance, however, is coupled with an unbalanced activation of glutathione metabolic pathways. The activity and transcript abundance of glutathione peroxidases, which convert reduced glutathione (GSH) to oxidized glutathione (GSSG), increased in infested resistant plants. However, the enzymatic activity and transcript abundance of glutathione reductases, which convert GSSG back to GSH, did not change. This unbalanced regulation of the glutathione oxidation/reduction cycle indicates the existence of an alternative pathway to regenerate GSH from GSSG to maintain a stable GSSG/GSH ratio. Our data suggest the possibility that GSSG is transported from cytosol to apoplast to serve as an oxidant for class III peroxidases to generate reactive oxygen species for plant defense against Hessian fly larvae. Our results provide a foundation for elucidating the molecular processes involved in glutathione-mediated plant resistance to Hessian fly and potentially other pests as well. PMID:25627558

  8. Head capsule deformities in midge larvae exposed to Burlington Harbor (Lake Champlain) sediments -- field and laboratory investigations

    SciTech Connect

    Lester, D.; Williams, A.; McIntosh, A.; Lacey, R.

    1994-12-31

    Investigations of sediment associated contaminants in Burlington Harbor indicated the harbor contains elevated levels of a number of pollutants. Lead, silver, mercury and total PAH levels exceed NOAA`s ER-M at numerous sites in the harbor. Benzo(a)pyrene concentrations (ranging from 0.055 to 6.64 ug/g (dry wt.)) exceed the ER-M at a number of sites. Pyrene, phenanthrene, fluoranthene, chrysene, anthracene and fluorene also exceed the ER-M at a number of stations within the harbor. Despite these relatively high levels of contaminants found in harbor sediments, solid phase and pore water exposures with Ceriodaphnia dubia indicate acute toxicity at only a limited number of sites. Examination of midge larvae populations from the harbor, however, indicates a high rate of head capsule deformities at some sites. Preliminary work which exposed laboratory cultures of Chironomus tentans to harbor sediment induced a 17% incidence in deformities in the F{sub 1} generation, a 50% incidence in the F{sub 2} generation and a 75% in the F{sub 3} generation. The incidence of deformities decreased substantially when F{sub 3} generation organisms were reared in clean substrate. Laboratory cultures of C. tentans are being exposed to sediments from various harbor sites for determination of head capsule deformity induction. In addition, several generations of larvae will be reared in sediment to determine the overall impacts on survival and whether deformities increase in subsequent generations.

  9. Suitability of morphological parameters for instar determination of pestiferous midges Chironomus crassicaudatus and Glyptotendipes paripes (Diptera: Chironomidae) under laboratory conditions.

    PubMed

    Frouz, Jan; Ali, Arshad; Lobinske, Richard J

    2002-09-01

    The midges Chironomus crassicaudatus and Glyptotendipes paripes were reared in the laboratory on artificial food under constant temperature (30 degrees C) and a 14:10 h light: dark photoperiod for 31 days, from eggs laid by field-collected females. Sequential samples of developing immature stages were taken and measured. Eggs were on average 254 microm long and 102 microm wide at the widest point for C. crassicaudatus and 286 microm long and 113 microm wide at the widest point for G. paripes. Mean larval lengths ranged from 0.9 mm after hatching to 16.3 mm before pupation in C. crassicaudatus and from 0.8 mm after hatching to 9.7 mm before pupation in G. paripes. Mean length of pupae was 8.7 mm and 8.3 mm in C. crassicaudatus and G. paripes, respectively. Four morphometric head parameters (length, width, mentum width, and cephalolabial length) were tested for differentiation of larval instars. All parameters revealed 4 larval instars in both species, with head capsule width apparently the most sensitive indicator for instar differentiation. The cephalolabial length was the most sensitive indicator of sex differentiation in last instar. All investigated morphological parameters of head capsule of both species followed Dyar's law. PMID:12322946

  10. Developing acute-to-chronic toxicity ratios for lead, cadmium, and zinc using rainbow trout, a mayfly, and a midge

    USGS Publications Warehouse

    Mebane, C.A.; Hennessy, D.P.; Dillon, F.S.

    2008-01-01

    In order to estimate acute-to-chronic toxicity ratios (ACRs) relevant to a coldwater stream community, we exposed rainbow trout (Oncorhynchus mykiss) to cadmium (Cd), lead (Pb), and zinc (Zn) in 96-h acute and 60+ day early-life stage (ELS) exposures. We also tested the acute and sublethal responses of a mayfly (Baetis tricaudatus) and a midge (Chironomus dilutus, formerly C. tentans) with Pb. We examine the statistical interpretation of test endpoints and the acute-to-chronic ratio concept. Increasing the number of control replicates by 2 to 3x decreased the minimum detectable differences by almost half. Pb ACR estimates mostly increased with increasing acute resistance of the organisms (rainbow trout ACRs

  11. Spatial and Temporal Distribution of Non-Biting Midge Larvae Assemblages in Streams in a Mountainous Region in Southern Brazil

    PubMed Central

    Floss, Elzira Cecília Serafini; Secretti, Elisangela; Kotzian, Carla Bender; Spies, Marcia Regina; Pires, Mateus Marques

    2013-01-01

    The spatial and temporal structure of non-biting midge (Diptera: Chironomidae) larvae assemblages and some environmental factors that affect their distribution were analyzed in a montane river and its tributaries in a temperate climate region of southernmost Brazil. In total, 69 taxa were recorded after four seasonal samplings (winter, spring, summer, and autumn). The dominant taxa were Rheotanytarsus sp. 1, Rheotanytarsus sp. 2, Cricotopus sp. 2, and Polypedilum (Polypedilum) sp., although dominance varied among the four sampling sites. The variations in dominance, abundance, and richness among the different sites were affected by environmental characteristics, such as the presence of marginal vegetation and a heterogeneous substratum, and also by human activities. Strictly environmental factors, such as altitude, and factors related to annual weather patterns, such as mean temperature and precipitation, influenced the spatial and temporal distribution of certain taxa and the structure of faunal assemblages. The influence of the riparian vegetation and riverbed heterogeneity on the composition, richness, and abundance of the chironomid larvae assemblages indicates that human activities, such as deforestation and the construction of dams, constitute a serious threat to the conservation of these insects and to the fauna that depends on them for food. PMID:24784953

  12. Spatial and temporal distribution of non-biting midge larvae assemblages in streams in a mountainous region in southern Brazil.

    PubMed

    Floss, Elzira Cecília Serafini; Secretti, Elisangela; Kotzian, Carla Bender; Spies, Marcia Regina; Pires, Mateus Marques

    2013-01-01

    The spatial and temporal structure of non-biting midge (Diptera: Chironomidae) larvae assemblages and some environmental factors that affect their distribution were analyzed in a montane river and its tributaries in a temperate climate region of southernmost Brazil. In total, 69 taxa were recorded after four seasonal samplings (winter, spring, summer, and autumn). The dominant taxa were Rheotanytarsus sp. 1, Rheotanytarsus sp. 2, Cricotopus sp. 2, and Polypedilum (Polypedilum) sp., although dominance varied among the four sampling sites. The variations in dominance, abundance, and richness among the different sites were affected by environmental characteristics, such as the presence of marginal vegetation and a heterogeneous substratum, and also by human activities. Strictly environmental factors, such as altitude, and factors related to annual weather patterns, such as mean temperature and precipitation, influenced the spatial and temporal distribution of certain taxa and the structure of faunal assemblages. The influence of the riparian vegetation and riverbed heterogeneity on the composition, richness, and abundance of the chironomid larvae assemblages indicates that human activities, such as deforestation and the construction of dams, constitute a serious threat to the conservation of these insects and to the fauna that depends on them for food.

  13. Corethrellonema grandispiculosum n. gen., n. sp. and Aproctonema chapmani n. sp. (Nematoda: Tetradonematidae), Parasites of the Dipterous Insect Genera, Corethrella and Culicoides in Louisiana.

    PubMed

    Nickle, W R

    1969-01-01

    Two new nematodes of the family Tetradonematidae, parasitic in aquatic dipterous insects in Louisiana, are presented. Corethrellonema grandispiculosum n. gen., n. sp., from the chaoborid fly, Corethrella brakeleyi Coquillett, and Aproctonema chapmani n. sp., from the sand fly, Culicoides arboricola Root and Hoffman, are described and illustrated. The biology and life histories of these nematodes show that the adults occur in the last larval instar of the insect host. The adult nematodes mate in the body cavity of the insect, and later the female nematode, replete with eggs, exits from the larval fly causing the death of the insect. Male nematodes usually remain in the insect cadaver.

  14. Population Genetic Structure and Potential Incursion Pathways of the Bluetongue Virus Vector Culicoides brevitarsis (Diptera: Ceratopogonidae) in Australia.

    PubMed

    Tay, W T; Kerr, P J; Jermiin, L S

    2016-01-01

    Culicoides brevitarsis is a vector of the bluetongue virus (BTV), which infects sheep and cattle. It is an invasive species in Australia with an assumed Asian/South East Asian origin. Using one mitochondrial marker (i.e., part of the cytochrome oxidase subunit I gene) and six nuclear markers, we inferred population genetic structure and possible incursion pathways for Australian C. brevitarsis. Nine mitochondrial haplotypes, with low nucleotide sequence diversity (0.0-0.7%) among these, were identified in a sample of 70 individuals from seven sites. Both sets of markers revealed a homogeneous population structure, albeit with evidence of isolation by distance and two genetically distinct clusters distributed along a north-to-south cline. No evidence of a cryptic species complex was found. The geographical distribution of the mitochondrial haplotypes is consistent with at least two incursion pathways into Australia since the arrival of suitable livestock hosts. By contrast, 15 mitochondrial haplotypes, with up to four times greater nucleotide sequence diversity (0.0-2.9%) among these, were identified in a sample of 16 individuals of the endemic C. marksi (sampled from a site in South Australia and another in New South Wales). A phylogenetic tree inferred using the mitochondrial marker revealed that the Australian and Japanese samples of C. brevitarsis are as evolutionarily different from one another as some of the other Australian species (e.g., C. marksi, C. henryi, C. pallidothorax) are. The phylogenetic tree placed four of the species endemic to Australia (C. pallidothorax, C. bundyensis, C. marksi, C. henryi) in a clade, with a fifth such species (C. bunrooensis) sharing a common ancestor with that clade and a clade comprising two Japanese species (C. verbosus, C. kibunensis).

  15. Population Genetic Structure and Potential Incursion Pathways of the Bluetongue Virus Vector Culicoides brevitarsis (Diptera: Ceratopogonidae) in Australia

    PubMed Central

    Tay, W. T.; Kerr, P. J.; Jermiin, L. S.

    2016-01-01

    Culicoides brevitarsis is a vector of the bluetongue virus (BTV), which infects sheep and cattle. It is an invasive species in Australia with an assumed Asian/South East Asian origin. Using one mitochondrial marker (i.e., part of the cytochrome oxidase subunit I gene) and six nuclear markers, we inferred population genetic structure and possible incursion pathways for Australian C. brevitarsis. Nine mitochondrial haplotypes, with low nucleotide sequence diversity (0.0–0.7%) among these, were identified in a sample of 70 individuals from seven sites. Both sets of markers revealed a homogeneous population structure, albeit with evidence of isolation by distance and two genetically distinct clusters distributed along a north-to-south cline. No evidence of a cryptic species complex was found. The geographical distribution of the mitochondrial haplotypes is consistent with at least two incursion pathways into Australia since the arrival of suitable livestock hosts. By contrast, 15 mitochondrial haplotypes, with up to four times greater nucleotide sequence diversity (0.0–2.9%) among these, were identified in a sample of 16 individuals of the endemic C. marksi (sampled from a site in South Australia and another in New South Wales). A phylogenetic tree inferred using the mitochondrial marker revealed that the Australian and Japanese samples of C. brevitarsis are as evolutionarily different from one another as some of the other Australian species (e.g., C. marksi, C. henryi, C. pallidothorax) are. The phylogenetic tree placed four of the species endemic to Australia (C. pallidothorax, C. bundyensis, C. marksi, C. henryi) in a clade, with a fifth such species (C. bunrooensis) sharing a common ancestor with that clade and a clade comprising two Japanese species (C. verbosus, C. kibunensis). PMID:26771743

  16. A Broad Assessment of Factors Determining Culicoides imicola Abundance: Modelling the Present and Forecasting Its Future in Climate Change Scenarios

    PubMed Central

    Acevedo, Pelayo; Ruiz-Fons, Francisco; Estrada, Rosa; Márquez, Ana Luz; Miranda, Miguel Angel; Gortázar, Christian; Lucientes, Javier

    2010-01-01

    Bluetongue (BT) is still present in Europe and the introduction of new serotypes from endemic areas in the African continent is a possible threat. Culicoides imicola remains one of the most relevant BT vectors in Spain and research on the environmental determinants driving its life cycle is key to preventing and controlling BT. Our aim was to improve our understanding of the biotic and abiotic determinants of C. imicola by modelling its present abundance, studying the spatial pattern of predicted abundance in relation to BT outbreaks, and investigating how the predicted current distribution and abundance patterns might change under future (2011–2040) scenarios of climate change according to the Intergovernmental Panel on Climate Change. C. imicola abundance data from the bluetongue national surveillance programme were modelled with spatial, topoclimatic, host and soil factors. The influence of these factors was further assessed by variation partitioning procedures. The predicted abundance of C. imicola was also projected to a future period. Variation partitioning demonstrated that the pure effect of host and topoclimate factors explained a high percentage (>80%) of the variation. The pure effect of soil followed in importance in explaining the abundance of C. imicola. A close link was confirmed between C. imicola abundance and BT outbreaks. To the best of our knowledge, this study is the first to consider wild and domestic hosts in predictive modelling for an arthropod vector. The main findings regarding the near future show that there is no evidence to suggest that there will be an important increase in the distribution range of C. imicola; this contrasts with an expected increase in abundance in the areas where it is already present in mainland Spain. What may be expected regarding the future scenario for orbiviruses in mainland Spain, is that higher predicted C. imicola abundance may significantly change the rate of transmission of orbiviruses. PMID:21151914

  17. Population Genetic Structure and Potential Incursion Pathways of the Bluetongue Virus Vector Culicoides brevitarsis (Diptera: Ceratopogonidae) in Australia.

    PubMed

    Tay, W T; Kerr, P J; Jermiin, L S

    2016-01-01

    Culicoides brevitarsis is a vector of the bluetongue virus (BTV), which infects sheep and cattle. It is an invasive species in Australia with an assumed Asian/South East Asian origin. Using one mitochondrial marker (i.e., part of the cytochrome oxidase subunit I gene) and six nuclear markers, we inferred population genetic structure and possible incursion pathways for Australian C. brevitarsis. Nine mitochondrial haplotypes, with low nucleotide sequence diversity (0.0-0.7%) among these, were identified in a sample of 70 individuals from seven sites. Both sets of markers revealed a homogeneous population structure, albeit with evidence of isolation by distance and two genetically distinct clusters distributed along a north-to-south cline. No evidence of a cryptic species complex was found. The geographical distribution of the mitochondrial haplotypes is consistent with at least two incursion pathways into Australia since the arrival of suitable livestock hosts. By contrast, 15 mitochondrial haplotypes, with up to four times greater nucleotide sequence diversity (0.0-2.9%) among these, were identified in a sample of 16 individuals of the endemic C. marksi (sampled from a site in South Australia and another in New South Wales). A phylogenetic tree inferred using the mitochondrial marker revealed that the Australian and Japanese samples of C. brevitarsis are as evolutionarily different from one another as some of the other Australian species (e.g., C. marksi, C. henryi, C. pallidothorax) are. The phylogenetic tree placed four of the species endemic to Australia (C. pallidothorax, C. bundyensis, C. marksi, C. henryi) in a clade, with a fifth such species (C. bunrooensis) sharing a common ancestor with that clade and a clade comprising two Japanese species (C. verbosus, C. kibunensis). PMID:26771743

  18. Isolation of bluetongue virus serotype 1 from Culicoides vector captured in livestock farms and sequence analysis of the viral genome segment-2.

    PubMed

    Dadawala, A I; Biswas, S K; Rehman, W; Chand, K; De, A; Mathapati, B S; Kumar, P; Chauhan, H C; Chandel, B S; Mondal, B

    2012-08-01

    Bluetongue virus serotype-1 (BTV-1) was isolated from Culicoides oxystoma vectors captured on livestock farms in two places of Gujarat, India. The viruses were isolated on BHK-21 cells, which produced characteristic BTV-related cytopathic effects between 24 and 48 h post-infection. Virus antigen was demonstrated in infected cells at different passage by a BTV-specific sandwich ELISA. Further, polyacrylamide gel electrophoresis and silver staining of viral genomic RNA revealed ten double-stranded RNA segments characteristic of BTV. Serotype of the isolates was identified by virus neutralization and PCR coupled with sequencing. The isolates were designated as SKN-7 and SKN-8 and their genome segment-2 (VP2) were sequenced. Phylogenetic analyses revealed very close relationship between them although they are not identical. SKN-8 showed closer relationship with a recently isolated BTV-1 from goat. Bluetongue virus was earlier isolated from Culicoides in adjacent state more than 20 years ago, although the serotype of the virus was not determined.

  19. A new species of the predaceous midge genus Brachypogon Kieffer from the Neotropical Region and first description of the female of Brachypogon (Isohelea) cuacuahuitlus Huerta & Borkent (Diptera: Ceratopogonidae).

    PubMed

    Huerta, Herón; Spinelli, Gustavo R

    2016-01-01

    The predaceous midge genus Brachypogon Kieffer is presently known in Mexico by Brachypogon (Brachypogon) fuscivenosus (Lutz, 1914), B. (B.) bimaculatus Spinelli & Grogan, 1998, B. (B.) woodruffi Spinelli & Grogan, 1998 and B. (Isohelea) cuacuahuitlus Huerta & Borkent, 2005. In this contribution a new species, Brachypogon (Brachypogon) ginue, is described and illustrated from a male specimen collected in Tlanchinol, State of Hidalgo, Mexico. This new species belongs to the impar species group. The first description of the female of Brachypogon (Isohelea) cuacuahuitlus Huerta & Borkent is also provided. PMID:27395848

  20. Biting midges of the tribe Ceratopogonini (Diptera: Ceratopogonidae) from the Middle East, with keys and descriptions of new species.

    PubMed

    Alwin-Kownacka, Alicja; Szadziewski, Ryszard; Szwedo, Jacek

    2016-01-01

    Middle East predatory biting midges of the tribe Ceratopogonini, covering 22 species of 7 genera are reviewed. Three new species are described and illustrated: Allohelea israelensis Szadziewski & Alwin sp. nov., Kolenohelea levantica Szadziewski & Alwin sp. nov. and Serromyia galilaeae Szadziewski & Alwin sp. nov. The genus Boreohelea Clastrier & Delécolle, 1990 syn. nov. is recognized as a junior synonym of Allohelea Kieffer, 1917. Thysanognathus nilogenes Kieffer, 1925 syn. nov. from Egypt is a junior synonym of Alluaudomyia melanosticta (Ingram & Macfie, 1922). Keys to identification of subfamilies, tribes, genera and species of Ceratopogonini of the Middle East are also provided. PMID:27394208

  1. Prevalence and dynamics of the zoosporic pathogen Catenaria uncinata in a natural population of the midge Glyptotendipes lobiferus.

    PubMed

    Martin, W Wallace; Warren, Alyssa

    2016-09-01

    A qPCR assay specific for zoospores of Catenaria uncinata, a fungal parasite in eggs of the midge Glyptotendipes lobiferus, was developed and used in parallel with traditional microscopic methods in a season-long study of a C. uncinata/G. lobiferus association in a local pond. Twenty-six consecutive weekly collections of egg masses were screened with a microscope to obtain percentages of infection and mortality in organogenetic egg masses and weekly water samples were processed by absolute quantification using qPCR to obtain estimates of zoospore density. Overall, 36.0% of G. lobiferus egg masses were infected to varying degrees and 11.2% of eggs were killed by C. uncinata. Continuous infection of egg masses occurred during a 6-wk period in May-June and a 7-wk period in September-October. Infection by C. uncinata was absent during a 10-week interval between periods of infection. Abrupt declines in zoospore density occurred during both infection periods and occurred only when water temperatures met or exceeded the viability threshold for zoospores (⩾31.0°C). The episodic death of zoospores during weeks in which egg infection and mortality levels were continuous likely resulted from distribution of zoospores throughout the water column and a temperature gradient in which zoospores sampled near the surface were subjected to lethal temperatures while non-sampled zoospores at lower depths were provided low temperature sanctuary. The hiatus of infection during the 10-week interval was likely due to lethal temperatures throughout the water column as average water temperatures exceeded 31.0°C over the period. A positive correlation between weekly zoospore densities obtained from qPCR and levels of infection/mortality in egg masses obtained from counts with a microscope supports the use of the qPCR assay alone in future studies that can rapidly and accurately determine parasite presence, prevalence and geographical range. PMID:27418147

  2. Ecdysteroid synthesis and imaginal disc development in the midge Chironomus riparius as biomarkers for endocrine effects of tributyltin.

    PubMed

    Hahn, Torsten; Schulz, Ralf

    2002-05-01

    Acute effects of the endocrine disruptor bis(tri-n-butyltin) oxide (TBTO) on molting-hormone biosynthesis and imaginal-disc development were investigated in larvae of the midge Chironomus riparius (Meigen). Ecdysteroid synthesis was measured by 24-h incubation of molting-hormone-synthesizing tissues (prothoracic glands) in vitro with or without the addition of TBTO. The amount of ecdysteroids produced was analyzed by radioimmunoassay. Developmental effects in vivo were investigated by determining the developmental phase of the genital imaginal discs before and after a 48-h exposure to TBTO in water. Sex-specific effects were found with both endpoints. Ecdysteroid synthesis was significantly reduced (analysis of variance [ANOVA], p < or = 0.005) in female larvae at all concentrations (TBTO-Sn at 50, 500, and 5,000 ng/L), whereas a significant elevation of the biosynthesis rate occurred in male larvae in the 500-ng/L treatment (ANOVA, p < or = 0.05). In vivo experiments with development of the genital imaginal disc within a 48-h exposure period revealed a significantly slower development in female larvae and a significantly faster development in male larvae (contingency tables, p < or = 0.001) at all concentrations tested (TBTO-Sn at 10, 50, 200, and 1,000 ng/L). These results partly coincided with the in vitro effects on molting-hormone synthesis. The 48-h median lethal concentration (LC50) was 25 microg/L (20-30 microg/L 95% confidence intervals). The combination of in vitro and in vivo methods has proven to be a useful approach for the detection of endocrine effects of TBTO in C. riparius at levels 2,000-fold below the LC50 value. High sensitivity and short test duration suggest that chironomids may have potential as freshwater sentinel organisms for endocrine-disrupting chemicals. PMID:12013127

  3. Quantitative Temperature Reconstructions from Holocene and Late Glacial Lake Sediments in the Tropical Andes using Chironomidae (non-biting midges)

    NASA Astrophysics Data System (ADS)

    Matthews-Bird, F.; Gosling, W. D.; Brooks, S. J.; Montoya, E.; Coe, A. L.

    2014-12-01

    Chironomidae (non-biting midges) is a family of two-winged aquatic insects of the order Diptera. They are globally distributed and one of the most diverse families within aquatic ecosystems. The insects are stenotopic, and the rapid turnover of species and their ability to colonise quickly favourable habitats means chironomids are extremely sensitive to environmental change, notably temperature. Through the development of quantitative temperature inference models chironomids have become important palaeoecological tools. Proxies capable of generating independent estimates of past climate are crucial to disentangling climate signals and ecosystem response in the palaeoecological record. This project has developed the first modern environmental calibration data set in order to use chironomids from the Tropical Andes as quantitative climate proxies. Using surface sediments from c. 60 lakes from Bolivia, Peru and Ecuador we have developed an inference model capable of reconstructing temperatures, with a prediction error of 1-2°C, from fossil assemblages. Here we present the first Lateglacial and Holocene chironomid-inferred temperature reconstructions from two sites in the tropical Andes. The first record, from a high elevation (4153 m asl) lake in the Bolivian Andes, shows persistently cool temperatures for the past 15 kyr, punctuated by warm episodes in the early Holocene (9-10 kyr BP). The chironomid-inferred Holocene temperature trends from a lake sediment record on the eastern Andean flank of Ecuador (1248 m asl) spanning the last 5 millennia are synchronous with temperature changes in the NGRIP ice core record. The temperature estimates suggest along the eastern flank of the Andes, at lower latitudes (~1°S), climate closely resemble the well-established fluctuations of the Northern Hemisphere for this time period. Late-glacial climate fluctuations across South America are still disputed with some palaeoecological records suggesting evidence for Younger Dryas

  4. Evolution of early development in dipterans: reverse-engineering the gap gene network in the moth midge Clogmia albipunctata (Psychodidae).

    PubMed

    Crombach, Anton; García-Solache, Mónica A; Jaeger, Johannes

    2014-09-01

    Understanding the developmental and evolutionary dynamics of regulatory networks is essential if we are to explain the non-random distribution of phenotypes among the diversity of organismic forms. Here, we present a comparative analysis of one of the best understood developmental gene regulatory networks today: the gap gene network involved in early patterning of insect embryos. We use gene circuit models, which are fitted to quantitative spatio-temporal gene expression data for the four trunk gap genes hunchback (hb), Krüppel (Kr), giant (gt), and knirps (kni)/knirps-like (knl) in the moth midge Clogmia albipunctata, and compare them to equivalent reverse-engineered circuits from our reference species, the vinegar fly Drosophila melanogaster. In contrast to the single network structure we find for D. melanogaster, our models predict four alternative networks for C. albipunctata. These networks share a core structure, which includes the central regulatory feedback between hb and knl. Other interactions are only partially determined, as they differ between our four network structures. Nevertheless, our models make testable predictions and enable us to gain specific insights into gap gene regulation in C. albipunctata. They suggest a less central role for Kr in C. albipunctata than in D. melanogaster, and show that the mechanisms causing an anterior shift of gap domains over time are largely conserved between the two species, although shift dynamics differ. The set of C. albipunctata gene circuit models presented here will be used as the starting point for data-constrained in silico evolutionary simulations to study patterning transitions in the early development of dipteran species. PMID:24911671

  5. Morphological and Molecular Revision of the Genus Ozirhincus (Diptera: Cecidomyiidae)—Long-Snouted Seed-Feeding Gall Midges on Asteraceae

    PubMed Central

    Dorchin, Netta; Astrin, Jonas J.; Bodner, Levona; Harris, Keith M.

    2015-01-01

    The Palaearctic gall-midge genus Ozirhincus is unique among the Cecidomyiidae for its morphology and biology. Unlike most other phytophagous gall midges, species in this genus do not induce galls but develop inside achenes of Asteraceae plants. The heads of adults are characterized by an unusually elongate proboscis, the function of which is unclear. Despite a lot of attention from taxonomists in the 19th and early 20th century, a proper revision of the genus has been hindered by complex host associations, the loss of most relevant type material, and the lack of a thorough comparative study of all life stages. The present revision integrated morphological, molecular, and life-history data to clearly define species boundaries within Ozirhincus, and delimit host-plant ranges for each of them. A phylogenetic analysis based on the mitochondrial COI and 16S genes confirmed the validity of four distinct species but did not resolve the relationships among them. All species are oligophages, and some may occur together on the same host plant. Species with wider host-plant ranges have wider European and circum-Mediterranean distribution ranges, whereas species with narrower host ranges are limited to Europe and the Russian Far East. As part of the present work, O. hungaricus is reinstated from synonymy, O. tanaceti is synonymized under O. longicollis, neotypes are designated for O. longicollis and O. millefolii, and a lectotype is designated for O. anthemidis. PMID:26134526

  6. Relative sensitivity of an amphipod Hyalella azteca, a midge Chironomus dilutus, and a unionid mussel Lampsilis siliquoidea to a toxic sediment

    USGS Publications Warehouse

    Ingersoll, Christopher G.; Kunz, James L.; Hughes, James P.; Wang, Ning; Ireland, D. Scott; Mount, Dave R.; Hockett, Russ J; Valenti, Ted W

    2015-01-01

    The objective of the present study was to evaluate the relative sensitivity of test organisms in exposures to dilutions of a highly toxic sediment contaminated with metals and organic compounds. One dilution series was prepared using control sand (low total organic carbon [TOC; <0.1%, low binding capacity for contaminants]) and a second dilution series was prepared using control sediment from West Bearskin Lake, Minnesota, USA (high TOC [~10% TOC, higher binding capacity for contaminants]). Test organisms included an amphipod (Hyalella azteca; 10-d and 28-d exposures), a midge (Chironomus dilutus; 20-d and 48-d exposures started with <1-h-old larvae, and 13-d and 48-d exposures started with 7-d-old larvae), and a unionid mussel (Lampsilis siliquoidea; 28-d exposures). Relative species sensitivitydepended on the toxicity endpoint and the diluent. All 3 species were more sensitive in sand dilutions than in West Bearskin Lake sediment dilutions. The <1-h-old C. dilutus were more sensitive than 7-d-old C. dilutus, but replicate variability was high in exposures started with the younger midge larvae. Larval biomass and adult emergence endpoints of C. dilutus exhibited a similar sensitivity. Survival, weight, and biomass of H. azteca were more sensitive endpoints in 28-d exposures than in 10-d exposures. Weight and biomass of L. siliquoidea were sensitive endpoints in both sand and West Bearskin Lake sediment dilutions. Metals, ammonia, oil, and other organic contaminants may have contributed to the observed toxicity.

  7. Man-biting species of Chrysops meigen, Culicoides latreille and Simulium latreille in Ethiopia, with discussion of their vector potentialities.

    PubMed

    White, G B

    1977-01-01

    Human filariasis and its vectors are little known in Ethiopia. Wuchereia bancrofti is confined to the western lowlands and cannot be the aetiological agent of elephantiasis in the highlands. Onchocerca volvulus is widespread in the south-western highlands. Loa loa and Dipetalonema perstans are reported here for the first time and appear to be uncommon. Studies were conducted in 1973, mostly near Jimma in Kaffa Province, on potential vectors of all but the first of these parasites. Among Simuliidae, the only blackflies of apparent medical importance were S. woodi ethiopiense and a possibly new member of the S. damnosum complex. The former is less seasonal and much less numerous than the latter, but may be more widespread and important along smaller and higher streams. Onchocerca larvae were recovered from "damnosum", but not from the small number (46) of ethiopiense examined. In August, at the height of the rainy season, the biting-rate of ethiopiense at 1,710 m altitude on the Gilgil Ghibe river reached 9.5/man-hour at 10-1100 hours and about 12/man-hour at 14-1600 hours. At the same time and place, the attack of "damnosum" reached a midday climax of about 1,800/man-hour; this peak could be delayed or suppressed by rain. Another possibly anthropophilic blackfly, S. dentulosum, tended to become most common in December afer the rainy season had passed, but proved incompetent to bite man successfully. The only feasible loiasis vector found in Ethiopia was Chrysops streptobalius; however, this tabanid was not closely associated with man. Up to 34/man-day were caught in watermeadows by the Gojeb river (altitude 1,160 m) in October. Man-biting species of Ceratopogonidae in various parts of Ethiopia were Culicoides fulvithorax, C. grahamii, C. kingi and C. milnei. The first two of these were anthropophilic in lowlands, but apparently not so in highlands. C. milnei was extremely abundant biting man highlands. C. milnei was extremely abundant biting man and domestic animals

  8. QTL Mapping in Three Rice Populations Uncovers Major Genomic Regions Associated with African Rice Gall Midge Resistance.

    PubMed

    Yao, Nasser; Lee, Cheng-Ruei; Semagn, Kassa; Sow, Mounirou; Nwilene, Francis; Kolade, Olufisayo; Bocco, Roland; Oyetunji, Olumoye; Mitchell-Olds, Thomas; Ndjiondjop, Marie-Noëlle

    2016-01-01

    African rice gall midge (AfRGM) is one of the most destructive pests of irrigated and lowland African ecologies. This study aimed to identify the quantitative trait loci (QTL) associated with AfRGM pest incidence and resistance in three independent bi-parental rice populations (ITA306xBW348-1, ITA306xTOG7106 and ITA306xTOS14519), and to conduct meta QTL (mQTL) analysis to explore whether any genomic regions are conserved across different genetic backgrounds. Composite interval mapping (CIM) conducted on the three populations independently uncovered a total of 28 QTLs associated with pest incidence (12) and pest severity (16). The number of QTLs per population associated with AfRGM resistance varied from three in the ITA306xBW348-1 population to eight in the ITA306xTOG7106 population. Each QTL individually explained 1.3 to 34.1% of the phenotypic variance. The major genomic region for AfRGM resistance had a LOD score and R2 of 60.0 and 34.1% respectively, and mapped at 111 cM on chromosome 4 (qAfrGM4) in the ITA306xTOS14519 population. The meta-analysis reduced the number of QTLs from 28 to 17 mQTLs, each explaining 1.3 to 24.5% of phenotypic variance, and narrowed the confidence intervals by 2.2 cM. There was only one minor effect mQTL on chromosome 1 that was common in the TOS14519 and TOG7106 genetic backgrounds; all other mQTLs were background specific. We are currently fine-mapping and validating the major effect genomic region on chromosome 4 (qAfRGM4). This is the first report in mapping the genomic regions associated with the AfRGM resistance, and will be highly useful for rice breeders. PMID:27508500

  9. QTL Mapping in Three Rice Populations Uncovers Major Genomic Regions Associated with African Rice Gall Midge Resistance

    PubMed Central

    Semagn, Kassa; Sow, Mounirou; Nwilene, Francis; Kolade, Olufisayo; Bocco, Roland; Oyetunji, Olumoye; Mitchell-Olds, Thomas; Ndjiondjop, Marie-Noëlle

    2016-01-01

    African rice gall midge (AfRGM) is one of the most destructive pests of irrigated and lowland African ecologies. This study aimed to identify the quantitative trait loci (QTL) associated with AfRGM pest incidence and resistance in three independent bi-parental rice populations (ITA306xBW348-1, ITA306xTOG7106 and ITA306xTOS14519), and to conduct meta QTL (mQTL) analysis to explore whether any genomic regions are conserved across different genetic backgrounds. Composite interval mapping (CIM) conducted on the three populations independently uncovered a total of 28 QTLs associated with pest incidence (12) and pest severity (16). The number of QTLs per population associated with AfRGM resistance varied from three in the ITA306xBW348-1 population to eight in the ITA306xTOG7106 population. Each QTL individually explained 1.3 to 34.1% of the phenotypic variance. The major genomic region for AfRGM resistance had a LOD score and R2 of 60.0 and 34.1% respectively, and mapped at 111 cM on chromosome 4 (qAfrGM4) in the ITA306xTOS14519 population. The meta-analysis reduced the number of QTLs from 28 to 17 mQTLs, each explaining 1.3 to 24.5% of phenotypic variance, and narrowed the confidence intervals by 2.2 cM. There was only one minor effect mQTL on chromosome 1 that was common in the TOS14519 and TOG7106 genetic backgrounds; all other mQTLs were background specific. We are currently fine-mapping and validating the major effect genomic region on chromosome 4 (qAfRGM4). This is the first report in mapping the genomic regions associated with the AfRGM resistance, and will be highly useful for rice breeders. PMID:27508500

  10. The Use of the Developmental Rate of the Aquatic Midge Chironomus riparius (Diptera, Chironomidae) in the Assessment of the Postsubmersion Interval.

    PubMed

    González Medina, Alejandro; Soriano Hernando, Óscar; Jiménez Ríos, Gilberto

    2015-05-01

    Nonbiting midges (Diptera, Chironomidae) are the most abundant members of the fauna associated with submerged carcasses, but their use in the medicolegal context is very restricted because of their complex ontogeny. In this case, the corpse of a woman was recovered in late spring from a river in Granada (Iberian Peninsula). It showed obvious signs of long permanence in the aquatic environment and, along with pulmonary and microscopical analyses, led to the conclusion that the cause of death was drowning. Several larvae-like specimens were sampled from the scalp and later identified by morphological external features as IV instar larvae of Chironomus riparius Meigen, 1804 (Diptera, Chironomidae). Sequencing of cytochrome oxidase subunit I was performed to confirm the identification. The knowledge of the biology of C. riparius at low temperatures was critical to assess a postsubmersion interval of 16-17 days.

  11. Contaminants in stream sediments from seven United States metropolitan areas: part II—sediment toxicity to the amphipod Hyalella azteca and the midge Chironomus dilutus

    USGS Publications Warehouse

    Kemble, Nile E.; Hardesty, Douglas K.; Ingersoll, Christopher G.; Kunz, James L.; Sibley, Paul K.; Calhoun, Daniel L.; Gilliom, Robert J.; Kuivila, Kathryn M.; Nowell, Lisa H.; Moran, Patrick W.

    2013-01-01

    Pyrethroids are hydrophobic compounds that have been observed to accumulate in sediments (Laskowski 2002). Toxicity of pyrethroids in field-collected sediment from small urban streams (Weston et al. 2005; Holmes et al. 2008; Ding et al. 2010; Domagalski et al. 2010) or with pyrethroids spiked into sediment (Amweg et al. 2006; Hintzen et al. 2009) have been evaluated primarily in 10 day lethality tests conducted with the amphipod Hyalella azteca. However, the sublethal effects in long-term exposures to pyrethroids in sediment have not been evaluated, and the distribution of pyrethroids sediments has not typically been evaluated in wadeable streams (Gilliom et al. 2006). This article is the second in a series that describe the results of a study of the distribution and toxicity of pyrethroids and other co-occurring trace elements and organic contaminants (PCBs, PAHs, OC pesticides) in stream sediments from 7 metropolitan areas across the United States (Moran et al. 2012). The study evaluated 98 sediment samples collected from streams ranging from undeveloped to highly urban and differs from previous studies by sampling larger wadeable streams and avoiding point sources (such as storm drains) and other inflows (Gilliom et al. 2006). Part 1 of the series characterizes sediment contaminants in relation to urbanization and other factors in the 7 metropolitan study areas (Nowell et al. 2012). Part 2 (this article) evaluates relationships between sediment chemistry and sediment toxicity in 28 day whole-sediment exposures conducted with the amphipod H. azteca and in 10 day whole-sediment exposure conducted with the midge Chironomus dilutus (USEPA United States Environmental Protection Agency 2000; ASTM American Society for Testing and Materials International 2012). Toxicity end points evaluated in the amphipod and midge exposures included the effects of these field-collected sediments on survival, weight, or biomass of the test organisms.

  12. Macrophage growth arrest by cyclic AMP defines a distinct checkpoint in the mid-G1 stage of the cell cycle and overrides constitutive c-myc expression.

    PubMed

    Rock, C O; Cleveland, J L; Jackowski, S

    1992-05-01

    Proliferation of a murine macrophage cell line (BAC1.2F5) in response to colony-stimulating factor 1 (CSF-1) is inhibited by prostaglandin E2 (PGE2)-mediated elevation of intracellular cyclic AMP (cAMP). When BAC1.2F5 cells were growth arrested in early G1 by CSF-1 starvation and stimulated to synchronously enter the cell cycle by readdition of growth factor, PGE2 inhibited [3H]thymidine incorporation when added before mid-G1, but its addition at later times did not block the onset of S phase. Reversible cell cycle arrest mediated by a cAMP analog required the presence of CSF-1 for cells to initiate DNA synthesis, whereas cells released from an aphidicolin block at the G1/S boundary entered S phase in the absence of CSF-1. PGE2 or cAMP analogs did not block the initial induction of c-myc mRNA by CSF-1 but abolished the CSF-1-dependent expression of c-myc mRNA in the mid-G1 stage of the cell cycle. The cAMP-mediated reduction in c-myc RNA levels was due to decreased c-myc transcription. However, CSF-1-dependent BAC1.2F5 clones infected with a c-myc retrovirus were growth arrested by cAMP analogs despite constitutive c-myc expression. Therefore, the reduction of endogenous c-myc expression by cAMP is neither necessary nor sufficient for growth inhibition.

  13. Cationic Lipid-Formulated DNA Vaccine against Hepatitis B Virus: Immunogenicity of MIDGE-Th1 Vectors Encoding Small and Large Surface Antigen in Comparison to a Licensed Protein Vaccine

    PubMed Central

    Endmann, Anne; Klünder, Katharina; Kapp, Kerstin; Riede, Oliver; Oswald, Detlef; Talman, Eduard G.; Schroff, Matthias; Kleuss, Christiane; Ruiters, Marcel H. J.; Juhls, Christiane

    2014-01-01

    Currently marketed vaccines against hepatitis B virus (HBV) based on the small (S) hepatitis B surface antigen (HBsAg) fail to induce a protective immune response in about 10% of vaccinees. DNA vaccination and the inclusion of PreS1 and PreS2 domains of HBsAg have been reported to represent feasible strategies to improve the efficacy of HBV vaccines. Here, we evaluated the immunogenicity of SAINT-18-formulated MIDGE-Th1 vectors encoding the S or the large (L) protein of HBsAg in mice and pigs. In both animal models, vectors encoding the secretion-competent S protein induced stronger humoral responses than vectors encoding the L protein, which was shown to be retained mainly intracellularly despite the presence of a heterologous secretion signal. In pigs, SAINT-18-formulated MIDGE-Th1 vectors encoding the S protein elicited an immune response of the same magnitude as the licensed protein vaccine Engerix-B, with S protein-specific antibody levels significantly higher than those considered protective in humans, and lasting for at least six months after the third immunization. Thus, our results provide not only the proof of concept for the SAINT-18-formulated MIDGE-Th1 vector approach but also confirm that with a cationic-lipid formulation, a DNA vaccine at a relatively low dose can elicit an immune response similar to a human dose of an aluminum hydroxide-adjuvanted protein vaccine in large animals. PMID:24992038

  14. Record of two species of Culicoides (Diptera, Ceratopogonidae) new for Madagascar and molecular study showing the paraphylies of the subgenus Oecacta and the Schultzei group.

    PubMed

    Augot, D; Randrianambinintsoa, F J; Gasser, A; Depaquit, J

    2013-08-01

    Culicoides are vectors of diseases of Veterinary Medicine importance (bluetongue, African horse sickness, Schmallenberg virus) all over the world. In the present study, we report two species new for Madagascar: C. nevilli and C. enderleini. They belong to the Schultzei group which is sometimes classified in the subgenus Oecacta and sometimes in the subgenus Remmia, depending on authors. Consequently, we carried out a molecular cladistics of these groups based on cytochrome C oxidase subunit I mtDNA sequences. We processed the Malagasy specimens and some C. furens (the Oecacta type-species) caught in Florida and we analyzed their sequences and those available in Genbank: C. schultzei, C. oxystoma, C. festivipennis, C. brunnicans, C. kibunensis, C. truncorum and C. vexans. C. (Avaritia) imicola have been selected as an outgroup. The maximum parsimony analysis showed the paraphylies of the Schultzei group (=Remmia) and of the subgenus Oecacta if the first group is excluded from the latter. Our results underline the doubtful current classification and need to be validated by other molecular markers in the future. PMID:23893801

  15. Effects of ultra-low volume and thermal fog malathion, Scourge and naled applied against caged adult Culicoides furens and Culex quinquefasciatus in open and vegetated terrain.

    PubMed

    Linley, J R; Jordan, S

    1992-03-01

    The adulticidal effect of ULV and thermal fog malathion, Scourge and naled was tested at 2x label dosage (1.42, 0.22, 0.39 oz/acre, respectively) against caged Culicoides furens and Culex quinquefasciatus in open and vegetated (orange grove) terrain. Cages were at 122 cm elevation and positioned at 15.2, 45.7, 76.2, 106.7, 137.2 and 167.6 m from the line of insecticide release. Ultra-low volume applications of all 3 insecticides were markedly more effective than thermal fog under all conditions, especially in vegetated terrain. Of the 3 insecticides, malathion performed the poorest, especially against Cx. quinquefasciatus (in which there was some resistance) and particularly when applied as thermal fog. Scourge and naled were about equally effective. The best adulticide against C. furens was naled, which was clearly superior applied as ULV. It yielded 75% mortality out to 283 m in the open, and to 38 m in the presence of dense vegetation. PMID:1583493

  16. The protective effect of rapid cold-hardening develops more quickly in frozen versus supercooled larvae of the Antarctic midge, Belgica antarctica.

    PubMed

    Kawarasaki, Yuta; Teets, Nicholas M; Denlinger, David L; Lee, Richard E

    2013-10-15

    During the austral summer, larvae of the terrestrial midge Belgica antarctica (Diptera: Chironomidae) experience highly variable and often unpredictable thermal conditions. In addition to remaining freeze tolerant year-round, larvae are capable of swiftly increasing their cold tolerance through the rapid cold-hardening (RCH) response. The present study compared the induction of RCH in frozen versus supercooled larvae. At the same induction temperature, RCH occurred more rapidly and conferred a greater level of cryoprotection in frozen versus supercooled larvae. Furthermore, RCH in frozen larvae could be induced at temperatures as low as -12°C, which is the lowest temperature reported to induce RCH. Remarkably, as little as 15 min at -5°C significantly enhanced larval cold tolerance. Not only is protection from RCH acquired swiftly, but it is also quickly lost after thawing for 2 h at 2°C. Because the primary difference between frozen and supercooled larvae is cellular dehydration caused by freeze concentration of body fluids, we also compared the effects of acclimation in dehydrated versus frozen larvae. Because slow dehydration without chilling significantly increased larval survival to a subsequent cold exposure, we hypothesize that cellular dehydration caused by freeze concentration promotes the rapid acquisition of cold tolerance in frozen larvae.

  17. The protective effect of rapid cold-hardening develops more quickly in frozen versus supercooled larvae of the Antarctic midge, Belgica antarctica.

    PubMed

    Kawarasaki, Yuta; Teets, Nicholas M; Denlinger, David L; Lee, Richard E

    2013-10-15

    During the austral summer, larvae of the terrestrial midge Belgica antarctica (Diptera: Chironomidae) experience highly variable and often unpredictable thermal conditions. In addition to remaining freeze tolerant year-round, larvae are capable of swiftly increasing their cold tolerance through the rapid cold-hardening (RCH) response. The present study compared the induction of RCH in frozen versus supercooled larvae. At the same induction temperature, RCH occurred more rapidly and conferred a greater level of cryoprotection in frozen versus supercooled larvae. Furthermore, RCH in frozen larvae could be induced at temperatures as low as -12°C, which is the lowest temperature reported to induce RCH. Remarkably, as little as 15 min at -5°C significantly enhanced larval cold tolerance. Not only is protection from RCH acquired swiftly, but it is also quickly lost after thawing for 2 h at 2°C. Because the primary difference between frozen and supercooled larvae is cellular dehydration caused by freeze concentration of body fluids, we also compared the effects of acclimation in dehydrated versus frozen larvae. Because slow dehydration without chilling significantly increased larval survival to a subsequent cold exposure, we hypothesize that cellular dehydration caused by freeze concentration promotes the rapid acquisition of cold tolerance in frozen larvae. PMID:23868837

  18. Seroepidemiology of bluetongue in South Bengal

    PubMed Central

    Halder, Arkendu; Joardar, Siddhartha N.; Isore, Devi Prasad; Samanta, Indranil; Parui, Panchanan; Banerjee, Dhriti; Lodh, Chandan

    2016-01-01

    Aim: With the aim of revealing the epidemiological intricacies of bluetongue (BT) in the southern part of West Bengal state, the present study was undertaken to assess seroprevalence of BT along with identification of the vector of the disease, i.e., Culicoides midges available in the region in their breeding season with conducive environmental factors, if any. Materials and Methods: A total of 1509 (sheep-504, goat-1005) samples were collected from three different agroclimatic zones of South Bengal viz. new alluvial, red laterite and coastal saline. To detect anti-BT antibodies in the collected serum samples, indirect-enzyme-linked immunosorbent assay (i-ELISA) was performed. Culicoides midges were collected from those agro-climatic zones of South Bengal for species identification. The meteorological parameters, viz. temperature (maximum and minimum), rainfall and relative humidity of three agro-climatic zones of South Bengal were analyzed for the months of July to December during 2010-2013. Results: The overall seropositivity was 33.13% and 30.24% in sheep and goat, respectively as assessed by i-ELISA. In South Bengal, the predominant species of Culicoides found were Culicoides schultzei, Culicoides palpifer and Culicoides definitus. Conclusion: Since virus transmitting species of Culicoides midges could be detected in South Bengal, besides high seropositivity in ruminants, the possibility of circulating BT virus in South Bengal is quite imminent. PMID:27051176

  19. Climate variability in the Siberian Arctic over the past millennium: midge-based inferences from lakes of the Sakha (Yakutia) Republic

    NASA Astrophysics Data System (ADS)

    Ilyashuk, Boris; van Hardenbroek, Maarten; Heiri, Oliver; Lotter, André F.

    2010-05-01

    Our study aims at reconstructing climatic variability and climate impact on lakes over the past millennium in the Siberian Arctic, the coldest region of Eurasia. Here we present climate inferences based on the stratigraphic analysis of fossil chironomid assemblages (non-biting midges) from sediments of three arctic lakes (one millennial and two centennial records) located in the northeastern part of the Sakha (Yakutia) Republic (70°N, 147°E). Changes in chironomid assemblages in the millennial record clearly show the most significant climatic events of the past millennium, namely the Medieval Warm Period, the Little Ice Age, and the recent warming of 20th century. During relatively warm phases chironomid assemblages are dominated by the warm-adapted Chironomus anthracinus-type, whereas cooler phases are characterized by taxa such as Micropsectra insignilobus-type and Sergentia coracina-type. The pattern of chironomid-inferred climate changes in this Asian part of the Arctic, as represented by chironomid sample scores in a Principal Components Analysis (PCA), is comparable to that recorded in a tree-ring based summer air temperature reconstruction from this region, and broadly similar to those found in other high-resolution millennial records across the European and Western Hemisphere Arctic (e.g., Svalbard, Greenland, the Canadian Arctic). The recent warming of the 20th century is also well visible in both centennial chironomid records. PCA scores for the chironomid samples of recent decades fall outside the range of variability during the first half of the 20th century but are within the range of the millennial-scale variability. Our reconstructions suggest that the recent warming is unusual in the context of the variability of the past centuries but is, within the millennial climate variability, comparable to the Medieval Climate Anomaly.

  20. Predicting chronic toxicity of sediments spiked with zinc: An evaluation of the acid-volatile sulfide model using a life-cycle test with the midge Chironomus tentans

    SciTech Connect

    Sibley, P.K.; Ankley, G.T.; Cotter, A.M.; Leonard, E.N.

    1996-12-01

    The development of sediment quality criteria for the cationic metals cadmium, copper, lead, nickel, and zinc has focused on the use of acid-volatile sulfide (AVS) as the primary normalization phase for predicting interstitial pore-water concentrations and bioavailability of the metals. To date, most research in support of AVS in this context has utilized short-term laboratory exposures, with a relative paucity of information pertaining to long-term exposures. The purpose of this study, therefore, was to investigate the use of AVS as a predictor of metal toxicity to a benthic organism in a long-term laboratory exposure. Clean sediment was spiked with zinc to obtain nominal treatments ranging from {minus}2.34 to 58.5 {micro} g/g dry weight with respect to the molar difference between simultaneously extracted metal (SEM) and AVS. The test was initiated with newly hatched larvae of the midge Chironomus tentans and carried through one complete generation (56 d) during which survival, growth, emergence, and reproduction were monitored. When the molar difference between SEM and AVS was < 0, the concentration of zinc in the sediment interstitial water was low and no adverse effects were observed for any of the biological endpoints measured. Conversely, when SEM-AVS exceeded 0, a dose-dependent increase in the relative concentration of zinc in the pore water was detected. However, the absolute concentration of pore-water zinc at each treatment declined over the course of the study, corresponding to an increase in sediment AVS and to a loss of zinc due to diffusion into the overlying water, which was renewed twice daily. Only when SEM-AVS exceeded 0 were significant reductions in survival, growth, emergence, and reproduction observed. Together, the chemical and biological data from this study compare favorably with observations made in short-term exposures and thus support the use of AVS as a normalization phase for predicting toxicity in metal-contaminated sediments.

  1. Effects of carbamazepine and two of its metabolites on the non-biting midge Chironomus riparius in a sediment full life cycle toxicity test.

    PubMed

    Heye, Katharina; Becker, Dennis; Lütke Eversloh, Christian; Durmaz, Vedat; Ternes, Thomas A; Oetken, Matthias; Oehlmann, Jörg

    2016-07-01

    The antiepileptic drug carbamazepine (CBZ) and its main metabolites carbamazepine-10,11-epoxide (EP-CBZ) and 10,11-dihydro-10,11-dihydroxy-carbamazepine (DiOH-CBZ) were chosen as test substances to assess chronic toxicity on the non-biting midge Chironomus riparius. All the three substances were tested in a 40-day sediment full life cycle test (according to OECD 233) in which mortality, emergence, fertility, and clutch size were evaluated. In addition, these parameters were considered to calculate the population growth rate which represents an integrated measure to assess population relevant effects. With an LC50 of 0.20 mg/kg (time-weighted mean), the metabolite EP-CBZ was significantly more toxic than the parent substance CBZ (LC50: 1.1 mg/kg). Especially mortality, emergence, and fertility showed to be sensitive parameters under the exposure to CBZ and EP-CBZ. By using classical molecular dynamics (MD) simulations, the binding of CBZ to the ecdysone receptor was investigated as one possible mode of action (MoA) but appeared to be unlikely. The second metabolite DiOH-CBZ did not cause any effects within the tested concentration rage (0.17-1.2 mg/kg). Even though CBZ was less toxic compared to EP-CBZ, CBZ is found in the environment at much higher concentrations and therefore causes a higher potential risk for sediment dwelling organisms compared to its metabolites. Nevertheless, the current study illustrates the importance of including commonly found metabolites into the risk assessment of parent substances. PMID:27064208

  2. Palaeoclimatological and palaeolimnological records from fossil midges and tree-rings: the role of the North Atlantic Oscillation in eastern Finland through the Medieval Climate Anomaly and Little Ice Age

    NASA Astrophysics Data System (ADS)

    Luoto, Tomi P.; Helama, Samuli

    2010-08-01

    Hydrological changes and air temperature variability are reconstructed from the sediments of Lake Pieni-Kauro, eastern Finland during the Medieval Climate Anomaly (MCA) and Little Ice Age (LIA) using transfer functions derived from midge (Insecta: Nematocera)-based calibration models. The reconstructions are compared with a regional tree-ring chronology and sediment physical properties are determined to track depositional changes. An objective of the study is to examine the long-term relationship between the North Atlantic Oscillation (NAO) and climate (temperature, precipitation). Our results show that the MCA was characterized by warm and dry summer conditions, which were accompanied by changes in the sediment magnetic susceptibility values most likely representing major forest fires during the tree-ring indicated MCA megadrought. However, the midge-based stream flow reconstruction shows increased values during the MCA, thus implying enhanced spring floods after snowy winters. During the LIA, the tree-ring data indicate that a generally wetter climate prevailed during summers, but the stream flow reconstruction indicates less snowy winters. In the terms of long-term climatology, the present results show support to the concept that the NAO has a positive correlation between winter precipitation and annual temperature and a negative correlation between summer precipitation in eastern Finland. Thus, the results may serve as important background data for global change assessments.

  3. The European vectors of Bluetongue virus: are there species complexes, single species or races in Culicoides obsoletus and C. pulicaris detectable by sequencing ITS-1, ITS-2 and 18S-rDNA?

    PubMed

    Kiehl, Ernst; Walldorf, Volker; Klimpel, Sven; Al-Quraishy, Saleh; Mehlhorn, Heinz

    2009-08-01

    When studying the vectorship of Culicoides species during the outbreak of Bluetongue disease (BTD) in Central Europe, the question arose whether the most common species and additionally proven vectors of BTV (C. obsoletus and C. pulicaris) are definitive species or do they belong to so-called complexes, since the determination based on morphological criteria is not very significant and knowledge on the life cycles is poor or even absent. Therefore, the present molecular biological study on their ITS-1, ITS-2 and 18SrDNA characteristics was initiated to investigate specimens, which had been determined by their wing morphology during an entomological monitoring in the years 2007 and 2008 at 91 farms in Germany (Mehlhorn et al. 2009). This study revealed novel types respectively different forms, which appeared very similar to Culicoides obsoletus, but showed slightly varying wing patterns. The molecular biological data were compared to those in data banks and combined to provisional dendrograms. The ITS-1 and ITS-2 analysis showed that the specimens determined in the monitoring as C. obsoletus inclusive those with different wing pattern correlate significantly with the data of C. obsoletus in the data banks and surrounded the data bank specifications of C. montanus and C. scoticus so closely that the latter might be only hardly separate species. A similar interpretation can also be drawn when looking at the 18S rDNA dendrogram. Thus, C. scoticus and C. montanus might be races of C. obsoletus rather than separate species. With respect to the ITS-1 and ITS-2 characteristics of C. pulicaris females, which morphologically and by size can be significantly differentiated from C. obsoletus, it was seen that this species is significantly situated on another rame of the dendrograms and in very close relationship to C. punctatus and C. lupicaris, so that the latter might also be only races of C. pulicaris. One of the two other most common species found in Northrhine

  4. Host and Potential Vector Susceptibility to an Emerging Orbivirus in the United States: Epizootic Hemorrhagic Disease Virus Serotype 6

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Epizootic hemorrhagic disease (EHD) viruses (EHDV) are orbiviruses transmitted by Culicoides biting midges to domestic and wild ruminants. EHDV-1 and -2 are enzootic in the U.S., where EHD is the most significant viral disease of white-tailed deer (WTD; Odocoileus virginianus) and reports of EHD in ...

  5. Evaluation of toxicity to the amphipod, Hyalella azteca, and to the midge, Chironomus dilutus; and bioaccumulation by the oligochaete, Lumbriculus variegatus, with exposure to PCB-contaminated sediments from Anniston, Alabama

    USGS Publications Warehouse

    Ingersoll, Christopher G.; Steevens, Jeffery A.; MacDonald, Donald D.; Brumbaugh, William G.; Coady, Matthew R.; Farrar, J. Daniel; Lotufo, Guilherme R.; Kemble, Nile E.; Kunz, James L.; Stanley, Jacob K.; Sinclair, Jesse A.

    2014-01-01

    The U.S. Environmental Protection Agency (USEPA) requested that as part of the remedial investigation for the Anniston, Alabama Polychlorinated Biphenyl (PCB) Site (Anniston PCB Site), that Pharmacia Corporation and Solutia Inc. (P/S) perform long-term reproduction toxicity tests with the amphipod, Hyalella azteca, and the midge, Chironomus dilutus, and bioaccumulation tests with the oligochaete, Lumbriculus variegatus, using sediment samples collected from reference locations and from Operable Unit 4 of the Anniston PCB Site. The sediment toxicity testing and sediment bioaccumulation results will be used by ARCADIS U.S., Inc. (ARCADIS) as part of a weight-of-evidence assessment to evaluate risks and establish sediment remediation goals for contaminants to sediment-dwelling organisms inhabiting the Anniston PCB Site. The goal of this study was to characterize relations between sediment chemistry and sediment toxicity and relations between sediment chemistry and sediment bioaccumulation in samples of sediments collected from the Anniston PCB Site. A total of 32 samples were evaluated from six test sites and one reference site to provide a wide range in concentrations of chemicals of potential concern (COPCs) including PCBs in samples of whole sediment. The goal of this study was not to determine the extent of sediment contamination across the Anniston PCB Site. Hence, the test sites or samples collected from within a test site were not selected to represent the spatial extent of sediment contamination across the Anniston PCB Site. Sediment chemistry, pore-water chemistry, and sediment toxicity data were generated for 26 sediment samples from the Anniston PCB Site. All of the samples were evaluated to determine if they qualified as reference sediment samples. Those samples that met the chemical selection criteria and biological selection criteria were identified as reference samples and used to develop the reference envelope for each toxicity test endpoint. Physical

  6. Evaluation of toxicity to the amphipod, Hyalella azteca, and to the midge, Chironomus dilutus; and bioaccumulation by the oligochaete, Lumbriculus variegatus, with exposure to PCB-contaminated sediments from Anniston, Alabama

    USGS Publications Warehouse

    Ingersoll, Christopher G.; Steevens, Jeffery A.; MacDonald, Donald D.; Brumbaugh, William G.; Coady, Matthew R.; Farrar, J. Daniel; Lotufo, Guilherme R.; Kemble, Nile E.; Kunz, James L.; Stanley, Jacob K.; Sinclair, Jesse A.; Ingersoll, Christopher G.; Steevens, Jeffery A.; MacDonald, Donald D.

    2014-01-01

    The U.S. Environmental Protection Agency (USEPA) requested that as part of the remedial investigation for the Anniston, Alabama Polychlorinated Biphenyl (PCB) Site (Anniston PCB Site), that Pharmacia Corporation and Solutia Inc. (P/S) perform long-term reproduction toxicity tests with the amphipod, Hyalella azteca, and the midge, Chironomus dilutus, and bioaccumulation tests with the oligochaete, Lumbriculus variegatus, using sediment samples collected from reference locations and from Operable Unit 4 of the Anniston PCB Site. The sediment toxicity testing and sediment bioaccumulation results will be used by ARCADIS U.S., Inc. (ARCADIS) as part of a weight-of-evidence assessment to evaluate risks and establish sediment remediation goals for contaminants to sediment-dwelling organisms inhabiting the Anniston PCB Site. The goal of this study was to characterize relations between sediment chemistry and sediment toxicity and relations between sediment chemistry and sediment bioaccumulation in samples of sediments collected from the Anniston PCB Site. A total of 32 samples were evaluated from six test sites and one reference site to provide a wide range in concentrations of chemicals of potential concern (COPCs) including PCBs in samples of whole sediment. The goal of this study was not to determine the extent of sediment contamination across the Anniston PCB Site. Hence, the test sites or samples collected from within a test site were not selected to represent the spatial extent of sediment contamination across the Anniston PCB Site. Sediment chemistry, pore-water chemistry, and sediment toxicity data were generated for 26 sediment samples from the Anniston PCB Site. All of the samples were evaluated to determine if they qualified as reference sediment samples. Those samples that met the chemical selection criteria and biological selection criteria were identified as reference samples and used to develop the reference envelope for each toxicity test endpoint. Physical

  7. Schmallenberg virus in Germany 2011-2014: searching for the vectors.

    PubMed

    Kameke, Daniela; Werner, Doreen; Hoffmann, Bernd; Lutz, Walburga; Kampen, Helge

    2016-02-01

    Following the emergence of Schmallenberg virus (SBV) in 2011, 21,397 culicoid biting midges (Diptera: Ceratopogonidae) from targeted and non-targeted sampling activities carried out during the summer months of 2011 to 2013 and in late 2014 in various regions in Germany were analyzed for the virus by real-time RT-PCR. While no SBV was found in biting midges collected during 2011 and 2013, 2 out of 334 pools including 20 and 22 non-engorged females of the Obsoletus complex sampled in 2012 tested positive for the SBV S-segment with C(t) values of 42.46 and 35.45. In addition, 673 black flies (Diptera: Simuliidae) captured during the same studies were screened for the presence of SBV and proved negative. In late autumn 2014, biting midges were collected again in a limited study in eastern Germany after some cases of SBV infection had occurred in a quarantine station for cattle. Due to the unfavorable seasonal weather conditions, only few specimens were caught, and these were also negative for SBV. The German experience suggests that biting midge collections launched only after an outbreak and are not locally targeted may be ineffective as to virus detection. It rather might be advisable to collect biting midges at sentinel farms on a permanent basis so to have material available to be examined in the case of a disease outbreak.

  8. Bluetongue Virus Serotype 1 Outbreak in the Basque Country (Northern Spain) 2007–2008. Data Support a Primary Vector Windborne Transport

    PubMed Central

    García-Lastra, Rodrigo; Leginagoikoa, Iratxe; Plazaola, Jose M.; Ocabo, Blanca; Aduriz, Gorka; Nunes, Telmo; Juste, Ramón A.

    2012-01-01

    Background Bluetongue (BT) is a vector-borne disease of ruminants that has expanded its traditional global distribution in the last decade. Recently, BTV-1 emerged in Southern Spain and caused several outbreaks in livestock reaching the north of the country. The aim of this paper was to review the emergence of BTV-1 in the Basque Country (Northern Spain) during 2007 and 2008 analyzing the possibility that infected Culicoides were introduced into Basque Country by winds from the infected areas of Southern Spain. Methodology/Principal Findings We use a complex HYSPLIT (Hybrid Single-Particle Lagrangian Integrated Trajectory) model to draw wind roses and backward wind trajectories. The analysis of winds showed September 28 to October 2 as the only period for the introduction of infected midges in the Basque Country. These wind trajectories crossed through the areas affected by serotype 1 on those dates in the South of the Iberian Peninsula. Additionally meteorological data, including wind speed and humidity, and altitude along the trajectories showed suitable conditions for Culicoides survival and dispersion. Conclusions/Significance An active infection in medium-long distance regions, wind with suitable speed, altitude and trajectory, and appropriate weather can lead to outbreaks of BTV-1 by transport of Culicoides imicola, not only over the sea (as reported previously) but also over the land. This shows that an additional factor has to be taken into account for the control of the disease which is currently essentially based on the assumption that midges will only spread the virus in a series of short hops. Moreover, the epidemiological and serological data cannot rule out the involvement of other Culicoides species in the spread of the infection, especially at a local level. PMID:22479628

  9. Schmallenberg virus infection.

    PubMed

    Wernike, K; Elbers, A; Beer, M

    2015-08-01

    Since Schmallenberg virus, an orthobunyavirus of the Simbu serogroup, was identified near the German-Dutch border for the first time in late 2011 it has spread extremely quickly and caused a large epidemic in European livestock. The virus, which is transmitted by Culicoides biting midges, infects domestic and wild ruminants. Adult animals show only mild clinical symptoms or none at all, whereas an infection during a critical period of gestation can lead to abortion, stillbirth or the birth of severely malformed offspring. The impact of the disease is usually greater in sheep than in cattle. Vaccination could be an important aspect of disease control. PMID:26601441

  10. Mansonelliasis, a neglected parasitic disease in Haiti.

    PubMed

    Raccurt, Christian Pierre; Brasseur, Philippe; Boncy, Jacques

    2014-09-01

    Reported in Haiti as early as 1923, Mansonella ozzardi is still a neglected disease ignored by the health authorities of the country. This review is an update on the geographic distribution of the coastal foci of mansonelliasis in Haiti, the epidemiological profile and prevalence rates of microfilariae in people living in endemic areas, the clinical impact of the parasite on health and the efficiency of the transmission of the parasite among three Culicoides biting-midge species identified as vectors in Haiti. Additionally, interest in establishing a treatment programme to combat this parasite using a single dose of ivermectin is emphasised.

  11. Mansonelliasis, a neglected parasitic disease in Haiti

    PubMed Central

    Raccurt, Christian Pierre; Brasseur, Philippe; Boncy, Jacques

    2014-01-01

    Reported in Haiti as early as 1923, Mansonella ozzardi is still a neglected disease ignored by the health authorities of the country. This review is an update on the geographic distribution of the coastal foci of mansonelliasis in Haiti, the epidemiological profile and prevalence rates of microfilariae in people living in endemic areas, the clinical impact of the parasite on health and the efficiency of the transmission of the parasite among three Culicoides biting-midge species identified as vectors in Haiti. Additionally, interest in establishing a treatment programme to combat this parasite using a single dose of ivermectin is emphasised. PMID:25317697

  12. Mansonelliasis, a neglected parasitic disease in Haiti.

    PubMed

    Raccurt, Christian Pierre; Brasseur, Philippe; Boncy, Jacques

    2014-09-01

    Reported in Haiti as early as 1923, Mansonella ozzardi is still a neglected disease ignored by the health authorities of the country. This review is an update on the geographic distribution of the coastal foci of mansonelliasis in Haiti, the epidemiological profile and prevalence rates of microfilariae in people living in endemic areas, the clinical impact of the parasite on health and the efficiency of the transmission of the parasite among three Culicoides biting-midge species identified as vectors in Haiti. Additionally, interest in establishing a treatment programme to combat this parasite using a single dose of ivermectin is emphasised. PMID:25317697

  13. Experimental oral infection of bluetongue virus serotype 8 in type I interferon receptor-deficient mice.

    PubMed

    Calvo-Pinilla, Eva; Nieto, José María; Ortego, Javier

    2010-11-01

    The identification of transmission routes for bluetongue virus (BTV) is essential to improve the control of the disease. Although BTV is primarily transmitted by several species of Culicoides biting midges, there has been evidence of transplacental and oral transmission. We now report that IFNAR((-/-)) mice are susceptible to oral infection by BTV-8. Viraemia, clinical manifestations and tissue lesions are similar to those in intravenously infected mice. In addition, we show that the oral cavity and oesophagus are susceptible to BTV infection and replication, suggesting that these organs are possible entry routes during BTV oral infection.

  14. Rearing and Maintaining Midge Cultures (Chironomus tentans) for Laboratory Studies.

    ERIC Educational Resources Information Center

    Hein, John; Mahadeva, Madhu N.

    1992-01-01

    The life history of the Chironomus tentans can be observed in easily established and maintained laboratory cultures. Projects for the classroom include observing hydration of an egg mass; embryonic development, hatching and larval feeding; larval activity; and mating activity. (MDH)

  15. Integrated Taxonomy and DNA Barcoding of Alpine Midges (Diptera: Chironomidae).

    PubMed

    Montagna, Matteo; Mereghetti, Valeria; Lencioni, Valeria; Rossaro, Bruno

    2016-01-01

    Rapid and efficient DNA-based tools are recommended for the evaluation of the insect biodiversity of high-altitude streams. In the present study, focused principally on larvae of the genus Diamesa Meigen 1835 (Diptera: Chironomidae), the congruence between morphological/molecular delimitation of species as well as performances in taxonomic assignments were evaluated. A fragment of the mitochondrial cox1 gene was obtained from 112 larvae, pupae and adults (Diamesinae, Orthocladiinae and Tanypodinae) that were collected in different mountain regions of the Alps and Apennines. On the basis of morphological characters 102 specimens were attributed to 16 species, and the remaining ten specimens were identified to the genus level. Molecular species delimitation was performed using: i) distance-based Automatic Barcode Gap Discovery (ABGD), with no a priori assumptions on species identification; and ii) coalescent tree-based approaches as the Generalized Mixed Yule Coalescent model, its Bayesian implementation and Bayesian Poisson Tree Processes. The ABGD analysis, estimating an optimal intra/interspecific nucleotide distance threshold of 0.7%-1.4%, identified 23 putative species; the tree-based approaches, identified between 25-26 entities, provided nearly identical results. All species belonging to zernyi, steinboecki, latitarsis, bertrami, dampfi and incallida groups, as well as outgroup species, are recovered as separate entities, perfectly matching the identified morphospecies. In contrast, within the cinerella group, cases of discrepancy arose: i) the two morphologically separate species D. cinerella and D. tonsa are neither monophyletic nor diagnosable exhibiting low values of between-taxa nucleotide mean divergence (0.94%); ii) few cases of larvae morphological misidentification were observed. Head capsule color is confirmed to be a valid character able to discriminate larvae of D. zernyi, D. tonsa and D. cinerella, but it is here better defined as a color gradient between the setae submenti and genal setae. DNA barcodes performances were high: average accuracy was ~89% and precision of ~99%. On the basis of the present data, we can thus conclude that molecular identification represents a promising tool that could be effectively adopted in evaluating biodiversity of high-altitude streams. PMID:26938660

  16. Integrated Taxonomy and DNA Barcoding of Alpine Midges (Diptera: Chironomidae)

    PubMed Central

    Montagna, Matteo; Mereghetti, Valeria; Lencioni, Valeria; Rossaro, Bruno

    2016-01-01

    Rapid and efficient DNA-based tools are recommended for the evaluation of the insect biodiversity of high-altitude streams. In the present study, focused principally on larvae of the genus Diamesa Meigen 1835 (Diptera: Chironomidae), the congruence between morphological/molecular delimitation of species as well as performances in taxonomic assignments were evaluated. A fragment of the mitochondrial cox1 gene was obtained from 112 larvae, pupae and adults (Diamesinae, Orthocladiinae and Tanypodinae) that were collected in different mountain regions of the Alps and Apennines. On the basis of morphological characters 102 specimens were attributed to 16 species, and the remaining ten specimens were identified to the genus level. Molecular species delimitation was performed using: i) distance-based Automatic Barcode Gap Discovery (ABGD), with no a priori assumptions on species identification; and ii) coalescent tree-based approaches as the Generalized Mixed Yule Coalescent model, its Bayesian implementation and Bayesian Poisson Tree Processes. The ABGD analysis, estimating an optimal intra/interspecific nucleotide distance threshold of 0.7%-1.4%, identified 23 putative species; the tree-based approaches, identified between 25–26 entities, provided nearly identical results. All species belonging to zernyi, steinboecki, latitarsis, bertrami, dampfi and incallida groups, as well as outgroup species, are recovered as separate entities, perfectly matching the identified morphospecies. In contrast, within the cinerella group, cases of discrepancy arose: i) the two morphologically separate species D. cinerella and D. tonsa are neither monophyletic nor diagnosable exhibiting low values of between-taxa nucleotide mean divergence (0.94%); ii) few cases of larvae morphological misidentification were observed. Head capsule color is confirmed to be a valid character able to discriminate larvae of D. zernyi, D. tonsa and D. cinerella, but it is here better defined as a color gradient between the setae submenti and genal setae. DNA barcodes performances were high: average accuracy was ~89% and precision of ~99%. On the basis of the present data, we can thus conclude that molecular identification represents a promising tool that could be effectively adopted in evaluating biodiversity of high-altitude streams. PMID:26938660

  17. VP2 Exchange and NS3/NS3a Deletion in African Horse Sickness Virus (AHSV) in Development of Disabled Infectious Single Animal Vaccine Candidates for AHSV

    PubMed Central

    van de Water, Sandra G. P.; van Gennip, René G. P.; Potgieter, Christiaan A.; Wright, Isabel M.

    2015-01-01

    ABSTRACT African horse sickness virus (AHSV) is a virus species in the genus Orbivirus of the family Reoviridae. There are nine serotypes of AHSV showing different levels of cross neutralization. AHSV is transmitted by species of Culicoides biting midges and causes African horse sickness (AHS) in equids, with a mortality rate of up to 95% in naive horses. AHS has become a serious threat for countries outside Africa, since endemic Culicoides species in moderate climates appear to be competent vectors for the related bluetongue virus (BTV). To control AHS, live-attenuated vaccines (LAVs) are used in Africa. We used reverse genetics to generate “synthetic” reassortants of AHSV for all nine serotypes by exchange of genome segment 2 (Seg-2). This segment encodes VP2, which is the serotype-determining protein and the dominant target for neutralizing antibodies. Single Seg-2 AHSV reassortants showed similar cytopathogenic effects in mammalian cells but displayed different growth kinetics. Reverse genetics for AHSV was also used to study Seg-10 expressing NS3/NS3a proteins. We demonstrated that NS3/NS3a proteins are not essential for AHSV replication in vitro. NS3/NS3a of AHSV is, however, involved in the cytopathogenic effect in mammalian cells and is very important for virus release from cultured insect cells in particular. Similar to the concept of the bluetongue disabled infectious single animal (BT DISA) vaccine platform, an AHS DISA vaccine platform lacking NS3/NS3a expression was developed. Using exchange of genome segment 2 encoding VP2 protein (Seg-2[VP2]), we will be able to develop AHS DISA vaccine candidates for all current AHSV serotypes. IMPORTANCE African horse sickness virus is transmitted by species of Culicoides biting midges and causes African horse sickness in equids, with a mortality rate of up to 95% in naive horses. African horse sickness has become a serious threat for countries outside Africa, since endemic Culicoides species in moderate

  18. Bluetongue.

    PubMed

    Maclachlan, N J; Mayo, C E; Daniels, P W; Savini, G; Zientara, S; Gibbs, E P J

    2015-08-01

    Summary Bluetongue (BT) is an arthropod-transmitted viral disease of non-African ungulates, principally sheep. The disease results from vascular injury analogous to that of human haemorrhagic viral fevers, with characteristic tissue infarction, haemorrhage, vascular leakage, oedema, and hypovolaemic shock. Importantly, BT is not zoonotic. Bluetongue virus (BTV) infection of ruminants and vector Culicoides midges is endemic throughout many tropical and temperate regions of the world; however, within this global range the virus exists within relatively discrete ecosystems (syn. episystems) where specific constellations of BTV serotypes are spread by different species of biting Culicoides midges. Recently discovered goat-associated BTVs, notably BTV serotype 25 (BTV-25) in central Europe, appear to have distinctive biological properties and an epidemiology that is not reliant on Culicoides midges as vectors for virus transmission. Bluetongue virus infection of ruminants is often subclinical, but outbreaks of severe disease occur regularly at the upper and lower limits of the virus's global range, where infection is distinctly seasonal. There have been recent regional alterations in the global distribution of BTV infection, particularly in Europe. It is proposed that climate change is responsible for these events through its impact on vector midges. However, the role of anthropogenic factors in mediating emergence of BTV into new areas remains poorly defined; for example, it is not clear to what extent anthropogenic factors were responsible for the recent translocation to northern and eastern Europe of live attenuated vaccine viruses and an especially virulent strain of BTV-8 with distinctive properties. Without thorough characterisation of all environmental and anthropogenic drivers of the recent emergence of BT in northern Europe and elsewhere, it is difficult to predict what the future holds in terms of global emergence of BTV infection. Accurate and convenient

  19. A Modified Vaccinia Ankara Virus (MVA) Vaccine Expressing African Horse Sickness Virus (AHSV) VP2 Protects Against AHSV Challenge in an IFNAR −/− Mouse Model

    PubMed Central

    Castillo-Olivares, Javier; Calvo-Pinilla, Eva; Casanova, Isabel; Bachanek-Bankowska, Katarzyna; Chiam, Rachael; Maan, Sushila; Nieto, Jose Maria; Ortego, Javier; Mertens, Peter Paul Clement

    2011-01-01

    African horse sickness (AHS) is a lethal viral disease of equids, which is transmitted by Culicoides midges that become infected after biting a viraemic host. The use of live attenuated vaccines has been vital for the control of this disease in endemic regions. However, there are safety concerns over their use in non-endemic countries. Research efforts over the last two decades have therefore focused on developing alternative vaccines based on recombinant baculovirus or live viral vectors expressing structural components of the AHS virion. However, ethical and financial considerations, relating to the use of infected horses in high biosecurity installations, have made progress very slow. We have therefore assessed the potential of an experimental mouse-model for AHSV infection for vaccine and immunology research. We initially characterised AHSV infection in this model, then tested the protective efficacy of a recombinant vaccine based on modified vaccinia Ankara expressing AHS-4 VP2 (MVA-VP2). PMID:21298069

  20. When DNA barcoding and morphology mesh: Ceratopogonidae diversity in Finnmark, Norway

    PubMed Central

    Stur, Elisabeth; Borkent, Art

    2014-01-01

    Abstract DNA barcoding in Ceratopogonidae has been restricted to interpreting the medically and veterinary important members of Culicoides Latreille. Here the technique is utilised, together with morphological study, to interpret all members of the family in a select area. Limited sampling from the county of Finnmark in northernmost Norway indicated the presence of 54 species, including 14 likely new to science, 16 new to Norway, and one new to Europe. No species were previously recorded from this county. Only 93 species were known for all of Norway before this survey, indicating how poorly studied the group is. We evaluate and discuss morphological characters commonly used in identification of biting midges and relate species diagnoses to released DNA barcode data from 223 specimens forming 58 barcode clusters in our dataset. DNA barcodes and morphology were congruent for all species, except in three morphological species where highly divergent barcode clusters indicate the possible presence of cryptic species. PMID:25589864

  1. Epidemiologic survey of Mansonella ozzardi in Corail, Haiti.

    PubMed

    Raccurt, Christian P; Brasseur, Philippe; Cicéron, Micheline; Boncy, Jacques

    2014-06-01

    An epidemiologic (cross-sectional study) survey on 462 inhabitants in Corail, Haiti showed that 16.5% were infected with Mansonella ozzardi. This finding was determined from a single 20-μL sample of finger prick blood from each person. Among children, < 2% had a detectable microfilaremia. In persons > 15 years of age, the prevalence of infection for males and females was 23% and 21%, respectively. In general, the microfilaremias were low and 70% of positive persons had < 10 microfilariae per 20 μL of blood; only 5% had > 50 microfilariae. This study shows that persons living near mangrove marshes that are breeding sites for Culicoides furens and C. barbosai biting midges, which are recognized vectors of M. ozzardi in Haiti, are consequently more frequently infected than those living in downtown area of Corail or inland. PMID:24710617

  2. Epidemiologic Survey of Mansonella ozzardi in Corail, Haiti

    PubMed Central

    Raccurt, Christian P.; Brasseur, Philippe; Cicéron, Micheline; Boncy, Jacques

    2014-01-01

    An epidemiologic (cross-sectional study) survey on 462 inhabitants in Corail, Haiti showed that 16.5% were infected with Mansonella ozzardi. This finding was determined from a single 20-μL sample of finger prick blood from each person. Among children, < 2% had a detectable microfilaremia. In persons > 15 years of age, the prevalence of infection for males and females was 23% and 21%, respectively. In general, the microfilaremias were low and 70% of positive persons had < 10 microfilariae per 20 μL of blood; only 5% had > 50 microfilariae. This study shows that persons living near mangrove marshes that are breeding sites for Culicoides furens and C. barbosai biting midges, which are recognized vectors of M. ozzardi in Haiti, are consequently more frequently infected than those living in downtown area of Corail or inland. PMID:24710617

  3. Isolation of Bluetongue Virus 24 from India - An Exotic Serotype to Australasia.

    PubMed

    Krishnajyothi, Y; Maan, S; Kandimalla, K; Maan, N S; Tutika, R B; Reddy, Y V; Kumar, A; Mrunalini, N; Reddy, G H; Putty, K; Ahmed, S M; Reddy, Y N; Hemadri, D; Singh, K P; Mertens, P P C; Hegde, N R; Rao, P P

    2016-08-01

    Bluetongue (BT) is a viral disease of ruminants and is caused by different serotypes of bluetongue virus (BTV), which is transmitted by several species of Culicoides midges. The disease is endemic in tropical areas, and incursions have been observed in some of the temperate areas. Twenty-seven recognized serotypes of BTV have been reported so far. Some serotype viruses have been shown to circulate in certain geographical areas. BTV-24 has been reported from Africa, the Mediterranean and the Americas, whereas it is exotic to Australasia. Here, we report isolation of BTV-24 from India and show that it has high sequence homology in genome segment 2 with other Western isolates of BTV-24. Entry of this serotype into Australasian region is a cause of concern. PMID:27241307

  4. Ecological study on antimicrobial-resistant zoonotic bacteria transmitted by flies in cattle farms.

    PubMed

    Mohammed, Asmaa N; Abdel-Latef, Gihan K; Abdel-Azeem, Naglaa M; El-Dakhly, Khaled Mohamed

    2016-10-01

    Flies were qualitatively and quantitatively monitored on both livestock animals and the surrounding environment to investigate their role as a potential carrier for antimicrobial-resistant bacteria of zoonotic importance in cattle farms. This was done by the use of visual observations and animal photography; meanwhile, in the surrounding environment, flies were collected using sticky cards and then microscopically identified. Representative fly samples were cultured for bacterial isolation, biochemical identification, and then tested against common 12 antibiotics. The total average of dipterous flies in examined farms was 400.42 ± 6.2. Culicoides biting midges were the most common existing species (70.01 %) followed by house flies, stable flies, and mosquitoes (18.31, 7.74, and 3.91 %, respectively) at X (2) = 9.0, P < 0.05. The most predominant bacterial isolates were Escherichia coli (22.6 %), Staphylococcus aureus and Enterobacter (17.3 % each), coagulase-negative Staphylococci (CNS) (14.7 %), Klebsiella sp. (8 %), Salmonella spp. (6.7 %), and Shigella spp. and Proteus spp. (6.7 % each). The tested bacterial isolates were resistant to variant antibiotics used. S. aureus exhibited 100 % resistance to colistine. However, E. coli revealed 92.9 and 78.6 % resistance against tetracycline and colistine, respectively. Both Salmonella spp. and Shigella spp. were 100 % resistant to penicillin, and Klebsiella sp. had 100 % resistance to tetracycline. In conclusion, Culicoides biting midges and house flies could be considered as a potential carrier for multi-drug-resistant bacteria of zoonotic importance. Furthermore, cows' environment has an essential role in propagation and wide spread of antimicrobial-resistant bacterial pathogens.

  5. Using shared needles for subcutaneous inoculation can transmit bluetongue virus mechanically between ruminant hosts

    PubMed Central

    Darpel, Karin E.; Barber, James; Hope, Andrew; Wilson, Anthony J.; Gubbins, Simon; Henstock, Mark; Frost, Lorraine; Batten, Carrie; Veronesi, Eva; Moffat, Katy; Carpenter, Simon; Oura, Chris; Mellor, Philip S.; Mertens, Peter P. C.

    2016-01-01

    Bluetongue virus (BTV) is an economically important arbovirus of ruminants that is transmitted by Culicoides spp. biting midges. BTV infection of ruminants results in a high viraemia, suggesting that repeated sharing of needles between animals could result in its iatrogenic transmission. Studies defining the risk of iatrogenic transmission of blood-borne pathogens by less invasive routes, such as subcutaneous or intradermal inoculations are rare, even though the sharing of needles is common practice for these inoculation routes in the veterinary sector. Here we demonstrate that BTV can be transmitted by needle sharing during subcutaneous inoculation, despite the absence of visible blood contamination of the needles. The incubation period, measured from sharing of needles, to detection of BTV in the recipient sheep or cattle, was substantially longer than has previously been reported after experimental infection of ruminants by either direct inoculation of virus, or through blood feeding by infected Culicoides. Although such mechanical transmission is most likely rare under field condition, these results are likely to influence future advice given in relation to sharing needles during veterinary vaccination campaigns and will also be of interest for the public health sector considering the risk of pathogen transmission during subcutaneous inoculations with re-used needles. PMID:26853457

  6. Arbovirus surveillance from 1990 to 1995 in the Barkedji area (Ferlo) of Senegal, a possible natural focus of Rift Valley fever virus.

    PubMed

    Traoré-Lamizana, M; Fontenille, D; Diallo, M; Bâ, Y; Zeller, H G; Mondo, M; Adam, F; Thonon, J; Maïga, A

    2001-07-01

    Surveillance for mosquito-borne viruses was conducted in Barkedji area from 1990 to 1995, following an outbreak of Rift Valley fever (RVF) virus in southern Mauritania. Mosquitoes, sand flies, and midges were collected from human bait and trapped by solid-state U.S. Army battery-powered CDC miniature light traps baited with dry ice or animals (sheep or chickens) at four ponds. Overall, 237,091 male and female mosquitoes representing 52 species in eight genera, 214,967 Phlebotomine sand flies, and 2,527 Culicoides were collected, identified, and tested for arboviruses in 9,490 pools (7,050 pools of female and 331 of male mosquitoes, 2,059 pools of sand flies and 50 pools of Culicoides). Viruses isolated included one Alphavirus, Babanki (BBK); six Flaviviruses, Bagaza (BAG), Ar D 65239, Wesselsbron (WSL), West Nile (WN), Koutango (KOU), Saboya (SAB); two Bunyavirus, Bunyamwera (BUN) and Ngari (NRI); two Phleboviruses, Rift Valley fever (RVF) and Gabek Forest (GF); one Orbivirus, Ar D 66707 (Sanar); one Rhabdovirus, Chandipura (CHP); and one unclassified virus, Ar D 95537. Based on repeated isolations, high field infection rates and abundance, Culex appeared to be the vectors of BAG, BBK, Ar D 65239 (BAG-like), and WN viruses, Ae. vexans and Ae. ochraceus of RVF virus, Mansonia of WN and BAG viruses, Mimomyia of WN and BAG viruses, and Phlebotomine of SAB, CHP, Ar D 95537, and GF viruses. Our data indicate that RVF virus circulated repeatedly in the Barkedji area.

  7. Haemosporidian vector research: marriage of molecular and microscopical approaches is essential.

    PubMed

    Valkiūnas, Gediminas

    2011-08-01

    Many species of malaria and related haemosporidian parasites (Haemosporida) are responsible for diseases in wild and domestic animals. These pathogens are exclusively transmitted by blood-sucking dipteran insects (Diptera). Traditional vector studies, which are based mainly on experimental infection and subsequent dissection of insects, are time-consuming, so progress in the identification of the vectors has been slow. Since the discovery of haemosporidians in wildlife by V. Danilewsky in 1884, it took over 70 years to determine the main vector groups of these parasites. However, precise vector-parasite relationships remain insufficiently investigated in wildlife, particularly at the species level of haemosporidians and their vectors. Molecular tools have provided innovative opportunities to speed such research. In this issue of Molecular Ecology, Martínez-de la Puente et al. (2011) collected, for the first time, a significant PCR-based set of data on the presence of lineages of the pigment-forming haemosporidians (species of Haemoproteus and Plasmodium) in biting midges (Culicoides). They identified numerous associations between Culicoides spp. and Haemoproteus spp., indicating directions for future targeting vector studies of haemoproteids.

  8. Using shared needles for subcutaneous inoculation can transmit bluetongue virus mechanically between ruminant hosts.

    PubMed

    Darpel, Karin E; Barber, James; Hope, Andrew; Wilson, Anthony J; Gubbins, Simon; Henstock, Mark; Frost, Lorraine; Batten, Carrie; Veronesi, Eva; Moffat, Katy; Carpenter, Simon; Oura, Chris; Mellor, Philip S; Mertens, Peter P C

    2016-01-01

    Bluetongue virus (BTV) is an economically important arbovirus of ruminants that is transmitted by Culicoides spp. biting midges. BTV infection of ruminants results in a high viraemia, suggesting that repeated sharing of needles between animals could result in its iatrogenic transmission. Studies defining the risk of iatrogenic transmission of blood-borne pathogens by less invasive routes, such as subcutaneous or intradermal inoculations are rare, even though the sharing of needles is common practice for these inoculation routes in the veterinary sector. Here we demonstrate that BTV can be transmitted by needle sharing during subcutaneous inoculation, despite the absence of visible blood contamination of the needles. The incubation period, measured from sharing of needles, to detection of BTV in the recipient sheep or cattle, was substantially longer than has previously been reported after experimental infection of ruminants by either direct inoculation of virus, or through blood feeding by infected Culicoides. Although such mechanical transmission is most likely rare under field condition, these results are likely to influence future advice given in relation to sharing needles during veterinary vaccination campaigns and will also be of interest for the public health sector considering the risk of pathogen transmission during subcutaneous inoculations with re-used needles. PMID:26853457

  9. Development and Evaluation of Real Time RT-PCR Assays for Detection and Typing of Bluetongue Virus

    PubMed Central

    Maan, Narender Singh; Belaganahalli, Manjunatha N.; Potgieter, Abraham C.; Kumar, Vinay; Batra, Kanisht; Wright, Isabel M.; Kirkland, Peter D.; Mertens, Peter P. C.

    2016-01-01

    Bluetongue virus is the type species of the genus Orbivirus, family Reoviridae. Bluetongue viruses (BTV) are transmitted between their vertebrate hosts primarily by biting midges (Culicoides spp.) in which they also replicate. Consequently BTV distribution is dependent on the activity, geographic distribution, and seasonal abundance of Culicoides spp. The virus can also be transmitted vertically in vertebrate hosts, and some strains/serotypes can be transmitted horizontally in the absence of insect vectors. The BTV genome is composed of ten linear segments of double-stranded (ds) RNA, numbered in order of decreasing size (Seg-1 to Seg-10). Genome segment 2 (Seg-2) encodes outer-capsid protein VP2, the most variable BTV protein and the primary target for neutralising antibodies. Consequently VP2 (and Seg-2) determine the identity of the twenty seven serotypes and two additional putative BTV serotypes that have been recognised so far. Current BTV vaccines are serotype specific and typing of outbreak strains is required in order to deploy appropriate vaccines. We report development and evaluation of multiple ‘TaqMan’ fluorescence-probe based quantitative real-time type-specific RT-PCR assays targeting Seg-2 of the 27+1 BTV types. The assays were evaluated using orbivirus isolates from the ‘Orbivirus Reference Collection’ (ORC) held at The Pirbright Institute. The assays are BTV-type specific and can be used for rapid, sensitive and reliable detection / identification (typing) of BTV RNA from samples of infected blood, tissues, homogenised Culicoides, or tissue culture supernatants. None of the assays amplified cDNAs from closely related but heterologous orbiviruses, or from uninfected host animals or cell cultures. PMID:27661614

  10. Disease prevention and anti-vector campaigns: insects.

    PubMed

    Esterhuizen, J

    2015-04-01

    Control of insect vector populations is an integral part of disease management but has many challenges. Area-wide campaigns, mainly based on insecticide administration, are most effective for control of insect populations, whereas disease prevention is more localised and protects a smaller number of animals against insect vector contact. Various control and prevention techniques are available for use against most insectvectors and are illustrated here by focusing on two important insect groups: biting midges and tsetse flies. Biting midges (Culicoides) present a major threat and challenge to disease and vector control because of limited large-scale control options and the huge population sizes and wide distribution of these insects. Localised disease prevention forms the basis for control, and there is a need for better understanding of the ecology and biology of these insects in order to develop large-scale control techniques. The necessary techniques to effectively control tsetse flies (Glossina) and trypanosomosis exist for both localised and area-wide control. The development of a new, cost-efficient device has had a significant impact in the control of both human and animal trypanosomosis. This is especially relevant in Uganda, where the movement of livestock for trading purposes is implicated in disease distribution and poses an immediate health threat where the two forms of the disease overlap. Although many successes have been achieved, continued research and development is needed to keep abreast of the multitude of challenges in insect vector control.

  11. Effects of aerial applications of naled on nontarget insects at Parris Island, South Carolina.

    PubMed

    Breidenbaugh, M S; de Szalay, F A

    2010-04-01

    Testing impacts of large-scale aerial spraying to control public health pests under realistic field conditions are needed to understand impacts on natural populations of nontarget insects. Responses of terrestrial insects to aerial applications of an organophosphate insecticide, naled, used for mosquito and biting midge control were studied on Parris Island Marine Corps Recruit Depot, Parris Island, SC. Aerial applications were made with C-130 aircraft at dusk in 2003 and in 2005. In 2003, we sampled two locations on Parris Island with Malaise traps before and after spraying, and used Before-After analyses to examine changes in terrestrial insect diversity and abundance. In 2005, we sampled insects with yellow pan traps at three locations on Parris Island and at an untreated control site. A Before-After Control-Impact analysis at each location was conducted to compare changes. In 2003, numbers of four of 12 common taxa (Dolichopodidae, Sarcophagidae, Syrphidae, Tachinidae) were lower after sprays. However, there were no significant changes in numbers of common taxa or total numbers in 2005. Shannon diversities (H') were not different in either year indicating that sprays had minimal impact on overall community biodiversity. In contrast, populations of pestiferous biting midges (Culicoides spp.) collected in CDC-style traps were reduced by 94-99% after spraying in both years; mosquito numbers declined by 88.2% in 2003 and 92.5% in 2005, after sprays. PMID:20388292

  12. Using remote sensing and machine learning for the spatial modelling of a bluetongue virus vector

    NASA Astrophysics Data System (ADS)

    Van doninck, J.; Peters, J.; De Baets, B.; Ducheyne, E.; Verhoest, N. E. C.

    2012-04-01

    Bluetongue is a viral vector-borne disease transmitted between hosts, mostly cattle and small ruminants, by some species of Culicoides midges. Within the Mediterranean basin, C. imicola is the main vector of the bluetongue virus. The spatial distribution of this species is limited by a number of environmental factors, including temperature, soil properties and land cover. The identification of zones at risk of bluetongue outbreaks thus requires detailed information on these environmental factors, as well as appropriate epidemiological modelling techniques. We here give an overview of the environmental factors assumed to be constraining the spatial distribution of C. imicola, as identified in different studies. Subsequently, remote sensing products that can be used as proxies for these environmental constraints are presented. Remote sensing data are then used together with species occurrence data from the Spanish Bluetongue National Surveillance Programme to calibrate a supervised learning model, based on Random Forests, to model the probability of occurrence of the C. imicola midge. The model will then be applied for a pixel-based prediction over the Iberian peninsula using remote sensing products for habitat characterization.

  13. Disease prevention and anti-vector campaigns: insects.

    PubMed

    Esterhuizen, J

    2015-04-01

    Control of insect vector populations is an integral part of disease management but has many challenges. Area-wide campaigns, mainly based on insecticide administration, are most effective for control of insect populations, whereas disease prevention is more localised and protects a smaller number of animals against insect vector contact. Various control and prevention techniques are available for use against most insectvectors and are illustrated here by focusing on two important insect groups: biting midges and tsetse flies. Biting midges (Culicoides) present a major threat and challenge to disease and vector control because of limited large-scale control options and the huge population sizes and wide distribution of these insects. Localised disease prevention forms the basis for control, and there is a need for better understanding of the ecology and biology of these insects in order to develop large-scale control techniques. The necessary techniques to effectively control tsetse flies (Glossina) and trypanosomosis exist for both localised and area-wide control. The development of a new, cost-efficient device has had a significant impact in the control of both human and animal trypanosomosis. This is especially relevant in Uganda, where the movement of livestock for trading purposes is implicated in disease distribution and poses an immediate health threat where the two forms of the disease overlap. Although many successes have been achieved, continued research and development is needed to keep abreast of the multitude of challenges in insect vector control. PMID:26470462

  14. [THE CYTOGENETIC CHARACTERISTIC OF SOME PALEARCTIC POPULATIONS OF HOLARCTIC MIDGE GLYPTOTENDIPES BARBIPES STAEGER (DIPTERA, CHIRONOMIDAE)].

    PubMed

    Petrova, N A; Zhirov, S V

    2015-01-01

    Set and frequencies of inversion banding sequences in polytene chromosomes in the Palearctic natural populations of a Holarctic chironomid Glyptotendipes barbipes (2n = 8) (the Northwest of Russia, Irkutsk region, Kirghizia, Armenia) have been investigated. The majority of larvae were heterozygotes on inversions. Distinctions in a set and frequencies of inversions between populations form different regions have been ascertained. We have established that G. barbipes karyotype in the populations studied includes inversion banding sequences that are endemic for Palearctic (p'barG2), and also the general sequences met both in Palearctic, and in Nearctic (h'barB3, h'barC3, h'baE2, h'barF2). PMID:27012098

  15. Effects of bioirrigation of non-biting midges (Diptera: Chironomidae) on lake sediment respiration.

    PubMed

    Baranov, Viktor; Lewandowski, Jörg; Romeijn, Paul; Singer, Gabriel; Krause, Stefan

    2016-01-01

    Bioirrigation or the transport of fluids into the sediment matrix due to the activities of organisms such as bloodworms (larvae of Diptera, Chironomidae), has substantial impacts on sediment respiration in lakes. However, previous quantifications of bioirrigation impacts of Chironomidae have been limited by technical challenges such as the difficulty to separate faunal and bacterial respiration. This paper describes a novel method based on the bioreactive tracer resazurin for measuring respiration in-situ in non-sealed systems with constant oxygen supply. Applying this new method in microcosm experiments revealed that bioirrigation enhanced sediment respiration by up to 2.5 times. The new method is yielding lower oxygen consumption than previously reported, as it is only sensitive to aerobic heterotrophous respiration and not to other processes causing oxygen decrease. Hence it decouples the quantification of respiration of animals and inorganic oxygen consumption from microbe respiration in sediment. PMID:27256514

  16. Polypedilum nubifer, a Chironomid Midge (Diptera: Chironomidae) new to Florida that has nuisance potential

    SciTech Connect

    Jacobsen, R.E.; Perry, S.A.

    2007-03-15

    We document the first record of Polypedilum nubifer in Pan-America. This eurytopic species often reaches severe nuisance population sizes in Australia, Asia, and Hawaii in warm, shallow, eutrophic waters subject to drying. A large population was discovered in newly-constructed infiltration basins and neighboring marshes along the eastern boundary of Everglades National Park. Presently, this population appears minimally invasive to Park marshes and is far removed from urban areas. However, we anticipate this species could disperse and attain nuisance population sizes in suitable urban and agricultural habitats in south Florida. (author)

  17. The effects of binary UV filter mixtures on the midge Chironomus riparius.

    PubMed

    Ozáez, Irene; Morcillo, Gloria; Martínez-Guitarte, José-Luis

    2016-06-15

    Organic ultraviolet (UV) filters are used in a wide variety of products, including cosmetics, to prevent damage from UV light in tissues and industrial materials. Their extensive use has raised concerns about potential adverse effects in human health and aquatic ecosystems that accumulate these pollutants. To increase sun radiation protection, UV filters are commonly used in mixtures. Here, we studied the toxicity of binary mixtures of 4-methylbenzylidene camphor (4MBC), octyl-methoxycinnamate (OMC), and benzophenone-3 (BP-3), by evaluating the larval mortality of Chironomus riparius. Also molecular endpoints have been analyzed, including alterations in the expression levels of a gene related with the endocrine system (EcR, ecdysone receptor) and a gene related with the stress response (hsp70, heat shock protein 70). The results showed that the mortality caused by binary mixtures was similar to that observed for each compound alone; however, some differences in LC50 were observed between groups. Gene expression analysis showed that EcR mRNA levels increased in the presence of 0.1mg/L 4MBC but returned to normal levels after exposure to mixtures of 4MBC with 0.1, 1, and 10mg/L of BP-3 or OMC. In contrast, the hsp70 mRNA levels increased after exposure to the combinations tested of 4MBC and BP-3 or OMC mixtures. These data suggest that 4MBC, BP-3, and OMC may have antagonist effects on EcR gene transcription and a synergistic effect on hsp70 gene activation. This is the first experimental study to show the complex patterned effects of UV filter mixtures on invertebrates. The data suggest that the interactions within these chemicals mixtures are complex and show diverse effects on various endpoints. PMID:26971216

  18. Studies on the chironomid midges (Diptera, Chironomidae) of the Nansei Islands, southern Japan.

    PubMed

    Sasa, M

    1990-06-01

    The Nansei Islands are located in the subtropical zone of the western Pacific Ocean between Kyushu and Taiwan, and are composed of the two main island groups, the Amami and the Ryukyu Archipelagoes. This area has been known for the presence of a number of indigenous animal species. Prior to the present studies, collections of the chironomids mainly in the urban areas of the three main islands of the Ryukyus were carried out by Sasa and Hasegawa, and a total of 42 species, including 25 new species, were recorded. Additional collections of the chironomids mainly in the mountainous areas of this region were carried out by the present author during 1988 and 1989, and a total of 26 species (including 12 new species) were recorded from Amami Island, and a total of 27 species (including 10 new species) were recorded from the Ryukyu Islands. Eight species among them, including 3 new species, were common to the two archipelagos. PMID:2214255

  19. The effects of binary UV filter mixtures on the midge Chironomus riparius.

    PubMed

    Ozáez, Irene; Morcillo, Gloria; Martínez-Guitarte, José-Luis

    2016-06-15

    Organic ultraviolet (UV) filters are used in a wide variety of products, including cosmetics, to prevent damage from UV light in tissues and industrial materials. Their extensive use has raised concerns about potential adverse effects in human health and aquatic ecosystems that accumulate these pollutants. To increase sun radiation protection, UV filters are commonly used in mixtures. Here, we studied the toxicity of binary mixtures of 4-methylbenzylidene camphor (4MBC), octyl-methoxycinnamate (OMC), and benzophenone-3 (BP-3), by evaluating the larval mortality of Chironomus riparius. Also molecular endpoints have been analyzed, including alterations in the expression levels of a gene related with the endocrine system (EcR, ecdysone receptor) and a gene related with the stress response (hsp70, heat shock protein 70). The results showed that the mortality caused by binary mixtures was similar to that observed for each compound alone; however, some differences in LC50 were observed between groups. Gene expression analysis showed that EcR mRNA levels increased in the presence of 0.1mg/L 4MBC but returned to normal levels after exposure to mixtures of 4MBC with 0.1, 1, and 10mg/L of BP-3 or OMC. In contrast, the hsp70 mRNA levels increased after exposure to the combinations tested of 4MBC and BP-3 or OMC mixtures. These data suggest that 4MBC, BP-3, and OMC may have antagonist effects on EcR gene transcription and a synergistic effect on hsp70 gene activation. This is the first experimental study to show the complex patterned effects of UV filter mixtures on invertebrates. The data suggest that the interactions within these chemicals mixtures are complex and show diverse effects on various endpoints.

  20. Vinclozolin alters the expression of hormonal and stress genes in the midge Chironomus riparius.

    PubMed

    Aquilino, Mónica; Sánchez-Argüello, Paloma; Martínez-Guitarte, José-Luis

    2016-05-01

    Vinclozolin is a fungicide used in agriculture that can reach aquatic ecosystems and affect the organisms living there. Its effects have been intensively studied in vertebrates, where it acts as an antiandrogen, but there is a lack of information about its mechanistic effects on invertebrates. In this work, we analyzed the response of genes related to the endocrine system, the stress response, and the detoxification mechanisms of Chironomus riparius fourth instar larvae after 24h and 48h exposures to 20 (69.9nM), 200 (699nM), and 2000μg/L (6.99μM) of Vinclozolin. Survival analysis showed that this compound has low toxicity, as it was not lethal for this organism at the concentrations used. However, this fungicide was shown to modify the transcriptional activity of the ecdysone response pathway genes EcR, E74, and Kr-h1 by increasing their mRNA levels. While no changes were observed in disembodied, a gene related with the ecdysone synthesis metabolic pathway, Cyp18A1, which is involved in the inactivation of the active form of ecdysone, was upregulated. Additionally, the expression of two genes related to other hormones, FOXO and MAPR, did not show any changes when Vinclozolin was present. The analysis of stress response genes showed significant changes in the mRNA levels of Hsp70, Hsp24, and Gp93, indicating that Vinclozolin activates the cellular stress mechanisms. Finally, the expressions of the genes Cyp4G and GstD3, which encode enzymes involved in phase I and phase II detoxification, respectively, were analyzed. It was found that their mRNA levels were altered by Vinclozolin, suggesting their involvement in the degradation of this compound. For the first time, these results show evidence that Vinclozolin can modulate gene expression, leading to possible significant endocrine alterations of the insect endocrine system. These results also offer new clues about the mode of action of this compound in invertebrates.

  1. Effects of bioirrigation of non-biting midges (Diptera: Chironomidae) on lake sediment respiration

    PubMed Central

    Baranov, Viktor; Lewandowski, Jörg; Romeijn, Paul; Singer, Gabriel; Krause, Stefan

    2016-01-01

    Bioirrigation or the transport of fluids into the sediment matrix due to the activities of organisms such as bloodworms (larvae of Diptera, Chironomidae), has substantial impacts on sediment respiration in lakes. However, previous quantifications of bioirrigation impacts of Chironomidae have been limited by technical challenges such as the difficulty to separate faunal and bacterial respiration. This paper describes a novel method based on the bioreactive tracer resazurin for measuring respiration in-situ in non-sealed systems with constant oxygen supply. Applying this new method in microcosm experiments revealed that bioirrigation enhanced sediment respiration by up to 2.5 times. The new method is yielding lower oxygen consumption than previously reported, as it is only sensitive to aerobic heterotrophous respiration and not to other processes causing oxygen decrease. Hence it decouples the quantification of respiration of animals and inorganic oxygen consumption from microbe respiration in sediment. PMID:27256514

  2. Vinclozolin alters the expression of hormonal and stress genes in the midge Chironomus riparius.

    PubMed

    Aquilino, Mónica; Sánchez-Argüello, Paloma; Martínez-Guitarte, José-Luis

    2016-05-01

    Vinclozolin is a fungicide used in agriculture that can reach aquatic ecosystems and affect the organisms living there. Its effects have been intensively studied in vertebrates, where it acts as an antiandrogen, but there is a lack of information about its mechanistic effects on invertebrates. In this work, we analyzed the response of genes related to the endocrine system, the stress response, and the detoxification mechanisms of Chironomus riparius fourth instar larvae after 24h and 48h exposures to 20 (69.9nM), 200 (699nM), and 2000μg/L (6.99μM) of Vinclozolin. Survival analysis showed that this compound has low toxicity, as it was not lethal for this organism at the concentrations used. However, this fungicide was shown to modify the transcriptional activity of the ecdysone response pathway genes EcR, E74, and Kr-h1 by increasing their mRNA levels. While no changes were observed in disembodied, a gene related with the ecdysone synthesis metabolic pathway, Cyp18A1, which is involved in the inactivation of the active form of ecdysone, was upregulated. Additionally, the expression of two genes related to other hormones, FOXO and MAPR, did not show any changes when Vinclozolin was present. The analysis of stress response genes showed significant changes in the mRNA levels of Hsp70, Hsp24, and Gp93, indicating that Vinclozolin activates the cellular stress mechanisms. Finally, the expressions of the genes Cyp4G and GstD3, which encode enzymes involved in phase I and phase II detoxification, respectively, were analyzed. It was found that their mRNA levels were altered by Vinclozolin, suggesting their involvement in the degradation of this compound. For the first time, these results show evidence that Vinclozolin can modulate gene expression, leading to possible significant endocrine alterations of the insect endocrine system. These results also offer new clues about the mode of action of this compound in invertebrates. PMID:26966872

  3. Studies on the chironomid midges (Diptera, Chironomidae) of the Nansei Islands, southern Japan.

    PubMed

    Sasa, M

    1990-06-01

    The Nansei Islands are located in the subtropical zone of the western Pacific Ocean between Kyushu and Taiwan, and are composed of the two main island groups, the Amami and the Ryukyu Archipelagoes. This area has been known for the presence of a number of indigenous animal species. Prior to the present studies, collections of the chironomids mainly in the urban areas of the three main islands of the Ryukyus were carried out by Sasa and Hasegawa, and a total of 42 species, including 25 new species, were recorded. Additional collections of the chironomids mainly in the mountainous areas of this region were carried out by the present author during 1988 and 1989, and a total of 26 species (including 12 new species) were recorded from Amami Island, and a total of 27 species (including 10 new species) were recorded from the Ryukyu Islands. Eight species among them, including 3 new species, were common to the two archipelagos.

  4. New species and records of frog-biting midges from southern Brazil (Diptera: Corethrellidae).

    PubMed

    Amaral, André P; Pinho, Luiz Carlos

    2015-01-01

    Corethrella borkenti sp. n. is described, based on female and male adults, pupae and larvae, collected from tank bromeliads in the Atlantic Forest of southern Brazil. The larva and pupa of C. alticola Lane, 1939 are described for the first time. New distributional records for C. alticola and C. vittata Lane, 1939 extend their distributions to the southern Atlantic Forest. A key to pupae of peruviana group is given. PMID:25947691

  5. Atypical mechanoreceptors in larvae of biting midges Forcipomyia nigra (Diptera: Ceratopogonidae).

    PubMed

    Urbanek, Aleksandra; Kapusta, Małgorzata

    2016-09-01

    The dorsolateral setae of Forcipomyia nigra have been investigated. They are mechanoreceptors, sensilla trichoidea, innerved by a single neuron. The tubular body is located at the base of the hair shaft. Although the fine structure of the dorsolateral setae is similar to dorsal setae that perform a double function: secretion of a hygroscopic viscous substance through the pores and mechanoreception dorsolateral setae, they do not secrete any fluid. In both types of setae, trichogen cells (hair forming cells) produce the hair shafts and thereafter do not retract from the cavity of the setae. They contain a large polyploid nucleus and expanded bundles of microtubules. In dorsolateral mechanoreceptors, the microtubules form a network around the nucleus of the trichogen cell and are especially numerous in the cytoplasm invading the interior of the seta, which is evidenced by immunofluorescence light microscopy. No tormogen cell, responsible for the production of the setal socket, was found. Our observations indicate that the dorsolateral setae are solely mechanoreceptors but their trichogen cells reveal some glandular activity. PMID:27428285

  6. New combinations and changes in the classification of Ceratopogonidae (Diptera, biting midges).

    PubMed

    Borkent, Art

    2015-01-01

    This short article contains some necessary taxonomic changes prior to the publication of a chapter on the Ceratopogonidae by the author for the upcoming Manual of Afrotropical Diptera and spearheaded by Ashley Kirk-Spriggs. Some additional placements of three genera to a recently redefined tribe are also included. PMID:26249516

  7. Hypersensitivity to larvae of chironomids (non-biting midges). Cross-sensitization with crustaceans.

    PubMed

    Eriksson, N E; Ryden, B; Jonsson, P

    1989-07-01

    In 2,368 consecutive adult patients with asthma and/or rhinitis the incidence of positive skin prick test (SPT) with a chironomid extract (CHIR) (produced from "red feather mosquito larvae" used as fish food) was 14% (26% in atopics and 4% in non-atopics). RAST with chironomid was positive in 4% of 110 consecutive sera (8% in atopic sera). Significant correlations were found between RAST and SPT results with chironomid and between SPT results with CHIR and with various crustaceans. Correlations were also found reciprocally among SPT results with different crustaceans and between some crustaceans and moluscs (clam and oyster) as well as among RAST results with chironomid, shrimp and crab. Inhibition experiments showed that chironomid extracts inhibited RAST with shrimp, and vice versa. It is concluded that Chironomidae might be allergens of clinical importance in asthma and rhinitis in Sweden, that cross-allergy exists between chironomids and shrimp and that cross-allergy also might occur among chironomids, crustaceans and molluscs.

  8. Serosurveillance of Schmallenberg virus in Switzerland using bulk tank milk samples.

    PubMed

    Balmer, Sandra; Vögtlin, Andrea; Thür, Barbara; Büchi, Martina; Abril, Carlos; Houmard, Matthias; Danuser, Jürg; Schwermer, Heinzpeter

    2014-10-15

    Infections with Schmallenberg virus (SBV), a novel Orthobunyavirus transmitted by biting midges, can cause abortions and malformations of newborns and severe symptoms in adults of domestic and wild ruminants. Understanding the temporal and spatial distribution of the virus in a certain territory is important for the control and prevention of the disease. In this study, seroprevalence of antibodies against SBV and the spatial spread of the virus was investigated in Swiss dairy cattle applying a milk serology technique on bulk milk samples. The seroprevalence in cattle herds was significantly higher in December 2012 (99.5%) compared to July 2012 (19.7%). This high between-herd seroprevalence in cattle herds was observed shortly after the first detection of viral infections. Milk samples originating from farms with seropositive animals taken in December 2012 (n=209; mean 160%) revealed significantly higher S/P% ratios than samples collected in July 2012 (n=48; mean 103.6%). This finding suggests a high within-herd seroprevalence in infected herds which makes testing of bulk tank milk samples for the identification farms with past exposures to SBV a sensitive method. It suggests also that within-herd transmission followed by seroconversion still occurred between July and December. In July 2012, positive bulk tank milk samples were mainly restricted to the western part of Switzerland whereas in December 2012, all samples except one were positive. A spatial analysis revealed a separation of regions with and without positive farms in July 2012 and no spatial clustering within the regions with positive farms. In contrast to the spatial dispersion of bluetongue virus, a virus that is also transmitted by Culicoides midges, in 2008 in Switzerland, the spread of SBV occurred from the western to the eastern part of the country. The dispersed incursion of SBV took place in the western part of Switzerland and the virus spread rapidly to the remaining territory. This spatial

  9. Developing a preventive immunization approach against insect bite hypersensitivity using recombinant allergens: A pilot study.

    PubMed

    Jonsdottir, Sigridur; Hamza, Eman; Janda, Jozef; Rhyner, Claudio; Meinke, Andreas; Marti, Eliane; Svansson, Vilhjalmur; Torsteinsdottir, Sigurbjorg

    2015-07-15

    Insect bite hypersensitivity (IBH) is an allergic dermatitis of horses caused by bites of midges (Culicoides spp.). IgE-mediated reactions are often involved in the pathogenesis of this disease. IBH does not occur in Iceland due to the absence of Culicoides, but it occurs with a high frequency in Icelandic horses exported to mainland Europe, where Culicoides are present. We hypothesize that immunization with the Culicoides allergens before export could reduce the incidence of IBH in exported Icelandic horses. The aim of the present study was therefore to compare intradermal and intralymphatic vaccination using four purified recombinant allergens, in combination with a Th1 focusing adjuvant. Twelve horses were vaccinated three times with 10μg of each of the four recombinant Culicoides nubeculosus allergens. Six horses were injected intralymphatically, three with and three without IC31(®), and six were injected intradermally, in the presence or absence of IC31(®). Antibody responses were measured by immunoblots and ELISA, potential sensitization in a sulfidoleukotriene release test and an intradermal test, cytokine and FoxP3 expression with real time PCR following in vitro stimulation of PBMC. Immunization with the r-allergens induced a significant increase in levels of r-allergen-specific IgG1, IgG1/3, IgG4/7, IgG5 and IgG(T). Application of the r-allergens in IC31(®) adjuvant resulted in a significantly higher IgG1, IgG1/3, IgG4/7 allergen-specific response. Intralymphatic injection was slightly more efficient than intradermal injection, but the difference did not reach significance. Testing of the blocking activity of the sera from the horses immunized intralymphatically with IC31(®) showed that the generated IgG antibodies were able to partly block binding of serum IgE from an IBH-affected horse to these r-allergens. Furthermore, IgG antibodies bound to protein bands on blots of C. nubeculosus salivary gland extract. No allergen-specific IgE was induced and

  10. African horse sickness.

    PubMed

    Mellor, Philip Scott; Hamblin, Christopher

    2004-01-01

    African horse sickness virus (AHSV) causes a non-contagious, infectious insect-borne disease of equids and is endemic in many areas of sub-Saharan Africa and possibly Yemen in the Arabian Peninsula. However, periodically the virus makes excursions beyond its endemic areas and has at times extended as far as India and Pakistan in the east and Spain and Portugal in the west. The vectors are certain species of Culicoides biting midge the most important of which is the Afro-Asiatic species C. imicola. This paper describes the effects that AHSV has on its equid hosts, aspects of its epidemiology, and present and future prospects for control. The distribution of AHSV seems to be governed by a number of factors including the efficiency of control measures, the presence or absence of a long term vertebrate reservoir and, most importantly, the prevalence and seasonal incidence of the major vector which is controlled by climate. However, with the advent of climate-change the major vector, C. imicola, has now significantly extended its range northwards to include much of Portugal, Spain, Italy and Greece and has even been recorded from southern Switzerland. Furthermore, in many of these new locations the insect is present and active throughout the entire year. With the related bluetongue virus, which utilises the same vector species of Culicoides this has, since 1998, precipitated the worst outbreaks of bluetongue disease ever recorded with the virus extending further north in Europe than ever before and apparently becoming endemic in that continent. The prospects for similar changes in the epidemiology and distribution of AHSV are discussed.

  11. Ecological Drivers of Mansonella perstans Infection in Uganda and Patterns of Co-endemicity with Lymphatic Filariasis and Malaria

    PubMed Central

    Stensgaard, Anna-Sofie; Vounatsou, Penelope; Onapa, Ambrose W.; Utzinger, Jürg; Pedersen, Erling M.; Kristensen, Thomas K.; Simonsen, Paul E.

    2016-01-01

    Background Mansonella perstans is a widespread, but relatively unknown human filarial parasite transmitted by Culicoides biting midges. Although it is found in many parts of sub-Saharan Africa, only few studies have been carried out to deepen the understanding of its ecology, epidemiology, and health consequences. Hence, knowledge about ecological drivers of the vector and parasite distribution, integral to develop spatially explicit models for disease prevention, control, and elimination strategies, is limited. Methodology We analyzed data from a comprehensive nationwide survey of M. perstans infection conducted in 76 schools across Uganda in 2000–2003, to identify environmental drivers. A suite of Bayesian geostatistical regression models was fitted, and the best fitting model based on the deviance information criterion was utilized to predict M. perstans infection risk for all of Uganda. Additionally, we investigated co-infection rates and co-distribution with Wuchereria bancrofti and Plasmodium spp. infections observed at the same survey by mapping geographically overlapping areas. Principal Findings Several bioclimatic factors were significantly associated with M. perstans infection levels. A spatial Bayesian regression model showed the best fit, with diurnal temperature range, normalized difference vegetation index, and cattle densities identified as significant covariates. This model was employed to predict M. perstans infection risk at non-sampled locations. The level of co-infection with W. bancrofti was low (0.3%), due to limited geographic overlap. However, where the two infections did overlap geographically, a positive association was found. Conclusions/Significance This study presents the first geostatistical risk map for M. perstans in Uganda. We confirmed a widespread distribution of M. perstans, and identified important potential drivers of risk. The results provide new insight about the ecologic preferences of this otherwise poorly known filarial

  12. Free-living ciliates as potential reservoirs for eukaryotic parasites: occurrence of a trypanosomatid in the macronucleus of Euplotes encysticus

    PubMed Central

    2014-01-01

    Background Flagellates of the family Trypanosomatidae are obligate endoparasites, which can be found in various hosts. Several genera infect insects and occur as monoxenous parasites especially in representatives of Diptera and Hemiptera. These trypanosomatid flagellates probably share the worldwide distribution of their hosts, which are often infested by large numbers of endoparasites. Traditionally, their taxonomy was based on morphology, host origin, and life cycle. Here we report the characterization of a trypanosomatid infection detected in a protozoan, a ciliate collected from a polluted freshwater pond in a suburb of New Delhi (India). Methods Live observations and morphological studies applying light, fluorescence and transmission electron microscopy were conducted. Molecular analyses of host and parasite were performed and used for phylogenetic reconstructions and species (host) or genus level (parasite) identification. Results Although the morphological characteristics were not revealing, a high similarity of the trypanosomatids 18S rRNA gene sequence to Herpetomonas ztiplika and Herpetomonas trimorpha (Kinetoplastida, Trypanosomatidae), both parasites of biting midges (Culicoides kibunensis and Culicoides truncorum, respectively) allowed the assignment to this genus. The majority of the host population displayed a heavy infection that significantly affected the shape of the host macronucleus, which was the main site of parasite localization. In addition, the growth rate of host cultures, identified as Euplotes encysticus according to cell morphology and 18S rRNA gene sequence, was severely impacted by the infection. Conclusions The host-parasite system described here represents a recent example of free-living protists acting as environmental reservoirs for parasitic eukaryotic microorganisms. PMID:24774858

  13. Identification of Anhydrobiosis-related Genes from an Expressed Sequence Tag Database in the Cryptobiotic Midge Polypedilum vanderplanki (Diptera; Chironomidae)*

    PubMed Central

    Cornette, Richard; Kanamori, Yasushi; Watanabe, Masahiko; Nakahara, Yuichi; Gusev, Oleg; Mitsumasu, Kanako; Kadono-Okuda, Keiko; Shimomura, Michihiko; Mita, Kazuei; Kikawada, Takahiro; Okuda, Takashi

    2010-01-01

    Some organisms are able to survive the loss of almost all their body water content, entering a latent state known as anhydrobiosis. The sleeping chironomid (Polypedilum vanderplanki) lives in the semi-arid regions of Africa, and its larvae can survive desiccation in an anhydrobiotic form during the dry season. To unveil the molecular mechanisms of this resistance to desiccation, an anhydrobiosis-related Expressed Sequence Tag (EST) database was obtained from the sequences of three cDNA libraries constructed from P. vanderplanki larvae after 0, 12, and 36 h of desiccation. The database contained 15,056 ESTs distributed into 4,807 UniGene clusters. ESTs were classified according to gene ontology categories, and putative expression patterns were deduced for all clusters on the basis of the number of clones in each library; expression patterns were confirmed by real-time PCR for selected genes. Among up-regulated genes, antioxidants, late embryogenesis abundant (LEA) proteins, and heat shock proteins (Hsps) were identified as important groups for anhydrobiosis. Genes related to trehalose metabolism and various transporters were also strongly induced by desiccation. Those results suggest that the oxidative stress response plays a central role in successful anhydrobiosis. Similarly, protein denaturation and aggregation may be prevented by marked up-regulation of Hsps and the anhydrobiosis-specific LEA proteins. A third major feature is the predicted increase in trehalose synthesis and in the expression of various transporter proteins allowing the distribution of trehalose and other solutes to all tissues. PMID:20833722

  14. New Record of the Biting Midge Leptoconops noei in Northern Spain: Notes on Its Seasonal Abundance and Flying Height Preference

    PubMed Central

    González, Mikel A.; López, Sergio; Goldarazena, Arturo

    2013-01-01

    During the summers of 2004–2006, harmful outbreaks of Leptoconops noei Clastrier and Coluzzi (Diptera: Ceratopogonidae) occurred in a small region in the southern part of Alava (Basque Country, Spain). Two types of traps were placed for monitoring L. noei: CDC traps baited with dry ice in eight different locations and sticky traps at three different heights (two, four, and six meters). A total of 1,823 adults were captured with dry ice traps and 163 specimens with sticky papers. Dry-baited collections occurred between June and August in two of the eight samplings places. Significant differences were observed concerning the vertical distribution of L. noei. The most specimens were captured at a height of two meters. A specific area near the riverside composed of sandy matter was described as the main developmental site for L. noei. This is the first record of L. noei in Spain. PMID:23909239

  15. Cryptic species in the nuisance midge Polypedilum nubifer (Skuse (Diptera: Chironomidae) and the status of Tripedilum Kieffer.

    PubMed

    Cranston, Peter S; Martin, Jon; Spies, Martin

    2016-01-01

    Polypedilum nubifer (Skuse, 1889), originally described from Australia, is an apparently widespread species of Chironomidae (Diptera) that can attain nuisance densities in some eutrophic water bodies. Appropriate management depends upon the identity and ability to distinguish from potential cryptic taxa. A morphological study of larvae, pupae and adults of both sexes confirmed P. nubifer as widely distributed and frequently abundant, but also revealed two previously cryptic species of limited distribution in northern Australia. These species are described as new and illustrated in all stages here. Polypedilum quasinubifer Cranston sp. n. is described from north-west Queensland, Australia and also from Thailand and Singapore. Polypedilum paranubifer Cranston sp. n. is known only from retention ponds of a uranium mine in Northern Territory, Australia. Unusual morphological features of P. nubifer including alternate Lauterborn organs on the larval antenna, cephalic tubules on the pupa and frontal tubercles on the adult head are present in both new species as well. Newly slide-mounted types of Polypedilum pelostolum Kieffer, 1912 (lectotype designated here) confirm synonymy to Chironomus nubifer Skuse, 1889, examined also as newly-slide mounted types. Reviewed plus new evidence does not support recognition of Tripedilum Kieffer, 1921 as a separate taxon; therefore, Tripedilum is returned to junior synonymy with Polypedilum s. str. PMID:27394199

  16. Fluctuating asymmetry and mentum gaps in populations of the midge Chironomus riparius (Diptera: Chironomidae) from a metal-contaminated River

    SciTech Connect

    Groenendijk, D.; Zeinstra, L.W.M.; Postma, J.F.

    1998-10-01

    The developmental stability of both metal-exposed and nonexposed Chironomus riparius populations from the lowland River Dommel was investigated using fluctuating asymmetry (FA) and the incidence of mentum gaps. It was hypothesized that larval development was affected by the influx of Cd, Zn, Fe, Cu, and Pb directly by chemical stress, as well as through inbreeding of metal-adapted and nonadapted specimens. Morphological para/meters were therefore assessed in field-collected larvae and in clean, laboratory-cultured, first-generation (F1) larvae. Fluctuating asymmetry values and mentum gap incidence at contaminated field sites were significantly higher than at clean, upstream locations. Furthermore, FA values of clean, laboratory-cultured F1 larvae generally fell to reference values, indicating the direct effect of metal pollution on developmental aberrations. Mentum gaps were not observed in clean F1 cultures. Slightly elevated FA values were, however, still observed in clean F1 larvae from polluted locations downstream from the metal input. This residual disturbance was thought to reflect genetic stress emerging from interbreeding between metal-adapted and nonadapted specimens. Fluctuating asymmetry and mentum gaps together serve as a useful ecotoxicological marker for metal stress and, when combined with in situ studies and F1 cultures, allow for analysis of the response of animal populations to spatial and temporal gradients in metal exposure.

  17. Identification and reassessment of the specific status of some tropical freshwater midges (Diptera: Chironomidae) using DNA barcode data.

    PubMed

    Pramual, Pairot; Simwisat, Kusumart; Martin, Jon

    2016-01-01

    Chironomidae are a highly diverse group of insects. Members of this family are often included in programs monitoring the health of freshwater ecosystems. However, a difficulty in morphological identification, particularly of larval stages is the major obstacle to this application. In this study, we tested the efficiency of mitochondrial cytochrome c oxidase I (COI) sequences as the DNA barcoding region for species identification of Chironomidae in Thailand. The results revealed 14 species with a high success rate (>90%) for the correct species identification, which suggests the potential usefulness of the technique. However, some morphological species possess high (>3%) intraspecific genetic divergence that suggests these species could be species complexes and need further morphological or cytological examination. Sequence-based species delimitation analyses indicated that most specimens identified as Chironomus kiiensis, Tokunaga 1936, in Japan are conspecific with C. striatipennis, Kieffer 1912, although a small number form a separate cluster. A review of the descriptions of Kiefferulus tainanus (Kieffer 1912) and its junior synonym, K. biroi (Kieffer 1918), following our results, suggests that this synonymy is probably not correct and that K. tainanus occurs in Japan, China and Singapore, while K. biroi occurs in India and Thailand. Our results therefore revealed the usefulness of DNA barcoding for correct species identification of Chironomidae, particularly the immature stages. In addition, DNA barcodes could also uncover hidden diversity that can guide further taxonomic study, and offer a more efficient way to identify species than morphological analysis where large numbers of specimens are involved, provided the identifications of DNA barcodes in the databases are correct. Our studies indicate that this is not the case, and we identify cases of misidentifications for C. flaviplumus, Tokunaga 1940 and K. tainanus. PMID:27395909

  18. Support for the evolutionary speed hypothesis from intraspecific population genetic data in the non-biting midge Chironomus riparius.

    PubMed

    Oppold, Ann-Marie; Pedrosa, João A M; Bálint, Miklós; Diogo, João B; Ilkova, Julia; Pestana, João L T; Pfenninger, Markus

    2016-02-24

    The evolutionary speed hypothesis (ESH) proposes a causal mechanism for the latitudinal diversity gradient. The central idea of the ESH is that warmer temperatures lead to shorter generation times and increased mutation rates. On an absolute time scale, both should lead to an acceleration of selection and drift. Based on the ESH, we developed predictions regarding the distribution of intraspecific genetic diversity: populations of ectothermic species with more generations per year owing to warmer ambient temperatures should be more differentiated from each other, accumulate more mutations and show evidence for increased mutation rates compared with populations in colder regions. We used the multivoltine insect species Chironomus riparius to test these predictions with cytochrome oxidase I (COI) sequence data and found that populations from warmer regions are indeed significantly more differentiated and have significantly more derived haplotypes than populations from colder regions. We also found a significant correlation of the annual mean temperature with the population mutation parameter θ that serves as a proxy for the per generation mutation rate under certain assumptions. This pattern could be corroborated with two nuclear loci. Overall, our results support the ESH and indicate that the thermal regime experienced may be crucially driving the evolution of ectotherms and may thus ultimately govern their speciation rate. PMID:26888029

  19. The bud midge Prodiplosis longifila: Damage characteristics, potential distribution and presence on a new crop host in Colombia.

    PubMed

    Hernandez, Luis M; Guzman, Yoan C; Martínez-Arias, Adriana; Manzano, Maria R; Selvaraj, John J

    2015-01-01

    The Dipteran Prodiplosis longifila is a severe pest, mainly of Solanaceae, in South America and some years ago it damaged Tahiti lime crops in the United States. It is a potential invasive pest. Despite its presence in Colombia, nothing is known regarding the taxonomic identification of P. longifila or the characteristics of the damage it produces. Moreover, the current and potential distributions of this pest are unknown. To determine these factors, P. longifila was sampled in several Solanaceae- and Citrus (x) latifolia (Tahiti lime)-producing areas in Colombia. The larvae consumed tender foliage, flowers and fruits in tomato, fruits in sweet pepper, and buds in Tahiti lime. P. longifila was not found in asparagus or in potatoes. Its presence in Tahiti lime was previously unknown in Colombia. Adults recovered in the laboratory were taxonomically identified using male morphological characteristics such as the shapes of the genitalia, antenna and wing. P. longifila was found in the Andean region of Colombia. The ecological niche model for populations found in tomato suggests that P. longifila is limited in its distribution by altitude and variables associated with temperature and precipitation. The highest probability of occurrence is in areas where tomato, sweet pepper and the new host, Tahiti lime, are grown. Therefore, it is necessary to implement preventive measures, such as planting tomato materials free of P. longifila larvae, in areas where the pest is not yet present but where there is the potential for its development. PMID:25977894

  20. Overexpression of long non-coding RNAs following exposure to xenobiotics in the aquatic midge Chironomus riparius.

    PubMed

    Martínez-Guitarte, José-Luis; Planelló, Rosario; Morcillo, Gloria

    2012-04-01

    Non-coding RNAs (ncRNAs) represent an important transcriptional output of eukaryotic genomes. In addition to their functional relevance as housekeeping and regulatory elements, recent studies have suggested their involvement in rather unexpected cellular functions. The aim of this work was to analyse the transcriptional behaviour of non-coding RNAs in the toxic response to pollutants in Chironomus riparius, a reference organism in aquatic toxicology. Three well-characterized long non-coding sequences were studied: telomeric repeats, Cla repetitive elements and the SINE CTRT1. Transcription levels were evaluated by RT-PCR after 24-h exposures to three current aquatic contaminants: bisphenol A (BPA), benzyl butyl phthalate (BBP) and the heavy metal cadmium (Cd). Upregulation of telomeric transcripts was found after BPA treatments. Moreover, BPA significantly activated Cla transcription, which also appeared to be increased by cadmium, whereas BBP did not affect the transcription levels of these sequences. Transcription of SINE CTRT1 was not altered by any of the chemicals tested. These data are discussed in the light of previous studies that have shown a response by long ncRNAS (lncRNAs) to cellular stressors, indicating a relationship with environmental stimuli. Our results demonstrated for the first time the ability of bisphenol A to activate non-coding sequences mainly located at telomeres and centromeres. Overall, this study provides evidence that xenobiotics can induce specific responses in ncRNAs derived from repetitive sequences that could be relevant in the toxic response, and also suggests that ncRNAs could represent a novel class of potential biomarkers in toxicological assessment.

  1. Effects of TFM and Bayer 73 on in vivo oxygen consumption of the aquatic midge Chironomus tentans

    USGS Publications Warehouse

    Kawatski, J.A.; Dawson, V.K.; Reuvers, J.L.

    1974-01-01

    Exposure of fourth instar larvae of Chironomus tentans to 2.0-8.0 mg/liter of TFM (3-trifluormethyl-4-nitrophenol) for 6 hr at 22 A? 0.5 C in soft water resulted in a significantly increased rate of larval oxygen consumption compared to that of control larvae, as measured with the Warburg respirometer. Maximum stimulation of oxygen consumption occurred with 8.0 mg/liter of TFM, and 1.0 mg/liter of TFM had no measurable effect on basal respiration. When hardness of exposure water was progressively increased, the effect of TFM on oxygen consumption was diminished. Bayer 73 (5,2'-dichloro-4'-nitrosalicylanilide) stimulated oxygen consumption at 0.75 and 1.0 mg/liter, had no significant effect at concentrations less that 0.75 mg/liter, and inhibited oxygen consumption at concentrations of 1.20 mg/liter or greater. Mixtures of TFM and Bayer 73, in the ratio of 98:2, had no greater effect on oxygen consumption than TFM alone.

  2. Unbalanced activation of glutathione metabolic pathways suggests potential involvement in plant defense against the gall midge mayetiola destructor in wheat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glutathione, a thiol tripeptide of '-glutamylcysteinylglycine, exists abundantly in nearly all organisms. Glutathione participates in various physiological processes involved in redox reactions by serving as an electron donor/acceptor. In this study, we found that the abundance of total glutathion...

  3. Survival in extreme environment by "preserve-expand-specialize" strategy: lessons from comparative genomics of an anhydrobiotic midge.

    NASA Astrophysics Data System (ADS)

    Gusev, Oleg; Sugimoto, Manabu; Novikova, Nataliya; Sychev, Vladimir; Okuda, Takashi; Kikawada, Takahiro

    2012-07-01

    Anhydrobiotic chironomid larvae of Polypedilum vanderplanki (Diptera) can withstand prolonged complete desiccation as well as other external stresses including ionizing radiation. Recent experiments showed that this insect is able to survive long-tern exposure to real outer space. At the same time, we found that dehydration causes alterations in chromatin structure and a severe fragmentation of nuclear DNA in the cells of the larvae despite successful anhydrobiosis. Analysis of several remote populations of the chironomid in Africa that desiccation-related DNA damage might be a driving genetic force for rapid radiation within the species. First results of ongoing genome project suggest that origin and evolution of anhydrobiosis in this single insect species related to rapid duplication of the genes, coding late embryogenesis abundant proteins (LEA) and other molecular agents directly involved in desiccation resistance in the cells. Analysis of genome-wide mRNA expression profiles in the larvae subjected to desiccation shows that joint-activity of large multiple-genes coding regions in the genome involved in control of anhydrobiosis-related molecular adaptations in the chironomid.

  4. The bud midge Prodiplosis longifila: Damage characteristics, potential distribution and presence on a new crop host in Colombia.

    PubMed

    Hernandez, Luis M; Guzman, Yoan C; Martínez-Arias, Adriana; Manzano, Maria R; Selvaraj, John J

    2015-01-01

    The Dipteran Prodiplosis longifila is a severe pest, mainly of Solanaceae, in South America and some years ago it damaged Tahiti lime crops in the United States. It is a potential invasive pest. Despite its presence in Colombia, nothing is known regarding the taxonomic identification of P. longifila or the characteristics of the damage it produces. Moreover, the current and potential distributions of this pest are unknown. To determine these factors, P. longifila was sampled in several Solanaceae- and Citrus (x) latifolia (Tahiti lime)-producing areas in Colombia. The larvae consumed tender foliage, flowers and fruits in tomato, fruits in sweet pepper, and buds in Tahiti lime. P. longifila was not found in asparagus or in potatoes. Its presence in Tahiti lime was previously unknown in Colombia. Adults recovered in the laboratory were taxonomically identified using male morphological characteristics such as the shapes of the genitalia, antenna and wing. P. longifila was found in the Andean region of Colombia. The ecological niche model for populations found in tomato suggests that P. longifila is limited in its distribution by altitude and variables associated with temperature and precipitation. The highest probability of occurrence is in areas where tomato, sweet pepper and the new host, Tahiti lime, are grown. Therefore, it is necessary to implement preventive measures, such as planting tomato materials free of P. longifila larvae, in areas where the pest is not yet present but where there is the potential for its development.

  5. Two new species of predatory biting midges of the genus Alluaudomyia from Europe and the Canary Islands (Diptera: Ceratopogonidae).

    PubMed

    Szadziewski, Ryszard; Dominiak, Patrycja; Filatov, Serhii

    2015-01-01

    Alluaudomyia canariensis Szadziewski & Dominiak sp. nov. from the Canary Islands and A. wyskokensis Szadziewski & Dominiak sp. nov. from Poland and Ukraine are described and illustrated. The genus Alluaudomyia is reported from the Canary Islands for the first time. The article is supplemented with a checklist and an identification key for the species so far recorded from Europe and the Canary Islands. PMID:26624483

  6. The same ELA class II risk factors confer equine insect bite hypersensitivity in two distinct populations.

    PubMed

    Andersson, Lisa S; Swinburne, June E; Meadows, Jennifer R S; Broström, Hans; Eriksson, Susanne; Fikse, W Freddy; Frey, Rebecka; Sundquist, Marie; Tseng, Chia T; Mikko, Sofia; Lindgren, Gabriella

    2012-03-01

    Insect bite hypersensitivity (IBH) is a chronic allergic dermatitis common in horses. Affected horses mainly react against antigens present in the saliva from the biting midges, Culicoides ssp, and occasionally black flies, Simulium ssp. Because of this insect dependency, the disease is clearly seasonal and prevalence varies between geographical locations. For two distinct horse breeds, we genotyped four microsatellite markers positioned within the MHC class II region and sequenced the highly polymorphic exons two from DRA and DRB3, respectively. Initially, 94 IBH-affected and 93 unaffected Swedish born Icelandic horses were tested for genetic association. These horses had previously been genotyped on the Illumina Equine SNP50 BeadChip, which made it possible to ensure that our study did not suffer from the effects of stratification. The second population consisted of 106 unaffected and 80 IBH-affected Exmoor ponies. We show that variants in the MHC class II region are associated with disease susceptibility (p (raw) = 2.34 × 10(-5)), with the same allele (COR112:274) associated in two separate populations. In addition, we combined microsatellite and sequencing data in order to investigate the pattern of homozygosity and show that homozygosity across the entire MHC class II region is associated with a higher risk of developing IBH (p = 0.0013). To our knowledge this is the first time in any atopic dermatitis suffering species, including man, where the same risk allele has been identified in two distinct populations.

  7. Climate Change Influences on the Global Potential Distribution of Bluetongue Virus.

    PubMed

    Samy, Abdallah M; Peterson, A Townsend

    2016-01-01

    The geographic distribution of arboviruses has received considerable attention after several dramatic emergence events around the world. Bluetongue virus (BTV) is classified among category "A" diseases notifiable to the World Organization of Animal Health (OIE), and is transmitted among ruminants by biting midges of the genus Culicoides. Here, we developed a comprehensive occurrence data set to map the current distribution, estimate the ecological niche, and explore the future potential distribution of BTV globally using ecological niche modeling and based on diverse future climate scenarios from general circulation models (GCMs) for four representative concentration pathways (RCPs). The broad ecological niche and potential geographic distribution of BTV under present-day conditions reflected the disease's current distribution across the world in tropical, subtropical, and temperate regions. All model predictions were significantly better than random expectations. As a further evaluation of model robustness, we compared our model predictions to 331 independent records from most recent outbreaks from the Food and Agriculture Organization Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases Information System (EMPRES-i); all were successfully anticipated by the BTV model. Finally, we tested ecological niche similarity among possible vectors and BTV, and could not reject hypotheses of niche similarity. Under future-climate conditions, the potential distribution of BTV was predicted to broaden, especially in central Africa, United States, and western Russia.

  8. Where are the horses? With the sheep or cows? Uncertain host location, vector-feeding preferences and the risk of African horse sickness transmission in Great Britain

    PubMed Central

    Lo Iacono, Giovanni; Robin, Charlotte A.; Newton, J. Richard; Gubbins, Simon; Wood, James L. N.

    2013-01-01

    Understanding the influence of non-susceptible hosts on vector-borne disease transmission is an important epidemiological problem. However, investigation of its impact can be complicated by uncertainty in the location of the hosts. Estimating the risk of transmission of African horse sickness (AHS) in Great Britain (GB), a virus transmitted by Culicoides biting midges, provides an insightful example because: (i) the patterns of risk are expected to be influenced by the presence of non-susceptible vertebrate hosts (cattle and sheep) and (ii) incomplete information on the spatial distribution of horses is available because the GB National Equine Database records owner, rather than horse, locations. Here, we combine land-use data with available horse owner distributions and, using a Bayesian approach, infer a realistic distribution for the location of horses. We estimate the risk of an outbreak of AHS in GB, using the basic reproduction number (R0), and demonstrate that mapping owner addresses as a proxy for horse location significantly underestimates the risk. We clarify the role of non-susceptible vertebrate hosts by showing that the risk of disease in the presence of many hosts (susceptible and non-susceptible) can be ultimately reduced to two fundamental factors: first, the abundance of vectors and how this depends on host density, and, second, the differential feeding preference of vectors among animal species. PMID:23594817

  9. Evaluation of a diagnostic ELISA for insect bite hypersensitivity in horses using recombinant Obsoletus complex allergens.

    PubMed

    van der Meide, Nathalie M A; Savelkoul, Huub F J; Meulenbroeks, Chantal; Ducro, Bart J; Tijhaar, Edwin

    2014-04-01

    Culicoides spp. of the Obsoletus complex belong to the most important species of midge, involved in causing insect bite hypersensitivity (IBH) in horses in The Netherlands. The aim of the current study was to evaluate seven different Obsoletus complex-derived recombinant allergens (Cul o 1-Cul o 7) and to compare these with Obsoletus complex whole body extract (WBE) in an IgE ELISA, using sera of 194 clinically-confirmed cases of IBH and 175 unaffected horses. The highest test accuracy was obtained with WBE, followed by Cul o 2, 3 and 5. Two ELISAs with a combination of recombinant allergens, Combi-1 (Cul o 3, 5 and 7) and Combi-2 (Cul o 1, 2, 5 and 7) were additionally performed and both resulted in high test accuracies close to that obtained with WBE. Combi-1 resulted in the best sensitivity and specificity, both 89%. Both Combi-1 and Combi-2 performed less well with samples collected in winter, but over 70% of the IBH-affected horses could still be identified. In conclusion, a combination of three Obsoletus complex recombinant allergens (Cul o 3, 5 and 7) could potentially replace Obsoletus complex WBE in an IgE ELISA for diagnosis of IBH in horses.

  10. Comparing the effect of modeled climatic variables on the distribution of African horse sickness in South Africa and Namibia.

    PubMed

    Liebenberg, Danica; van Hamburg, Huib; Piketh, Stuart; Burger, Roelof

    2015-12-01

    Africa horse sickness (AHS) is a lethal disease of horses with a seasonal occurrence that is influenced by environmental conditions that favor the development of Culicoides midges (Diptera: Ceratopogonidae). This study compared and evaluated the relationship of various modeled climatic variables with the distribution and abundance of AHS in South Africa and Namibia. A comprehensive literature review of the historical AHS reported data collected from the Windhoek archives as well as annual reports from the Directorate of Veterinary services in Namibia were conducted. South African AHS reported data were collected from the South African Department of Agriculture, Forestry, and Fisheries. Daily climatic data were extracted for the time period 1993-2011 from the ERA-interim re-analysis dataset. The principal component analysis of the complete dataset indicated a significant statistical difference between Namibia and South Africa for the various climate variables and the outbreaks of AHS. The most influential parameters in the distribution of AHS included humidity, precipitation, evaporation, and minimum temperature. In South Africa, temperature had the most significant effect on the outbreaks of AHS, whereas in Namibia, humidity and precipitation were the main drivers. The maximum AHS cases in South Africa occurred at temperatures of 20-22° C and relative humidity between 50-70%. Furthermore, anthropogenic effects must be taken into account when trying to understand the distribution of AHS.

  11. Generation of Recombinant Modified Vaccinia Virus Ankara Encoding VP2, NS1, and VP7 Proteins of Bluetongue Virus.

    PubMed

    Marín-López, Alejandro; Ortego, Javier

    2016-01-01

    Modified Vaccinia Virus Ankara (MVA) is employed widely as an experimental vaccine vector for its lack of replication in mammalian cells and high expression level of foreign/heterologous genes. Recombinant MVAs (rMVAs) are used as platforms for protein production as well as vectors to generate vaccines against a high number of infectious diseases and other pathologies. The portrait of the virus combines desirable elements such as high-level biological safety, the ability to activate appropriate innate immune mediators upon vaccination, and the capacity to deliver substantial amounts of heterologous antigens. Recombinant MVAs encoding proteins of bluetongue virus (BTV), an Orbivirus that infects domestic and wild ruminants transmitted by biting midges of the Culicoides species, are excellent vaccine candidates against this virus. In this chapter we describe the methods for the generation of rMVAs encoding VP2, NS1, and VP7 proteins of bluetongue virus as a model example for orbiviruses. The protocols included cover the cloning of VP2, NS1, and VP7 BTV-4 genes in a transfer plasmid, the construction of recombinant MVAs, the titration of virus working stocks and the protein expression analysis by immunofluorescence and radiolabeling of rMVA infected cells as well as virus purification.

  12. Schmallenberg disease in sheep or goats: Past, present and future.

    PubMed

    Lievaart-Peterson, K; Luttikholt, S; Peperkamp, K; Van den Brom, R; Vellema, P

    2015-12-14

    Schmallenberg disease has emerged in North-Western Europe in 2011 and has since spread widely, even across the European borders. It has the potency to infect many, mainly ruminant, species, but seems to lack zoonotic potential. Horizontal transmission occurs through various Culicoides biting midges and subsequent trans-placental transmission causes teratogenic effects. In some small ruminants, clinical signs, including fever, decreased milk production and diarrhea occur during the viraemic phase, but infection is mostly asymptomatic. However, fetal Schmallenberg virus infection in naïve ewes and goats can result in stillborn offspring, showing a congenital arthrogryposis-hydranencephaly syndrome. The economic impact of infection depends on the number of malformed lambs, but is generally limited. There is debate on whether Schmallenberg virus has newly emerged or is re-emerging, since it is likely one of the ancestors of Shamonda virus, both Orthobunyaviruses belonging to the species Sathuperi virus within the Simbu serogroup viruses. Depending on the vector-borne transmission and the serologic status, future outbreaks of Schmallenberg disease induced congenital disease are expected.

  13. Climate Change Influences on the Global Potential Distribution of Bluetongue Virus

    PubMed Central

    Samy, Abdallah M.; Peterson, A. Townsend

    2016-01-01

    The geographic distribution of arboviruses has received considerable attention after several dramatic emergence events around the world. Bluetongue virus (BTV) is classified among category “A” diseases notifiable to the World Organization of Animal Health (OIE), and is transmitted among ruminants by biting midges of the genus Culicoides. Here, we developed a comprehensive occurrence data set to map the current distribution, estimate the ecological niche, and explore the future potential distribution of BTV globally using ecological niche modeling and based on diverse future climate scenarios from general circulation models (GCMs) for four representative concentration pathways (RCPs). The broad ecological niche and potential geographic distribution of BTV under present-day conditions reflected the disease’s current distribution across the world in tropical, subtropical, and temperate regions. All model predictions were significantly better than random expectations. As a further evaluation of model robustness, we compared our model predictions to 331 independent records from most recent outbreaks from the Food and Agriculture Organization Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases Information System (EMPRES-i); all were successfully anticipated by the BTV model. Finally, we tested ecological niche similarity among possible vectors and BTV, and could not reject hypotheses of niche similarity. Under future-climate conditions, the potential distribution of BTV was predicted to broaden, especially in central Africa, United States, and western Russia. PMID:26959424

  14. Bluetongue: a historical and epidemiological perspective with the emphasis on South Africa

    PubMed Central

    2012-01-01

    Bluetongue (BT) is a non-contagious, infectious, arthropod transmitted viral disease of domestic and wild ruminants that is caused by the bluetongue virus (BTV), the prototype member of the Orbivirus genus in the family Reoviridae. Bluetongue was first described in South Africa, where it has probably been endemic in wild ruminants since antiquity. Since its discovery BT has had a major impact on sheep breeders in the country and has therefore been a key focus of research at the Onderstepoort Veterinary Research Institute in Pretoria, South Africa. Several key discoveries were made at this Institute, including the demonstration that the aetiological agent of BT was a dsRNA virus that is transmitted by Culicoides midges and that multiple BTV serotypes circulate in nature. It is currently recognized that BT is endemic throughout most of South Africa and 22 of the 26 known serotypes have been detected in the region. Multiple serotypes circulate each vector season with the occurrence of different serotypes depending largely on herd-immunity. Indigenous sheep breeds, cattle and wild ruminants are frequently infected but rarely demonstrate clinical signs, whereas improved European sheep breeds are most susceptible. The immunization of susceptible sheep remains the most effective and practical control measure against BT. In order to protect sheep against multiple circulating serotypes, three pentavalent attenuated vaccines have been developed. Despite the proven efficacy of these vaccines in protecting sheep against the disease, several disadvantages are associated with their use in the field. PMID:22973992

  15. Impact of temperature, feeding preference and vaccination on Schmallenberg virus transmission in Scotland.

    PubMed

    Bessell, Paul R; Auty, Harriet K; Searle, Kate R; Handel, Ian G; Purse, Bethan V; de C Bronsvoort, B Mark

    2014-07-18

    First identified in 2011, Schmallenberg virus (SBV) is principally transmitted by Culicoides midges and affects ruminants. Clinical presentation is typified by foetal abnormalities, but despite very high infection rates, relatively few animals present with clinical signs. In this paper we further develop a previously published stochastic mathematical model of SBV spread to investigate the optimal deployment of a vaccine for SBV in Scotland, a country that has experienced only sporadic and isolated cases of SBV. We consider the use of the vaccine under different temperatures and explore the effects of a vector preference for feeding on cattle. We demonstrate that vaccine impact is optimised by targeting it at the high risk areas in the south of Scotland, or vaccinating only cattle. At higher than average temperatures, and hence increased transmission potential, the relative impact of vaccination is considerably enhanced. Vaccine impact is also enhanced if vectors feed preferentially on cattle. These findings are of considerable importance when planning control strategies for SBV and also have important implications for management of other arboviruses such as Bluetongue virus. Environmental determinants and feeding preferences should be researched further to inform development of effective control strategies.

  16. Mansonella ozzardi: a neglected New World filarial nematode.

    PubMed

    Lima, Nathália F; Veggiani Aybar, Cecilia A; Dantur Juri, María J; Ferreira, Marcelo U

    2016-05-01

    Mansonella ozzardi (Nematoda: Onchocercidae) is an understudied filarial nematode, originally described by Patrick Manson in 1897, that can be transmitted by two families of dipteran vectors, biting midges (most of them members of the genus Culicoides) and black flies (genus Simulium). With a patchy geographic distribution from southern Mexico to northwestern Argentina, human infection with M. ozzardi is highly prevalent in some of the Caribbean islands, along riverine communities in the Amazon Basin, and on both sides of the border between Bolivia and Argentina. There is no clinical entity unequivocally associated with M. ozzardi infection, although fever, arthralgia, headache, cold lower extremities, and itchy cutaneous rashes are occasionally mentioned in case report series. More recently, ocular manifestations (especially keratitis) have been associated with mansonelliasis, opening an important area of investigation. Here, we briefly review the biology, epidemiology, pathogenesis, and clinical aspects of M. ozzardi infection and point to some existing knowledge gaps, aiming to stimulate a research agenda to help filling them. PMID:27376501

  17. African horse sickness: The potential for an outbreak in disease-free regions and current disease control and elimination techniques.

    PubMed

    Robin, M; Page, P; Archer, D; Baylis, M

    2016-09-01

    African horse sickness (AHS) is an arboviral disease of equids transmitted by Culicoides biting midges. The virus is endemic in parts of sub-Saharan Africa and official AHS disease-free status can be obtained from the World Organization for Animal Health on fulfilment of a number of criteria. AHS is associated with case fatality rates of up to 95%, making an outbreak among naïve horses both a welfare and economic disaster. The worldwide distributions of similar vector-borne diseases (particularly bluetongue disease of ruminants) are changing rapidly, probably due to a combination of globalisation and climate change. There is extensive evidence that the requisite conditions for an AHS epizootic currently exist in disease-free countries. In particular, although the stringent regulations enforced upon competition horses make them extremely unlikely to redistribute the virus, there are great concerns over the effects of illegal equid movement. An outbreak of AHS in a disease free region would have catastrophic effects on equine welfare and industry, particularly for international events such as the Olympic Games. While many regions have contingency plans in place to manage an outbreak of AHS, further research is urgently required if the equine industry is to avoid or effectively contain an AHS epizootic in disease-free regions. This review describes the key aspects of AHS as a global issue and discusses the evidence supporting concerns that an epizootic may occur in AHS free countries, the planned government responses, and the roles and responsibilities of equine veterinarians. PMID:27292229

  18. Impact of temperature, feeding preference and vaccination on Schmallenberg virus transmission in Scotland

    PubMed Central

    Bessell, Paul R.; Auty, Harriet K.; Searle, Kate R.; Handel, Ian G.; Purse, Bethan V.; de C. Bronsvoort, B. Mark

    2014-01-01

    First identified in 2011, Schmallenberg virus (SBV) is principally transmitted by Culicoides midges and affects ruminants. Clinical presentation is typified by foetal abnormalities, but despite very high infection rates, relatively few animals present with clinical signs. In this paper we further develop a previously published stochastic mathematical model of SBV spread to investigate the optimal deployment of a vaccine for SBV in Scotland, a country that has experienced only sporadic and isolated cases of SBV. We consider the use of the vaccine under different temperatures and explore the effects of a vector preference for feeding on cattle. We demonstrate that vaccine impact is optimised by targeting it at the high risk areas in the south of Scotland, or vaccinating only cattle. At higher than average temperatures, and hence increased transmission potential, the relative impact of vaccination is considerably enhanced. Vaccine impact is also enhanced if vectors feed preferentially on cattle. These findings are of considerable importance when planning control strategies for SBV and also have important implications for management of other arboviruses such as Bluetongue virus. Environmental determinants and feeding preferences should be researched further to inform development of effective control strategies. PMID:25034464

  19. Where are the horses? With the sheep or cows? Uncertain host location, vector-feeding preferences and the risk of African horse sickness transmission in Great Britain.

    PubMed

    Lo Iacono, Giovanni; Robin, Charlotte A; Newton, J Richard; Gubbins, Simon; Wood, James L N

    2013-06-01

    Understanding the influence of non-susceptible hosts on vector-borne disease transmission is an important epidemiological problem. However, investigation of its impact can be complicated by uncertainty in the location of the hosts. Estimating the risk of transmission of African horse sickness (AHS) in Great Britain (GB), a virus transmitted by Culicoides biting midges, provides an insightful example because: (i) the patterns of risk are expected to be influenced by the presence of non-susceptible vertebrate hosts (cattle and sheep) and (ii) incomplete information on the spatial distribution of horses is available because the GB National Equine Database records owner, rather than horse, locations. Here, we combine land-use data with available horse owner distributions and, using a Bayesian approach, infer a realistic distribution for the location of horses. We estimate the risk of an outbreak of AHS in GB, using the basic reproduction number (R0), and demonstrate that mapping owner addresses as a proxy for horse location significantly underestimates the risk. We clarify the role of non-susceptible vertebrate hosts by showing that the risk of disease in the presence of many hosts (susceptible and non-susceptible) can be ultimately reduced to two fundamental factors: first, the abundance of vectors and how this depends on host density, and, second, the differential feeding preference of vectors among animal species.

  20. African horse sickness: The potential for an outbreak in disease-free regions and current disease control and elimination techniques.

    PubMed

    Robin, M; Page, P; Archer, D; Baylis, M

    2016-09-01

    African horse sickness (AHS) is an arboviral disease of equids transmitted by Culicoides biting midges. The virus is endemic in parts of sub-Saharan Africa and official AHS disease-free status can be obtained from the World Organization for Animal Health on fulfilment of a number of criteria. AHS is associated with case fatality rates of up to 95%, making an outbreak among naïve horses both a welfare and economic disaster. The worldwide distributions of similar vector-borne diseases (particularly bluetongue disease of ruminants) are changing rapidly, probably due to a combination of globalisation and climate change. There is extensive evidence that the requisite conditions for an AHS epizootic currently exist in disease-free countries. In particular, although the stringent regulations enforced upon competition horses make them extremely unlikely to redistribute the virus, there are great concerns over the effects of illegal equid movement. An outbreak of AHS in a disease free region would have catastrophic effects on equine welfare and industry, particularly for international events such as the Olympic Games. While many regions have contingency plans in place to manage an outbreak of AHS, further research is urgently required if the equine industry is to avoid or effectively contain an AHS epizootic in disease-free regions. This review describes the key aspects of AHS as a global issue and discusses the evidence supporting concerns that an epizootic may occur in AHS free countries, the planned government responses, and the roles and responsibilities of equine veterinarians.

  1. African horse sickness.

    PubMed

    Zientara, S; Weyer, C T; Lecollinet, S

    2015-08-01

    African horse sickness (AHS) is a devastating disease of equids caused by an arthropod-borne virus belonging to the Reoviridae family, genus Orbivirus. It is considered a major health threat for horses in endemic areas in sub-Saharan Africa. African horse sickness virus (AHSV) repeatedly caused large epizootics in the Mediterranean region (North Africa and southern Europe in particular) as a result of trade in infected equids. The unexpected emergence of a closely related virus, the bluetongue virus, in northern Europe in 2006 has raised fears about AHSV introduction into Europe, and more specifically into AHSV-free regions that have reported the presence of AHSV vectors, e.g. Culicoides midges. North African and European countries should be prepared to face AHSV incursions in the future, especially since two AHSV serotypes (serotypes 2 and 7) have recently spread northwards to western (e.g. Senegal, Nigeria, Gambia) and eastern Africa (Ethiopia), where historically only serotype 9 had been isolated. The authors review key elements of AHS epidemiology, surveillance and prophylaxis. PMID:26601437

  2. Comparing the effect of modeled climatic variables on the distribution of African horse sickness in South Africa and Namibia.

    PubMed

    Liebenberg, Danica; van Hamburg, Huib; Piketh, Stuart; Burger, Roelof

    2015-12-01

    Africa horse sickness (AHS) is a lethal disease of horses with a seasonal occurrence that is influenced by environmental conditions that favor the development of Culicoides midges (Diptera: Ceratopogonidae). This study compared and evaluated the relationship of various modeled climatic variables with the distribution and abundance of AHS in South Africa and Namibia. A comprehensive literature review of the historical AHS reported data collected from the Windhoek archives as well as annual reports from the Directorate of Veterinary services in Namibia were conducted. South African AHS reported data were collected from the South African Department of Agriculture, Forestry, and Fisheries. Daily climatic data were extracted for the time period 1993-2011 from the ERA-interim re-analysis dataset. The principal component analysis of the complete dataset indicated a significant statistical difference between Namibia and South Africa for the various climate variables and the outbreaks of AHS. The most influential parameters in the distribution of AHS included humidity, precipitation, evaporation, and minimum temperature. In South Africa, temperature had the most significant effect on the outbreaks of AHS, whereas in Namibia, humidity and precipitation were the main drivers. The maximum AHS cases in South Africa occurred at temperatures of 20-22° C and relative humidity between 50-70%. Furthermore, anthropogenic effects must be taken into account when trying to understand the distribution of AHS. PMID:26611969

  3. Climate Change Influences on the Global Potential Distribution of Bluetongue Virus.

    PubMed

    Samy, Abdallah M; Peterson, A Townsend

    2016-01-01

    The geographic distribution of arboviruses has received considerable attention after several dramatic emergence events around the world. Bluetongue virus (BTV) is classified among category "A" diseases notifiable to the World Organization of Animal Health (OIE), and is transmitted among ruminants by biting midges of the genus Culicoides. Here, we developed a comprehensive occurrence data set to map the current distribution, estimate the ecological niche, and explore the future potential distribution of BTV globally using ecological niche modeling and based on diverse future climate scenarios from general circulation models (GCMs) for four representative concentration pathways (RCPs). The broad ecological niche and potential geographic distribution of BTV under present-day conditions reflected the disease's current distribution across the world in tropical, subtropical, and temperate regions. All model predictions were significantly better than random expectations. As a further evaluation of model robustness, we compared our model predictions to 331 independent records from most recent outbreaks from the Food and Agriculture Organization Emergency Prevention System for Transboundary Animal and Plant Pests and Diseases Information System (EMPRES-i); all were successfully anticipated by the BTV model. Finally, we tested ecological niche similarity among possible vectors and BTV, and could not reject hypotheses of niche similarity. Under future-climate conditions, the potential distribution of BTV was predicted to broaden, especially in central Africa, United States, and western Russia. PMID:26959424

  4. Spatial epidemiological analysis of bovine encephalomyelitis outbreaks caused by Akabane virus infection in western Japan in 2011.

    PubMed

    Hayama, Yoko; Moriguchi, Sachiko; Yanase, Tohru; Ishikura, Youji; Abe, Shigeki; Higashi, Tomoko; Ishikawa, Hajime; Yamamoto, Takehisa; Kobayashi, Sota; Murai, Kiyokazu; Tsutsui, Toshiyuki

    2016-04-01

    Akabane disease, which is distributed in temperate and tropical regions in the world, is a vector-borne disease of ruminants caused by the Akabane virus, transmitted by Culicoides biting midges. In 2011, outbreaks of Akabane viral encephalomyelitis occurred in the Shimane Prefecture in western Japan. In this study, a spatial epidemiological analysis was conducted to understand environmental factors associated with the spread of Akabane disease. By applying a conditional autoregressive model, the relationship between infection and environmental variables was explored. The results showed that the dominance of farmlands and the presence of infected farms within a 3-km radius had a significant effect on infection. This result implies that land use, which would relate with the vector habitat, and the presence of neighboring infected farms as a source of infection may have influenced the spread of the disease in this region. These findings provide basic insights into the spread of Akabane disease and useful suggestions for developing a surveillance program and preventive measures against the disease. PMID:26898692

  5. Epizootic haemorrhagic disease.

    PubMed

    Maclachlan, N J; Zientara, S; Savini, G; Daniels, P W

    2015-08-01

    Summary Epizootic haemorrhagic disease (EHD) is an arthropod-transmitted viral disease of certain wild ungulates, notably North American white-tailed deer and, more rarely, cattle. The disease in white-tailed deer results from vascular injury analogous to that caused by bluetongue virus (BTV), to which EHD virus (EHDV) is closely related. There are seven serotypes of EHDV recognised, and Ibaraki virus, which is the cause of sporadic disease outbreaks in cattle in Asia, is included in EHDV serotype 2. The global distribution and epidemiology of BTV and EHDV infections are also similar, as both viruses occur throughout temperate and tropical regions of the world where they are transmitted by biting Culicoides midges and infect a wide variety of domestic and wild ungulates. However, the global distribution and epidemiology of EHDV infection are less well characterised than they are for BTV. Whereas most natural and experimental EHDV infections (other than Ibaraki virus infection) of livestock are subclinical or asymptomatic, outbreaks of EHD have recently been reported among cattle in the Mediterranean Basin, Reunion Island, South Africa, and the United States. Accurate and convenient laboratory tests are increasingly available for the sensitive and specific serological and virological diagnosis of EHDV infection and confirmation of EHD in animals, but commercial vaccines are available only for prevention of Ibaraki disease and not for protection against other strains and serotypes of EHDV. PMID:26601439

  6. Biological responses of midge (Chironomus riparius) and lamprey (Lampetra fluviatilis) larvae in ecotoxicity assessment of PCDD/F-, PCB- and Hg-contaminated river sediments.

    PubMed

    Salmelin, J; Karjalainen, A K; Hämäläinen, H; Leppänen, M T; Kiviranta, H; Kukkonen, J V K; Vuori, K M

    2016-09-01

    We evaluated the utility of chironomid and lamprey larval responses in ecotoxicity assessment of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/F)-, polychlorinated biphenyls (PCB)- and mercury (Hg)-contaminated river sediments. Sediment samples were collected from the River Kymijoki with a known industrial pollution gradient. Sediment for the controls and lamprey larvae were obtained from an uncontaminated river nearby. Contamination levels were verified with sediment and tissue PCDD/F, PCB and Hg analyses. Behaviour of sediment-exposed chironomid and lamprey larvae were measured with Multispecies Freshwater Biomonitor© utilizing quadrupole impedance conversion technique. In addition, mortality, growth and head capsule deformity incidence of chironomids were used as ecotoxicity indicators. WHOPCDD/F+PCB-TEQ in the R. Kymijoki sediments ranged from the highest upstream 22.36 ng g(-1) dw to the lowest 1.50 ng g(-1) near the river mouth. The sum of PCDD/Fs and PCBs correlated strongly with Hg sediment concentrations, which ranged from <0.01 to 1.15 μg g(-1). Lamprey tissue concentrations of PCDD/Fs were two orders and PCBs one order of magnitude higher in the R. Kymijoki compared to the reference. Chironomid growth decreased in contaminated sediments and was negatively related to sediment ∑PCDD/Fs, WHOPCDD/F+PCB-TEQ and Hg. There were no significant differences in larval mortality or chironomid mentum deformity incidence between the sediment exposures. The distinct behavioural patterns of both species indicate overall applicability of behavioural MFB measurements of these species in sediment toxicity bioassays. Chironomids spent less and lampreys more time in locomotion in the most contaminated sediment compared to the reference, albeit statistically significant differences were not detected. Lamprey larvae had also a greater activity range in some of the contaminated sediments than in the reference. High pollutant levels in lamprey indicate risks for biomagnification in the food webs, with potential health risks to humans consuming fish. PMID:27282370

  7. Biological responses of midge (Chironomus riparius) and lamprey (Lampetra fluviatilis) larvae in ecotoxicity assessment of PCDD/F-, PCB- and Hg-contaminated river sediments.

    PubMed

    Salmelin, J; Karjalainen, A K; Hämäläinen, H; Leppänen, M T; Kiviranta, H; Kukkonen, J V K; Vuori, K M

    2016-09-01

    We evaluated the utility of chironomid and lamprey larval responses in ecotoxicity assessment of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/F)-, polychlorinated biphenyls (PCB)- and mercury (Hg)-contaminated river sediments. Sediment samples were collected from the River Kymijoki with a known industrial pollution gradient. Sediment for the controls and lamprey larvae were obtained from an uncontaminated river nearby. Contamination levels were verified with sediment and tissue PCDD/F, PCB and Hg analyses. Behaviour of sediment-exposed chironomid and lamprey larvae were measured with Multispecies Freshwater Biomonitor© utilizing quadrupole impedance conversion technique. In addition, mortality, growth and head capsule deformity incidence of chironomids were used as ecotoxicity indicators. WHOPCDD/F+PCB-TEQ in the R. Kymijoki sediments ranged from the highest upstream 22.36 ng g(-1) dw to the lowest 1.50 ng g(-1) near the river mouth. The sum of PCDD/Fs and PCBs correlated strongly with Hg sediment concentrations, which ranged from <0.01 to 1.15 μg g(-1). Lamprey tissue concentrations of PCDD/Fs were two orders and PCBs one order of magnitude higher in the R. Kymijoki compared to the reference. Chironomid growth decreased in contaminated sediments and was negatively related to sediment ∑PCDD/Fs, WHOPCDD/F+PCB-TEQ and Hg. There were no significant differences in larval mortality or chironomid mentum deformity incidence between the sediment exposures. The distinct behavioural patterns of both species indicate overall applicability of behavioural MFB measurements of these species in sediment toxicity bioassays. Chironomids spent less and lampreys more time in locomotion in the most contaminated sediment compared to the reference, albeit statistically significant differences were not detected. Lamprey larvae had also a greater activity range in some of the contaminated sediments than in the reference. High pollutant levels in lamprey indicate risks for biomagnification in the food webs, with potential health risks to humans consuming fish.

  8. Description of a new species of Aphanogmus Thomson (Hymenoptera, Ceraphronidae) that parasitizes acarivorous gall midges of Feltiella (Diptera, Cecidomyiidae) in Japan

    PubMed Central

    Matsuo, Kazunori; Ganaha-Kikumura, Tomoko; Ohno, Suguru; Yukawa, Junichi

    2016-01-01

    Abstract In 2008–2009, we reared small ceraphronids (about 0.5 mm in body length) from cocoons that had been made possibly by two acarivorous species, Feltiella acarisuga (Vallot) and Feltiella acarivora (Zehntner) (Diptera: Cecidomyiidae) in Okinawa, Japan. Detailed morphological observation revealed that the ceraphronid was a new species of Aphanogmus Thomson (Hymenoptera: Ceraphronidae). We describe it as Aphanogmus flavigastris Matsuo, sp. n. Identification of the Aphanogmus species is essential to evaluate its possibly negative effects on the predatory activity of Feltiella species that have been used as control agents against tetranychid mites. PMID:27408578

  9. Effect of acute exposure to cadmium on the expression of heat-shock and hormone-nuclear receptor genes in the aquatic midge Chironomus riparius.

    PubMed

    Planelló, R; Martínez-Guitarte, J L; Morcillo, G

    2010-03-01

    Cadmium is a widespread and highly toxic pollutant of particular ecotoxicological relevance for aquatic ecosystems where it accumulates. To identify biomarkers for ecotoxicity monitoring, the effect of cadmium on the expression of different genes related to the stress response as well as to the ecdysone hormone-signalling pathway was studied in the aquatic larvae of Chironomus riparius (Diptera, Chironomidae), a standard test organism in aquatic toxicology testing. Reverse Transcription Polymerase Chain Reaction (RT-PCR) was used to evaluate the effects of acute and short-term cadmium exposures (10mM CdCl(2), 12h and 24h) on the expression of hsp70, hsc70, hsp90 and hsp40 genes, as well as on that of the ecdysone hormonal-receptor genes (EcR and usp). A significant 3-fold increase in the level of hsp70 gene transcripts was induced by the treatment, whereas neither the other stress genes tested (hsp90 and hsp40) nor the constitutive form of hsp70, hsc70, was affected in the larvae exposed to cadmium. These results show that hsp70 is differentially activated to other environmentally regulated heat-shock genes, and constitutes a biomarker of exposure to this toxic metal. In addition, we also found that cadmium is able to alter the expression of the ecdysone receptor gene (EcR), whose mRNA level is significantly increased whereas usp levels remained unaltered. This finding, evidenced for the first time in invertebrates, supports the view that cadmium has the ability to mimic the effect of the hormone by the activation of the ecdysone nuclear receptor, which may partly explain the endocrine disruption capability that has been previously suggested for this toxic metal. Our research adds to the growing evidence implicating heavy metals, and cadmium in particular, as potential endocrine disruptive agents and may have significant implications for ecological risk assessment of endocrine-disrupting compounds in invertebrates.

  10. Description of a new species of Aphanogmus Thomson (Hymenoptera, Ceraphronidae) that parasitizes acarivorous gall midges of Feltiella (Diptera, Cecidomyiidae) in Japan.

    PubMed

    Matsuo, Kazunori; Ganaha-Kikumura, Tomoko; Ohno, Suguru; Yukawa, Junichi

    2016-01-01

    In 2008-2009, we reared small ceraphronids (about 0.5 mm in body length) from cocoons that had been made possibly by two acarivorous species, Feltiella acarisuga (Vallot) and Feltiella acarivora (Zehntner) (Diptera: Cecidomyiidae) in Okinawa, Japan. Detailed morphological observation revealed that the ceraphronid was a new species of Aphanogmus Thomson (Hymenoptera: Ceraphronidae). We describe it as Aphanogmus flavigastris Matsuo, sp. n. Identification of the Aphanogmus species is essential to evaluate its possibly negative effects on the predatory activity of Feltiella species that have been used as control agents against tetranychid mites. PMID:27408578

  11. Who Cares if Barbie Loves Midge, as Long as They Get the Dreamhouse?: Poor and Working Class Lesbians of the New Millennium.

    ERIC Educational Resources Information Center

    Carter, Julie Hope

    1998-01-01

    In-depth interviews with 10 working-class lesbians, aged 16-22, examined how they envisioned their lives, their experiences related to sexual orientation growing up and in school, meanings and consequences of being poor and working class, and additional difficulties for minority-group lesbians. Most interviewees had goals of partaking in the…

  12. The spruce shoot gall midges (Diptera: Cecidomyiidae): Piceacecis, a new genus for a non-native pest of Norway spruce from Europe and its native American relative

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dasineura abietiperda (Henschel), a European pest of Norway spruce, Picea abies (Pinaceae), is reported as new to North America. Damage symptoms are illustrated and an outline of its biology is given. A new genus, Piceacecis Gagné is described to include it and its North American relative, Phytophag...

  13. A new species of gall midge associated with Diplopterys pubipetala (A.Juss.) Anderson and Davis (Malpighiaceae) from Altinópolis, São Paulo, Brazil.

    PubMed

    Urso-Guimarães, M V; Carmo-Neto, A M

    2015-01-01

    Clinodiplosis bellum sp. nov. associated with Diplopterys pubipetala (A.Juss.) Anderson and Davis (Malpighiaceae) from Brazil are described. This is the first species of Clinodiplosis described to State of São Paulo and the first formal description of Diplopterys pubipetala (Malpighiaceae) as host plant of Cecidomyiidae species. Description and illustration of the Clinodiplosis bellum sp. nov. (Diptera: Cecidomyiidae) are given.

  14. Effects of clay minerals and organic matter in formulated sediments on the bioavailability of sediment-associated uranium to the freshwater midge, Chironomus dilutus.

    PubMed

    Crawford, Sarah E; Liber, Karsten

    2015-11-01

    It is well established that bioavailability influences metal toxicity in aquatic ecosystems. However, the factors and mechanisms that influence uranium (U) bioavailability and toxicity in sediment have not been thoroughly evaluated, despite evidence that suggests different sediment components can influence the sorption and interaction of some metals. Given that dissolved U is generally accepted as being the primary bioavailable fraction of U, it is hypothesized that adsorption and interaction of U with different sediment components will influence the bioavailability of U in sediment. We investigated the effects of key sediment physicochemical properties on the bioavailability of U to a model freshwater benthic invertebrate, Chironomus dilutus. Several 10-day spiked sediment bioaccumulation experiments were performed, exposing C. dilutus larvae to a variety of formulated sediments spiked with different concentrations of U (5, 50 and/or 200 mg U/kg d.w.). Mean accumulation of U in C. dilutus larvae decreased significantly from 1195 to 10 mg U/kg d.w. as kaolin clay content increased from 0% to 60% in sediment spiked with 50 mg U/kg d.w. Similarly, higher organic matter content also resulted in a significant reduction of U bioaccumulation in C. dilutus larvae, indicating a reduction in U bioavailability. Concentrations of U in both the overlying water and sediment pore water displayed a strong positive relationship to U bioaccumulation in C. dilutus larvae (r(2) = 0.77, p<0.001 and r(2) = 0.57, p < 0.001, respectively) for all experiments, while total U concentrations in the sediment had a poor relationship to U bioaccumulation (r(2) = 0.10, p = 0.028). Results from this research confirm that sediment clay and organic matter content play a significant role in altering U bioavailability, which is important in informing risk assessments of U contaminated sites and in the development of site-specific sediment quality guidelines for U.

  15. Evaluation of corn plant as potential banker plant for supporting predatory gall Midge, Feltiella acarisuga (Diptera: Cecidomyiidae) against Tetranychus urticae (Acari: Tetranychidae) in greenhouse vegetable production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is one of the most important and highly polyphagous pests of vegetables and other crops worldwide. In this study, several experiments were conducted under laboratory and greenhouse conditions to evaluate whether corn plant ...

  16. Joint effects of density and a growth inhibitor on the life history and population growth rate of the midge Chironomus riparius.

    PubMed

    Hooper, Helen L; Sibly, Richard M; Hutchinson, Thomas H; Maund, Stephen J

    2005-05-01

    Results of previous laboratory studies suggest that high population density often buffers the effects of chemical stressors that predominately increase mortality. Mortality stressors act to release more resources for the survivors and, therefore, produce less-than-additive effects. By contrast, growth stressors are expected to have opposite results or more-than-additive effects. We investigated the effects of a growth inhibitor (lufenuron) on larval growth and survival of Chironomus riparius and examined its joint effects with density on population growth rate (PGR). Exposure to 60 microg/kg sediment or greater inhibited larval growth, and exposure to 88 microg/kg or greater often resulted in mortality before reaching emergence. The effects of lufenuron, however, differed with population density. At 88 microg/kg, mortalities and, to a lesser extent, reduced fecundity resulted in a reduction in PGR at low density. Conversely, when populations were initiated at high density, PGR was similar to that of controls, because the few survivors reached maturity sooner and started producing offspring earlier. The effect of density as a growth stressor therefore was stronger than the effect of lufenuron, which had effects similar to those of a mortality stressor and produced less-than-additive effects. Long-term studies under field conditions, however, are needed before less-than-additive effects are considered to be the norm. PMID:16110992

  17. A Modeling Framework to Describe the Transmission of Bluetongue Virus within and between Farms in Great Britain

    PubMed Central

    Szmaragd, Camille; Wilson, Anthony J.; Carpenter, Simon; Wood, James L. N.; Mellor, Philip S.; Gubbins, Simon

    2009-01-01

    Background Recently much attention has been given to developing national-scale micro-simulation models for livestock diseases that can be used to predict spread and assess the impact of control measures. The focus of these models has been on directly transmitted infections with little attention given to vector-borne diseases such as bluetongue, a viral disease of ruminants transmitted by Culicoides biting midges. Yet BT has emerged over the past decade as one of the most important diseases of livestock. Methodology/Principal Findings We developed a stochastic, spatially-explicit, farm-level model to describe the spread of bluetongue virus (BTV) within and between farms. Transmission between farms was modeled by a generic kernel, which includes both animal and vector movements. Once a farm acquired infection, the within-farm dynamics were simulated based on the number of cattle and sheep kept on the farm and on local temperatures. Parameter estimates were derived from the published literature and using data from the outbreak of bluetongue in northern Europe in 2006. The model was validated using data on the spread of BTV in Great Britain during 2007. The sensitivity of model predictions to the shape of the transmission kernel was assessed. Conclusions/Significance The model is able to replicate the dynamics of BTV in Great Britain. Although uncertainty remains over the precise shape of the transmission kernel and certain aspects of the vector, the modeling approach we develop constitutes an ideal framework in which to incorporate these aspects as more and better data become available. Moreover, the model provides a tool with which to examine scenarios for the spread and control of BTV in Great Britain. PMID:19890400

  18. Quantitative Risk Assessment for African Horse Sickness in Live Horses Exported from South Africa

    PubMed Central

    Sergeant, Evan S.

    2016-01-01

    African horse sickness (AHS) is a severe, often fatal, arbovirus infection of horses, transmitted by Culicoides spp. midges. AHS occurs in most of sub-Saharan Africa and is a significant impediment to export of live horses from infected countries, such as South Africa. A stochastic risk model was developed to estimate the probability of exporting an undetected AHS-infected horse through a vector protected pre-export quarantine facility, in accordance with OIE recommendations for trade from an infected country. The model also allows for additional risk management measures, including multiple PCR tests prior to and during pre-export quarantine and optionally during post-arrival quarantine, as well as for comparison of risk associated with exports from a demonstrated low-risk area for AHS and an area where AHS is endemic. If 1 million horses were exported from the low-risk area with no post-arrival quarantine we estimate the median number of infected horses to be 5.4 (95% prediction interval 0.5 to 41). This equates to an annual probability of 0.0016 (95% PI: 0.00015 to 0.012) assuming 300 horses exported per year. An additional PCR test while in vector-protected post-arrival quarantine reduced these probabilities by approximately 12-fold. Probabilities for horses exported from an area where AHS is endemic were approximately 15 to 17 times higher than for horses exported from the low-risk area under comparable scenarios. The probability of undetected AHS infection in horses exported from an infected country can be minimised by appropriate risk management measures. The final choice of risk management measures depends on the level of risk acceptable to the importing country. PMID:26986002

  19. Haemosporidian infections in the Tengmalm's Owl (Aegolius funereus) and potential insect vectors of their transmission.

    PubMed

    Synek, Petr; Popelková, Alena; Koubínová, Darina; Šťastný, Karel; Langrová, Iva; Votýpka, Jan; Munclinger, Pavel

    2016-01-01

    Sedentary bird species are suitable model hosts for identifying potential vectors of avian blood parasites. We studied haemosporidian infections in the Tengmalm's Owl (Aegolius funereus) in the Ore Mountains of the Czech Republic using molecular detection methods. Sex of owl nestlings was scored using molecular sexing based on fragment analysis of PCR-amplified CHD1 introns. Observed infection prevalences in nestlings and adult owls were 51 and 86 %, respectively. Five parasite lineages were detected. Most of the infections comprised the Leucocytozoon AEFUN02 and STOCC06 lineages that probably refer to distinct Leucocytozoon species. Other lineages were detected only sporadically. Mixed infections were found in 49 % of samples. The main factor affecting the probability of infection was host age. No effect of individual sex on infection probability was evidenced. The youngest infected nestling was 12 days old. High parasite prevalence in the Tengmalm's Owl nestlings suggests that insect vectors must enter nest boxes to transmit parasites before fledging. Hence, we placed sticky insect traps into modified nest boxes, collected potential insect vectors, and examined them for the presence of haemosporidian parasites using molecular detection. We trapped 201 insects which were determined as biting midges from the Culicoides genus and two black fly species, Simulium (Nevermannia) vernum and Simulium (Eusimulium) angustipes. Six haemosporidian lineages were detected in the potential insect vectors, among which the Leucocytozoon lineage BT2 was common to the Tengmalm's Owl and the trapped insects. However, we have not detected the most frequently encountered Tengmalm's Owl Leucocytozoon lineages AEFUN02 and STOCC06 in insects.

  20. Genomic characterisation of Wongabel virus reveals novel genes within the Rhabdoviridae.

    PubMed

    Gubala, Aneta J; Proll, David F; Barnard, Ross T; Cowled, Chris J; Crameri, Sandra G; Hyatt, Alex D; Boyle, David B

    2008-06-20

    Viruses belonging to the family Rhabdoviridae infect a variety of different hosts, including insects, vertebrates and plants. Currently, there are approximately 200 ICTV-recognised rhabdoviruses isolated around the world. However, the majority remain poorly characterised and only a fraction have been definitively assigned to genera. The genomic and transcriptional complexity displayed by several of the characterised rhabdoviruses indicates large diversity and complexity within this family. To enable an improved taxonomic understanding of this family, it is necessary to gain further information about the poorly characterised members of this family. Here we present the complete genome sequence and predicted transcription strategy of Wongabel virus (WONV), a previously uncharacterised rhabdovirus isolated from biting midges (Culicoides austropalpalis) collected in northern Queensland, Australia. The 13,196 nucleotide genome of WONV encodes five typical rhabdovirus genes N, P, M, G and L. In addition, the WONV genome contains three genes located between the P and M genes (U1, U2, U3) and two open reading frames overlapping with the N and G genes (U4, U5). These five additional genes and their putative protein products appear to be novel, and their functions are unknown. Predictive analysis of the U5 gene product revealed characteristics typical of viroporins, and indicated structural similarities with the alpha-1 protein (putative viroporin) of viruses in the genus Ephemerovirus. Phylogenetic analyses of the N and G proteins of WONV indicated closest similarity with the avian-associated Flanders virus; however, the genomes of these two viruses are significantly diverged. WONV displays a novel and unique genome structure that has not previously been described for any animal rhabdovirus.

  1. Quantitative Risk Assessment for African Horse Sickness in Live Horses Exported from South Africa.

    PubMed

    Sergeant, Evan S; Grewar, John D; Weyer, Camilla T; Guthrie, Alan J

    2016-01-01

    African horse sickness (AHS) is a severe, often fatal, arbovirus infection of horses, transmitted by Culicoides spp. midges. AHS occurs in most of sub-Saharan Africa and is a significant impediment to export of live horses from infected countries, such as South Africa. A stochastic risk model was developed to estimate the probability of exporting an undetected AHS-infected horse through a vector protected pre-export quarantine facility, in accordance with OIE recommendations for trade from an infected country. The model also allows for additional risk management measures, including multiple PCR tests prior to and during pre-export quarantine and optionally during post-arrival quarantine, as well as for comparison of risk associated with exports from a demonstrated low-risk area for AHS and an area where AHS is endemic. If 1 million horses were exported from the low-risk area with no post-arrival quarantine we estimate the median number of infected horses to be 5.4 (95% prediction interval 0.5 to 41). This equates to an annual probability of 0.0016 (95% PI: 0.00015 to 0.012) assuming 300 horses exported per year. An additional PCR test while in vector-protected post-arrival quarantine reduced these probabilities by approximately 12-fold. Probabilities for horses exported from an area where AHS is endemic were approximately 15 to 17 times higher than for horses exported from the low-risk area under comparable scenarios. The probability of undetected AHS infection in horses exported from an infected country can be minimised by appropriate risk management measures. The final choice of risk management measures depends on the level of risk acceptable to the importing country. PMID:26986002

  2. Generation of virus like particles for epizootic hemorrhagic disease virus.

    PubMed

    Forzan, Mario; Maan, Sushila; Mazzei, Maurizio; Belaganahalli, Manjunatha N; Bonuccelli, Lucia; Calamari, Monica; Carrozza, Maria Luisa; Cappello, Valentina; Di Luca, Mariagrazia; Bandecchi, Patrizia; Mertens, Peter P C; Tolari, Francesco

    2016-08-01

    Epizootic hemorrhagic disease virus (EHDV) is a distinct species within the genus Orbivirus, within the family Reoviridae. The epizootic hemorrhagic disease virus genome comprises ten segments of linear, double stranded (ds) RNA, which are packaged within each virus particle. The EHDV virion has a three layered capsid-structure, generated by four major viral proteins: VP2 and VP5 (outer capsid layer); VP7 (intermediate, core-surface layer) and VP3 (innermost, sub-core layer). Although EHDV infects cattle sporadically, several outbreaks have recently occurred in this species in five Mediterranean countries, indicating a potential threat to the European cattle industry. EHDV is transmitted by biting midges of the genus Culicoides, which can travel long distances through wind-born movements (particularly over water), increasing the potential for viral spread in new areas/countries. Expression systems to generate self-assembled virus like particles (VLPs) by simultaneous expression of the major capsid-proteins, have been established for several viruses (including bluetongue virus). This study has developed expression systems for production of EHDV VLPs, for use as non-infectious antigens in both vaccinology and serology studies, avoiding the risk of genetic reassortment between vaccine and field strains and facilitating large scale antigen production. Genes encoding the four major-capsid proteins of a field strain of EHDV-6, were isolated and cloned into transfer vectors, to generate two recombinant baculoviruses. The expression of these viral genes was assessed in insect cells by monitoring the presence of specific viral mRNAs and by western blotting. Electron microscopy studies confirmed the formation and purification of assembled VLPs. PMID:27473984

  3. Testing of UK Populations of Culex pipiens L. for Schmallenberg Virus Vector Competence and Their Colonization

    PubMed Central

    Manley, Robyn; Harrup, Lara E.; Veronesi, Eva; Stubbins, Francesca; Stoner, Jo; Gubbins, Simon; Wilson, Anthony; Batten, Carrie; Koenraadt, Constantianus J. M.; Henstock, Mark; Barber, James; Carpenter, Simon

    2015-01-01

    Background Schmallenberg virus (SBV), an arboviral pathogen of ruminants, emerged in northern Europe during 2011 and has subsequently spread across a vast geographic area. While Culicoides biting midges (Diptera: Ceratopogonidae) have been identified as a biological transmission agent of SBV, the role of mosquitoes (Diptera: Culicidae) as potential vectors has not been defined beyond small-scale field collections in affected areas. Culex pipiens L. are one of the most widespread mosquitoes in northern Europe; they are present on farms across the region and have previously been implicated as vectors of several other arboviruses. We assessed the ability of three colony lines of Cx. pipiens, originating from geographically diverse field populations, to become fully infected by SBV using semi-quantitative real-time RT-PCR (sqPCR). Findings Two colony lines of Cx. pipiens were created in the UK (‘Brookwood’ and ‘Caldbeck’) from field collections of larvae and pupae and characterised using genetic markers. A third strain of Cx. pipiens from CVI Wageningen, The Netherlands, was also screened during experiments. Intrathoracic inoculation of the Brookwood line resulted in infections after 14 days that were characterised by high levels of RNA throughout individuals, but which demonstrated indirect evidence of salivary gland barriers. Feeding of 322 individuals across the three colony lines on a membrane based infection system resulted in no evidence of full dissemination of SBV, although infections did occur in a small proportion of Cx. pipiens from each line. Conclusions/Significance This study established two novel lines of Cx. pipiens mosquitoes of UK origin in the laboratory and subsequently tested their competence for SBV. Schmallenberg virus replication and dissemination was restricted, demonstrating that Cx. pipiens is unlikely to be an epidemiologically important vector of the virus in northern Europe. PMID:26291533

  4. Full-Genome Sequencing as a Basis for Molecular Epidemiology Studies of Bluetongue Virus in India.

    PubMed

    Maan, Sushila; Maan, Narender S; Belaganahalli, Manjunatha N; Rao, Pavuluri Panduranga; Singh, Karam Pal; Hemadri, Divakar; Putty, Kalyani; Kumar, Aman; Batra, Kanisht; Krishnajyothi, Yadlapati; Chandel, Bharat S; Reddy, G Hanmanth; Nomikou, Kyriaki; Reddy, Yella Narasimha; Attoui, Houssam; Hegde, Nagendra R; Mertens, Peter P C

    2015-01-01

    Since 1998 there have been significant changes in the global distribution of bluetongue virus (BTV). Ten previously exotic BTV serotypes have been detected in Europe, causing severe disease outbreaks in naïve ruminant populations. Previously exotic BTV serotypes were also identified in the USA, Israel, Australia and India. BTV is transmitted by biting midges (Culicoides spp.) and changes in the distribution of vector species, climate change, increased international travel and trade are thought to have contributed to these events. Thirteen BTV serotypes have been isolated in India since first reports of the disease in the country during 1964. Efficient methods for preparation of viral dsRNA and cDNA synthesis, have facilitated full-genome sequencing of BTV strains from the region. These studies introduce a new approach for BTV characterization, based on full-genome sequencing and phylogenetic analyses, facilitating the identification of BTV serotype, topotype and reassortant strains. Phylogenetic analyses show that most of the equivalent genome-segments of Indian BTV strains are closely related, clustering within a major eastern BTV 'topotype'. However, genome-segment 5 (Seg-5) encoding NS1, from multiple post 1982 Indian isolates, originated from a western BTV topotype. All ten genome-segments of BTV-2 isolates (IND2003/01, IND2003/02 and IND2003/03) are closely related (>99% identity) to a South African BTV-2 vaccine-strain (western topotype). Similarly BTV-10 isolates (IND2003/06; IND2005/04) show >99% identity in all genome segments, to the prototype BTV-10 (CA-8) strain from the USA. These data suggest repeated introductions of western BTV field and/or vaccine-strains into India, potentially linked to animal or vector-insect movements, or unauthorised use of 'live' South African or American BTV-vaccines in the country. The data presented will help improve nucleic acid based diagnostics for Indian serotypes/topotypes, as part of control strategies.

  5. Type I interferon limits the capacity of bluetongue virus to infect hematopoietic precursors and dendritic cells in vitro and in vivo.

    PubMed

    Rodríguez-Calvo, Teresa; Rojas, José-Manuel; Martín, Verónica; Sevilla, Noemí

    2014-01-01

    Hematopoietic stem cells (HSCs) give rise to progenitors with potential to produce multiple cell types, including dendritic cells (DCs). DCs are the principal antigen-presenting cells and represent the crucial link between innate and adaptive immune responses. Bluetongue virus (BTV), an economically important Orbivirus of the Reoviridae family, causes a hemorrhagic disease mainly in sheep and occasionally in other species of ruminants. BTV is transmitted between its mammalian hosts by certain species of biting midges (Culicoides spp.) and is a potent alpha interferon (IFN-α) inducer. In the present report, we show that BTV infects cells of hematopoietic origin but not HSCs in immunocompetent sheep. However, BTV infects HSCs in the absence of type I IFN (IFN-I) signaling in vitro and in vivo. Infection of HSCs in vitro results in cellular death by apoptosis. Furthermore, BTV infects bone marrow-derived DCs (BM-DCs), interfering with their development to mature DCs in the absence of type I IFN signaling. Costimulatory molecules CD80 and CD86 and costimulatory molecules CD40 and major histocompatibility complex class II (MHC-II) are affected by BTV infection, suggesting that BTV interferes with DC antigen-presenting capacity. In vivo, different DC populations are also affected during the course of infection, probably as a result of a direct effect of BTV replication in DCs and the production of infectious virus. These new findings suggest that BTV infection of HSCs and DCs can impair the immune response, leading to persistence or animal death, and that this relies on IFN-I.

  6. Quantitative Risk Assessment for African Horse Sickness in Live Horses Exported from South Africa.

    PubMed

    Sergeant, Evan S; Grewar, John D; Weyer, Camilla T; Guthrie, Alan J

    2016-01-01

    African horse sickness (AHS) is a severe, often fatal, arbovirus infection of horses, transmitted by Culicoides spp. midges. AHS occurs in most of sub-Saharan Africa and is a significant impediment to export of live horses from infected countries, such as South Africa. A stochastic risk model was developed to estimate the probability of exporting an undetected AHS-infected horse through a vector protected pre-export quarantine facility, in accordance with OIE recommendations for trade from an infected country. The model also allows for additional risk management measures, including multiple PCR tests prior to and during pre-export quarantine and optionally during post-arrival quarantine, as well as for comparison of risk associated with exports from a demonstrated low-risk area for AHS and an area where AHS is endemic. If 1 million horses were exported from the low-risk area with no post-arrival quarantine we estimate the median number of infected horses to be 5.4 (95% prediction interval 0.5 to 41). This equates to an annual probability of 0.0016 (95% PI: 0.00015 to 0.012) assuming 300 horses exported per year. An additional PCR test while in vector-protected post-arrival quarantine reduced these probabilities by approximately 12-fold. Probabilities for horses exported from an area where AHS is endemic were approximately 15 to 17 times higher than for horses exported from the low-risk area under comparable scenarios. The probability of undetected AHS infection in horses exported from an infected country can be minimised by appropriate risk management measures. The final choice of risk management measures depends on the level of risk acceptable to the importing country.

  7. European Bluetongue Serotype 8: Disease Threat Assessment for U.S. Sheep.

    PubMed

    Drolet, Barbara S; Reister-Hendricks, Lindsey M; Podell, Brendan K; Breitenbach, Jonathan E; McVey, D Scott; van Rijn, Piet A; Bowen, Richard A

    2016-06-01

    Bluetongue virus (BTV) is an orbivirus transmitted by biting midges (Culicoides spp.) that can result in moderate to high morbidity and mortality primarily in sheep and white-tailed deer. Although only 5 serotypes of BTV are considered endemic to the United States, as many as 11 incursive serotypes have been detected in livestock and wildlife in the past 16 years. Introductions of serotypes, with unknown virulence and disease risk, are constant threats to US agriculture. One potential incursive serotype of particular concern is the European strain of BTV-8, which was introduced into Northern Europe in 2006 and caused unprecedented livestock disease and mortality during the 2006-2007 vector seasons. To assess disease risk of BTV-8 in a common white-faced American sheep breed, eight Polled Dorset yearlings were experimentally infected and monitored for clinical signs. Viremia and viral tissue distribution were detected and quantified by real-time qRT-PCR. Overall, clinical disease was moderate with no mortality. Viremia reached as high as 9.7 log10 particles/mL and persisted at 5 logs or higher through the end of the study (28 days). Virus distribution in tissues was extensive with the highest mean titers at the peak of viremia (day 8) in the kidney (8.38 log10 particles/mg) and pancreas (8.37 log10 particles/mg). Virus persisted in tissues of some sheep at 8 logs or higher by day 28. Results of this study suggest that should BTV-8 emerge in the United States, clinical disease in this common sheep breed would likely be similar in form, duration, and severity to what is typically observed in severe outbreaks of endemic serotypes, not the extraordinary disease levels seen in Northern Europe. In addition, a majority of exposed sheep would be expected to survive and act as significant BTV-8 reservoirs with high titer viremias for subsequent transmission to other livestock and wildlife populations. PMID:27111674

  8. Onchocerca sweetae (Nematoda: Filarioidea): notes on the intermediate host.

    PubMed

    Spratt, D M; Dyce, A L; Standfast, H A

    1978-03-01

    Microfilariae of Onchocerca sweetae are broadly distributed in the superficial layers of the dermis of the water buffalo (Bubalus bubalis). A total of 2855 insects representing 20 species were collected from O. sweetae-infected bait buffaloes. Only one species, Culicoides sp. "M", ingested microfilariae from buffalo skin. Larval development of O. sweetae was observed in the thorax of this species. Atotal of 829 insects, representing 7 species and including 749 parous Culicoides spp. were collected from light and Manitoba traps. Developing filarioid larvae were observed only in Culicoides sp. "M". It is concluded that Culicoides sp. "M" is a natural intermediate host of O. sweetae in the Northern Territory of Australia.

  9. Bluetongue Virus NS4 Protein Is an Interferon Antagonist and a Determinant of Virus Virulence

    PubMed Central

    Ratinier, Maxime; Shaw, Andrew E.; Barry, Gerald; Gu, Quan; Di Gialleonardo, Luigina; Janowicz, Anna; Varela, Mariana; Randall, Richard E.; Caporale, Marco

    2016-01-01

    ABSTRACT Bluetongue virus (BTV) is the causative agent of bluetongue, a major infectious disease of ruminants with serious consequences to both animal health and the economy. The clinical outcome of BTV infection is highly variable and dependent on a variety of factors related to both the virus and the host. In this study, we show that the BTV nonstructural protein NS4 favors viral replication in sheep, the animal species most affected by bluetongue. In addition, NS4 confers a replication advantage on the virus in interferon (IFN)-competent primary sheep endothelial cells and immortalized cell lines. We determined that in cells infected with an NS4 deletion mutant (BTV8ΔNS4), there is increased synthesis of type I IFN compared to cells infected with wild-type BTV-8. In addition, using RNA sequencing (RNA-seq), we show that NS4 modulates the host IFN response and downregulates mRNA levels of type I IFN and interferon-stimulated genes. Moreover, using reporter assays and protein synthesis assays, we show that NS4 downregulates the activities of a variety of promoters, such as the cytomegalovirus immediate-early promoter, the IFN-β promoter, and a promoter containing interferon-stimulated response elements (ISRE). We also show that the NS4 inhibitory activity on gene expression is related to its nucleolar localization. Furthermore, NS4 does not affect mRNA splicing or cellular translation. The data obtained in this study strongly suggest that BTV NS4 is an IFN antagonist and a key determinant of viral virulence. IMPORTANCE Bluetongue is one of the main infectious diseases of ruminants and is caused by bluetongue virus (BTV), an arthropod-borne virus transmitted from infected to susceptible animals by Culicoides biting midges. Bluetongue has a variable clinical outcome that can be related to both virus and host factors. It is therefore critical to understand the interplay between BTV and the host immune responses. In this study, we show that a nonstructural protein

  10. Detection of bluetongue virus RNA in field-collected Culicoides spp. (Diptera: Ceratopogonidae) following the discovery of bluetongue virus serotype 1 in white-tailed deer and cattle in Louisiana

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In November 2004, bluetongue virus (family Reoviridae, genus Orbivirus, BTV) serotype 1 (BTV-1) was detected for the first time in the United States from a hunter-killed deer in St. Mary Parish, LA. In 2005, sera surveys were conducted on three cattle farms near the area where the deer was found, an...

  11. Systemic Imidacloprid Affects Intraguild Parasitoids Differently

    PubMed Central

    Roe, R. Michael; Bacheler, Jack S.

    2015-01-01

    Toxoneuron nigriceps (Viereck) (Hymenoptera, Braconidae) and Campoletis sonorensis (Cameron) (Hymenoptera, Ichneumonidae) are solitary endoparasitoids of the tobacco budworm, Heliothis virescens (Fabricius) (Lepidoptera, Noctuidae). They provide biological control of H. virescens populations in Southeastern US agricultural production systems. Field and greenhouse experiments conducted from 2011–2014 compared parasitism rates of parasitoids that developed inside H. virescens larvae fed on tobacco plants treated with and without imidacloprid. The parasitoids in our study did not have a similar response. Toxoneuron nigriceps had reduced parasitism rates, but parasitism rates of C. sonorensis were unaffected. Preliminary data indicate that adult female lifespans of T. nigriceps are also reduced. ELISA was used to measure concentrations of neonicotinoids, imidacloprid and imidacloprid metabolites in H. virescens larvae that fed on imidacloprid-treated plants and in the parasitoids that fed on these larvae. Concentrations were detectable in the whole bodies of parasitized H. virescens larvae, T. nigriceps larvae and T. nigriceps adults, but not in C. sonorensis larvae and adults. These findings suggest that there are effects of imidacloprid on multiple trophic levels, and that insecticide use may differentially affect natural enemies with similar feeding niches. PMID:26658677

  12. Gene expression profiling reveals decreased expression of two hemoglobin genes associated with increased consumption of oxygen in Chironomus tentans exposed to atrazine: a possible mechanism for adapting to oxygen deficiency.

    PubMed

    Anderson, Troy D; Jin-Clark, Ying; Begum, Khurshida; Starkey, Sharon R; Zhu, Kun Yan

    2008-01-31

    Atrazine is an extensively used triazine herbicide in agricultural and residential areas and has been routinely detected in many surface and ground waters. This study reveals various up- and down-regulated genes associated with hypoxic stress in atrazine-treated fourth-instar Chironomus tentans larvae (midges) by using restriction fragment differential display-PCR. Two down-regulated hemoglobin cDNAs were isolated from the midges. Northern blot analysis indicated CteHb-IIbeta and CteHb-III mRNA expressions decreased by 36 and 21%, respectively, in midges exposed to atrazine at 1 microg/L for 96h. Decreased hemoglobin gene expression was associated with elevated oxygen consumption in atrazine-treated midges. Midges exposed to atrazine at 1 microg/L increased their oxygen consumption by 47%, whereas midges exposed to atrazine at 1000 microg/L for 48h increased their oxygen consumption by 66%. Our study demonstrates for the first time that atrazine, at environmentally relevant concentrations, can elevate respiration, possibly eliciting counteractive measures at the transcriptional level to adapt to oxygen deficiency in an ecologically important aquatic insect. Our results further suggest that the ability to modulate both the quantity and quality of Hb serves as an adaptive response to counteract the initial onset of oxygen deficiency induced by atrazine in midges.

  13. Ecosystem linkages revealed by experimental lake-derived isotope signal in heathland food webs.

    PubMed

    Hoekman, David; Bartrons, Mireia; Gratton, Claudio

    2012-11-01

    Cross-ecosystem movement of nutrients and biomass can have important effects on recipient systems. Emerging aquatic insects are subsidies to terrestrial ecosystems and can influence foodweb interactions in riparian systems. In a 2-year field experiment, we simulated aquatic insect deposition by adding adult midge carcasses (150 g dry mass m(-2) year(-1)) to 1-m(2) heathland plots at a site with low natural midge deposition. We established four levels of midge-addition treatments and measured stable isotopes (δ(13)C and δ(15)N) in plants and arthropods within each treatment. We used a multiple-source isotope Bayesian mixing model to estimate the terrestrial versus aquatic contribution to the diets of arthropods. Aquatic resources were incorporated into plant, detritivore, and predator biomass. Detritivorous Collembola showed the greatest difference in isotope values (+3 ‰ δ(15)N and +4 ‰ δ(13)C) between midge-addition and reference treatments. Isotope values of small spiders followed the same trend of enrichment as Collembola while other arthropods (mites and large spiders) were only enriched after 2 years of midge addition. Although predator diets did not change, they became isotopically enriched via their likely prey (Collembola). Plants also had elevated δ(15)N (+1 ‰) in midge-addition treatments. The time required and amount of midge-derived C and N detected varied and depended on trophic position. Midge-derived nutrients were no longer present in arthropod biomass in the year following midge addition. Aquatic insect carcasses can be rapidly incorporated into terrestrial food webs in nearshore habitats, and repeated inputs can be detected at multiple trophic levels, thus highlighting the importance of the detrital pathway for aquatic to terrestrial cross-ecosystem subsidies.

  14. Time-Frequency Analysis Reveals Pairwise Interactions in Insect Swarms.

    PubMed

    Puckett, James G; Ni, Rui; Ouellette, Nicholas T

    2015-06-26

    The macroscopic emergent behavior of social animal groups is a classic example of dynamical self-organization, and is thought to arise from the local interactions between individuals. Determining these interactions from empirical data sets of real animal groups, however, is challenging. Using multicamera imaging and tracking, we studied the motion of individual flying midges in laboratory mating swarms. By performing a time-frequency analysis of the midge trajectories, we show that the midge behavior can be segmented into two distinct modes: one that is independent and composed of low-frequency maneuvers, and one that consists of higher-frequency nearly harmonic oscillations conducted in synchrony with another midge. We characterize these pairwise interactions, and make a hypothesis as to their biological function. PMID:26197145

  15. Time-Frequency Analysis Reveals Pairwise Interactions in Insect Swarms

    NASA Astrophysics Data System (ADS)

    Puckett, James G.; Ni, Rui; Ouellette, Nicholas T.

    2015-06-01

    The macroscopic emergent behavior of social animal groups is a classic example of dynamical self-organization, and is thought to arise from the local interactions between individuals. Determining these interactions from empirical data sets of real animal groups, however, is challenging. Using multicamera imaging and tracking, we studied the motion of individual flying midges in laboratory mating swarms. By performing a time-frequency analysis of the midge trajectories, we show that the midge behavior can be segmented into two distinct modes: one that is independent and composed of low-frequency maneuvers, and one that consists of higher-frequency nearly harmonic oscillations conducted in synchrony with another midge. We characterize these pairwise interactions, and make a hypothesis as to their biological function.

  16. IN SITU BIOASSAY CHAMBER FOR ASSESSMENT OF SEDIMENT TOXICITY AND BIOACCUMULATION USING BENTHIC INVERTEBRATES

    EPA Science Inventory

    In this study, we describe the construction of a simple, inexpensive bioassay chamber for testing sediment toxicity (survival and growth) and bioaccumulation under field conditions using the midge Chironomus tentans and the oligochaete Lumbriculus variegatus. The test chamber is ...

  17. The bottom fauna of Lake Huron

    USGS Publications Warehouse

    Teter, Howard D.

    1960-01-01

    The examination of 63 bottom samples, collected in Lake Huron in 1952 and 1956, revealed that Pontoporeia affinis was the dominant organism in both deep and shallow water. The next most abundant organisms in deep water were oligochaetes, fingernail clams, and midge larvae. Midge larvae were more numerous than either oligochaetes or fingernail clams in shallow water. The nmnber of organisms per square meter was similar to that determined from a similar study on Lake Michigan.

  18. Shock chloramination: potential treatment for Chironomidae (Diptera) larvae nuisance abatement in water supply systems.

    PubMed

    Broza, M; Halpern, M; Teltsch, B; Porat, R; Gasith, A

    1998-08-01

    In the early 1990s, infestations of midge larvae (Chironomidae, Chironomus sp.) were discovered in the potable water system of Tel Aviv, Israel. Control measures, such as draining and cleaning tanks, spraying water into the tank's air space, and electrocution traps of midge adults, were either inadequate or ineffective. In this system, monochloramine concentrations of up to 0.75 mg/liter are used routinely as a secondary disinfectant. This chemical was tested in the laboratory as a toxicant of midge larvae. The mortality of 4th instar midge larvae after short exposure to high chloramine concentrations (LC50 values of 32 mg/liter for 75 min) suggested the efficacy of instituting a Shock Chloramination treatment program. Tanks were partially drained until they contained only 20 cm of water and were then temporarily disconnected. Chloramine was added to this water to produce a concentration of approximately 70 mg/liter for 1-2 h. Subsequently, all dead chironomids were flushed out, and the tank was refilled to attain the operational volume of water. A 2nd identical treatment of water in the tank was suggested 7 d later to kill midges from reproductive adults and egg-masses that survived the 1st treatment. This treatment program was tested in commercial covered tanks and gave complete control of these pests for 6-10 wk. These results suggest that this treatment program may effectively prevent midge outbreaks in Israel's drinking water supply system during the height of the summer. PMID:9725031

  19. Distribution and phenology of Dasineura oxycoccana (Diptera: Cecidomyiidae) in Michigan blueberries.

    PubMed

    Hahn, Noel G; Isaacs, Rufus

    2012-06-01

    The blueberry gall midge, Dasineura oxycoccana Johnson, is a serious pest of rabbiteye blueberries in Florida, Georgia, and Mississippi, and a potential pest of southern and northern highbush blueberries. Its damage has been observed with increasing frequency in highbush blueberry plantings in the Great Lakes region, including in Wisconsin and in Michigan. Unlike in rabbiteye blueberry plantings, where blueberry gall midge primarily damages flowering buds, it is found to damage only the vegetative shoots of northern highbush blueberry. In this study, farms throughout Michigan were surveyed for the presence of blueberry gall midge and it was found in 43 of 46 sampled farms in 11 counties. From 2009-2011, several monitoring techniques, including yellow sticky traps, emergence traps, observational sampling, and vegetative shoot dissections were used to determine the ecology of this species in blueberry fields in southwest Michigan. Emergence traps were most useful in early detection of blueberry gall midge in April, and observational sampling for damage symptoms and vegetative shoot dissections revealed multiple population peaks throughout July and August. Infestation was detected in vegetative shoot tips in all parts of the bushes, with initial infestation greatest at the base of bushes. Degree day accumulations until first midge detection and peak infestation suggest some potential for predicting key events in the pest's phenology. This information about the distribution and timing of infestation will be useful in developing management strategies for blueberry gall midge infestation.

  20. High Prevalence of Mansonella perstans Filariasis in Rural Senegal

    PubMed Central

    Bassene, Hubert; Sambou, Masse; Fenollar, Florence; Clarke, Siân; Djiba, Sawdiatou; Mourembou, Gaël; L. Y., Alioune Badara; Raoult, Didier; Mediannikov, Oleg

    2015-01-01

    Large parts of African and American countries are colonized by Mansonella, a very common but poorly described filarial nematode. Bloodsucking flies of the genus Culicoides are suspected to be the vector of Mansonella perstans, but no study in Senegal has confirmed that Culicoides can transmit the parasite. Designed specific real-time quantitative polymerase chain reaction (qPCR) can be used to identify microfilaria in stained blood smears. This study was performed in July and December 2010 in the southeastern Senegal, which is known to be endemic for M. perstans. We analyzed 297 blood smears from febrile and afebrile resident people by qPCR. The global prevalence of M. perstans was approximately 14.5% in both febrile and afebrile individuals. The age group of > 30 years had the highest prevalence (22.0%). No Culicoides among 1,159 studied specimens was positive for M. perstans and its vector in Senegal still requires identification. PMID:26078318

  1. High Prevalence of Mansonella perstans Filariasis in Rural Senegal.

    PubMed

    Bassene, Hubert; Sambou, Masse; Fenollar, Florence; Clarke, Siân; Djiba, Sawdiatou; Mourembou, Gaël; L Y, Alioune Badara; Raoult, Didier; Mediannikov, Oleg

    2015-09-01

    Large parts of African and American countries are colonized by Mansonella, a very common but poorly described filarial nematode. Bloodsucking flies of the genus Culicoides are suspected to be the vector of Mansonella perstans, but no study in Senegal has confirmed that Culicoides can transmit the parasite. Designed specific real-time quantitative polymerase chain reaction (qPCR) can be used to identify microfilaria in stained blood smears. This study was performed in July and December 2010 in the southeastern Senegal, which is known to be endemic for M. perstans. We analyzed 297 blood smears from febrile and afebrile resident people by qPCR. The global prevalence of M. perstans was approximately 14.5% in both febrile and afebrile individuals. The age group of > 30 years had the highest prevalence (22.0%). No Culicoides among 1,159 studied specimens was positive for M. perstans and its vector in Senegal still requires identification. PMID:26078318

  2. Seroepidemiology of Bivens Arm virus infections of cattle in Florida, St. Croix and Puerto Rico.

    PubMed

    Tuekam, T; Greiner, E C; Gibbs, E P

    1991-07-01

    Bivens Arm virus (BAV) is a newly discovered rhabdovirus infecting cattle and water buffalo in Florida. The virus is classified as a member of the Tibrogargan group, members of which have hitherto been found only in Australasia. They are considered to be transmitted by Culicoides species. Bivens Arm virus was first isolated from Culicoides insignis which suggests that BAV is also transmitted by this genus. A serological survey of two small groups of cattle raised in St. Croix and Puerto Rico, in the Caribbean, established that antibody to BAV, or a closely related virus, exists on both island. A retrospective analysis of seroconversions to BAV in sentinel calves in Florida, relative to populations of potential Culicoides vectors, failed to demonstrate any statistically significant correlation.

  3. Spatio-temporal patterns of Epizootic Hemorrhagic Disease (EHD) occurrence in the Continental USA (1980-2010)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Statement of the hypothesis or research question. Epizootic Hemorrhagic Disease (EHD) is a Culicoides insect-borne viral disease of wild and domestic ruminants commonly reported in the USA. While the severity of disease varies by geographic location, mortality rates can be as high as 90...

  4. Comparison of cellular and humoral immunoassays for the assessment of summer eczema in horses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to compare and analyze three common diagnostic methods for summer eczema (SE) in horses, an allergic dermatitis caused by bites of Culicoides spp. Nine horses with a medical history of SE and nine control animals were intradermally challenged with whole body extracts ...

  5. The Dutch strain of BTV-8 in white-tailed deer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bluetongue virus (BTV), family Reoviridae, genus Orbivirus, contains ten double stranded RNA segments encoding at least ten viral proteins. Bluetongue (BT) is an arthropod-borne disease; transmission to ruminants, including cattle, sheep, goats, and deer species by bites of species of Culicoides. In...

  6. Immune responses to ectoparasites of horses, with a focus on insect bite hypersensitivity.

    PubMed

    Wilson, A D

    2014-11-01

    Horses are affected by a wide variety of arthropod ectoparasites, ranging from lice which spend their entire life on the host, through ticks which feed over a period of days, to numerous biting insects that only transiently visit the host to feed. The presence of ectoparasites elicits a number of host responses including innate inflammatory responses, adaptive immune reactions and altered behaviour; all of which can reduce the severity of the parasite burden. All of these different responses are linked through immune mechanisms mediated by mast cells and IgE antibodies which have an important role in host resistance to ectoparasites, yet immune responses also cause severe pathological reactions. One of the best described examples of such pathological sequelae is insect bite hypersensitivity (IBH) of horses; an IgE-mediated type 1 hypersensitivity to the salivary proteins of Culicoides spp. associated with T-helper-2 production of IL4 and IL13. Importantly, all horses exposed to Culicoides have an expanded population of Culicoides antigen-specific T cells with this pattern of cytokine production, but in those which remain healthy, the inflammatory reaction is tempered by the presence of FoxP3+ CD4+ regulatory T cells that express IL10 and TGF-beta, which suppresses the IL4 production by Culicoides antigen-activated T cells.

  7. [Risk assessment of bluetongue disease incursion into Germany using geographic information system (GIS)].

    PubMed

    Koslowsky, Sylvia; Staubach, Christoph; Kramer, Mathias; Wieler, Lothar H

    2004-01-01

    Using a geographic information system (GIS), by analysis of the relationship between the spatial distribution of cattle density and the risk factors temperature, altitude and rainfall, we defined geographical habitats enabling optimal development and competence of Culicoides spp. to transmit Bluetongue-Virus (BTV): Risk zones (low, high, highest risk) were identified mainly in Baden-Württemberg, Hessen and Rheinland-Pfalz if persistently infected ruminants are imported into these zones in summer (June to August mainly), based on the current climatic conditions, BTD outbreaks are considered a real possibility. Overwintering of the virus seems unlikely. However, global warming will lead to a steady increase of the size of the risk zones. In addition, the possibility of primary outbreaks increases. The reason for this is not only the expected northern shift of Culicoides imicola, but in addition an increasing vector competence of domestic Culicoides species. We therefore recommend the storage of vaccines as well as conducting ecological studies analysing the presence of Culicoides vectors. Using the data from these studies, it will be possible to produce updated quantitative risk assessment via GIS.

  8. A novel EPS-producing strain of Bacillus licheniformis isolated from a shallow vent off Panarea Island (Italy).

    PubMed

    Spanò, Antonio; Gugliandolo, Concetta; Lentini, Valeria; Maugeri, Teresa L; Anzelmo, Gianluca; Poli, Annarita; Nicolaus, Barbara

    2013-07-01

    A haloalkaliphilic, thermophilic Bacillus strain (T14), isolated from a shallow hydrothermal vent of Panarea Island (Italy), produced a new exopolysaccharide (EPS). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain T14 was highly related (99 % similarity) to Bacillus licheniformis DSM 13(T) and Bacillus sonorensis DSM 13779(T). Further DNA-DNA hybridization analysis revealed 79.40 % similarity with B. licheniformis DSM 13(T) and 39.12 % with B. sonorensis DSM 13779(T). Sucrose (5 %) was the most efficient carbon source for growth and EPS production. The highest EPS production (366 mg l(-1)) was yielded in fermenter culture at 300 rpm after 48 h of incubation. The purified fraction EPS1 contained fructose/fucose/glucose/galactosamine/mannose in a relative proportion of 1.0:0.75:0.28:tr:tr and possessed a molecular weight of 1,000 kDa displaying a trisaccharide unit constituted by sugars with a β-manno-pyranosidic configuration. Screening for biological activity showed anti-cytotoxic effect of EPS1 against Avarol in brine shrimp test, indicating a potential use in the development of novel drugs. PMID:23397221

  9. Assessing the Economic Importance of Dasineura oxycoccana (Diptera: Cecidomyiidae) in Northern Highbush Blueberries.

    PubMed

    Hahn, Noel G; Isaacs, Rufus

    2015-08-01

    Infestation by blueberry gall midge, Dasineura oxycoccana Johnson, is common in northern highbush blueberries, but its effects on crop productivity are unknown. We examined whether infestation by blueberry gall midge reduces flower bud production when compared with uninfested shoots, and how infestation at different times affects the crop response. From the fall of 2009 to the spring of 2011, the number of flower buds on infested and uninfested shoots of blueberry bushes was counted and compared. Despite causing branching of vegetative growth, there was no significant effect of infestation on flower bud production. During the summer of 2010, damaged shoots were marked throughout the growing season in June, July, or August. The number of flower buds set per shoot declined with later infestation dates, and shoots damaged in August had significantly fewer buds than those damaged in June and July. We discuss the implications of these findings for management of blueberry gall midge in northern highbush blueberry. PMID:26470334

  10. Assessing the Economic Importance of Dasineura oxycoccana (Diptera: Cecidomyiidae) in Northern Highbush Blueberries.

    PubMed

    Hahn, Noel G; Isaacs, Rufus

    2015-08-01

    Infestation by blueberry gall midge, Dasineura oxycoccana Johnson, is common in northern highbush blueberries, but its effects on crop productivity are unknown. We examined whether infestation by blueberry gall midge reduces flower bud production when compared with uninfested shoots, and how infestation at different times affects the crop response. From the fall of 2009 to the spring of 2011, the number of flower buds on infested and uninfested shoots of blueberry bushes was counted and compared. Despite causing branching of vegetative growth, there was no significant effect of infestation on flower bud production. During the summer of 2010, damaged shoots were marked throughout the growing season in June, July, or August. The number of flower buds set per shoot declined with later infestation dates, and shoots damaged in August had significantly fewer buds than those damaged in June and July. We discuss the implications of these findings for management of blueberry gall midge in northern highbush blueberry.

  11. Food of freshwater drum in western Lake Erie

    USGS Publications Warehouse

    Bur, Michael T.

    1982-01-01

    The abundance of freshwater drum (Aplodinotus grunniens) suggests they play an important role in the Lake Erie ecosystem. Our analysis of freshwater drum digestive tracts and macrobenthic samples collected from western Lake Erie indicates that drum were selective feeders. Planktonic cladocerans and larval midges (Chironomidae) were the primary prey organisms eaten by drum. Young-of-the-year fed mostly on cladocerans, while yearling and older drum ate both cladocerans and midge larvae. Decapods, pelecypods, and fish were found only in the digestive tracts of drum longer than 250 mm. While the most abundant organisms in benthic samples were cladocerans (ephippial) and oligochaetes (89.5% by number), they constituted less than 1% of the diet. An evaluation of food selectivity, using Ivlev's index of electivity for benthic organisms, indicated that adult drum preferred midges to any other benthic food.

  12. Identifying consumer-resource population dynamics using paleoecological data.

    PubMed

    Einarsson, Árni; Hauptfleisch, Ulf; Leavitt, Peter R; Ives, Anthony R

    2016-02-01

    Ecologists have long been fascinated by cyclic population fluctuations, because they suggest strong interactions between exploiter and victim species. Nonetheless, even for populations showing high-amplitude fluctuations, it is often hard to identify which species are the key drivers of the dynamics, because data are generally only available for a single species. Here, we use a paleoecological approach to investigate fluctuations in the midge population in Lake Mývatn, Iceland, which ranges over several orders of magnitude in irregular, multigeneration cycles. Previous circumstantial evidence points to consumer-resource interactions between midges and their primary food, diatoms, as the cause of these high-amplitude fluctuations. Using a pair of sediment cores from the lake, we reconstructed 26 years of dynamics of midges using egg remains and of algal groups using diagnostic pigments. We analyzed these data using statistical methods that account for both the autocorrelated nature of paleoecological data and measurement error caused by the mixing of sediment layers. The analyses revealed a signature of consumer-resource interactions in the fluctuations of midges and diatoms: diatom abundance (as inferred from biomarker pigment diatoxanthin) increased when midge abundance was low, and midge abundance (inferred from egg capsules) decreased when diatom abundance was low. Similar patterns were not found for pigments characterizing the other dominant primary producer group in the lake (cyanobacteria), subdominant algae (cryptophytes), or ubiquitous but chemically unstable biomarkers of total algal abundance (chlorophyll a); however, a significant but weaker pattern was found for the chemically stable indicator of total algal populations (β-carotene) to which diatoms are the dominant contributor. These analyses provide the first paleoecological evaluation of specific trophic interactions underlying high amplitude population fluctuations in lakes. PMID:27145611

  13. Identifying consumer-resource population dynamics using paleoecological data.

    PubMed

    Einarsson, Árni; Hauptfleisch, Ulf; Leavitt, Peter R; Ives, Anthony R

    2016-02-01

    Ecologists have long been fascinated by cyclic population fluctuations, because they suggest strong interactions between exploiter and victim species. Nonetheless, even for populations showing high-amplitude