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Sample records for male house mosquitoes

  1. Targeting male mosquito swarms to control malaria vector density

    PubMed Central

    Sawadogo, Simon Peguedwinde; Niang, Abdoulaye; Bilgo, Etienne; Millogo, Azize; Maïga, Hamidou; Dabire, Roch K.; Tripet, Frederic; Diabaté, Abdoulaye

    2017-01-01

    Malaria control programs are being jeopardized by the spread of insecticide resistance in mosquito vector populations. It has been estimated that the spread of resistance could lead to an additional 120000 deaths per year, and interfere with the prospects for sustained control or the feasibility of achieving malaria elimination. Another complication for the development of resistance management strategies is that, in addition to insecticide resistance, mosquito behavior evolves in a manner that diminishes the impact of LLINs and IRS. Mosquitoes may circumvent LLIN and IRS control through preferential feeding and resting outside human houses and/or being active earlier in the evening before people go to sleep. Recent developments in our understanding of mosquito swarming suggest that new tools targeting mosquito swarms can be designed to cut down the high reproductive rate of malaria vectors. Targeting swarms of major malaria vectors may provide an effective control method to counteract behavioral resistance developed by mosquitoes. Here, we evaluated the impact of systematic spraying of swarms of Anopheles gambiae s.l. using a mixed carbamate and pyrethroid aerosol. The impact of this intervention on vector density, female insemination rates and the age structure of males was measured. We showed that the resulting mass killing of swarming males and some mate-seeking females resulted in a dramatic 80% decrease in population size compared to a control population. A significant decrease in female insemination rate and a significant shift in the age structure of the male population towards younger males incapable of mating were observed. This paradigm-shift study therefore demonstrates that targeting primarily males rather than females, can have a drastic impact on mosquito population. PMID:28278212

  2. Male Mosquitoes as Vehicles for Insecticide

    PubMed Central

    Mains, James W.; Brelsfoard, Corey L.; Dobson, Stephen L.

    2015-01-01

    Background The auto-dissemination approach has been shown effective at treating cryptic refugia that remain unaffected by existing mosquito control methods. This approach relies on adult mosquito behavior to spread larvicide to breeding sites at levels that are lethal to immature mosquitoes. Prior studies demonstrate that ‘dissemination stations,’ deployed in mosquito-infested areas, can contaminate adult mosquitoes, which subsequently deliver the larvicide to breeding sites. In some situations, however, preventative measures are needed, e.g., to mitigate seasonal population increases. Here we examine a novel approach that combines elements of autocidal and auto-dissemination strategies by releasing artificially reared, male mosquitoes that are contaminated with an insecticide. Methodology Laboratory and field experiments examine for model-predicted impacts of pyriproxyfen (PPF) directly applied to adult male Aedes albopictus, including (1) the ability of PPF-treated males to cross-contaminate females and to (2) deliver PPF to breeding sites. Principal Findings Similar survivorship was observed in comparisons of PPF-treated and untreated males. Males contaminated both female adults and oviposition containers in field cage tests, at levels that eliminated immature survivorship. Field trials demonstrate an ability of PPF-treated males to transmit lethal doses to introduced oviposition containers, both in the presence and absence of indigenous females. A decline in the Ae. albopictus population was observed following the introduction of PPF-treated males, which was not observed in two untreated field sites. Conclusions/Significance The results demonstrate that, in cage and open field trials, adult male Ae. albopictus can tolerate PPF and contaminate, either directly or indirectly, adult females and immature breeding sites. The results support additional development of the proposed approach, in which male mosquitoes act as vehicles for insecticide delivery

  3. Field performance of engineered male mosquitoes.

    PubMed

    Harris, Angela F; Nimmo, Derric; McKemey, Andrew R; Kelly, Nick; Scaife, Sarah; Donnelly, Christl A; Beech, Camilla; Petrie, William D; Alphey, Luke

    2011-10-30

    Dengue is the most medically important arthropod-borne viral disease, with 50-100 million cases reported annually worldwide. As no licensed vaccine or dedicated therapy exists for dengue, the most promising strategies to control the disease involve targeting the predominant mosquito vector, Aedes aegypti. However, the current methods to do this are inadequate. Various approaches involving genetically engineered mosquitoes have been proposed, including the release of transgenic sterile males. However, the ability of laboratory-reared, engineered male mosquitoes to effectively compete with wild males in terms of finding and mating with wild females, which is critical to the success of these strategies, has remained untested. We report data from the first open-field trial involving a strain of engineered mosquito. We demonstrated that genetically modified male mosquitoes, released across 10 hectares for a 4-week period, mated successfully with wild females and fertilized their eggs. These findings suggest the feasibility of this technology to control dengue by suppressing field populations of A. aegypti.

  4. Toxic Effect of Blood Feeding in Male Mosquitoes

    PubMed Central

    Nikbakhtzadeh, Mahmood R.; Buss, Garrison K.; Leal, Walter S.

    2016-01-01

    Blood- and sugar feeding of female mosquitoes has been frequently observed in the laboratory and in the field, but only sugar feeding of males has been reported. Here, we describe for the first time that Culex quinquefasciatus males feed on blood as well. Blood feeding easily happened on a blood-soaked cotton roll and, to a lesser extent, through a thin artificial layer. Mating history of a male specimen does not affect his blood feeding behavior. Male mosquitoes feed on blood even when they have a readily available sugar source. Nevertheless, feeding on blood reduces the survival rate of males to just a few days, as compared to more than a month for mosquitoes fed only on sugar. Comparing survival of male mosquitoes fed on blood only, sugar only, and a combination of both clearly demonstrated that mortality is not affected by malnutrition (reduced sugar levels), but rather due to ingested blood. On average male mosquitoes ingested ca. 0.5 μl of blood, i.e., about 10% of the amount of blood ingested by an engorged female. Although this unexpected observation of blood feeding in the laboratory by male mosquitoes is interesting, structural impairment prevents male feeding on vertebrate blood. In agreement with the literature, male and female proboscises and stylets were in general of similar size, but male mandibles were significantly shorter than female counterparts, thus explaining their inability to pierce through skin layers. PMID:26858651

  5. Mouthparts of male Aedes (Stegomyia) mosquitoes.

    PubMed

    Wahid, Isra; Sunahara, Toshihiko; Mogi, Motoyoshi

    2002-06-01

    Mouthparts of adult males of 17 strains of 8 species from the subgenus Stegomyia of the genus Aedes, including 5 strains of Aedes aegypti and 6 strains of Aedes albopictus, were examined. Lengths of maxillae, mandibles, maxillary palpi, and proboscises were measured under light microscopy and their detailed structures were examined by scanning electron microscopy. Lengths were presented as ratios to proboscis lengths. In contrast to previous reports, mandibles were found in all 5 strains of male Ae. aegypti examined. Variations in maxillary and mandibular lengths were significant among strains, even within Ae. aegypti and Ae. albopictus. High variation of these structures among and within species indicates that the average length of these structures in only 1 species may not be a reliable representative of a subgenus, and those of 1 strain may not be reliable for a species. However, their range in length (maxillae 0.13-0.50, mandibles 0.04-0.17 length of the proboscis) may be regarded as a subgeneric attribute. Maxillae and mandibles distinctly shorter than the proboscis, together with their delicate structures and the large coefficient of variation, suggest that they exist only as vestigial structures. A positive correlation was found between lengths of maxillae and those of mandibles, but mandibles are usually shorter than maxillae. The hypopharynx is discernible from the labium wall by its texture and border, and this suggests that it was a free stylet in the past.

  6. Odorant receptor from the southern house mosquito narrowly tuned to the oviposition attractant skatole.

    PubMed

    Hughes, David T; Pelletier, Julien; Luetje, Charles W; Leal, Walter S

    2010-08-01

    Oviposition attractants are environmental cues that allow Culex gravid female mosquitoes to locate suitable sites for egg-laying and, therefore, may be exploited for environmentally friendly strategies for controlling mosquito populations. Naturally occurring skatole has been identified as an oviposition attractant for the Southern House mosquito, Culex quinquefasciatus. Previously, we identified in Cx. quinquefasciatus female antennae an olfactory receptor neuron (ORN) highly sensitive to skatole and an odorant-binding protein involved in the detection of this semiochemical. Here, we describe the characterization of an odorant receptor (OR), CquiOR10, which is narrowly tuned to skatole when expressed in the Xenopus oocyte system. Odorant-induced response profiles generated by heterologously expressed CquiOR10 suggest that this OR is expressed in the mosquito ORN sensitive to skatole. However, geranylacetone, which stimulates the antennal ORN, was not detected by CquiOR10-expressing oocytes, thus raising interesting questions about reception of oviposition attractants in mosquitoes.

  7. Devising novel strategies against vector mosquitoes and house flies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 1932, the United States Department of Agriculture established an entomological research laboratory in Orlando, Florida. The initial focus of the program was on investigations of mosquitoes (including malaria vectors under conditions “simulating those of South Pacific jungles”) and other insects ...

  8. A push-pull system to reduce house entry of malaria mosquitoes

    PubMed Central

    2014-01-01

    Background Mosquitoes are the dominant vectors of pathogens that cause infectious diseases such as malaria, dengue, yellow fever and filariasis. Current vector control strategies often rely on the use of pyrethroids against which mosquitoes are increasingly developing resistance. Here, a push-pull system is presented, that operates by the simultaneous use of repellent and attractive volatile odorants. Method/Results Experiments were carried out in a semi-field set-up: a traditional house which was constructed inside a screenhouse. The release of different repellent compounds, para-menthane-3,8-diol (PMD), catnip oil e.o. and delta-undecalactone, from the four corners of the house resulted in significant reductions of 45% to 81.5% in house entry of host-seeking malaria mosquitoes. The highest reductions in house entry (up to 95.5%), were achieved by simultaneously repelling mosquitoes from the house (push) and removing them from the experimental set-up using attractant-baited traps (pull). Conclusions The outcome of this study suggests that a push-pull system based on attractive and repellent volatiles may successfully be employed to target mosquito vectors of human disease. Reductions in house entry of malaria vectors, of the magnitude that was achieved in these experiments, would likely affect malaria transmission. The repellents used are non-toxic and can be used safely in a human environment. Delta-undecalactone is a novel repellent that showed higher effectiveness than the established repellent PMD. These results encourage further development of the system for practical implementation in the field. PMID:24674451

  9. Review: Improving our knowledge of male mosquito biology in relation to genetic control programmes.

    PubMed

    Lees, Rosemary Susan; Knols, Bart; Bellini, Romeo; Benedict, Mark Q; Bheecarry, Ambicadutt; Bossin, Hervé Christophe; Chadee, Dave D; Charlwood, Jacques; Dabiré, Roch K; Djogbenou, Luc; Egyir-Yawson, Alexander; Gato, René; Gouagna, Louis Clément; Hassan, Mo'awia Mukhtar; Khan, Shakil Ahmed; Koekemoer, Lizette L; Lemperiere, Guy; Manoukis, Nicholas C; Mozuraitis, Raimondas; Pitts, R Jason; Simard, Frederic; Gilles, Jeremie R L

    2014-04-01

    The enormous burden placed on populations worldwide by mosquito-borne diseases, most notably malaria and dengue, is currently being tackled by the use of insecticides sprayed in residences or applied to bednets, and in the case of dengue vectors through reduction of larval breeding sites or larviciding with insecticides thereof. However, these methods are under threat from, amongst other issues, the development of insecticide resistance and the practical difficulty of maintaining long-term community-wide efforts. The sterile insect technique (SIT), whose success hinges on having a good understanding of the biology and behaviour of the male mosquito, is an additional weapon in the limited arsenal against mosquito vectors. The successful production and release of sterile males, which is the mechanism of population suppression by SIT, relies on the release of mass-reared sterile males able to confer sterility in the target population by mating with wild females. A five year Joint FAO/IAEA Coordinated Research Project brought together researchers from around the world to investigate the pre-mating conditions of male mosquitoes (physiology and behaviour, resource acquisition and allocation, and dispersal), the mosquito mating systems and the contribution of molecular or chemical approaches to the understanding of male mosquito mating behaviour. A summary of the existing knowledge and the main novel findings of this group is reviewed here, and further presented in the reviews and research articles that form this Acta Tropica special issue.

  10. SEX DETERMINATION. A male-determining factor in the mosquito Aedes aegypti.

    PubMed

    Hall, Andrew Brantley; Basu, Sanjay; Jiang, Xiaofang; Qi, Yumin; Timoshevskiy, Vladimir A; Biedler, James K; Sharakhova, Maria V; Elahi, Rubayet; Anderson, Michelle A E; Chen, Xiao-Guang; Sharakhov, Igor V; Adelman, Zach N; Tu, Zhijian

    2015-06-12

    Sex determination in the mosquito Aedes aegypti is governed by a dominant male-determining factor (M factor) located within a Y chromosome-like region called the M locus. Here, we show that an M-locus gene, Nix, functions as an M factor in A. aegypti. Nix exhibits persistent M linkage and early embryonic expression, two characteristics required of an M factor. Nix knockout with clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 resulted in largely feminized genetic males and the production of female isoforms of two key regulators of sexual differentiation: doublesex and fruitless. Ectopic expression of Nix resulted in genetic females with nearly complete male genitalia. Thus, Nix is both required and sufficient to initiate male development. This study provides a foundation for mosquito control strategies that convert female mosquitoes into harmless males.

  11. Flock house virus replicates and expresses green fluorescent protein in mosquitoes.

    PubMed

    Dasgupta, Ranjit; Cheng, Li-Lin; Bartholomay, Lyric C; Christensen, Bruce M

    2003-07-01

    Flock house virus (FHV) is a non-enveloped, positive-sense RNA virus of insect origin that belongs to the family Nodaviridae. FHV has been shown to overcome the kingdom barrier and to replicate in plants, insects, yeast and mammalian cells. Although of insect origin, FHV has not previously been shown to replicate in mosquitoes. We have tested FHV replication in vitro in C6/36 cells (derived from neonatal Aedes albopictus) and in vivo in four different genera of mosquitoes, Aedes, Culex, Anopheles and Armigeres. FHV replicated to high titres in C6/36 cells that had been subcloned to support maximum growth of FHV. When adult mosquitoes were orally fed or injected with the virus, FHV antigen was detected in various tissues and infectious virus was recovered. Vectors developed from an infectious cDNA clone of a defective-interfering RNA, derived from FHV genomic RNA2, expressed green fluorescent protein in Drosophila cells and adult mosquitoes. This demonstrates the potential of FHV-based vectors for expression of foreign genes in mosquitoes and possibly other insects.

  12. Comparative repellent properties of certain chemicals against mosquitoes, house flies and cockroaches using modified techniques.

    PubMed

    Vartak, P H; Tungikar, V B; Sharma, R N

    1994-09-01

    Several terpenoids were assessed for their repellent/toxic properties against mosquitoes (Aedes aegypti), house flies (Musca domestica) and cockroaches (Periplaneta americana). Impregnated wide mesh netting was used in the case of the Dipterans, while treated filtered paper was employed for the bioassays with cockroaches. Persistence of the repellent chemicals was studied. Doses ranged from 5-20 gm/M2 for the Dipterans and 25-100 mg per 4 x 4 cm filter paper for the cockroaches. Dimethyl phthalate (DMP) offered the maximum protection of the chemicals tested against mosquitoes but was not so effective against house flies and cockroaches. Citral and Eugenol were effective against all the three test insects. Other test compounds afforded varying degrees of protection. Application strategy and utility of the findings are discussed.

  13. The influence of house construction on the indoor abundance of mosquitoes.

    PubMed

    Howell, Paul I; Chadee, Dave D

    2007-06-01

    This study examined the potential effects of different house construction features on the indoor abundance of culicine mosquitoes in Trinidad (TT) and the Dominican Republic (DR) using xenomonitoring surveys. To assess these effects, a survey was taken of different homes in both countries alongside concurrent indoor resting mosquito collections to determine which features may be correlated with a greater abundance. Between June 2002 and April 2003 data were collected from 104 homes in TT and 121 homes in the DR. In TT, 61 (58.65%) of the homes were located in urban areas and 43 (41.35%) were located in rural villages, whereas in the DR 40 (33.06%) were located in rural areas, and 81 (66.94%) in the urban area. Overall, a total of 1,630 mosquitoes were collected in TT, of which 77% were Culex quinquefasciatus, whereas 459 mosquitoes were collected from the DR, of which 46% were Cx. quinquefasciatus. It was found that in TT and the DR the mean number of Cx. quinquefasciatus mosquitoes was greater in cement homes than in either wood or other poorer quality homes (TT cement 17.43, others 14.43; DR cement 4.24, others 3.41). In TT it was found that homes that had painted interiors were significantly more likely to have a high abundance of mosquitoes resting indoors compared to homes without painted interiors (OR 2.90, CI 1.09-8.72). Likewise, having a painted exterior was not significant, but only slightly so, in TT as having a detrimental effect (OR 2.14, CI 0.89-6.67). Similarly, having a painted interior or exterior was also found to be a predictor of a high abundance of indoor resting mosquitoes in the DR (interior OR 3.13, CI 1.41-6.92; exterior OR 1.97, CI .91-4.26). Reduced adult abundance in TT was correlated with homes being built on stilts, with more than four people sleeping in the home, and having a painted interior. In the DR, reductions were correlated with homes where residents slept under a bed net and with people who lived in a rural location. Changes

  14. Male Aedes aegypti mosquitoes use JH III transferred during copulation to influence previtellogenic ovary physiology and affect the reproductive output of female mosquitoes.

    PubMed

    Clifton, Mark E; Correa, Stefano; Rivera-Perez, Crisalejandra; Nouzova, Marcela; Noriega, Fernando G

    2014-05-01

    The effect of male accessory gland substances on female reproductive physiology has been previously described as "activating" egg development. However, no mechanism has been described that can explain how male mosquitoes are able to influence egg development in female mosquitoes. To investigate how male mosquitoes are able to influence ovarian physiology and reproductive output we explored three main questions: (1) Do mating and male accessory gland substances affect ovarian physiology and alter markers of oocyte quality during the previtellogenic resting stage? (2) Does the male accessory gland contain JH III and is JH III transferred to the female during copulation? (3) Finally, does the nutritional history of the male affect the amount of JH III transferred to the female and alter reproductive output? By answering these questions it is clear that male mosquitoes are able to alter the female's resource allocation priorities towards reproduction by transferring JH III during copulation; reducing the rate of previtellogenic resorption and increasing the amount of stored ovarian lipids. These changes improve an individual follicle's likelihood of development after a blood meal. In addition, males maintained under better nutritional conditions make and transfer more JH III, prevent more follicular resorption and realize higher fecundities than other males. Together these results illustrate one mechanism behind the "activating" effect of mating described as well as the role sugar feeding plays in male mosquitoes.

  15. Male Aedes aegypti mosquitoes use JH III transferred during copulation to influence previtellogenic ovary physiology and affect the reproductive output of female mosquitoes

    PubMed Central

    Clifton, Mark E.; Correa, Stefano; Rivera-Perez, Crisalejandra; Nouzova, Marcela; Noriega, Fernando G.

    2014-01-01

    The effect of male accessory gland substances on female reproductive physiology has been previously described as “activating” egg development. However, no mechanism has been described that can explain how male mosquitoes are able to influence egg development in female mosquitoes. To investigate how male mosquitoes are able to influence ovarian physiology and reproductive output we explored three main questions: 1) Do mating and male accessory gland substances affect ovarian physiology and alter markers of oocyte quality during the previtellogenic resting stage? 2) Does the male accessory gland contain JH III and is JH III transferred to the female during copulation? 3) Finally, does the nutritional history of the male affect the amount of JH III transferred to the female and alter reproductive output? By answering these questions it is clear that male mosquitoes are able to alter the female’s resource allocation priorities towards reproduction by transferring JH III during copulation; reducing the rate of previtellogenic resorption and increasing the amount of stored ovarian lipids. These changes improve an individual follicle’s likelihood of development after a blood meal. In addition, males maintained under better nutritional conditions make and transfer more JH III, prevent more follicular resorption and realize higher fecundities than other males. Together these results illustrate one mechanism behind the “activating” effect of mating described as well as the role sugar feeding plays in male mosquitoes. PMID:24657670

  16. Safe housing ensured by an electric field screen that excludes insect-net permeating haematophagous mosquitoes carrying human pathogens

    NASA Astrophysics Data System (ADS)

    Matsuda, Y.; Kakutani, K.; Nonomura, T.; Kimbara, J.; Osamura, K.; Kusakar, S.; Toyoda, H.

    2015-10-01

    An electric field screen can be used to keep mosquitoes out of houses with open windows. In this study, doubly charged dipolar electric field screens (DD-screens) were used to capture mosquitoes entering through a window. The screen had two components: three layers of insulated conductor iron wires (ICWs) in parallel arrays and two electrostatic direct current (DC) voltage generators that supplied negative or positive voltages to the ICWs. Within each layer, the ICWs were parallel at 5-mm intervals, and connected to each other and to a negative or positive voltage generator. The negatively and positively charged ICWs are represented as ICW(-) and ICW(+), respectively. The screen consisted of one ICW(+) layer with an ICW(-) layer on either side. The Asian tiger mosquito (Aedes albopictus) and house mosquito (Culex pipiens) were used as models of vectors carrying viral pathogens. Adult mosquitoes were blown into the space between the ICWs by sending compressed air through the tip of an insect aspirator to determine the voltage range that captured all of the test insects. Wind speed was measured at the surface of the ICW using a sensitive anemometer. The result showed that at ≥ 1.2 kV, the force was strong enough that the ICWs captured all of the mosquitoes, despite a wind speed of 7 m/s. Therefore, the DD-screen could serve as a physical barrier to prevent noxious mosquitoes from entering houses with good air penetration.

  17. Sustained housing-type social buffering following social housing in male rats.

    PubMed

    Kiyokawa, Yasushi; Ishida, Aya; Takeuchi, Yukari; Mori, Yuji

    2016-05-01

    In social animals, recovery from the adverse effects of distressing stimuli is promoted by subsequent cohousing with a conspecific animal(s). This phenomenon has been termed housing-type social buffering. We previously found that social housing induced housing-type social buffering in fear-conditioned male rats. This buffering took the form of attenuated conditioned hyperthermia in response to an auditory conditioned stimulus (CS). Here, we assessed whether this social buffering is sustained even if the subject is housed alone after a period of social housing. When fear-conditioned subjects were housed alone during a 48-h period between conditioning and re-exposure to the auditory CS, they exhibited conditioned hyperthermia in response to the CS. However, conditioned hyperthermia was not observed when the 12-h period of social housing began 24 and 36h after conditioning during the 48-h period. This was not the case when the 12-h period of social housing began 0 and 12h after the conditioning. These results suggest that housing-type social buffering is sustained for 12h after the 12-h period of social housing. We next considered whether increasing the duration of social housing would extend the period of social buffering. We observed social buffering of conditioned hyperthermia 24 and 48, but not 96h after a 24-h period of social housing. These results suggest that social buffering was extended when the duration of social housing was increased. Taken together, our findings indicate that housing-type social buffering is sustained after a period of social housing.

  18. Environmental forcing shapes regional house mosquito synchrony in a warming temperate island.

    PubMed

    Chaves, Luis Fernando; Higa, Yukiko; Lee, Su Hyun; Jeong, Ji Yeon; Heo, Sang Taek; Kim, Miok; Minakawa, Noboru; Lee, Keun Hwa

    2013-08-01

    Seasonal changes in the abundance of exothermic organisms can be expected with climate change if warmer temperatures can induce changes in their phenology. Given the increased time for ectothermic organism development at lower temperatures, we asked whether population dynamics of the house mosquito, Culex pipiens s.l. (L.) (Diptera: Culicidae), in Jeju-do (South Korea), an island with a gradient of warming temperatures from north to south, showed differences in sensitivity to changes in temperature along the warming gradient. In addition, we asked whether synchrony, that is, the degree of concerted fluctuations in mosquito abundance across locations, was affected by the temperature gradient. We found the association of mosquito abundance with temperature to be delayed by 2 wk in the north when compared with the south. The abundance across all our sampling locations had a flat synchrony profile that could reflect impacts of rainfall and average temperature on the average of all our samples. Finally, our results showed that population synchrony across space can emerge even when abundance is differentially impacted by an exogenous factor across an environmental gradient.

  19. Targeting male mosquito mating behaviour for malaria control.

    PubMed

    Diabate, Abdoulaye; Tripet, Frédéric

    2015-06-26

    Malaria vector control relies heavily on the use of Long-Lasting Insecticidal Nets (LLINs) and Indoor Residual Spraying (IRS). These, together with the combined drug administration efforts to control malaria, have reduced the death toll to less than 700,000 deaths/year. This progress has engendered real excitement but the emergence and spread of insecticide resistance is challenging our ability to sustain and consolidate the substantial gains that have been made. Research is required to discover novel vector control tools that can supplement and improve the effectiveness of those currently available. Here, we argue that recent and continuing progress in our understanding of male mating biology is instrumental in the implementation of new approaches based on the release of either conventional sterile or genetically engineered males. Importantly, further knowledge of male biology could also lead to the development of new interventions, such as sound traps and male mass killing in swarms, and contribute to new population sampling tools. We review and discuss recent advances in the behavioural ecology of male mating with an emphasis on the potential applications that can be derived from such knowledge. We also highlight those aspects of male mating ecology that urgently require additional study in the future.

  20. Dispersal of male and female Culex quinquefasciatus and Aedes albopictus mosquitoes using stable isotope enrichment

    PubMed Central

    Roark, E. Brendan; Hamer, Gabriel L.

    2017-01-01

    The dispersal patterns of mosquito vectors are important drivers of vector-borne infectious disease dynamics and understanding movement patterns is pivotal to devise successful intervention strategies. Here, we investigate the dispersal patterns of two globally important mosquito vectors, Aedes albopictus and Culex quinquefasciatus, by marking naturally-occurring larvae with stable isotopes (13C or 15N). Marked individuals were captured with 32 CDC light trap, 32 gravid trap, and 16 BG Sentinel at different locations within two-kilometer radii of six larval habitats enriched with either 13C or 15N. In total, 720 trap nights from July to August 2013 yielded a total of 32,140 Cx. quinquefasciatus and 7,722 Ae. albopictus. Overall, 69 marked female mosquitoes and 24 marked male mosquitoes were captured throughout the study period. The distance that Cx. quinquefasciatus females traveled differed for host-seeking and oviposition-seeking traps, with females seeking oviposition sites traveling further than those seeking hosts. Our analysis suggests that 41% of Cx. quinquefasciatus females that were host-seeking occurred 1–2 kilometer from their respective natal site, while 59% remained within a kilometer of their natal site. In contrast, 59% of Cx. quinquefasciatus females that were seeking oviposition sites occurred between 1–2 kilometer away from their larval habitat, while 15% occurred > 2 kilometer away from their natal site. Our analysis estimated that approximately 100% of Ae. albopictus females remained within 1 km of their respective natal site, with 79% occurring within 250m. In addition, we found that male Ae. albopictus dispersed farther than females, suggesting male-biased dispersal in this Ae. albopictus population. This study provides important insights on the dispersal patterns of two globally relevant vector species, and will be important in planning next generation vector control strategies that mitigate mosquito-borne disease through sterile insect

  1. Transient population dynamics of mosquitoes during sterile male releases: modelling mating behaviour and perturbations of life history parameters.

    PubMed

    Stone, Christopher M

    2013-01-01

    The release of genetically-modified or sterile male mosquitoes offers a promising form of mosquito-transmitted pathogen control, but the insights derived from our understanding of male mosquito behaviour have not fully been incorporated into the design of such genetic control or sterile-male release methods. The importance of aspects of male life history and mating behaviour for sterile-male release programmes were investigated by projecting a stage-structured matrix model over time. An elasticity analysis of transient dynamics during sterile-male releases was performed to provide insight on which vector control methods are likely to be most synergistic. The results suggest that high mating competitiveness and mortality costs of released males are required before the sterile-release method becomes ineffective. Additionally, if released males suffer a mortality cost, older males should be released due to their increased mating capacity. If released males are of a homogenous size and size-assortative mating occurs in nature, this can lead to an increase in the abundance of large females and reduce the efficacy of the population-suppression effort. At a high level of size-assortative mating, the disease transmission potential of the vector population increases due to male releases, arguing for the release of a heterogeneously-sized male population. The female population was most sensitive to perturbations of density-dependent components of larval mortality and female survivorship and fecundity. These findings suggest source reduction might be a particularly effective complement to mosquito control based on the sterile insect technique (SIT). In order for SIT to realize its potential as a key component of an integrated vector-management strategy to control mosquito-transmitted pathogens, programme design of sterile-male release programmes must account for the ecology, behaviour and life history of mosquitoes. The model used here takes a step in this direction and can

  2. Genetics and evolution of hybrid male sterility in house mice.

    PubMed

    White, Michael A; Stubbings, Maria; Dumont, Beth L; Payseur, Bret A

    2012-07-01

    Comparative genetic mapping provides insights into the evolution of the reproductive barriers that separate closely related species. This approach has been used to document the accumulation of reproductive incompatibilities over time, but has only been applied to a few taxa. House mice offer a powerful system to reconstruct the evolution of reproductive isolation between multiple subspecies pairs. However, studies of the primary reproductive barrier in house mice-hybrid male sterility-have been restricted to a single subspecies pair: Mus musculus musculus and Mus musculus domesticus. To provide a more complete characterization of reproductive isolation in house mice, we conducted an F(2) intercross between wild-derived inbred strains from Mus musculus castaneus and M. m. domesticus. We identified autosomal and X-linked QTL associated with a range of hybrid male sterility phenotypes, including testis weight, sperm density, and sperm morphology. The pseudoautosomal region (PAR) was strongly associated with hybrid sterility phenotypes when heterozygous. We compared QTL found in this cross with QTL identified in a previous F(2) intercross between M. m. musculus and M. m. domesticus and found three shared autosomal QTL. Most QTL were not shared, demonstrating that the genetic basis of hybrid male sterility largely differs between these closely related subspecies pairs. These results lay the groundwork for identifying genes responsible for the early stages of speciation in house mice.

  3. Genetics and Evolution of Hybrid Male Sterility in House Mice

    PubMed Central

    White, Michael A.; Stubbings, Maria; Dumont, Beth L.; Payseur, Bret A.

    2012-01-01

    Comparative genetic mapping provides insights into the evolution of the reproductive barriers that separate closely related species. This approach has been used to document the accumulation of reproductive incompatibilities over time, but has only been applied to a few taxa. House mice offer a powerful system to reconstruct the evolution of reproductive isolation between multiple subspecies pairs. However, studies of the primary reproductive barrier in house mice—hybrid male sterility—have been restricted to a single subspecies pair: Mus musculus musculus and Mus musculus domesticus. To provide a more complete characterization of reproductive isolation in house mice, we conducted an F2 intercross between wild-derived inbred strains from Mus musculus castaneus and M. m. domesticus. We identified autosomal and X-linked QTL associated with a range of hybrid male sterility phenotypes, including testis weight, sperm density, and sperm morphology. The pseudoautosomal region (PAR) was strongly associated with hybrid sterility phenotypes when heterozygous. We compared QTL found in this cross with QTL identified in a previous F2 intercross between M. m. musculus and M. m. domesticus and found three shared autosomal QTL. Most QTL were not shared, demonstrating that the genetic basis of hybrid male sterility largely differs between these closely related subspecies pairs. These results lay the groundwork for identifying genes responsible for the early stages of speciation in house mice. PMID:22554891

  4. Isolation and identification of mosquito (Aedes aegypti) biting deterrent fatty acids from male inflorescences of breadfruit (Artocarpus altilis (Parkinson)Fosberg)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dried male inflorescences of breadfruit (Artocarpus altilis, Moraceae) are burned in communities throughout Oceania to repel flying insects, including mosquitoes. This study was conducted to identify chemicals responsible for mosquito deterrence. Various crude extracts were evaluated, and the most a...

  5. Female Adult Aedes albopictus Suppression by Wolbachia-Infected Male Mosquitoes

    PubMed Central

    Mains, James W.; Brelsfoard, Corey L.; Rose, Robert I.; Dobson, Stephen L.

    2016-01-01

    Dengue, chikungunya and zika viruses are pathogens with an increasing global impact. In the absence of an approved vaccine or therapy, their management relies on controlling the mosquito vectors. But traditional controls are inadequate, and the range of invasive species such as Aedes albopictus (Asian Tiger Mosquito) is expanding. Genetically modified mosquitoes are being tested, but their use has encountered regulatory barriers and public opposition in some countries. Wolbachia bacteria can cause a form of conditional sterility, which can provide an alternative to genetic modification or irradiation. It is unknown however, whether openly released, artificially infected male Ae. albopictus can competitively mate and sterilize females at a level adequate to suppress a field population. Also, the unintended establishment of Wolbachia at the introduction site could result from horizontal transmission or inadvertent female release. In 2014, an Experimental Use Permit from the United States Environmental Protection Agency approved a pilot field trial in Lexington, Kentucky, USA. Here, we present data showing localized reduction of both egg hatch and adult female numbers. The artificial Wolbachia type was not observed to establish in the field. The results are discussed in relation to the applied use of Wolbachia-infected males as a biopesticide to suppress field populations of Ae. albopictus. PMID:27659038

  6. The role of male harassment on female fitness for the dengue vector mosquito Aedes aegypti.

    PubMed

    Helinski, Michelle E H; Harrington, Laura C

    2012-08-01

    Sexual harassment studies in insects suggest that females can incur several kinds of costs from male harassment and mating. Here, we examined direct and indirect costs of male harassment on components of female fitness in the predominantly monandrous mosquito Aedes aegypti. To disentangle the costs of harassment versus the costs of mating, we held females at a low or high density with males whose claspers were modified to prevent insemination, and compared these to females held with normal males and to those held with females or alone. A reduced longevity was observed when females were held under high density conditions with males or females, regardless if male claspers had been modified. There was no consistent effect of harassment on female fecundity. Net reproductive rate (R0) was higher in females held at low density with normal males compared to females held with males in the other treatments, even though only a small number of females showed direct evidence of remating. Indirect costs and benefits that were not due to harassment alone were observed. Daughters of females held with normal males at high density had reduced longevity compared to daughters from females held without conspecifics. However, their fitness (R0) was higher compared to females in all other treatments. Overall, our results indicate that A. aegypti females do not suffer a fitness cost from harassment of males when kept at moderate densities, and they suggest the potential for benefits obtained from ejaculate components.

  7. Pathways of expansion and multiple introductions illustrated by large genetic differentiation among worldwide populations of the southern house mosquito.

    PubMed

    Fonseca, Dina M; Smith, Julie L; Wilkerson, Richard C; Fleischer, Robert C

    2006-02-01

    The southern house mosquito Culex quinquefasciatus is a principal vector of human lymphatic filariasis, several encephalitides (including West Nile virus), avian malaria, and poxvirus, but its importance as a vector varies considerably among regions. This species has spread with humans and is ubiquitous in tropical urban and suburban environments. This was the first mosquito to reach Hawaii and we performed a worldwide genetic survey using micro-satellite loci to identify its source. Our analyses showed divergent Old World and New World genetic signatures in Cx. quinquefasciatus with further distinctions between east and west African, Asian, and Pacific populations that correlate with the epidemiology of human filariasis. We found that in Hawaii south Pacific mosquitoes have largely replaced the original New World introduction of Cx. quinquefasciatus, consistent with their reported expansion to higher elevations. We hypothesize worldwide pathways of expansion of this disease vector.

  8. Seasonal weather, nutrients, and conspecific presence impacts on the southern house mosquito oviposition dynamics in combined sewage overflows.

    PubMed

    Nguyen, An T; Williams-Newkirk, Amanda J; Kitron, Uriel D; Chaves, Luis F

    2012-11-01

    Combined sewage overflows have created favorable conditions for the establishment of the southern house mosquito, Culex quinquefasciatus Say (Diptera: Culicidae), larvae in natural creeks that would otherwise be unsuitable for the development of this mosquito species. Here, we show the results from a seminatural experiment carried over the three seasons of mosquito activity (spring, summer, and fall) in Tanyard Creek, Atlanta, GA. In this study we manipulated the amount of nutrients by further enriching combined sewage overflow water, and tracked weather variables, organic nutrient concentration, exposure time to conspecifics, and the number of egg rafts collected in experimental containers. We found season and nutrient enrichment to be the most important variables explaining the differences in egg rafts counts. Further analyses suggest that temperature may also play a role in seasonal oviposition patterns. The results from this study suggest that nutrient enrichment and adequate temperatures are important factors shaping Cx. quinquefasciatus oviposition seasonality in combined sewage overflows.

  9. Silent, generic and plant kairomone sensitive odorant receptors from the Southern house mosquito.

    PubMed

    Xu, Pingxi; Choo, Young-Moo; Pelletier, Julien; Sujimoto, Fernando R; Hughes, David T; Zhu, Fen; Atungulu, Elizabeth; Cornel, Anthony J; Luetje, Charles W; Leal, Walter S

    2013-09-01

    The Southern house mosquito Culex quinquefasciatus has the largest repertoire of odorant receptors (ORs) of all mosquitoes and dipteran species whose genomes have been sequenced to date. Previously, we have identified and de-orphanized two ORs expressed in female antennae, CquiOR2 and CquiOR10, which are sensitive to oviposition attractants. In view of a new nomenclature for the Culex genome (VectorBase) we renamed these ORs as CquiOR21 (formerly CquiOR10) and CquiOR121 (CquiOR2). In addition, we selected ORs from six different phylogenetic groups for deorphanization. We cloned four of them by using cDNA from female antennae as a template. Attempts to clone CquiOR87 and CquiOR110 were unsuccessful either because they are pseudogenes or are not expressed in adult female antennae, the main olfactory tissue. By contrast, CquiOR1, CquiOR44, CquiOR73, and CquiOR161 were highly expressed in female antennae. To de-orphanize these ORs, we employed the Xenopus oocyte recording system. CquiORx-CquiOrco-expressed oocytes were challenged with a panel of 90 compounds, including known oviposition attractants, human and vertebrate host odorants, plant kairomones, and naturally occurring repellents. While CquiOR161 did not respond to any test compound in two different laboratories, CquiOR1 showed the features of a generic OR, with strong responses to 1-octen-3-ol and other ligands. CquiOR44 and CquiOR73 showed preference to plant-derived terpenoids and phenolic compounds, respectively. While fenchone was the best ligand for the former, 3,5-dimethylphenol elicited the strongest responses in the latter. The newly de-orphanized ORs may be involved in reception of plant kairomones and/or natural repellents.

  10. Silent, Generic and Plant Kairomone Sensitive Odorant Receptors from the Southern House Mosquito

    PubMed Central

    Xu, Pingxi; Choo, Young-Moo; Pelletier, Julien; Sujimoto, Fernando R.; Hughes, David T.; Zhu, Fen; Atungulu, Elizabeth; Cornel, Anthony J.; Luetje, Charles W.; Leal, Walter S.

    2013-01-01

    The Southern house mosquito Culex quinquefasciatus has the largest repertoire of odorant receptors (ORs) of all mosquitoes and dipteran species whose genomes have been sequenced to date. Previously, we have identified and de-orphanized two ORs expressed in female antennae, CquiOR2 and CquiOR10, which are sensitive to oviposition attractants. In view of a new nomenclature for the Culex genome (VectorBase) we renamed these ORs as CquiOR21 (formerly CquiOR10) and CquiOR121 (CquiOR2). In addition, we selected ORs from six different phylogenetic groups for deorphanization. We cloned four of them by using cDNA from female antennae as a template. Attempts to clone CquiOR87 and CquiOR110 were unsuccessful either because they are pseudogenes or are not expressed in adult female antennae, the main olfactory tissue. By contrast, CquiOR1, CquiOR44, CquiOR73, and CquiOR161 were highly expressed in female antennae. To de-orphanize these ORs, we employed the Xenopus oocyte recording system. CquiORx-CquiOrco-expressed oocytes were challenged with a panel of 90 compounds, including known oviposition attractants, human and vertebrate host odorants, plant kairomones, and naturally occuring repellents. While CquiOR161 did not respond to any test compound in two different laboratories, CquiOR1 showed the features of a generic OR, with strong responses to 1-octen-3-ol and other ligands. CquiOR44 and CquiOR73 showed preference to plant-derived terpenoids and phenolic compounds, respectively. While fenchone was the best ligand for the former, 3,5-dimethylphenol elicited the strongest responses in the latter. The newly de-orphanized ORs may be involved in reception of plant kairomones and/or natural repellents. PMID:23876610

  11. Heterosis Increases Fertility, Fecundity, and Survival of Laboratory-Produced F1 Hybrid Males of the Malaria Mosquito Anopheles coluzzii.

    PubMed

    Ekechukwu, Nkiru E; Baeshen, Rowida; Traorè, Sékou F; Coulibaly, Mamadou; Diabate, Abdoulaye; Catteruccia, Flaminia; Tripet, Frédéric

    2015-10-23

    The success of vector control strategies aiming to decrease disease transmission via the release of sterile or genetically-modified male mosquitoes critically depends on mating between laboratory-reared males and wild females. Unfortunately, mosquito colonization, laboratory rearing, and genetic manipulations can all negatively affect male competitiveness. Heterosis is commonly used to produce domestic animals with enhanced vigor and homogenous genetic background and could therefore potentially improve the mating performance of mass-reared male mosquitoes. Here, we produced enhanced hybrid males of the malaria mosquito Anopheles coluzzii by crossing two strains colonized >35 and 8 years ago. We compared the amount of sperm and mating plug proteins they transferred to females, as well as their insemination rate, reproductive success and longevity under various experimental conditions. Across experiments, widespread adaptations to laboratory mating were detected in the older strain. In large-group mating experiments, no overall hybrid advantage in insemination rates and the amount of sperm and accessory gland proteins transferred to females was detected. Despite higher sperm activity, hybrid males did not appear more fecund. However, individual-male mating and laboratory-swarm experiments revealed that hybrid males, while inseminating fewer females than older inbred males, were significantly more fertile, producing larger mating plugs and drastically increasing female fecundity. Heterotic males also showed increased longevity. These results validate the use of heterosis for creating hybrid males with improved fitness from long-established inbred laboratory strains. Therefore, this simple approach could facilitate disease control strategies based on male mosquito releases with important ultimate benefits to human health.

  12. Heterosis Increases Fertility, Fecundity, and Survival of Laboratory-Produced F1 Hybrid Males of the Malaria Mosquito Anopheles coluzzii

    PubMed Central

    Ekechukwu, Nkiru E.; Baeshen, Rowida; Traorè, Sékou F.; Coulibaly, Mamadou; Diabate, Abdoulaye; Catteruccia, Flaminia; Tripet, Frédéric

    2015-01-01

    The success of vector control strategies aiming to decrease disease transmission via the release of sterile or genetically-modified male mosquitoes critically depends on mating between laboratory-reared males and wild females. Unfortunately, mosquito colonization, laboratory rearing, and genetic manipulations can all negatively affect male competitiveness. Heterosis is commonly used to produce domestic animals with enhanced vigor and homogenous genetic background and could therefore potentially improve the mating performance of mass-reared male mosquitoes. Here, we produced enhanced hybrid males of the malaria mosquito Anopheles coluzzii by crossing two strains colonized >35 and 8 years ago. We compared the amount of sperm and mating plug proteins they transferred to females, as well as their insemination rate, reproductive success and longevity under various experimental conditions. Across experiments, widespread adaptations to laboratory mating were detected in the older strain. In large-group mating experiments, no overall hybrid advantage in insemination rates and the amount of sperm and accessory gland proteins transferred to females was detected. Despite higher sperm activity, hybrid males did not appear more fecund. However, individual-male mating and laboratory-swarm experiments revealed that hybrid males, while inseminating fewer females than older inbred males, were significantly more fertile, producing larger mating plugs and drastically increasing female fecundity. Heterotic males also showed increased longevity. These results validate the use of heterosis for creating hybrid males with improved fitness from long-established inbred laboratory strains. Therefore, this simple approach could facilitate disease control strategies based on male mosquito releases with important ultimate benefits to human health. PMID:26497140

  13. A comparison of gravid and under-house CO2-baited CDC light traps for mosquito species of public health importance in Houston, Texas.

    PubMed

    White, Stephanie L; Ward, Michael P; Budke, Christine M; Cyr, Tracy; Bueno, Rudy

    2009-11-01

    The relative efficacy of gravid and under-house CO2 traps for monitoring mosquito species of public health importance within the Houston metroplex area was assessed. Gravid and under-house traps were colocated at 10 sites and monitored weekly between 1 March to 31 May 2007. The most numerous species caught was Culex pipiens quinquefasciatus Say. Other species of public health importance caught in gravid and under-house traps included Culex restuans Theobald, Aedes aegypti (L.), and Aedes albopictus Skuse. Adjusting for the week of collection, gravid traps caught significantly more mosquitoes (mean 23.1 per trap) in the study area than under-house traps (mean 3.6 per trap). However, under-house traps caught a greater variety of mosquito species (13) than gravid traps (11). Gravid and under-house traps only caught nine of 15 of the same mosquito species during the study period. In this study area, gravid traps should be used as the primary method of surveillance for mosquito-borne diseases of public health importance during the early part of the season, because of greater catch numbers of mosquitoes that pose a public health risk.

  14. Prevention of mosquitoes (Diptera: Culicidae) and house flies (Diptera: Muscidae) from entering simulated aircraft with commercial air curtain units.

    PubMed

    Carlson, David A; Hogsette, Jerome A; Kline, Daniel L; Geden, Chris D; Vandermeer, Robert K

    2006-02-01

    Commercially available air curtain units were used to create air barriers to prevent mosquitoes and house flies from entering a simulated aircraft doorway together with passengers. Two assemblies of simulated passenger bridge and aircraft were constructed, and airflow measurements were recorded to confirm airflow characteristics for several combinations of commercial units. Three mosquito species were selected for different host-seeking characteristics, and house flies were selected to represent a large, strong-flying insect. Batches of 20 or 200 insects of four species were released into the passenger bridge just before 25 persons passed through the assembly, then insects that entered the aircraft cabin were recovered. Results showed that horizontal plus vertical or vertical-mounted air curtain units with the airflow directed at a 45 degrees angle into the passenger bridge excluded 95-99% of the mosquitoes and 95-100% of the house flies, respectively. Airflows were measured and estimated to be effective if the mean was > 4 m/s in the critical area in the center of the converging airflows. The study validates the concept that air barriers can effectively prevent the passage of flying insects into an aircraft.

  15. Cold storage of the northern house mosquito, Culex pipiens, in the absence of diapause

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One major obstacle in vector biology experimentation is the rearing of mosquitoes. Most mosquito colonies require substantial effort to maintain, including a blood meal at least once a month for optimal performance. While the induction of diapause can be used to reduce the amount of work required ...

  16. Occurrence of a mosquito vector in bird houses: Developmental consequences and potential epidemiological implications.

    PubMed

    Dieng, Hamady; Hassan, Rahimah Binti; Hassan, Ahmad Abu; Ghani, Idris Abd; Abang, Fatimah Bt; Satho, Tomomitsu; Miake, Fumio; Ahmad, Hamdan; Fukumitsu, Yuki; Hashim, Nur Aida; Zuharah, Wan Fatma; Kassim, Nur Faeza Abu; Majid, Abdul Hafiz Ab; Selvarajoo, Rekha; Nolasco-Hipolito, Cirilo; Ajibola, Olaide Olawunmi; Tuen, Andrew Alek

    2015-05-01

    Even with continuous vector control, dengue is still a growing threat to public health in Southeast Asia. Main causes comprise difficulties in identifying productive breeding sites and inappropriate targeted chemical interventions. In this region, rural families keep live birds in backyards and dengue mosquitoes have been reported in containers in the cages. To focus on this particular breeding site, we examined the capacity of bird fecal matter (BFM) from the spotted dove, to support Aedes albopictus larval growth. The impact of BFM larval uptake on some adult fitness traits influencing vectorial capacity was also investigated. In serial bioassays involving a high and low larval density (HD and LD), BFM and larval standard food (LSF) affected differently larval development. At HD, development was longer in the BFM environment. There were no appreciable mortality differences between the two treatments, which resulted in similar pupation and adult emergence successes. BFM treatment produced a better gender balance. There were comparable levels of blood uptake and egg production in BFM and LSF females at LD; that was not the case for the HD one, which resulted in bigger adults. BFM and LSF females displayed equivalent lifespans; in males, this parameter was shorter in those derived from the BFM/LD treatment. Taken together these results suggest that bird defecations successfully support the development of Ae. albopictus. Due to their cryptic aspects, containers used to supply water to encaged birds may not have been targeted by chemical interventions.

  17. Selectivity of odorant-binding proteins from the southern house mosquito tested against physiologically relevant ligands

    PubMed Central

    Yin, Jiao; Choo, Young-Moo; Duan, Hongxia; Leal, Walter S.

    2015-01-01

    As opposed to humans, insects rely heavily on an acute olfactory system for survival and reproduction. Two major types of olfactory proteins, namely, odorant-binding proteins (OBPs) and odorant receptors (ORs), may contribute to the selectivity and sensitivity of the insects' olfactory system. Here, we aimed at addressing the question whether OBPs highly enriched in the antennae of the southern house mosquito, Culex quinquefasciatus, contribute at least in part to the selective reception of physiologically relevant compounds. Using a fluorescence reporter and a panel of 34 compounds, including oviposition attractants, human-derived attractants, and repellents, we measured binding affinities of CquiOBP1, CquiOBP2, and CquiOBP5. Based on dissociation constants, we surmised that CquiOBP2 is a carrier for the oviposition attractant skatole, whereas CquiOBP1 and CquiOBP5 might transport the oviposition pheromone MOP, a human-derived attractant nonanal, and the insect repellent picardin. Binding of these three ligands to CquiOBP1 was further analyzed by examining the influence of pH on apparent affinity as well as by docking these three ligands into CquiOBP1. Our findings suggest that CquiOBP1 might discriminate MOP from nonanal/picaridin on the basis of the midpoint transition of a pH-dependence conformational change, and that MOP is better accommodated in the binding cavity than the other two ligands. These findings, along with previous experimental evidence suggesting that CquiOBP1 does not detect nonanal in vivo, suggest that OBP selectivity may not be clearly manifested in their dissociation constants. PMID:25774136

  18. Isolation and identification of mosquito (Aedes aegypti ) biting deterrent fatty acids from male inflorescences of breadfruit (Artocarpus altilis (Parkinson) Fosberg).

    PubMed

    Jones, A Maxwell P; Klun, Jerome A; Cantrell, Charles L; Ragone, Diane; Chauhan, Kamlesh R; Brown, Paula N; Murch, Susan J

    2012-04-18

    Dried male inflorescences of breadfruit ( Artocarpus altilis , Moraceae) are burned in communities throughout Oceania to repel flying insects, including mosquitoes. This study was conducted to identify chemicals responsible for mosquito deterrence. Various crude extracts were evaluated, and the most active, the hydrodistillate, was used for bioassay-guided fractionation. The hydrodistillate and all fractions displayed significant deterrent activity. Exploratory GC-MS analysis revealed more than 100 distinctive peaks, and more than 30 compounds were putatively identified, including a mixture of terpenes, aldehydes, fatty acids, and aromatics. A systematic bioassay-directed study using adult Aedes aegypti females identified capric, undecanoic, and lauric acid as primary deterrent constituents. A synthetic mixture of fatty acids present in the most active fraction and individual fatty acids were all significantly more active than N,N-diethyl-m-toluamide (DEET). These results provide support for this traditional practice and indicate the potential of male breadfruit flowers and fatty acids as mosquito repellents.

  19. Castration promotes welfare in group-housed male Swiss outbred mice maintained in educational institutions.

    PubMed

    Vaughan, Lewis M; Dawson, Jane S; Porter, Paula R; Whittaker, Alexandra L

    2014-01-01

    Educational institutions maintain group-housed mice of both sexes for training veterinarians and technicians in husbandry, medication, and sampling procedures. Mice kept in all-male groups may experience poor welfare due to fighting. Castrated mice may be used to replace gonadally intact males for such training programs. In this prospective cohort study, 80 castrated and 80 control (intact) male mice were studied over 3 mo to monitor aggression frequency and injury levels. Behavioral observations were performed twice weekly by using an all-occurrences sampling method to quantify behavioral events and the number and severity of bite wounds. Under these housing conditions, group-housed male mice castrated postpubertally exhibited significantly less aggression than did intact male mice. Castration therefore improves welfare in group-housed male mice and thus provides a husbandry alternative to individually housing animals in nonstudy situations.

  20. Repellent plants provide affordable natural screening to prevent mosquito house entry in tropical rural settings--results from a pilot efficacy study.

    PubMed

    Mng'ong'o, Frank C; Sambali, Joseph J; Sabas, Eustachkius; Rubanga, Justine; Magoma, Jaka; Ntamatungiro, Alex J; Turner, Elizabeth L; Nyogea, Daniel; Ensink, Jeroen H J; Moore, Sarah J

    2011-01-01

    Sustained malaria control is underway using a combination of vector control, prompt diagnosis and treatment of malaria cases. Progress is excellent, but for long-term control, low-cost, sustainable tools that supplement existing control programs are needed. Conventional vector control tools such as indoor residual spraying and house screening are highly effective, but difficult to deliver in rural areas. Therefore, an additional means of reducing mosquito house entry was evaluated: the screening of mosquito house entry points by planting the tall and densely foliated repellent plant Lantana camara L. around houses. A pilot efficacy study was performed in Kagera Region, Tanzania in an area of high seasonal malaria transmission, where consenting families within the study village planted L. camara (Lantana) around their homes and were responsible for maintaining the plants. Questionnaire data on house design, socioeconomic status, malaria prevention knowledge, attitude and practices was collected from 231 houses with Lantana planted around them 90 houses without repellent plants. Mosquitoes were collected using CDC Light Traps between September 2008 and July 2009. Data were analysed with generalised negative binomial regression, controlling for the effect of sampling period. Indoor catches of mosquitoes in houses with Lantana were compared using the Incidence Rate Ratio (IRR) relative to houses without plants in an adjusted analysis. There were 56% fewer Anopheles gambiae s.s. (IRR 0.44, 95% CI 0.28-0.68, p<0.0001); 83% fewer Anopheles funestus s.s. (IRR 0.17, 95% CI 0.09-0.32, p<0.0001), and 50% fewer mosquitoes of any kind (IRR 0.50, 95% CI 0.38-0.67, p<0.0001) in houses with Lantana relative to controls. House screening using Lantana reduced indoor densities of malaria vectors and nuisance mosquitoes with broad community acceptance. Providing sufficient plants for one home costs US $1.50 including maintenance and labour costs, (30 cents per person). L. camara mode

  1. Repellent Plants Provide Affordable Natural Screening to Prevent Mosquito House Entry in Tropical Rural Settings—Results from a Pilot Efficacy Study

    PubMed Central

    Mng'ong'o, Frank C.; Sambali, Joseph J.; Sabas, Eustachkius; Rubanga, Justine; Magoma, Jaka; Ntamatungiro, Alex J.; Turner, Elizabeth L.; Nyogea, Daniel; Ensink, Jeroen H. J.; Moore, Sarah J.

    2011-01-01

    Sustained malaria control is underway using a combination of vector control, prompt diagnosis and treatment of malaria cases. Progress is excellent, but for long-term control, low-cost, sustainable tools that supplement existing control programs are needed. Conventional vector control tools such as indoor residual spraying and house screening are highly effective, but difficult to deliver in rural areas. Therefore, an additional means of reducing mosquito house entry was evaluated: the screening of mosquito house entry points by planting the tall and densely foliated repellent plant Lantana camara L. around houses. A pilot efficacy study was performed in Kagera Region, Tanzania in an area of high seasonal malaria transmission, where consenting families within the study village planted L. camara (Lantana) around their homes and were responsible for maintaining the plants. Questionnaire data on house design, socioeconomic status, malaria prevention knowledge, attitude and practices was collected from 231 houses with Lantana planted around them 90 houses without repellent plants. Mosquitoes were collected using CDC Light Traps between September 2008 and July 2009. Data were analysed with generalised negative binomial regression, controlling for the effect of sampling period. Indoor catches of mosquitoes in houses with Lantana were compared using the Incidence Rate Ratio (IRR) relative to houses without plants in an adjusted analysis. There were 56% fewer Anopheles gambiae s.s. (IRR 0.44, 95% CI 0.28–0.68, p<0.0001); 83% fewer Anopheles funestus s.s. (IRR 0.17, 95% CI 0.09–0.32, p<0.0001), and 50% fewer mosquitoes of any kind (IRR 0.50, 95% CI 0.38–0.67, p<0.0001) in houses with Lantana relative to controls. House screening using Lantana reduced indoor densities of malaria vectors and nuisance mosquitoes with broad community acceptance. Providing sufficient plants for one home costs US $1.50 including maintenance and labour costs, (30 cents per person). L. camara

  2. Risk factors for house-entry by culicine mosquitoes in a rural town and satellite villages in The Gambia

    PubMed Central

    Kirby, Matthew J; West, Philippa; Green, Clare; Jasseh, Momodou; Lindsay, Steve W

    2008-01-01

    Background Screening doors, windows and eaves of houses should reduce house entry by eusynanthropic insects, including the common African house mosquito Culex pipiens quinquefasciatus and other culicines. In the pre-intervention year of a randomized controlled trial investigating the protective effects of house screening against mosquito house entry, a multi-factorial risk factor analysis study was used to identify factors influencing house entry by culicines of nuisance biting and medical importance. These factors were house location, architecture, human occupancy and their mosquito control activities, and the number and type of domestic animals within the compound. Results 40,407 culicines were caught; the dominant species were Culex thalassius, Cx. pipiens s.l., Mansonia africanus, M. uniformis and Aedes aegypti. There were four times more Cx. pipiens s.l. in Farafenni town (geometric mean/trap/night = 8.1, 95% confidence intervals, CIs = 7.2–9.1) than in surrounding villages (2.1, 1.9–2.3), but over five times more other culicines in the villages (25.1, 22.1–28.7) than in town (4.6, 4.2–5.2). The presence of Cx. pipiens s.l. was reduced in both settings if the house had closed eaves (odds ratios, OR town = 0.62, 95% CIs = 0.49–0.77; OR village = 0.49, 0.33–0.73), but increased per additional person in the trapping room (OR town = 1.16, 1.09–1.24; OR village = 1.10, 1.02–1.18). In the town only, Cx. pipiens s.l. numbers were reduced if houses had a thatched roof (OR = 0.70, 0.51–0.96), for each additional cow tethered near the house (OR = 0.73, 0.65–0.82) and with increasing distance from a pit latrine (OR = 0.97, 0.95–0.99). In the villages a reduction in Cx. pipiens s.l. numbers correlated with increased horses in the compound (OR = 0.90, 0.82–0.99). The presence of all other culicines was reduced in houses with closed eaves (both locations), with horses tethered outside (village only) and with increasing room height (town only), but

  3. Mosquito, adult (image)

    MedlinePlus

    This illustration shows an adult southern house mosquito. This mosquito feeds on blood and is the carrier of many diseases, such as encephalitis, West Nile, dengue fever, yellow fever, and others. ( ...

  4. A Deep Insight into the Sialome of Male and Female Aedes aegypti Mosquitoes

    PubMed Central

    Ribeiro, José M. C.; Martin-Martin, Ines; Arcà, Bruno; Calvo, Eric

    2016-01-01

    Only adult female mosquitoes feed on blood, while both genders take sugar meals. Accordingly, several compounds associated with blood feeding (i.e. vasodilators, anti-clotting, anti-platelets) are found only in female glands, while enzymes associated with sugar feeding or antimicrobials (such as lysozyme) are found in the glands of both sexes. We performed de novo assembly of reads from adult Aedes aegypti female and male salivary gland libraries (285 and 90 million reads, respectively). By mapping back the reads to the assembled contigs, plus mapping the reads from a publicly available Ae. aegypti library from adult whole bodies, we identified 360 transcripts (including splice variants and alleles) overexpressed tenfold or more in the glands when compared to whole bodies. Moreover, among these, 207 were overexpressed fivefold or more in female vs. male salivary glands, 85 were near equally expressed and 68 were overexpressed in male glands. We call in particular the attention to C-type lectins, angiopoietins, female-specific Antigen 5, the 9.7 kDa, 12–14 kDa, 23.5 kDa, 62/34 kDa, 4.2 kDa, proline-rich peptide, SG8, 8.7 kDa family and SGS fragments: these polypeptides are all of unknown function, but due to their overexpression in female salivary glands and putative secretory nature they are expected to affect host physiology. We have also found many transposons (some of which novel) and several endogenous viral transcripts (probably acquired by horizontal transfer) which are overexpressed in the salivary glands and may play some role in tissue-specific gene regulation or represent a mechanism of virus interference. This work contributes to a near definitive catalog of male and female salivary gland transcripts from Ae. aegypti, which will help to direct further studies aiming at the functional characterization of the many transcripts with unknown function and the understanding of their role in vector-host interaction and pathogen transmission. PMID:26999592

  5. Pair housing differentially affects motivation to self-administer cocaine in male and female rats.

    PubMed

    Westenbroek, Christel; Perry, Adam N; Becker, Jill B

    2013-09-01

    Female rats exhibit greater intake and motivation to self-administer cocaine. In females but not males, isolation by itself is a stressor, which could lead to increased drug intake. Therefore, we hypothesized that social housing would buffer against stress and reduce the motivation to self-administer cocaine primarily in females. Male and female Sprague-Dawley rats were housed individually or in same-sex pairs. The individually housed rats and one of each pair were allowed to self-administer (SA) a low dose of cocaine (0.2 mg/kg/inf) on a fixed ratio (FR1) schedule for one week. Motivation for cocaine SA was measured for an additional 2 weeks on a progressive ratio schedule. Isolated females had greater cocaine-intake on the FR1 schedule and greater motivation to take cocaine than males. Pair-housing in females, but not males, attenuated the motivation to take cocaine. Isolated females, but not males, showed escalation of their motivation to take cocaine, which was attenuated by pair housing of females. Concluding, the motivation to take cocaine escalates in females but not males, and pair-housing of females attenuates this escalation.

  6. Steroids in house sparrows (Passer domesticus): Effects of POPs and male quality signalling.

    PubMed

    Nossen, Ida; Ciesielski, Tomasz M; Dimmen, Malene V; Jensen, Henrik; Ringsby, Thor Harald; Polder, Anuschka; Rønning, Bernt; Jenssen, Bjørn M; Styrishave, Bjarne

    2016-03-15

    At high trophic levels, environmental contaminants have been found to affect endocrinological processes. Less attention has been paid to species at lower trophic levels. The house sparrow (Passer domesticus) may be a useful model for investigating effects of POPs in mid-range trophic level species. In male house sparrows, ornamental traits involved in male quality signalling are important for female selection. These traits are governed by endocrinological systems, and POPs may therefore interfere with male quality signalling. The aim of the present study was to use the house sparrow as a mid-range trophic level model species to study the effects of environmental contaminants on endocrinology and male quality signalling. We analysed the levels of selected PCBs, PBDEs and OCPs and investigated the possible effects of these contaminants on circulating levels of steroid hormones (4 progestagens, 4 androgens and 3 estrogens) in male and female adult house sparrows from a population on the island Leka, Norway. Plasma samples were analysed for steroid hormones by GC-MS and liver samples were analysed for environmental contaminants by GC-ECD and GC-MS. In males, we also quantified ornament traits. It was hypothesised that POPs may have endocrine disrupting effects on the local house sparrow population and can thus interfere with the steroid hormone homeostasis. Among female house sparrows, bivariate correlations revealed negative relationships between POPs and estrogens. Among male sparrows, positive relationships between dihydrotestosterone levels and PCBs were observed. In males, positive relationships were also found between steroids and beak length, and between steroids and ornamental traits such as total badge size. This was confirmed by a significant OPLS model between beak length and steroids. Although sparrows are in the mid-range trophic levels, the present study indicates that POPs may affect steroid homeostasis in house sparrows, in particular for females. For

  7. Group housing of male CD1 mice: reflections from toxicity studies.

    PubMed

    Annas, A; Bengtsson, C; Törnqvist, E

    2013-04-01

    Owing to their naturally aggressive behaviour, male mice are often housed individually in toxicity studies. However, several publications advocate group-housing of mice to enable normal social behaviour and interactions between the animals. This refinement project aimed at facilitate group-housing in toxicity studies. A handling procedure, including key factors such as allocation into groups before sexual maturation, transfer of used nesting material into clean cages and avoidance of external changes, that makes group-housing of male CD-1 mice possible in long-term toxicity studies has been developed at Safety Assessment within AstraZeneca, Sweden. Observations on the effect on aggression/fighting in group-housed male mice following different procedures performed in toxicity studies have shown that temporary removal of animals from the group for blood or urine sampling does not affect the group dynamics. However, temporary removal of animals for mating leads to fighting if the animals are taken back to the original group. Treatment with test compound might affect the general condition of the animals and the social hierarchy could be changed. In such cases aggression/fighting might occur and the animals have to be separated. Our experience clearly indicates that group housing of male mice in long-term studies leads to more easily handled animals, as compared with individually housed mice.

  8. Male mice housed in groups engage in frequent fighting and show a lower response to additional bone loading than females or individually housed males that do not fight.

    PubMed

    Meakin, Lee B; Sugiyama, Toshihiro; Galea, Gabriel L; Browne, William J; Lanyon, Lance E; Price, Joanna S

    2013-05-01

    Experiments to investigate bone's physiological adaptation to mechanical loading frequently employ models that apply dynamic loads to bones in vivo and assess the changes in mass and architecture that result. It is axiomatic that bones will only show an adaptive response if the applied artificial loading environment differs in a significant way from that to which the bones have been habituated by normal functional loading. It is generally assumed that this normal loading is similar between experimental groups. In the study reported here we found that this was not always the case. Male and female 17-week-old C57BL/6 mice were housed in groups of six, and a single episode (40 cycles) of non-invasive axial loading, engendering 2,200 με on the medial surface of the proximal tibiae in sample mice, was applied to right tibiae on alternate days for two weeks. This engendered an adaptive increase in bone mass in females, but not males. Observation revealed the main difference in behaviour between males and females was that males were involved in fights 1.3 times per hour, whereas the females never fought. We therefore housed all mice individually. In females, there was a similar significant osteogenic response to loading in cortical and trabecular bone of both grouped and individual mice. In contrast, in males, adaptive increases in the loaded compared with non-loaded control bones was only apparent in animals housed individually. Our interpretation of these findings is that the frequent vigorous fighting that occurs between young adult males housed in groups could be sufficient to engender peak strains and strain rates that equal or exceed the stimulus derived from artificial loading. This indicates the importance of ensuring that physical activity is consistent between groups. Reducing the background level of the naturally engendered strain environment allows adaptive responses to artificial loading to be demonstrated at lower loads.

  9. Comparison of outcomes of homeless female and male veterans in transitional housing.

    PubMed

    Tsai, Jack; Rosenheck, Robert A; McGuire, James F

    2012-12-01

    Homelessness among female veterans is of national concern, but there have been few studies of how they differ from male veterans or whether they have different outcomes. This study compared 59 female and 1,181 male participants in a multi-site study of three VA-funded transitional housing programs over a 1-year period following completion of an episode of treatment. At baseline, female participants were younger, reported more psychiatric symptoms, had shorter histories of homelessness,were less likely to have substance use disorders, and were less likely to be working than males. After controlling for these baseline differences, there were no overall gender differences in outcomes measures of housing, employment,substance use, physical and mental health, or quality of life. These results suggest homeless female veterans have different characteristics than male veterans, but benefit equally from transitional housing.

  10. Increasing our knowledge of male mosquito biology in relation to genetic control programmes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The enormous burden placed on populations worldwide by mosquito-borne diseases, most notably malaria and dengue, is currently being tackled by the use of insecticides sprayed in residences or applied to bednets, and in the case of dengue vectors through reduction of larval breeding sites. However, t...

  11. A mosquito sperm's journey from male ejaculate to egg: Mechanisms, molecules, and methods for exploration

    PubMed Central

    Degner, Ethan C.

    2016-01-01

    SUMMARY The fate of mosquito sperm in the female reproductive tract has been addressed sporadically and incompletely, resulting in significant gaps in our understanding of sperm‐female interactions that ultimately lead to fertilization. As with other Diptera, mosquito sperm have a complex journey to their ultimate destination, the egg. After copulation, sperm spend a short time at the site of insemination where they are hyperactivated and quickly congregate near the entrance of the spermathecal ducts. Within minutes, they travel up the narrow ducts to the spermathecae, likely through the combined efforts of female transport and sperm locomotion. The female nourishes sperm and maintains them in these permanent storage organs for her entire life. When she is ready, the female coordinates the release of sperm with ovulation, and the descending egg is fertilized. Although this process has been well studied via microscopy, many questions remain regarding the molecular processes that coordinate sperm motility, movement through the reproductive tract, maintenance, and usage. In this review, we describe the current understanding of a mosquito sperm's journey to the egg, highlighting gaps in our knowledge of mosquito reproductive biology. Where insufficient information is available in mosquitoes, we describe analogous processes in other organisms, such as Drosophila melanogaster, as a basis for comparison, and we suggest future areas of research that will illuminate how sperm successfully traverse the female reproductive tract. Such studies may yield molecular targets that could be manipulated to control populations of vector species. Mol. Reprod. Dev. 83: 897–911, 2016. © 2016 The Authors. Molecular Reproduction and Development Published by Wiley Periodicals, Inc. PMID:27147424

  12. Fine-scale population genetic structure of a wildlife disease vector: The southern house mosquito on the island of Hawaii

    USGS Publications Warehouse

    Keyghobadi, N.; LaPointe, D.; Fleischer, R.C.; Fonseca, D.M.

    2006-01-01

    The southern house mosquito, Culex quinquefasciatus, is a widespread tropical and subtropical disease vector. In the Hawaiian Islands, where it was introduced accidentally almost two centuries ago, it is considered the primary vector of avian malaria and pox. Avian malaria in particular has contributed to the extinction and endangerment of Hawaii's native avifauna, and has altered the altitudinal distribution of native bird populations. We examined the population genetic structure of Cx. quinquefasciatus on the island of Hawaii at a smaller spatial scale than has previously been attempted, with particular emphasis on the effects of elevation on population genetic structure. We found significant genetic differentiation among populations and patterns of isolation by distance within the island. Elevation per se did not have a limiting effect on gene flow; however, there was significantly lower genetic diversity among populations at mid elevations compared to those at low elevations. A recent sample taken from just above the predicted upper altitudinal distribution of Cx. quinquefasciatus on the island of Hawaii was confirmed as being a temporary summer population and appeared to consist of individuals from more than one source population. Our results indicate effects of elevation gradients on genetic structure that are consistent with known effects of elevation on population dynamics of this disease vector. ?? 2006 The Authors.

  13. Functional circadian clock genes are essential for the overwintering diapause of the Northern house mosquito, Culex pipiens

    PubMed Central

    Meuti, Megan E.; Stone, Mary; Ikeno, Tomoko; Denlinger, David L.

    2015-01-01

    The short day lengths of late summer are used to program the overwintering adult diapause (dormancy) of the Northern house mosquito, Culex pipiens. Here, we investigated the role of clock genes in initiating this diapause and asked whether the circadian cycling of clock gene expression persists during diapause. We provide evidence that the major circadian clock genes continue to cycle throughout diapause and after diapause has been terminated. RNA interference (RNAi) was used to knock down the core circadian clock genes and to then assess the impact of the various clock genes on the ability of females to enter diapause. RNAi directed against negative circadian regulators (period, timeless and cryptochrome2) caused females that were reared under diapause-inducing, short day conditions to avert diapause. In contrast, knocking down the circadian-associated gene pigment dispersing factor caused females that were reared under diapause-averting, long day conditions to enter a diapause-like state. Our results implicate the circadian clock in the initiation of diapause in C. pipiens. PMID:25653422

  14. Myelination of the corpus callosum in male and female rats following complex environment housing during adulthood

    PubMed Central

    Markham, Julie A.; Herting, Megan M.; Luszpak, Agatha E.; Juraska, Janice M.; Greenough, William T.

    2009-01-01

    Myelination is an important process in brain development, and delays or abnormalities in this process have been associated with a number of conditions including autism, developmental delay, attention deficit disorder, and schizophrenia. Myelination can be sensitive to developmental experience; however, although the adult brain remains highly plastic, it is unknown whether myelination continues to be sensitive to experience during adulthood. Male and female rats were socially housed until four months of age, at which time they were moved into either a complex or “enriched” environment (EC) or an isolated condition (IC). Although the area of the splenium (posterior 20% of the callosum, which contains axons from visual cortical neurons) increased by about 10% following two months of EC housing, the area occupied by myelinated axons was not influenced by adult housing condition. Instead, it was the area occupied by glial cell processes and unmyelinated axons which significantly increased following EC housing. Neither the size nor the myelin content of the genu (anterior 15% of the callosum) was sensitive to manipulations of adult housing condition, but males had more area occupied by myelinated axons in both callosal regions. Finally, the inability of two months of complex environment housing during adulthood to impact the number of myelinated axons in the splenium was confirmed in a subset of animals using quantitative electron microscopy. We conclude that the sensitivity of myelination to experience is reduced in adulthood relative to development in both sexes. PMID:19596280

  15. Housing conditions and stimulus females: a robust social discrimination task for studying male rodent social recognition.

    PubMed

    Macbeth, Abbe H; Edds, Jennifer Stepp; Young, W Scott

    2009-01-01

    Social recognition (SR) enables rodents to distinguish between familiar and novel conspecifics, largely through individual odor cues. SR tasks utilize the tendency for a male to sniff and interact with a novel individual more than a familiar individual. Many paradigms have been used to study the roles of the neuropeptides oxytocin and vasopressin in SR. However, inconsistencies in results have arisen within similar mouse strains, and across different paradigms and laboratories, making reliable testing of SR difficult. The current protocol details a novel approach that is replicable across investigators and in different strains of mice. We created a protocol that uses gonadally intact, singly housed females presented within corrals to group-housed males. Housing females singly before testing is particularly important for reliable discrimination. This methodology will be useful for studying short-term social memory in rodents, and may also be applicable for longer term studies.

  16. Chronic Co-species Housing Mice and Rats Increased the Competitiveness of Male Mice.

    PubMed

    Liu, Ying-Juan; Li, Lai-Fu; Zhang, Yao-Hua; Guo, Hui-Fen; Xia, Min; Zhang, Meng-Wei; Jing, Xiao-Yuan; Zhang, Jing-Hua; Zhang, Jian-Xu

    2017-01-10

    Rats are predators of mice in nature. Nevertheless, it is a common practice to house mice and rats in a same room in some laboratories. In this study, we investigated the behavioral and physiological responsively of mice in long-term co-species housing conditions. Twenty-four male mice were randomly assigned to their original raising room (control) or a rat room (co-species-housed) for more than 6 weeks. In the open-field and light-dark box tests, the behaviors of the co-species-housed mice and controls were not different. In a 2-choice test of paired urine odors [rabbit urine (as a novel odor) vs. rat urine, cat urine (as a natural predator-scent) vs. rabbit urine, and cat urine vs. rat urine], the co-species-housed mice were more ready to investigate the rat urine odor compared with the controls and may have adapted to it. In an encounter test, the rat-room-exposed mice exhibited increased aggression levels, and their urines were more attractive to females. Correspondingly, the levels of major urinary proteins were increased in the co-species-housed mouse urine, along with some volatile pheromones. The serum testosterone levels were also enhanced in the co-species-housed mice, whereas the corticosterone levels were not different. The norepinephrine, dopamine, and 5-HT levels in the right hippocampus and striatum were not different between the 2. Our findings indicate that chronic co-species housing results in adaptation in male mice; furthermore, it appears that long-term rat-odor stimuli enhance the competitiveness of mice, which suggests that appropriate predator-odor stimuli may be important to the fitness of prey animals.

  17. Baculum morphology predicts reproductive success of male house mice under sexual selection

    PubMed Central

    2013-01-01

    Background Diversity in penile morphology is characterised by extraordinary variation in the size and shape of the baculum (penis bone) found in many mammals. Although functionally enigmatic, diversity in baculum form is hypothesised to result from sexual selection. According to this hypothesis, the baculum should influence the outcome of reproductive competition among males within promiscuous mating systems. However, a test of this key prediction is currently lacking. Results Here we show that baculum size explains significant variation in the reproductive success of male house mice under competitive conditions. After controlling for body size and other reproductive traits, the width (but not length) of the house mouse baculum predicts both the mean number of offspring sired per litter and total number of offspring sired. Conclusions By providing the first evidence linking baculum morphology to male reproductive success, our results support the hypothesis that evolutionary diversity in baculum form is driven by sexual selection. PMID:23800051

  18. Conditioning Individual Mosquitoes to an Odor: Sex, Source, and Time

    PubMed Central

    Sanford, Michelle R.; Tomberlin, Jeffery K.

    2011-01-01

    Olfactory conditioning of mosquitoes may have important implications for vector-pathogen-host dynamics. If mosquitoes learn about specific host attributes associated with pathogen infection, it may help to explain the heterogeneity of biting and disease patterns observed in the field. Sugar-feeding is a requirement for survival in both male and female mosquitoes. It provides a starting point for learning research in mosquitoes that avoids the confounding factors associated with the observer being a potential blood-host and has the capability to address certain areas of close-range mosquito learning behavior that have not previously been described. This study was designed to investigate the ability of the southern house mosquito, Culex quinquefasciatus Say to associate odor with a sugar-meal with emphasis on important experimental considerations of mosquito age (1.2 d old and 3–5 d old), sex (male and female), source (laboratory and wild), and the time between conditioning and testing (<5 min, 1 hr, 2.5 hr, 5 hr, 10 hr, and 24 hr). Mosquitoes were individually conditioned to an odor across these different experimental conditions. Details of the conditioning protocol are presented as well as the use of binary logistic regression to analyze the complex dataset generated from this experimental design. The results suggest that each of the experimental factors may be important in different ways. Both the source of the mosquitoes and sex of the mosquitoes had significant effects on conditioned responses. The largest effect on conditioning was observed in the lack of positive response following conditioning for females aged 3–5 d derived from a long established colony. Overall, this study provides a method for conditioning experiments involving individual mosquitoes at close range and provides for future discussion of the relevance and broader questions that can be asked of olfactory conditioning in mosquitoes. PMID:21887384

  19. Genotype and extra-pair paternity in the house wren: a rare-male effect?

    PubMed Central

    Masters, Brian S; Hicks, Bonnie G; Johnson, L Scott; Erb, Lori A

    2003-01-01

    Females in socially monogamous species may select extra-pair (EP) mates to increase the heterozygosity, and hence fitness, of their offspring. We tested this hypothesis in the house wren (Troglodytes aedon), a largely monogamous songbird in which EP young are common. We typed paired males and females, nestlings, and males on neighbouring territories, at five to seven microsatellite loci over 2 years in a Wyoming, USA, population. We identified EP sires at 20 nests with EP young. In pairwise comparisons, we found no significant differences between cuckolded within-pair (WP) males and EP sires in three measures of heterozygosity (mean d2, standardized heterozygosity and internal relatedness). However, EP sires had fewer alleles that were common within the population than did the WP males they cuckolded. Nearby males who were EP sires also had fewer common alleles than did nearby males who did not sire EP young. Females in our population may be more prone to accept copulations from males with rare genotypes than from males with common genotypes. Alternatively, selection of rare-male sperm may occur within the female reproductive tract. Because mating with rare males is likely to increase offspring heterozygosity, our data suggest that EP mating may provide genetic benefits to females. PMID:12965031

  20. Plasmodium AdoMetDC/ODC bifunctional enzyme is essential for male sexual stage development and mosquito transmission

    PubMed Central

    Hart, Robert J.; Ghaffar, Atif; Abdalal, Shaymaa; Perrin, Benjamin

    2016-01-01

    ABSTRACT Polyamines are positively-charged organic molecules that are important for cellular growth and division. Polyamines and their synthesizing enzymes are particularly abundant in rapidly proliferating eukaryotic cells such as parasitic protozoa and cancer cells. Polyamine biosynthesis inhibitors, such as Elfornithine, are now being considered for cancer prevention and have been used effectively against Trypanosoma brucei. Inhibitors of polyamine biosynthesis have caused growth arrest of Plasmodium falciparum blood stages in vitro, but in P. berghei only partial inhibition has been observed. While polyamine biosynthesis enzymes are characterized and conserved in Plasmodium spp., little is known on the biological roles of these enzymes inside malaria parasite hosts. The bifunctional polyamine biosynthesis enzyme S-adenosyl methionine decarboxylase/ornithine decarboxylase (AdoMetDC/ODC) was targeted for deletion in P. yoelii. Deletion of AdoMetDC/ODC significantly reduced blood stage parasitemia but Anopheles transmission was completely blocked. We showed that male gametocytogenesis and male gamete exflagellation were abolished and consequently no ookinetes or oocyst sporozoites could be generated from adometdc/odc(–) parasites. Supplementation of putrescine and spermidine did not rescue the defective phenotypes of male gametocytes and gametes of the knockout parasites. These results highlight the crucial role of polyamine homeostasis in the development and functions of Plasmodium erythrocytic stages in the blood and in the mosquito vector and validate polyamine biosynthesis pathway enzymes as drug targeting candidates for malaria parasite transmission blocking. PMID:27387533

  1. Influence of resource levels, organic compounds, and laboratory colonization on interspecific competition between the Asian tiger mosquito (Aedes albopictus) and the southern house mosquito (Culex quinquefasciatus)

    PubMed Central

    Allgood, David W.; Yee, Donald A.

    2013-01-01

    The mosquitoes Aedes albopictus (Skuse) and Culex quinquefasciatus (Say) (Diptera:Culicidae) are common inhabitants of tyres and other artificial containers, which constitute important peridomestic mosquito breeding habitats. We tested the hypotheses that interspecific resource competition between the larvae of these species is asymmetrical, that the concentration of chemicals associated with decomposing detritus affects their competitive outcome, and that wild and colonized strains of Cx. quinquefasciatus are affected differently by competition with Ae. albopictus. We conducted two laboratory competition experiments wherein we measured survivorship and estimated population growth (λ’) of both species under multiple mixed-species densities. Under varying resource levels, competition was asymmetrical with Ae. albopictus causing competitive reductions or exclusions of Cx. quinquefasciatus under limited resources. In a second experiment, which used both wild and colonized strains of Cx. quinquefasciatus, organic chemical compounds associated with decomposing detritus did not affect the competitive outcome. The colonized strain of Cx. quinquefasciatus had greater survivorship, adult mass, and faster development times than the wild strain, but both strains were similarly affected by competition with Ae. albopictus. Competition between these species may have important consequences for vector population dynamics, especially in areas where tyres and artificial containers constitute the majority of mosquito breeding habitats. PMID:24444185

  2. The copulatory plug delays ejaculation by rival males and affects sperm competition outcome in house mice.

    PubMed

    Sutter, A; Lindholm, A K

    2016-08-01

    Females of many species mate with multiple males (polyandry), resulting in male-male competition extending to post-copulation (sperm competition). Males adapt to such post-copulatory sexual selection by altering features of their ejaculate that increase its competitiveness and/or by decreasing the risk of sperm competition through female manipulation or interference with rival male behaviour. At ejaculation, males of many species deposit copulatory plugs, which are commonly interpreted as a male adaptation to post-copulatory competition and are thought to reduce or delay female remating. Here, we used a vertebrate model species, the house mouse, to study the consequences of copulatory plugs for post-copulatory competition. We experimentally manipulated plugs after a female's first mating and investigated the consequences for rival male behaviour and paternity outcome. We found that even intact copulatory plugs were ineffective at preventing female remating, but that plugs influenced the rival male copulatory behaviour. Rivals facing intact copulatory plugs performed more but shorter copulations and ejaculated later than when the plug had been fully or partially removed. This suggests that the copulatory plug represents a considerable physical barrier to rival males. The paternity share of first males increased with a longer delay between the first and second males' ejaculations, indicative of fitness consequences of copulatory plugs. However, when males provided little copulatory stimulation, the incidence of pregnancy failure increased, representing a potential benefit of intense and repeated copulation besides plug removal. We discuss the potential mechanisms of how plugs influence sperm competition outcome and consequences for male copulatory behaviour.

  3. The diapause program impacts renal excretion and molecular expression of aquaporins in the northern house mosquito, Culex pipiens.

    PubMed

    Yang, Liu; Denlinger, David L; Piermarini, Peter M

    2016-12-27

    Adult females of the mosquito Culex pipiens entering diapause increase sugar water ingestion and reduce evaporative water loss, but how these attributes of the diapause program impact activity of the renal excretory system remains unknown. Here we compared the renal excretory capacity of diapausing and non-diapausing females, as well as the molecular expression of aquaporin (AQP) genes that encode channels involved in transporting water and/or small metabolites. Baseline urine excretion rates in diapausing mosquitoes were higher than in those of their non-diapausing counterparts, possibly a consequence of the intense sugar feeding associated with diapause. But, diapausing mosquitoes exhibited a much lower capacity for diuresis than non-diapausing mosquitoes. The suppressed diuretic capacity likely reflects reduced investment in the energetically-expensive post-prandial diuresis, an event not observed in diapausing mosquitoes. The mRNA expression levels of two genes encoding AQPs, Eglp1 and Aqp12L, in diapausing mosquitoes were down-regulated (on day 14) and up-regulated (on both days 3 and 14), respectively, in whole body samples. These changes were not evident in the excretory system (i.e., Malpighian tubules and hindgut), which showed no differential expression of AQPs as a function of diapause. Several AQP mRNAs were, however, differentially expressed in the midgut, ovaries, and abdominal body wall of diapausing mosquitoes, suggesting that AQPs in these tissues may be playing important non-excretory roles that are unique to diapause physiology.

  4. Agonistic onset during development differentiates wild house mouse males (Mus domesticus)

    NASA Astrophysics Data System (ADS)

    Krackow, Sven

    2005-02-01

    Wild house mouse populations have been suggested to locally adapt to varying dispersal regimes by expressing divergent aggressivity phenotypes. This conjecture implies, first, genetic polymorphism for dispersive strategies which is supported by the finding of heritable variation for male dispersal tendency in feral house mice. Secondly, aggressivity is assumed to translate into dispersal rates. This speculation is reinforced by experimental evidence showing that non-agonistic males display lower dispersal propensity than same-aged males that have established agonistic dominance. However, the actual ontogenetic behavioural pattern and its variability among populations remain unknown. Hence, in this study the timing of agonistic onset is quantified within laboratory-reared fraternal pairs, and compared between descendants from two different feral populations. Males from the two populations (G and Z) differed strongly in agonistic development, as Z fraternal pairs had a 50% risk of agonistic onset before 23.5±2.7 days of age, while this took 57.3±5.4 days in males from population G. This difference coincided with significant genetic differentiation between the males of the two populations as determined by 11 polymorphic microsatellite markers. Furthermore, in population G, males from agonistic and amicable fraternal pairs exhibited significant genetic differentiation. These results corroborate the supposition of genetic variability for dispersive strategies in house mice, and identify the ontogenetic timing of agonistic phenotype development as the potential basis for genetic differentiation. This opens a unique opportunity to study the genetic determination of a complex mammalian behavioural syndrome in a life history context, using a simple laboratory paradigm.

  5. Fitness of transgenic mosquito Aedes aegypti males carrying a dominant lethal genetic system.

    PubMed

    Massonnet-Bruneel, Blandine; Corre-Catelin, Nicole; Lacroix, Renaud; Lees, Rosemary S; Hoang, Kim Phuc; Nimmo, Derric; Alphey, Luke; Reiter, Paul

    2013-01-01

    OX513A is a transgenic strain of Aedes aegypti engineered to carry a dominant, non-sex-specific, late-acting lethal genetic system that is repressed in the presence of tetracycline. It was designed for use in a sterile-insect (SIT) pest control system called RIDL® (Release of Insects carrying a Dominant Lethal gene) by which transgenic males are released in the field to mate with wild females; in the absence of tetracycline, the progeny from such matings will not survive. We investigated the mating fitness of OX513A in the laboratory. Male OX513A were as effective as Rockefeller (ROCK) males at inducing refractoriness to further mating in wild type females and there was no reduction in their ability to inseminate multiple females. They had a lower mating success but yielded more progeny than the wild-type comparator strain (ROCK) when one male of each strain was caged with a ROCK female. Mating success and fertility of groups of 10 males-with different ratios of RIDL to ROCK-competing for five ROCK females was similar, but the median longevity of RIDL males was somewhat (18%) lower. We conclude that the fitness under laboratory conditions of OX513A males carrying a tetracycline repressible lethal gene is comparable to that of males of the wild-type comparator strain.

  6. The Contribution of the Y Chromosome to Hybrid Male Sterility in House Mice

    PubMed Central

    Campbell, Polly; Good, Jeffrey M.; Dean, Matthew D.; Tucker, Priscilla K.; Nachman, Michael W.

    2012-01-01

    Hybrid sterility in the heterogametic sex is a common feature of speciation in animals. In house mice, the contribution of the Mus musculus musculus X chromosome to hybrid male sterility is large. It is not known, however, whether F1 male sterility is caused by X–Y or X-autosome incompatibilities or a combination of both. We investigated the contribution of the M. musculus domesticus Y chromosome to hybrid male sterility in a cross between wild-derived strains in which males with a M. m. musculus X chromosome and M. m. domesticus Y chromosome are partially sterile, while males from the reciprocal cross are reproductively normal. We used eight X introgression lines to combine different X chromosome genotypes with different Y chromosomes on an F1 autosomal background, and we measured a suite of male reproductive traits. Reproductive deficits were observed in most F1 males, regardless of Y chromosome genotype. Nonetheless, we found evidence for a negative interaction between the M. m. domesticus Y and an interval on the M. m. musculus X that resulted in abnormal sperm morphology. Therefore, although F1 male sterility appears to be caused mainly by X-autosome incompatibilities, X–Y incompatibilities contribute to some aspects of sterility. PMID:22595240

  7. X-y interactions underlie sperm head abnormality in hybrid male house mice.

    PubMed

    Campbell, Polly; Nachman, Michael W

    2014-04-01

    The genetic basis of hybrid male sterility in house mice is complex, highly polygenic, and strongly X linked. Previous work suggested that there might be interactions between the Mus musculus musculus X and the M. m. domesticus Y with a large negative effect on sperm head morphology in hybrid males with an F1 autosomal background. To test this, we introgressed the M. m. domesticus Y onto a M. m. musculus background and measured the change in sperm morphology, testis weight, and sperm count across early backcross generations and in 11th generation backcross males in which the opportunity for X-autosome incompatibilities is effectively eliminated. We found that abnormality in sperm morphology persists in M. m. domesticus Y introgression males, and that this phenotype is rescued by M. m. domesticus introgressions on the X chromosome. In contrast, the severe reductions in testis weight and sperm count that characterize F1 males were eliminated after one generation of backcrossing. These results indicate that X-Y incompatibilities contribute specifically to sperm morphology. In contrast, X-autosome incompatibilities contribute to low testis weight, low sperm count, and sperm morphology. Restoration of normal testis weight and sperm count in first generation backcross males suggests that a small number of complex incompatibilities between loci on the M. m. musculus X and the M. m. domesticus autosomes underlie F1 male sterility. Together, these results provide insight into the genetic architecture of F1 male sterility and help to explain genome-wide patterns of introgression across the house mouse hybrid zone.

  8. X–Y Interactions Underlie Sperm Head Abnormality in Hybrid Male House Mice

    PubMed Central

    Campbell, Polly; Nachman, Michael W.

    2014-01-01

    The genetic basis of hybrid male sterility in house mice is complex, highly polygenic, and strongly X linked. Previous work suggested that there might be interactions between the Mus musculus musculus X and the M. m. domesticus Y with a large negative effect on sperm head morphology in hybrid males with an F1 autosomal background. To test this, we introgressed the M. m. domesticus Y onto a M. m. musculus background and measured the change in sperm morphology, testis weight, and sperm count across early backcross generations and in 11th generation backcross males in which the opportunity for X–autosome incompatibilities is effectively eliminated. We found that abnormality in sperm morphology persists in M. m. domesticus Y introgression males, and that this phenotype is rescued by M. m. domesticus introgressions on the X chromosome. In contrast, the severe reductions in testis weight and sperm count that characterize F1 males were eliminated after one generation of backcrossing. These results indicate that X–Y incompatibilities contribute specifically to sperm morphology. In contrast, X–autosome incompatibilities contribute to low testis weight, low sperm count, and sperm morphology. Restoration of normal testis weight and sperm count in first generation backcross males suggests that a small number of complex incompatibilities between loci on the M. m. musculus X and the M. m. domesticus autosomes underlie F1 male sterility. Together, these results provide insight into the genetic architecture of F1 male sterility and help to explain genome-wide patterns of introgression across the house mouse hybrid zone. PMID:24504187

  9. Anopheles arabiensis egg treatment with dieldrin for sex separation leaves residues in male adult mosquitoes that can bioaccumulate in goldfish (Carassius auratus auratus)

    PubMed Central

    Yamada, Hanano; Jandric, Zora; Chhem-Kieth, Sorivan; Vreysen, Marc JB; Rathor, Mohammad N; Gilles, Jeremie RL; Cannavan, Andrew

    2013-01-01

    The sterile insect technique (SIT) is a biological control tactic that is used as a component of area-wide integrated pest management (AW-IPM) programs. The SIT can only be applied against disease-transmitting mosquitoes when only sterile male mosquitoes are released, and the blood-sucking and potentially disease-transmitting females are eliminated from the production line. For Anopheles arabiensis, a potent vector of malaria, a genetic sexing strain was developed whereby females can be eliminated by treating the eggs or larvae with the insecticide dieldrin. To evaluate the presence of dieldrin residues in male mosquitoes designated for SIT releases, a simple, sensitive, and accurate gas chromatography–electron capture detector (GC–ECD) method was developed. In addition, bioaccumulation and food chain transfer of these residues to fish after feeding with treated mosquitoes was demonstrated. The overall recovery from method validation studies was 77.3 ± 2.2% (mean ± relative standard deviation [RSD]) for the mosquitoes, and 99.1 ± 4.4% (mean ± RSD) for the fish. The average dieldrin concentration found in adult male An. arabiensis was 28.1 ± 2.9 µg/kg (mean ± standard deviation [SD]). A range of 23.9 ± 1.1 µg/kg to 73.9 ± 5.2 µg/kg (mean ± SD) of dieldrin was found in the fish samples. These findings indicate the need to reassess the environmental and health implications of control operations with a SIT component against An. arabiensis that involves using persistent organochlorines in the sexing process. PMID:23983078

  10. Female house mice avoid fertilization by t haplotype incompatible males in a mate choice experiment

    PubMed Central

    Manser, A; König, B; Lindholm, A K

    2015-01-01

    The t haplotype in house mice is a well-known selfish genetic element with detrimental, nonadditive fitness consequences to its carriers: recessive lethal mutations cause t/t homozygotes to perish in utero. Given the severe genetic incompatibility imposed by the t haplotype, we predict females to avoid fertilization by t haplotype incompatible males. Indeed, some of the strongest evidence for compatibility mate choice is related to the t haplotype in house mice. However, all previous evidence for compatibility mate choice in this system is based on olfactory preference. It is so far unknown how general these preferences are and whether they are relevant in an actual mating context. Here, we assess female compatibility mate choice related to t haplotypes in a setting that – for the first time – allowed females to directly interact and mate with males. This approach enabled us to analyse female behaviour during the testing period, and the resulting paternity success and fitness consequences of a given choice. We show that genetic incompatibilities arising from the t haplotype had severe indirect fitness consequences and t females avoided fertilization by t incompatible males. The results are inconclusive whether this avoidance of t fertilization by t females was caused by pre- or post-copulatory processes. PMID:25494878

  11. The best time to have sex: mating behaviour and effect of daylight time on male sexual competitiveness in the Asian tiger mosquito, Aedes albopictus (Diptera: Culicidae).

    PubMed

    Benelli, Giovanni

    2015-03-01

    Aedes albopictus is the most invasive mosquito worldwide and works as a vector for many important pathogens. Control tools rely to chemical treatments against larvae, indoor residual spraying and insecticide-treated bed nets. Recently, huge efforts have been carried out to propose new eco-friendly alternatives, such as evaluation of plant-borne compounds and sterile insect technique (SIT) programs. Success of SIT is dependent to the ability of sterile males to compete for mates with wild ones. Little is still known about mating behaviour of Aedes males. Most of the studies focus on comparisons of insemination ability in sterilised and wild males, while behavioural analyses of mating behaviour are lacking. Here, I quantified the courtship and mating behaviour of A. albopictus and evaluated how daylight hours affect male mating behaviour and success. A. albopictus males chased females facing them frontally, from behind, or from a lateral side. If the female allowed genital contact, copulation followed. Otherwise, females performed rejection kicks and/or flew away. Thirty-seven percent of males obtained a successful copulation (i.e. sperm transfer occurs), lasting 63 ± 4 s. Unsuccessful copulation (20 % of males) had shorter duration (18 ± 1 s). Successful copulations followed longer male courtships (39 ± 3 s), over courtships preceding unsuccessful copulation (20 ± 2 s) or male's rejection (22 ± 2 s). After copulation, the male rested 7 ± 0.4 s close to the female, then move off. In a semi-natural environment, male mating success was lower in early afternoon, over morning and late afternoon. However, little differences in courtship duration over daylight periods were found. This study adds knowledge to the reproductive behaviour of A. albopictus, which can be used to perform comparisons among courtship and mating ethograms from different mosquito species and strains, allowing monitoring and optimisation of mass rearing quality over time in SIT programs.

  12. Maturation of the immune system of the male house cricket, Acheta domesticus.

    PubMed

    Piñera, Angelica V; Charles, Heather M; Dinh, Tracy A; Killian, Kathleen A

    2013-08-01

    The immune system functions to counteract the wide range of pathogens an insect may encounter during its lifespan, ultimately maintaining fitness and increasing the likelihood of survival to reproductive maturity. In this study, we describe the maturation of the innate immune system of the male house cricket Acheta domesticus during the last two nymphal stages, and during early and late adulthood. Total hemolymph phenoloxidase enzyme activity, lysozyme-like enzyme activity, the number of circulating hemocytes, and encapsulation ability were all determined for each developmental stage or age examined. The number of circulating hemocytes and lysozyme-like enzyme activity were similar for all developmental stages examined. Nymphs and newly molted adult males, however, had significantly lower total phenoloxidase activity than later adult stages, yet nymphs were able to encapsulate a nylon thread just as well as adults. Encapsulation ability would thus appear to be independent of total phenoloxidase activity.

  13. Reproductive state, but not testosterone, reduces immune function in male house sparrows (Passer domesticus).

    PubMed

    Greenman, Chris G; Martin, Lynn B; Hau, Michaela

    2005-01-01

    The immune system requires energetic and nutritional resources to optimally defend organisms against pathogens and parasites. Because resources are typically limited, immune function may require a trade-off with other physiologically demanding activities. Here, we examined whether photoperiodically induced seasonal states (breeding, molting, or nonbreeding) affected the cutaneous immune response of captive male house sparrows (Passer domesticus). To assess immune function in these birds, we injected the mitogen phytohemagglutinin (PHA) into the patagium and measured the resulting wing web swelling. Molting and nonbreeding birds had similar immune responses to PHA injection. However, males in a breeding state showed lower immune responses than both molting and nonbreeding birds even though they did not actually breed. We tested whether this decrease in the PHA swelling response in birds in a breeding state was due to elevated plasma concentrations of testosterone (T) by administering T to birds in a nonbreeding state. Contrary to some evidence in the literature, T did not suppress the response to PHA in house sparrows. Our data show that passerine birds show seasonal modulation in immune function, even in benign environmental conditions. However, even though T is often cited as a strong immunosuppressant, it is not fully responsible for this seasonal modulation.

  14. Housing environment modulates physiological and behavioral responses to anxiogenic stimuli in trait anxiety male rats.

    PubMed

    Ravenelle, R; Santolucito, H B; Byrnes, E M; Byrnes, J J; Donaldson, S T

    2014-06-13

    Environmental enrichment can modulate mild and chronic stress, responses to anxiogenic stimuli as well as drug vulnerability in a number of animal models. The current study was designed to examine the impact of postnatal environmental enrichment on selectively bred 4th generation high- (HAn) and low-anxiety (LAn) male rats. After weaning, animals were placed in isolated (IE), social (SE) and enriched environments (EE) (e.g., toys, wheels, ropes, changed weekly). We measured anxiety-like behavior (ALB) on the elevated plus maze (EPM; trial 1 at postnatal day (PND) 46, trial 2 at PND 63), amphetamine (AMPH) (0.5mg/kg, IP)-induced locomotor behavior, basal and post anxiogenic stimuli changes in (1) plasma corticosterone, (2) blood pressure and (3) core body temperature. Initially, animals showed consistent trait differences on EPM with HAn showing more ALB but after 40 days in select housing, HAn rats reared in an EE showed less ALB and diminished AMPH-induced activity compared to HAn animals housed in IE and SE. In the physiological tests, animals housed in EE showed elevated adrenocortical responses to forced novel object exposure but decreased body temperature and blood pressure changes after an air puff stressor. All animals reared in EE and SE had elevated brain-derived neurotrophic factor (BDNF)-positive cells in the central amygdala (CeA), CA1 and CA2 hippocampal regions and the caudate putamen, but these differences were most pronounced in HAn rats for CeA, CA1 and CA2. Overall, these findings suggest that environmental enrichment offers benefits for trait anxiety rats including a reduction in behavioral and physiological responses to anxiogenic stimuli and AMPH sensitivity, and these responses correlate with changes in BDNF expression in the central amygdala, hippocampus and the caudate putamen.

  15. Histopathological effects of Aspergillus clavatus (Ascomycota: Trichocomaceae) on larvae of the southern house mosquito, Culex quinquefasciatus (Diptera: Culicidae).

    PubMed

    Bawin, Thomas; Seye, Fawrou; Boukraa, Slimane; Zimmer, Jean-Yves; Raharimalala, Fara Nantenaina; Ndiaye, Mady; Compere, Philippe; Delvigne, Frank; Francis, Frédéric

    2016-04-01

    Aspergillus clavatus (Ascomycota: Trichocomaceae) was previously found to be an opportunistic pathogen of mosquitoes (Diptera: Culicidae). In the present study, the mechanism leading to its insecticidal activity was investigated regarding histological damages on Culex quinquefasciatus larvae exposed to A. clavatus spores. Multiple concentration assays using spore suspensions (0.5-2.5 × 10(8) spores ml(-1)) revealed 17.0-74.3 % corrected mortalities after 48 h exposure. Heat-deactivated spores induced a lower mortality compared to nonheated spores suggesting that insecticidal effects are actively exerted. Spore-treated and untreated larvae were prepared for light microscopy as well as for scanning and transmission electron microscopy. Spores failed to adhere to the external body surface (except the mouth parts) of these aquatic immature stages but progressively filled the digestive tract where their metabolism seemed to activate. In parallel, the internal tissues of the larvae, i.e. the midgut wall, the skeletal muscles, and the cuticle-secreting epidermis, were progressively destroyed between 8 and 24 h of exposure. These observations suggest that toxins secreted by active germinating spores of A. clavatus in the digestive tract altered the larval tissues, leading to their necrosis and causing larval death. Fungal proliferation and sporulation then occurred during a saprophytic phase. A. clavatus enzymes or toxins responsible for these pathogenic effects need to be identified in further studies before any use of this fungus in mosquito control.

  16. Extra-pair young in house wren broods are more likely to be male than female

    PubMed Central

    Johnson, L. Scott; Thompson, Charles F.; Sakaluk, Scott K.; Neuhäuser, Markus; Johnson, Bonnie G.P.; Soukup, Sheryl Swartz; Forsythe, Shannon Janota; Masters, Brian S.

    2009-01-01

    Sex-allocation theory predicts that females should preferentially produce offspring of the sex with greater fitness potential. In socially monogamous animal species, extra-pair mating often increases the variance in fitness of sons relative to daughters. Thus, in situations where offspring sired by a female's extra-pair mate(s) will typically have greater fitness potential than offspring sired by the within-pair mate, sex-allocation theory predicts that females will bias the sex of offspring sired by extra-pair mates towards male. We examined the relationship between offspring sex and paternity over six breeding seasons in an Illinois population of the house wren (Troglodytes aedon), a cavity-nesting songbird. Out of the 2345 nestlings that had both sex and paternity assigned, 350 (15%) were sired by extra-pair males. The sex ratio of extra-pair offspring, 0.534, was significantly greater than the sex ratio of within-pair offspring, 0.492, representing an increase of 8.5 per cent in the proportion of sons produced. To our knowledge, this is the first confirmed report of female birds increasing their production of sons in association with extra-pair fertilization. Our results are consistent with the oft-mentioned hypothesis that females engage in extra-pair mating to increase offspring quality. PMID:19324727

  17. Physical interaction is not necessary for the induction of housing-type social buffering of conditioned hyperthermia in male rats.

    PubMed

    Kiyokawa, Yasushi; Kodama, Yuka; Takeuchi, Yukari; Mori, Yuji

    2013-11-01

    In social animals, housing with conspecific animals after a stressful event attenuates the subsequent adverse outcomes due to the event, and this has been called housing-type social buffering. We have previously found that housing-type social buffering attenuates the enhancement of hyperthermia and Fos expression in the paraventricular nucleus of the hypothalamus that occurs in response to an aversive conditioned stimulus in male rats. Here, we analyzed the role of physical interactions during social housing in the induction of housing-type social buffering. When a fear-conditioned subject was alone after the conditioning and then exposed to the conditioned stimulus, it showed behavioral, autonomic, and neural stress responses. However, social housing, during which physical interactions were prevented by wire mesh, attenuated these autonomic and neural stress responses, as has been seen in previous studies. These results suggested that physical interaction was not necessary for the induction of housing-type social buffering. With this social cohabitation model, we then found that social cohabitation increased Fos expression in the posterior complex of the anterior olfactory nucleus of the fear-conditioned subject. Social cohabitation also increased Fos expression in 11 brain regions, including the prefrontal cortex, the nucleus accumbens, the bed nucleus of the stria terminalis, and the medial, lateral, basal, and cortical amygdala. These results provide information about the neural mechanisms that induce housing-type social buffering.

  18. Mosquito Control

    MedlinePlus

    Jump to main content US EPA United States Environmental Protection Agency Search Search Share Facebook Twitter Google+ Pinterest Contact Us Mosquito Control About Mosquitoes General Information Life ...

  19. Two step male release strategy using transgenic mosquito lines to control transmission of vector-borne diseases.

    PubMed

    Carvalho, Danilo Oliveira; Costa-da-Silva, André Luis; Lees, Rosemary Susan; Capurro, Margareth Lara

    2014-04-01

    Mosquitoes are responsible for the transmission of pathogens that cause devastating human diseases such as malaria and dengue. The current increase in mean global temperature and changing sea level interfere with precipitation frequency and some other climatic conditions which, in general, influence the rate of development of insects and etiologic agents causing acceleration as the temperature rises. The most common strategy employed to combat target mosquito species is the Integrated Vector Management (IVM), which comprises the use of multiple activities and various approaches to preventing the spread of a vector in infested areas. IVM programmes are becoming ineffective; and the global scenario is threatening, requiring new interventions for vector control and surveillance. Not surprisingly, there is a growing need to find alternative methods to combat the mosquito vectors. The possibility of using transgenic mosquitoes to fight against those diseases has been discussed over the last two decades and this use of transgenic lines to suppress populations or to replace them is still under investigation through field and laboratory trials. As an alternative, the available transgenic strategies could be improved by coupling suppression and substitution strategies. The idea is to first release a suppression line to significantly reduce the wild population, and once the first objective is reached a second release using a substitution line could be then performed. Examples of targeting this approach against vectors of malaria and dengue are discussed.

  20. Effect of Male House Mouse Pheromone Components on Behavioral Responses of Mice in Laboratory and Field Experiments.

    PubMed

    Musso, Antonia E; Gries, Regine; Zhai, Huimin; Takács, Stephen; Gries, Gerhard

    2017-03-01

    Urine of male house mice, Mus musculus, is known to have primer pheromone effects on the reproductive physiology of female mice. Urine-mediated releaser pheromone effects that trigger certain behavioral responses are much less understood, and no field studies have investigated whether urine deposits by male or female mice, or synthetic mouse pheromone, increase trap captures of mice. In field experiments, we baited traps with bedding soiled with urine and feces of caged female or male mice, and recorded captures of mice in these and in control traps containing clean bedding. Traps baited with female bedding preferentially captured adult males, whereas traps baited with male bedding preferentially captured juvenile and adult females, indicating the presence of male- and female-specific sex pheromones in soiled bedding. Analyses of headspace volatiles emanating from soiled bedding by gas chromatography/mass spectrometry revealed that 3,4-dehydro-exo-brevicomin (DEB) was seven times more prevalent in male bedding and that 2-sec-butyl-4,5-dihydrothiazole (DHT) was male-specific. In a follow-up field experiment, traps baited with DEB and DHT captured 4 times more female mice than corresponding control traps, thus indicating that DEB and DHT are sex attractant pheromone components of house mouse males. Our study provides impetus to identify the sex attractant pheromone of female mice, and to develop synthetic mouse pheromone as a lure to enhance the efficacy of trapping programs for mouse control.

  1. Molecular structure of the prothoracicotropic hormone gene in the northern house mosquito, Culex pipiens, and its expression analysis in association with diapause and blood feeding.

    PubMed

    Zhang, Q; Denlinger, D L

    2011-04-01

    We cloned the gene that encodes prothoracicotropic hormone (PTTH) in the northern house mosquito, Culex pipiens, and investigated its expression profile in short-day (diapause-destined) and long-day (nondiapause-destined) individuals from the fourth-instar larval stage to 2 months of adulthood, as well as after a blood meal. The deduced C. pipiens PTTH (Cupip-PTTH) amino acid sequence contains seven cysteines with a specific spacing pattern. Sequence alignment suggests that Cupip-PTTH is 23% identical to Drosophila melanogaster PTTH, but is ≥59% identical to the PTTHs of other mosquitoes. Cupip-PTTH has structural characteristics similar to those of Bombyx mori PTTH and some vertebrate nerve growth factors with cysteine-knot motifs. PTTH transcripts exhibit a daily cycling profile during the final (fourth) larval instar, with peak abundance occurring late in the scotophase. The fourth-larval instar stage is one day longer in short-day larvae than in long-day larvae, resulting in larger larvae and adults. This additional day of larval development is associated with one extra PTTH cycle. No cycling was observed in pupae, but PTTH transcripts were slightly higher in short-day pupae than in long-day pupae throughout much of the pupal stage. PTTH expression persisted at a nearly constant level in diapausing adult females for the first month but then dropped by ∼50%, while expression decreased at the beginning of adulthood in nondiapausing females and then remained at a low level as long as the females were denied a blood meal. However, when nondiapausing females were offered a blood meal, PTTH transcripts rose approximately 7 fold in 2 h and remained elevated for 24 h. A few diapausing females (∼10%) will take a blood meal when placed in close proximity to a host, but much of the blood is ejected and such meals do not result in mature eggs. Yet, elevated PTTH mRNA expression was also observed in diapausing females that were force fed. Our results thus point to

  2. Captive-housed male cheetahs (Acinonyx jubatus soemmeringii) form naturalistic coalitions: measuring associations and calculating chance encounters.

    PubMed

    Chadwick, Carly L; Rees, Paul A; Stevens-Wood, Barry

    2013-01-01

    Cheetahs are known to reproduce poorly in captivity and research suggests that the reasons for this are behavioral, rather than physiological. In the wild, male cheetahs remain in stable groups, or coalitions, throughout their lifetime. Appropriate social group housing is important in enhancing welfare and reproductive success in captivity and this study examined the effect of changes in social group composition on the behavior of four male cheetahs: two siblings and two half siblings. During the study, the cheetahs were housed both in pairs and as a group of four, before one male was relocated. The remaining cheetahs were then housed in a trio. Affiliative behaviors were frequently shown within pairs and overt aggression was seldom observed. Association indices were calculated for each cheetah pair and corrected for chance encounters based on data generated from a Monte Carlo simulation. The indices showed that two coalitions existed before the relocated male departed. Following the relocation of one of the half siblings, the remaining cheetahs appeared to form a coalition of three, as the indices of association between the unrelated male and the siblings increased and allogrooming between unrelated individuals was observed. The findings of this study indicate that natural social groupings of male cheetahs can be successfully replicated in captivity, which could potentially improve the chances of reproductive success when they are introduced to female cheetahs.

  3. Daily rhythms of behavioral and hormonal patterns in male dromedary camels housed in boxes

    PubMed Central

    Aubè, Lydiane; Fatnassi, Meriem; Monaco, Davide; Khorchani, Touhami; Lacalandra, Giovanni Michele; Hammadi, Mohamed

    2017-01-01

    Background Daily rhythmicity has been observed for a number of hormonal and behavioral variables in mammals. It can be entrained by several external factors, such as light-dark cycle and scheduled feeding. In dromedary camels, daily rhythmicity has been documented only for melatonin secretion and body temperature. In this study, the daily rhythmicity of behavioral repertoire, cortisol and testosterone levels was investigated in captive male camels. Methods Six clinically healthy male dromedary camels (Camelus dromedarius) were used. The animals were housed in single boxes for 24 h daily and fed twice a day. Over a period of 48 h, behavioral observations were made and blood samples taken every two hours. The data were analyzed using diurnality index, conisor analysis and PROC mixed procedure. Results The diurnality index for rumination and lying down was close to 0 (respectively, 0.09 and 0.19), while the indices for stereotypy, standing, feeding and walking were close to 1 (respectively, 0.74, 0.84, 0.92 and 0.85). Cosinor analysis revealed daily rhythmicity for all behaviors and for cortisol levels (acrophase at 12:57) but not for testosterone. Rumination and lying down (inactive behaviors) reached a peak during the scotophase, whereas feeding, walking and stereotypy (active behaviors) reached a peak during the photophase around midday. Cortisol level and expression of stereotypies peaked before and after food distribution and were negatively correlated (r =  − 0.287, P = 0.005). Testosterone levels and expression of sexual behaviors were stimulated by the visual and olfactory contacts with the females and were positively correlated (r = 0.164, P = 0.040). Testosterone was also negatively correlated with cortisol (r =  − 0.297; P = 0.003). Discussion These preliminary results provided new knowledge about the daily rhythm of behaviors in camels housed in boxes, suggesting that camels exhibit diurnal behavior pattern in the maintenance conditions

  4. Crystal and solution structures of an odorant-binding protein from the southern house mosquito complexed with an oviposition pheromone

    SciTech Connect

    Mao, Yang; Xu, Xianzhong; Xu, Wei; Ishida, Yuko; Leal, Walter S.; Ames, James B.; Clardy, Jon

    2010-11-15

    Culex mosquitoes introduce the pathogens responsible for filariasis, West Nile virus, St. Louis encephalitis, and other diseases into humans. Currently, traps baited with oviposition semiochemicals play an important role in detection efforts and could provide an environmentally friendly approach to controlling their populations. The odorant binding proteins (OBPs) in the female's antenna play a crucial, if yet imperfectly understood, role in sensing oviposition cues. Here, we report the X-ray crystallography and NMR 3D structures of OBP1 for Culex quinquefasciatus (CquiOBP1) bound to an oviposition pheromone (5R,6S)-6-acetoxy-5-hexadecanolide (MOP). In both studies, CquiOBP1 had the same overall six-helix structure seen in other insect OBPs, but a detailed analysis revealed an important previously undescribed feature. There are two models for OBP-mediated signal transduction: (i) direct release of the pheromone from an internal binding pocket in a pH-dependent fashion and (ii) detection of a pheromone-induced conformational change in the OBP {center_dot} pheromone complex. Although CquiOBP1 binds MOP in a pH-dependent fashion, it lacks the C terminus required for the pH-dependent release model. This study shows that CquiOBP binds MOP in an unprecedented fashion using both a small central cavity for the lactone head group and a long hydrophobic channel for its tail.

  5. Synthesis, depletion and cell-type expression of a protein from the male accessory glands of the dengue vector mosquito Aedes aegypti

    PubMed Central

    Alfonso-Parra, Catalina; Avila, Frank W.; Deewatthanawong, Prasit; Sirot, Laura K.; Wolfner, Mariana F.; Harrington, Laura C.

    2014-01-01

    Aedes aegypti males transfer sperm and seminal fluid proteins (Sfps), primarily produced by male accessory glands (AGs), to females during mating. When collectively injected or transplanted into females, AG tissues and/or seminal fluid homogenates have profound effects on Aedes female physiology and behavior. To identify targets and design new strategies for vector control, it is important to understand the biology of the AGs. Thus, we examined characteristics of AG secretion and development in Ae. aegypti, using the AG-specific seminal fluid protein, AAEL010824, as a marker. We showed that AAEL010824 is first detectable by 12h post-eclosion, and increases in amount over the first 3 days of adult life. We then showed that the amount of AAEL0010824 in the AG decreases after mating, with each successive mating depleting it further; by 5 successive matings with no time for recovery, its levels are very low. AAEL010824 levels in a depleted male are replenished by 48hr post-mating. In addition to examining the level of AAEL010824 protein, we also characterized the expression of its gene. We did this by making a transgenic mosquito line that carries an Enhanced Green Fluorescence Protein (EGFP) fused to the AAEL0010824 promoter that we defined here. We showed that AAEL010824 is expressed in the anterior cells of the accessory glands, and that its RNA levels also respond to mating. In addition to further characterizing AAEL010824 expression, our results with the EGFP fusion provide a promoter for driving AG expression. By providing this information on the biology of an important male reproductive tissue and the production of one of its seminal proteins, our results lay the foundation for future work aimed at identifying novel targets for mosquito population control. PMID:25107876

  6. How Diverse Detrital Environments Influence Nutrient Stoichiometry between Males and Females of the Co-Occurring Container Mosquitoes Aedes albopictus, Ae. aegypti, and Culex quinquefasciatus

    PubMed Central

    Yee, Donald A.; Kaufman, Michael G.; Ezeakacha, Nnaemeka F.

    2015-01-01

    Allocation patterns of carbon and nitrogen in animals are influenced by food quality and quantity, as well as by inherent metabolic and physiological constraints within organisms. Whole body stoichiometry also may vary between the sexes who differ in development rates and reproductive allocation patterns. In aquatic containers, such as tree holes and tires, detrital inputs, which vary in amounts of carbon and nitrogen, form the basis of the mosquito-dominated food web. Differences in development times and mass between male and female mosquitoes may be the result of different reproductive constraints, which could also influence patterns of nutrient allocation. We examined development time, survival, and adult mass for males and females of three co-occurring species, Aedes albopictus, Ae. aegypti, and Culex quinquefasciatus, across environments with different ratios of animal and leaf detritus. We quantified the contribution of detritus to biomass using stable isotope analysis and measured tissue carbon and nitrogen concentrations among species and between the sexes. Development times were shorter and adults were heavier for Aedes in animal versus leaf-only environments, whereas Culex development times were invariant across detritus types. Aedes displayed similar survival across detritus types whereas C. quinquefasciatus showed decreased survival with increasing leaf detritus. All species had lower values of 15N and 13C in leaf-only detritus compared to animal, however, Aedes generally had lower tissue nitrogen compared to C. quinquefasciatus. There were no differences in the C:N ratio between male and female Aedes, however, Aedes were different than C. quinquefasciatus adults, with male C. quinquefasciatus significantly higher than females. Culex quinquefasciatus was homeostatic across detrital environments. These results allow us to hypothesize an underlying stoichiometric explanation for the variation in performance of different container species under similar

  7. Synthesis, depletion and cell-type expression of a protein from the male accessory glands of the dengue vector mosquito Aedes aegypti.

    PubMed

    Alfonso-Parra, Catalina; Avila, Frank W; Deewatthanawong, Prasit; Sirot, Laura K; Wolfner, Mariana F; Harrington, Laura C

    2014-11-01

    Aedes aegypti males transfer sperm and seminal fluid proteins (Sfps), primarily produced by male accessory glands (AGs), to females during mating. When collectively injected or transplanted into females, AG tissues and/or seminal fluid homogenates have profound effects on Aedes female physiology and behavior. To identify targets and design new strategies for vector control, it is important to understand the biology of the AGs. Thus, we examined characteristics of AG secretion and development in A. aegypti, using the AG-specific seminal fluid protein, AAEL010824, as a marker. We showed that AAEL010824 is first detectable by 12h post-eclosion, and increases in amount over the first 3 days of adult life. We then showed that the amount of AAEL0010824 in the AG decreases after mating, with each successive mating depleting it further; by 5 successive matings with no time for recovery, its levels are very low. AAEL010824 levels in a depleted male are replenished by 48 h post-mating. In addition to examining the level of AAEL010824 protein, we also characterized the expression of its gene. We did this by making a transgenic mosquito line that carries an Enhanced Green Fluorescence Protein (EGFP) fused to the AAEL0010824 promoter that we defined here. We showed that AAEL010824 is expressed in the anterior cells of the accessory glands, and that its RNA levels also respond to mating. In addition to further characterizing AAEL010824 expression, our results with the EGFP fusion provide a promoter for driving AG expression. By providing this information on the biology of an important male reproductive tissue and the production of one of its seminal proteins, our results lay the foundation for future work aimed at identifying novel targets for mosquito population control.

  8. How Diverse Detrital Environments Influence Nutrient Stoichiometry between Males and Females of the Co-Occurring Container Mosquitoes Aedes albopictus, Ae. aegypti, and Culex quinquefasciatus.

    PubMed

    Yee, Donald A; Kaufman, Michael G; Ezeakacha, Nnaemeka F

    2015-01-01

    Allocation patterns of carbon and nitrogen in animals are influenced by food quality and quantity, as well as by inherent metabolic and physiological constraints within organisms. Whole body stoichiometry also may vary between the sexes who differ in development rates and reproductive allocation patterns. In aquatic containers, such as tree holes and tires, detrital inputs, which vary in amounts of carbon and nitrogen, form the basis of the mosquito-dominated food web. Differences in development times and mass between male and female mosquitoes may be the result of different reproductive constraints, which could also influence patterns of nutrient allocation. We examined development time, survival, and adult mass for males and females of three co-occurring species, Aedes albopictus, Ae. aegypti, and Culex quinquefasciatus, across environments with different ratios of animal and leaf detritus. We quantified the contribution of detritus to biomass using stable isotope analysis and measured tissue carbon and nitrogen concentrations among species and between the sexes. Development times were shorter and adults were heavier for Aedes in animal versus leaf-only environments, whereas Culex development times were invariant across detritus types. Aedes displayed similar survival across detritus types whereas C. quinquefasciatus showed decreased survival with increasing leaf detritus. All species had lower values of 15N and 13C in leaf-only detritus compared to animal, however, Aedes generally had lower tissue nitrogen compared to C. quinquefasciatus. There were no differences in the C:N ratio between male and female Aedes, however, Aedes were different than C. quinquefasciatus adults, with male C. quinquefasciatus significantly higher than females. Culex quinquefasciatus was homeostatic across detrital environments. These results allow us to hypothesize an underlying stoichiometric explanation for the variation in performance of different container species under similar

  9. Larvicidal activity of selected plant hydrodistillate extracts against the house mosquito, Culex pipiens, a West Nile virus vector.

    PubMed

    Cetin, Huseyin; Yanikoglu, Atila; Cilek, James E

    2011-04-01

    The larvicidal activity of hydrodistillate extracts from Chrysanthemum coronarium L., Hypericum scabrum L., Pistacia terebinthus L. subsp. palaestina (Boiss.) Engler, and Vitex agnus castus L. was investigated against the West Nile vector, Culex pipiens L. (Diptera: Culicidae). Yield and identification of the major essential oils from each distillation was determined by GC-MS analyses. The major essential oil component for each plant species was as follows: α-pinene for P. terebinthus palaestina, and H. scabrum (45.3% and 42.3%, respectively), trans-β-caryophyllene for V. agnus castus (22.1%), and borneol for C. coronarium (20.9%). A series of distillate concentrations from these plants (that ranged from 1 ppm to 500 ppm, depending on plant species) were assessed against late third to early fourth C. pipiens larvae at 1, 6, and 24 h posttreatment. In general, larval mortality to water treated with a distillate increased as concentration and exposure time increased. H. scabrum and P. terebinthus palaestina were most effective against the mosquito larvae and both produced 100% mortality at 250 ppm at 24-h continuous exposure compared with the other plant species. Larval toxicity of the distillates at 24 h (LC(50) from most toxic to less toxic) was as follows: P. terebinthus palaestina (59.2 ppm) > H. scabrum (82.2 ppm) > V. agnus castus (83.3 ppm) > C. coronarium (311.2 ppm). But when LC(90) values were compared, relative toxicity ranking changed as follows: H. scabrum (185.9 ppm) > V. agnus castus (220.7 ppm) > P. terebinthus palaestina (260.7 ppm) > C. coronarium (496.3 ppm). Extracts of native Turkish plants continue to provide a wealth of potential sources for biologically active agents that may be applied against arthropod pests of man and animals.

  10. Pathways of Expansion and Multiple Introductions Illustrated by Large Genetic Differentiation Among Worldwide Populations of the Southern House Mosquito

    DTIC Science & Technology

    2006-01-01

    in each PCI~. To pre\\’Cnl contamination with male DNf\\. female 010- domens were not used. The DNA cxtraction and peR prepa· rations invulving Ihe...mixes of males and females . Fur- IheHllor.... ,IS mentioned before, the microsalcllite loci lIsed in Ihi, stud\\’ arc not scx·linked. \\"el1 ;~fter we...IfHJ If~r.il·llt· PATHWAYS OF EXPANSION AND MULTIPLE INTRODUCTIONS ILLUSTRATED BY LARGE GENETIC DIFFERENTIATION AMONG WORLDWIDE POPULATIONS OF THE

  11. Evaluation of sexual behavior of housed male camels (Camelus dromedarius) through female parades: correlation with climatic parameters.

    PubMed

    Fatnassi, Meriem; Padalino, Barbara; Monaco, Davide; Khorchani, Touhami; Lacalandra, Giovanni Michele; Hammadi, Mohamed

    2014-02-01

    Camels are seasonal breeders, and their sexual behavior is influenced by environmental conditions, but the relationship between climatic factors and sexual behavior has been poorly described in the available literature. Nowadays, the male camel living habit is shifting towards captivity; thus, this study was carried out to evaluate the sexual behavior of housed male dromedary camel through female's parades and to correlate it with climatic parameters. Four housed sires, reared for semen collection, and one dam were used and the trial lasted 8 weeks, considering the first week as control. Six days per week and during evenings, the female was brought near each males' boxes, while two observers filled a behavioral sampling ethogram and scored the male sexual behavior. After this parade, blood samples were taken from the female to evaluate the estradiol concentration. In addition, the following meteorological parameters were recorded, everyday, at 9:00 a.m. and 19:00 p.m.: pressure, wind, temperature, humidity, and H-index. The correlation between sexual behavioral score and female estradiol concentration and climate parameters was analyzed. All the behavioral parameters showed a significant upward trend; female estradiol concentration varied during the period and picked at week 5. Male sexual behavior was negatively correlated with morning H-index, wind, and temperature, and positively correlated with pressure and evening humidity, whereas it was not correlated with estrogen. In conclusion, female parade was a successful method to evaluate and stimulate the occurrence of housed male dromedary camel sexual activity that resulted to be negatively affected by hot temperature, warm wind, and lack of rain.

  12. Effect of different management systems on rutting behavior and behavioral repertoire of housed Maghrebi male camels (Camelus dromedarius).

    PubMed

    Fatnassi, Meriem; Padalino, Barbara; Monaco, Davide; Aubé, Lydiane; Khorchani, Touhami; Lacalandra, Giovanni Michele; Mohamed, Hammadi

    2014-06-01

    Camel management has been changing in recent years from an extensive to a semi-intensive or intensive system, particularly for breeding bulls and dairy dromedary camels. Captivity may affect animal welfare, and low libido is the major complaint for housed breeding bulls. Since welfare status could also affect reproductive performance, the aim of this study was to evaluate different management practices on behavior, particularly on sexual behavior, and to identify some behavioral needs of male dromedary camels reared for semen collection. The effects of the following management systems on their behavior were compared: (i) traditional: housing in a single stall for 24 h (H24), (ii) housing in a single stall for 23 h with 1 h free in the paddock (H23), and (iii) housing in a single stall for 22 h and 30 min with 1 h paddock time and 30 min exposure to a female camel herd (ExF). During the trial, blood cortisol concentrations were assessed and camels were filmed daily for 30 min in the mornings and during a female passage in the evenings. Videos were analyzed in order to fill out a focal sampling ethogram and to score sexual behavior. As a result, there were no differences between the H24 and H23 systems, whereas ExF had a significant positive impact on their sexual behavior score and behavioral repertoire, further reducing cortisol levels. Overall, it seems that male dromedary camel welfare status improves when their behavioral needs for social interaction and movement are satisfied.

  13. Temporal gene expression profiles of pre blood-fed adult females Immediately following eclosion in the southern house mosquito culex quinquefasciatus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prior to acquisition of the first host blood meal, the anautogenous mosquito Culex quinquefasciatus requires a period of time in order to prepare for the blood feeding and, later, vitellogenesis. In the current study, we conducted whole transcriptome analyses of adult female Culex mosquitoes to iden...

  14. Individual housing does not influence the adaptation of the pituitary-adrenal axis and other physiological variables to chronic stress in adult male rats.

    PubMed

    Giralt, M; Armario, A

    1989-03-01

    Although the influence of housing conditions on the physiological response to stress has been extensively studied for several years, no attempts have been made to investigate the effect of this variable on the capacity for adaptation to chronic stress. To this end, adult male rats were housed either individually or in groups of four per cage and subjected to 2 hr of daily immobilization stress for 14 days. Housing did not influence any of the physiological variables measured either in unstressed or in stressed rats except the corticosterone response to stress which was higher in individually housed rats. Of the behavioral measures, individual housing significantly decreased defecation rate in the novel environment. Other behavioral measures were not influenced by housing. Chronic stress significantly reduced ambulation but no significant interaction between housing and chronic stress was observed. Taken together, these data indicate that a short period of individual housing did not affect the physiological and behavioral consequences of repeated exposure to chronic stress.

  15. Mice do not habituate to metabolism cage housing--a three week study of male BALB/c mice.

    PubMed

    Kalliokoski, Otto; Jacobsen, Kirsten R; Darusman, Huda S; Henriksen, Trine; Weimann, Allan; Poulsen, Henrik E; Hau, Jann; Abelson, Klas S P

    2013-01-01

    The metabolism cage is a barren, non-enriched, environment, combining a number of recognized environmental stressors. We investigated the ability of male BALB/c mice to acclimatize to this form of housing. For three weeks markers of acute and oxidative stress, as well as clinical signs of abnormality were monitored. Forced swim tests were conducted to determine whether the animals experienced behavioral despair and the serotonergic integrity was tested using an 8-OH-DPAT challenge. The metabolism cage housed mice excreted approximately tenfold higher amounts of corticosterone metabolites in feces throughout the study when compared to controls. Urinary biomarkers confirmed that these mice suffered from elevated levels of oxidative stress, and increased creatinine excretions indicated increased muscle catabolism. Changes in the core body temperature (stress-induced hyperthermia) and the fur state of the mice also indicated impaired well-being in the metabolism cage housed mice. However, monitoring body weight and feed intake was found misleading in assessing the wellbeing of mice over a longer time course, and the forced swim test was found poorly suited for studying chronic stress in mice in the present setup. In conclusion, the mice were found not to acclimatize to the metabolism cages whereby concern for animal welfare would dictate that mice should be housed in this way for as short periods as possible. The elevated degree of HPA axis activity, oxidative stress, and increased overall metabolism warrant caution when interpreting data obtained from metabolism cage housed mice, as their condition cannot be considered representative of a normal physiology.

  16. Suppression of a Field Population of Aedes aegypti in Brazil by Sustained Release of Transgenic Male Mosquitoes.

    PubMed

    Carvalho, Danilo O; McKemey, Andrew R; Garziera, Luiza; Lacroix, Renaud; Donnelly, Christl A; Alphey, Luke; Malavasi, Aldo; Capurro, Margareth L

    2015-01-01

    The increasing burden of dengue, and the relative failure of traditional vector control programs highlight the need to develop new control methods. SIT using self-limiting genetic technology is one such promising method. A self-limiting strain of Aedes aegypti, OX513A, has already reached the stage of field evaluation. Sustained releases of OX513A Ae. aegypti males led to 80% suppression of a target wild Ae. aegypti population in the Cayman Islands in 2010. Here we describe sustained series of field releases of OX513A Ae. aegypti males in a suburb of Juazeiro, Bahia, Brazil. This study spanned over a year and reduced the local Ae. aegypti population by 95% (95% CI: 92.2%-97.5%) based on adult trap data and 81% (95% CI: 74.9-85.2%) based on ovitrap indices compared to the adjacent no-release control area. The mating competitiveness of the released males (0.031; 95% CI: 0.025-0.036) was similar to that estimated in the Cayman trials (0.059; 95% CI: 0.011-0.210), indicating that environmental and target-strain differences had little impact on the mating success of the OX513A males. We conclude that sustained release of OX513A males may be an effective and widely useful method for suppression of the key dengue vector Ae. aegypti. The observed level of suppression would likely be sufficient to prevent dengue epidemics in the locality tested and other areas with similar or lower transmission.

  17. Suppression of a Field Population of Aedes aegypti in Brazil by Sustained Release of Transgenic Male Mosquitoes

    PubMed Central

    Garziera, Luiza; Lacroix, Renaud; Donnelly, Christl A.; Alphey, Luke; Malavasi, Aldo; Capurro, Margareth L.

    2015-01-01

    The increasing burden of dengue, and the relative failure of traditional vector control programs highlight the need to develop new control methods. SIT using self-limiting genetic technology is one such promising method. A self-limiting strain of Aedes aegypti, OX513A, has already reached the stage of field evaluation. Sustained releases of OX513A Ae. aegypti males led to 80% suppression of a target wild Ae. aegypti population in the Cayman Islands in 2010. Here we describe sustained series of field releases of OX513A Ae. aegypti males in a suburb of Juazeiro, Bahia, Brazil. This study spanned over a year and reduced the local Ae. aegypti population by 95% (95% CI: 92.2%-97.5%) based on adult trap data and 81% (95% CI: 74.9-85.2%) based on ovitrap indices compared to the adjacent no-release control area. The mating competitiveness of the released males (0.031; 95% CI: 0.025-0.036) was similar to that estimated in the Cayman trials (0.059; 95% CI: 0.011 – 0.210), indicating that environmental and target-strain differences had little impact on the mating success of the OX513A males. We conclude that sustained release of OX513A males may be an effective and widely useful method for suppression of the key dengue vector Ae. aegypti. The observed level of suppression would likely be sufficient to prevent dengue epidemics in the locality tested and other areas with similar or lower transmission. PMID:26135160

  18. Upregulation of two actin genes and redistribution of actin during diapause and cold stress in the northern house mosquito, Culex pipiens.

    PubMed Central

    Kim, Mijung; Robich, Rebecca M.; Rinehart, Joseph P.; Denlinger, David L.

    2007-01-01

    Two actin genes cloned from Culex pipiens L. are upregulated during adult diapause. Though actins 1 and 2 were expressed throughout diapause, both genes were most highly expressed early in diapause. These changes in gene expression were accompanied by a conspicuous redistribution of polymerized actin that was most pronounced in the midguts of diapausing mosquitoes that were exposed to low temperature. In nondiapausing mosquitoes reared at 25°C and in diapausing mosquitoes reared at 18°C, polymerized actin was clustered at high concentrations at the intersections of the muscle fibers that form the midgut musculature. When adults 7–10 days post-eclosion were exposed to low temperature (-5°C for 12h), the polymerized actin was evenly distributed along the muscle fibers in both nondiapausing and diapausing mosquitoes. Exposure of older adults (1month post-eclosion) to low temperature (−5°C for 12h) elicited an even greater distribution of polymerized actin, an effect that was especially pronounced in diapausing mosquitoes. These changes in gene expression and actin distribution suggest a role for actins in enhancing survival of diapausing adults during the low temperatures of winter by fortification of the cytoskeleton. PMID:17078965

  19. The effects of group and single housing and automated animal monitoring on urinary corticosterone levels in male C57BL/6 mice.

    PubMed

    Kamakura, Remi; Kovalainen, Miia; Leppäluoto, Juhani; Herzig, Karl-Heinz; Mäkelä, Kari A

    2016-02-01

    Mice are used extensively in physiological research. Automated home-cage systems have been developed to study single-housed animals. Increased stress by different housing conditions might affect greatly the results when investigating metabolic responses. Urinary corticosteroid concentration is considered as a stress marker. The aim of the study was to compare the effects of different housing conditions and an automated home-cage system with indirect calorimetry located in an environmental chamber on corticosterone levels in mice. Male mice were housed in different conditions and in automated home-cage system to evaluate the effects of housing and measuring conditions on urine corticosterone levels. Corticosterone levels in single-housed mice in the laboratory animal center were consistently lower compared with the group-housed mice. Single-housed mice in a separate, small animal unit showed a rise in their corticosterone levels a day after they were separated to their individual cages, which decreased during the following 2 days. The corticosterone levels of group-housed mice in the same unit were increased during the first 7 days and then decreased. On day 7, the corticosterone concentrations of group-housed mice were significantly higher compared with that of single-housed mice, including the metabolic measurement protocol. In conclusion, single housing caused less stress when compared with group-housed mice. In addition, the urine corticosterone levels were decreased in single-housed mice before the metabolic measurement started. Thus, stress does not affect the results when utilizing the automated system for measuring metabolic parameters like food and water intake and calorimetry.

  20. Meiotic sex chromosome inactivation is disrupted in sterile hybrid male house mice.

    PubMed

    Campbell, Polly; Good, Jeffrey M; Nachman, Michael W

    2013-03-01

    In male mammals, the X and Y chromosomes are transcriptionally silenced in primary spermatocytes by meiotic sex chromosome inactivation (MSCI) and remain repressed for the duration of spermatogenesis. Here, we test the longstanding hypothesis that disrupted MSCI might contribute to the preferential sterility of heterogametic hybrid males. We studied a cross between wild-derived inbred strains of Mus musculus musculus and M. m. domesticus in which sterility is asymmetric: F1 males with a M. m. musculus mother are sterile or nearly so while F1 males with a M. m. domesticus mother are normal. In previous work, we discovered widespread overexpression of X-linked genes in the testes of sterile but not fertile F1 males. Here, we ask whether this overexpression is specifically a result of disrupted MSCI. To do this, we isolated cells from different stages of spermatogenesis and measured the expression of several genes using quantitative PCR. We found that X overexpression in sterile F1 primary spermatocytes is coincident with the onset of MSCI and persists in postmeiotic spermatids. Using a series of recombinant X genotypes, we then asked whether X overexpression in hybrids is controlled by cis-acting loci across the X chromosome. We found that it is not. Instead, one large interval in the proximal portion of the M. m. musculus X chromosome is associated with both overexpression and the severity of sterility phenotypes in hybrids. These results demonstrate a strong association between X-linked hybrid male sterility and disruption of MSCI and suggest that trans-acting loci on the X are important for the transcriptional regulation of the X chromosome during spermatogenesis.

  1. On-ground housing in “Mice Drawer System” (MDS) cage affects locomotor behaviour but not anxiety in male mice

    NASA Astrophysics Data System (ADS)

    Simone, Luciano; Bartolomucci, Alessandro; Palanza, Paola; Parmigiani, Stefano

    2008-03-01

    In the present study adult male mice were housed for 21 days in a housing modules of the Mice Drawer System (MDS). MDS is the facility that will support the research on board the International Space Station (ISS). Our investigation focused on: circadian rhythmicity of wide behavioural categories such as locomotor activity, food intake/drinking and resting; emotionality in the elevated plus maze (EPM); body weight. Housing in the MDS determined a strong up-regulation of activity and feeding behaviour and a concomitant decrease in inactivity. Importantly, housing in the MDS disrupted circadian rhythmicity in mice and also determined a decrease in body weight. Finally, when mice were tested in the EPM a clear hyperactivity (i.e. increased total transitions) was found, while no evidence for altered anxiety was detected. In conclusion, housing adult male mice in the MDS housing modules may affect their behaviour, circadian rhythmicity while having no effect on anxiety. It is suggested that to allow adaptation to the peculiar housing allowed by MDS a longer housing duration is needed.

  2. Behavioral and Biological Effects of Housing Conditions and Stress in Male Rats - Relevance to Heart Disease

    DTIC Science & Technology

    2006-08-01

    investigators have defined adolescence in the rat as 21-42 days old and up to day 55 for male rats (Spear & Brake , 1983; Ojeda & Urbanski, 1994; Faraday...based on Elliott et al. (2003) as recommended by R. Virmani (1999). Calipers (10mm) were used to measure the length of each heart form base to apex...experiment. First, the heart measures included in the experiment were simple and were made with 10 mm calipers . Electronic digital calipers would

  3. Effects of oral and intravenous administration of buspirone on food-cocaine choice in socially housed male cynomolgus monkeys.

    PubMed

    Czoty, Paul W; Nader, Michael A

    2015-03-13

    Drugs acting at D3 dopamine receptors have been suggested as medications for cocaine dependence. These experiments examined the effects of intravenously and orally administered buspirone, a D2-like receptor antagonist with high affinity for D3 and D4 receptors, on the relative reinforcing strength of cocaine in group-housed male cynomolgus monkeys. Use of socially housed monkeys permitted the assessment of whether social status, known to influence D2-like receptor availability, modulates the behavioral effects of buspirone. Buspirone was administered acutely to monkeys self-administering cocaine under a food-drug choice procedure in which a cocaine self-administration dose-effect curve was determined daily. When administered by either route, buspirone significantly decreased cocaine choice in dominant-ranked monkeys. In subordinate monkeys, however, i.v. buspirone was ineffective on average, and oral buspirone increased choice of lower cocaine doses. The effects of buspirone only differed according to route of administration in subordinate monkeys. Moreover, it is noteworthy that the effects of buspirone were similar to those of the D3 receptor-selective antagonist PG01037 and qualitatively different than those of less selective drugs that act at D2-like or serotonin (5-HT)1A receptors, suggesting a D3 and possibly D4 receptor mechanism of action for buspirone. Taken together, the data support the utility of drugs targeting D3/D4 receptors as potential treatments for cocaine addiction, particularly in combination with enriching environmental manipulations.

  4. Impact of the number of Robertsonian chromosomes on germ cell death in wild male house mice.

    PubMed

    Medarde, Nuria; Merico, Valeria; López-Fuster, M José; Zuccotti, Maurizio; Garagna, Silvia; Ventura, Jacint

    2015-06-01

    Previous studies in the house mouse have shown that the presence of Robertsonian (Rb) metacentric chromosomes in heterozygous condition affects the process of spermatogenesis. This detrimental effect mainly depends on the number of metacentrics involved and the complexity of the resulting meiotic figures. In this study, we aimed at elucidating the relationship between the chromosomal composition and spermatogenesis impairment in mice present in an area of chromosomal polymorphism (the so-called Barcelona system BRbS) in which Rb mice are surrounded by all acrocentric animals, no established metacentric races are present and the level of structural heterozygosity is relatively low. Using the terminal deoxinucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assay, we report higher frequency of apoptotic spermatogenetic cells in mice carrying six pairs of metacentrics at the homozygous state than in those carrying two or three fusions at the heterozygous state. Specifically, we detected a higher frequency of TUNEL-positive (T+) tubules and of T+ cells per tubule cross section and also a lower spermatid/spermatocyte ratio. These results indicate that the number of metacentrics at the homozygous state is more influential in determining apoptotic germ cell death than that of moderate chromosome heterozygosity. The percentage of germ cell death lower than 50 % found in our samples and the geographic distribution of the set of metacentrics within the BRbS indicate that although the spermatogenic alterations detected in this area could act as a partial barrier to gene flow, they are not sufficient to prevent Rb chromosomes from spreading in nature.

  5. Temporal Gene Expression Profiles of Pre Blood-Fed Adult Females Immediately Following Eclosion in the Southern House Mosquito Culex Quinquefasciatus

    PubMed Central

    Reid, William R.; Zhang, Lee; Liu, Nannan

    2015-01-01

    Prior to acquisition of the first host blood meal, the anautogenous mosquito Culex quinquefasciatus requires a period of time in order to prepare for the blood feeding and, later, vitellogenesis. In the current study, we conducted whole transcriptome analyses of adult female Culex mosquitoes to identify genes that may be necessary for both taking of the blood meal, and processing of the blood meal in adult female mosquitoes Cx. quinquefasciatus. We examined temporal expression of genes for the periods of post eclosion and prior to the female freely taking a blood meal. We further evaluated the temporal expression of certain genes for the periods after the taking of a blood meal to identify genes that may be necessary for both the taking of the blood meal, and the processing of the blood meal. We found that adult females required a minimum of 48 h post-eclosion before they freely took their first blood meal. We hypothesized that gene expression signatures were altered in the mosquitoes before blood feeding in preparation for the acquisition of the blood meal through changes in multiple gene expression. To identify the genes involved in the acquisition of blood feeding, we quantified the gene expression levels of adult female Cx. quinquefasciatus using RNA Seq throughout a pre-blooding period from 2 to 72 h post eclosion at 12 h intervals. A total of 325 genes were determined to be differentially-expressed throughout the pre-blooding period, with the majority of differentially-expressed genes occurring between the 2 h and 12 h post-eclosion time points. Among the up-regulated genes were salivary proteins, cytochrome P450s, odorant-binding proteins, and proteases, while the majority of the down-regulated genes were hypothetical or cuticular genes. In addition, Trypsin was found to be up-regulated immediately following blood feeding, while trypsin and chymotrypsin were up-regulated at 48h and 60h post blood-feeding, respectively, suggesting that these proteases are

  6. Homeless female U.S. veterans in a national supported housing program: comparison of individual characteristics and outcomes with male veterans.

    PubMed

    Tsai, Jack; Rosenheck, Robert A; Kane, Vincent

    2014-08-01

    As more women serve in the U.S. military, the proportion of females among homeless veterans is increasing. The current study compares the individual characteristics and 1-year outcomes of homeless female and male veterans in the Housing and Urban Development-Veterans Affairs Supportive Housing (HUD-VASH) program nationally. Administrative data on 43,853 veterans (10.69% females; 89.31% males) referred to HUD-VASH were analyzed for gender differences at baseline and over a 1-year period. Homeless female veterans were younger, had shorter homeless and incarceration histories, and were less likely to have substance use disorders than men. However, despite being less likely to report combat exposure, female veterans were more likely to have posttraumatic stress disorder. Homeless female veterans were also much more likely to have dependent children with them and to plan to live with family members in supported housing. Once admitted to HUD-VASH, there were no gender differences in attrition or main housing outcomes. Case managers were faster to admit female veterans to the program, reported better working alliances, and provided more services related to employment and income than male veterans. These findings suggest homeless female veterans may have certain strengths, including being younger, less involved in the criminal justice system, and more adept at relating to professional and natural supports; but special attention to noncombat trauma and family-oriented services may be needed.

  7. Mosquitoes established in Lhasa city, Tibet, China

    PubMed Central

    2013-01-01

    Background In 2009, residents of Lhasa city, Tibet Autonomous Region (TAR), China reported large numbers of mosquitoes and bites from these insects. It is unclear whether this was a new phenomenon, which species were involved, and whether these mosquitoes had established themselves in the local circumstances. Methods The present study was undertaken in six urban sites of Chengguan district Lhasa city, Tibet. Adult mosquitoes were collected by bed net trap, labor hour method and light trap in August 2009 and August 2012. The trapped adult mosquitoes were initially counted and identified according to morphological criteria, and a proportion of mosquitoes were examined more closely using a multiplex PCR assay. Results 907 mosquitoes of the Culex pipiens complex were collected in this study. Among them, 595 were females and 312 were males. There was no significant difference in mosquito density monitored by bed net trap and labor hour method in 2009 and 2012. Of 105 mosquitoes identified by multiplex PCR, 36 were pure mosquitoes (34.29%) while 69 were hybrids (65.71%). The same subspecies of Culex pipiens complex were observed by bed net trap, labor hour method and light trap in 2009 and 2012. Conclusion The local Culex pipiens complex comprises the subspecies Cx. pipiens pipiens, Cx. pipiens pallens, Cx. pipiens quinquefasciatus and its hybrids. Mosquitoes in the Cx. pipiens complex, known to be, potentially, vectors of periodic filariasis and encephalitis, are now present from one season to the next, and appear to be established in Lhasa City, TAR. PMID:24060238

  8. Mosquito Traps: An Innovative, Environmentally Friendly Technique to Control Mosquitoes

    PubMed Central

    Poulin, Brigitte; Lefebvre, Gaëtan; Muranyi-Kovacs, Camille; Hilaire, Samuel

    2017-01-01

    We tested the use of mosquito traps as an alternative to spraying insecticide in Camargue (France) following the significant impacts observed on the non-target fauna through Bti persistence and trophic perturbations. In a village of 600 inhabitants, 16 Techno Bam traps emitting CO2 and using octenol lures were set from April to November 2016. Trap performance was estimated at 70% overall based on mosquitoes landing on human bait in areas with and without traps. The reduction of Ochlerotatus caspius and Oc. detritus, the two species targeted by Bti spraying, was, respectively, 74% and 98%. Traps were less efficient against Anopheles hyrcanus (46%), which was more attracted by lactic acid than octenol lures based on previous tests. Nearly 300,000 mosquitoes from nine species were captured, with large variations among traps, emphasizing that trap performance is also influenced by surrounding factors. Environmental impact, based on the proportion of non-target insects captured, was mostly limited to small chironomids attracted by street lights. The breeding success of a house martin colony was not significantly affected by trap use, in contrast to Bti spraying. Our experiment confirms that the deployment of mosquito traps can offer a cost-effective alternative to Bti spraying for protecting local populations from mosquito nuisance in sensitive natural areas. PMID:28335456

  9. Sampling outdoor, resting Anopheles gambiae and other mosquitoes (Diptera: Culicidae) in western Kenya with clay pots.

    PubMed

    Odiere, M; Bayoh, M N; Gimnig, J; Vulule, J; Irungu, L; Walker, E

    2007-01-01

    Clay pots were analyzed as devices for sampling the outdoor resting fraction of Anopheles gambiae Giles (Diptera: Culicidae) and other mosquito species in a rural, western Kenya. Clay pots (Anopheles gambiae resting pots, herein AgREPOTs), outdoor pit shelters, indoor pyrethrum spray collections (PSC), and Colombian curtain exit traps were compared in collections done biweekly for nine intervals from April to June 2005 in 20 housing compounds. Of 10,517 mosquitoes sampled, 4,668 An. gambiae s.l. were sampled in total of which 63% were An. gambiae s.s. (46% female) and 37% were An. arabiensis (66% female). The clay pots were useful and practical for sampling both sexes of An. gambiae s.l. Additionally, 617 An. funestus (58% female) and 5,232 Culex spp. (males and females together) were collected. Temporal changes in abundance of An. gambiae s.l. were similarly revealed by all four sampling methods, indicating that the clay pots could be used as devices to quantify variation in mosquito population density. Dispersion patterns of the different species and sexes fit well the negative binomial distribution, indicating that the mosquitoes were aggregated in distribution. Aside from providing a useful sampling tool, the AgREPOT also may be useful as a delivery vehicle for insecticides or pathogens to males and females that enter and rest in them.

  10. Could dromedary camels develop stereotypy? The first description of stereotypical behaviour in housed male dromedary camels and how it is affected by different management systems.

    PubMed

    Padalino, Barbara; Aubé, Lydiane; Fatnassi, Meriem; Monaco, Davide; Khorchani, Touhami; Hammadi, Mohamed; Lacalandra, Giovanni Michele

    2014-01-01

    Dromedary camel husbandry has recently been evolving towards a semi-intensive system, due to the changes in use of the animal and the settlement of nomadic populations. Captivity could restrict its social activities, limiting the expression of various behavioural needs and causing the manifestation of stereotypy. The aims of this trial were, firstly, to identify and describe some stereotypical behaviours in captive male dromedary camels used for artificial insemination and, secondly, to study the effects on them of the following husbandry management systems: i) housing in single boxes for 24 hours (H24), ii) housing in single boxes for 23 hours with one hour free in the paddock (H23), and iii) housing in single boxes for 22 hours 30 min with 1 h of paddock time and 30 min exposure to a female camel herd (ExF). Every day, the camels were filmed in their single box in the morning for 30 minutes to record their behavioural activities and a focal animal sampling ethogram was filled in. In this study, male camels showed both oral and locomotor stereotypy most frequently when the bulls were reared in H24. Overall, this preliminary study is a starting point in the identification of stereotypies in male camels, reporting the positive effects of spending one hour outdoor and of social interaction with females.

  11. Could Dromedary Camels Develop Stereotypy? The First Description of Stereotypical Behaviour in Housed Male Dromedary Camels and How It Is Affected by Different Management Systems

    PubMed Central

    Padalino, Barbara; Aubé, Lydiane; Fatnassi, Meriem; Monaco, Davide; Khorchani, Touhami; Hammadi, Mohamed; Lacalandra, Giovanni Michele

    2014-01-01

    Dromedary camel husbandry has recently been evolving towards a semi-intensive system, due to the changes in use of the animal and the settlement of nomadic populations. Captivity could restrict its social activities, limiting the expression of various behavioural needs and causing the manifestation of stereotypy. The aims of this trial were, firstly, to identify and describe some stereotypical behaviours in captive male dromedary camels used for artificial insemination and, secondly, to study the effects on them of the following husbandry management systems: i) housing in single boxes for 24 hours (H24), ii) housing in single boxes for 23 hours with one hour free in the paddock (H23), and iii) housing in single boxes for 22 hours 30 min with 1 h of paddock time and 30 min exposure to a female camel herd (ExF). Every day, the camels were filmed in their single box in the morning for 30 minutes to record their behavioural activities and a focal animal sampling ethogram was filled in. In this study, male camels showed both oral and locomotor stereotypy most frequently when the bulls were reared in H24. Overall, this preliminary study is a starting point in the identification of stereotypies in male camels, reporting the positive effects of spending one hour outdoor and of social interaction with females. PMID:24586522

  12. Mathematical model in controlling dengue transmission with sterile mosquito strategies

    NASA Astrophysics Data System (ADS)

    Aldila, D.; Nuraini, N.; Soewono, E.

    2015-09-01

    In this article, we propose a mathematical model for controlling dengue disease transmission with sterile mosquito techniques (SIT). Sterile male introduced from lab in to habitat to compete with wild male mosquito for mating with female mosquito. Our aim is to displace gradually the natural mosquito from the habitat. Mathematical model analysis for steady states and the basic reproductive ratio are performed analytically. Numerical simulation are shown in some different scenarios. We find that SIT intervention is potential to controlling dengue spread among humans population

  13. Multivariate analysis of the effects of manganese on the reproductive physiology and behavior of the male house mouse

    SciTech Connect

    Gray, L.E. Jr.; Laskey, J.W.

    1980-07-01

    Chronic exposure to Mn/sub 3/O/sub 4/ in the diet at 1050 ppM Mn retarded the sexual development and lowered reactive locomotor activity levels in male mice. A multivariate analysis of variance indicated that testis, seminal vesicle, and preputial gland weights were significantly smaller as a result of Mn administration. These results support earlier observations of altered locomotor activity levels and reproductive development in male rats in the absence of other signs of toxicity.

  14. Effect of different housing systems on fattening performance, slaughter and carcass characteristics of Akkeçi (White Goat) male kids.

    PubMed

    Kor, Aşkin; Karaca, Serhat; Ertuğrul, Mehmet

    2011-03-01

    The aim of this study was to determine the fattening performance and the slaughter and carcass characteristics of Akkeçi (Saanen × Kilis (B(1)) crossbred) male kids raised in individual crates (IC) or in group pen housing (GP). In both GP and IC groups, total 13 heads of male kids, whose initial body weights were 21.43 ± 1.03 kg and 20.61 ± 0.98 kg, respectively, evaluated for their fattening performances. After 56 days of the fattening period, the final body weights and average daily weight gains of the GP and IC kids were recorded as 30.84 ± 0.82 kg and 25.84 ± 0.76 kg; 182.42 ± 14.77 g and 92.09 ± 13.76 g, respectively (P < 0.001). Adrenal gland weights of the GP and IC groups were similar as 1.66 ± 0.25 g and 1.77 ± 0.22 g, respectively. Although, the carcass conformation of kids was similar between groups, there were significant differences between GP and IC groups for some slaughter and carcass characteristics. In general, although housing kids reared in individual crates provides opportunity to individually feed and monitor a kid, the results obtained from the individual crates in the present study were not satisfactorily from the ethological and production points of view.

  15. Radiation biology of mosquitoes

    PubMed Central

    Helinski, Michelle EH; Parker, Andrew G; Knols, Bart GJ

    2009-01-01

    There is currently renewed interest in assessing the feasibility of the sterile insect technique (SIT) to control African malaria vectors in designated areas. The SIT relies on the sterilization of males before mass release, with sterilization currently being achieved through the use of ionizing radiation. This paper reviews previous work on radiation sterilization of Anopheles mosquitoes. In general, the pupal stage was irradiated due to ease of handling compared to the adult stage. The dose-response curve between the induced sterility and log (dose) was shown to be sigmoid, and there was a marked species difference in radiation sensitivity. Mating competitiveness studies have generally been performed under laboratory conditions. The competitiveness of males irradiated at high doses was relatively poor, but with increasing ratios of sterile males, egg hatch could be lowered effectively. Males irradiated as pupae had a lower competitiveness compared to males irradiated as adults, but the use of partially-sterilizing doses has not been studied extensively. Methods to reduce somatic damage during the irradiation process as well as the use of other agents or techniques to induce sterility are discussed. It is concluded that the optimal radiation dose chosen for insects that are to be released during an SIT programme should ensure a balance between induced sterility of males and their field competitiveness, with competitiveness being determined under (semi-) field conditions. Self-contained 60Co research irradiators remain the most practical irradiators but these are likely to be replaced in the future by a new generation of high output X ray irradiators. PMID:19917076

  16. MAN, MOSQUITOES AND MICROBES.

    ERIC Educational Resources Information Center

    SCHOONOVER, ROBERT A.

    THE CONTROL OF MOSQUITOES IS A MATTER OF INCREASING CONCERN IN THE STATE OF FLORIDA. A BRIEF DESCRIPTION OF THE LIFE CYCLE, VARIOUS SPECIES, CONTROL, AND DESCRIPTION OF DISEASES TRANSMITTED BY THE MOSQUITO WAS PRESENTED. THE ARTICLE CONCLUDED THAT MOSQUITO CONTROL IS NOT ONLY A HEALTH PROBLEM, BUT ALSO A MATTER OF IMPROVED ECONOMICS IN RELATION TO…

  17. [Progress on transgenic mosquitoes].

    PubMed

    Yang, Pin

    2011-04-30

    The genetically modified mosquitoes have been developed aiming to control mosquito-borne diseases by either reducing population sizes or replacing existing populations with vectors unable to transmit the disease. introduces some progress on the generation of transgenic mosquitoes and their fitness in wild population. This paper

  18. Mosquito Life Cycle

    EPA Pesticide Factsheets

    Knowing the stages of the mosquito's life will help you prevent mosquitoes around your home and help you choose the right pesticides for your needs, if you decide to use them. All mosquito species go through four distinct stages during their live cycle.

  19. Pre-copula acoustic behaviour of males in the malarial mosquitoes Anopheles coluzzii and Anopheles gambiae s.s. does not contribute to reproductive isolation.

    PubMed

    Simões, Patrício M V; Gibson, Gabriella; Russell, Ian J

    2017-02-01

    We reveal that males of two members of the Anopheles gambiae s.l. species complex, Anopheles coluzzii and Anopheles gambiae s.s. (hereafter A. gambiae), which are both malaria vectors, perform a stereotypical acoustic behaviour in response to pure tones at frequencies that encompass the frequency range of the female's flight-tones. This behaviour resembles that described for Culex quinquefasciatus and consists of phonotactic flight initiated by a steep increase in wing-beat frequency (WBF) followed by rapid frequency modulation (RFM) of WBF when in close proximity to the sound source. RFM was elicited without acoustic feedback or the presence of a live female, but it appears to be a stereotypic behaviour in the immediate lead up to copula formation. RFM is an independent and different behavioural process from harmonic convergence interactions used by male-female pairs for mate recognition at earlier stages of mating. Acoustic threshold for RFM was used to plot behavioural audiograms from free-flying A coluzzii and A gambiae males. These audiograms were almost identical (minima ∼400 Hz) and encompassed the WBF ranges of A coluzzii (378-601 Hz) and A gambiae (373-590 Hz) females, indicating that males of the two species share similar frequency tuning and range. Furthermore, no differences were found between the two species in their WBFs, RFM behaviour or harmonic convergence ratios. These results indicate that assortative mating between A coluzzii and A gambiae is unlikely to be based on male-specific acoustic behaviours during RFM. The significance of these findings in relation to possible mechanisms for assortative mating is discussed.

  20. Light and water are not simple conditions: fine tuning of animal housing in male C57BL/6 mice.

    PubMed

    Langgartner, Dominik; Foertsch, Sandra; Füchsl, Andrea M; Reber, Stefan O

    2017-01-01

    While animal housing conditions are highly controlled and standardized between different laboratories, there are still many subtle differences that unavoidably influence the host organisms and, consequently, interlaboratory reproducibility. Here, we investigated the physiological and immunological consequences between two light/dark cycle (LDC) lengths (14-h/10-h vs. 12-h/12-h LDC) and two commonly used forms of drinking water (acidified drinking water (AW) versus normal tap water (NW)) in single-housed (SH) mice. Our results indicate that SH mice bred under a 12-h/12-h LDC and NW at the supplier's facility showed increased basal morning plasma corticosterone (CORT) levels even 4 weeks after arrival at our animal facility employing a 14-h/10-h LDC and AW. This effect was even more pronounced two weeks after arrival and had abated after 8 weeks. In agreement, increased plasma adrenocorticotropic hormone (ACTH), adrenal in vitro ACTH sensitivity, as well as relative and absolute adrenal weight normalized during this 8-week exposure to the novel and unfamiliar 14-h/10-h LDC and AW. Employment of a 12-h/12-h LDC in our facility completely abrogated the CORT-elevating effects of the 14-h/10-h LDC, despite these animals drinking AW. When both the water and light conditions were matched to those at the supplier's facility, we observed a further reduction in adrenal weight, increased thymus weight, and decreased pro-inflammatory cytokine secretion of isolated and anti-CD3/28-stimulated mesenteric lymph node cells. In summary, our results indicate that prolonged alteration of both the light phase and drinking water represent severe and long-lasting stressors for laboratory rodents. These findings are of general interest for all scientists obtaining their experimental animals from conventional suppliers.

  1. Hey! A Mosquito Bit Me!

    MedlinePlus

    ... dientes Video: Getting an X-ray Hey! A Mosquito Bit Me! KidsHealth > For Kids > Hey! A Mosquito ... español ¡Ay! ¡Me picó un mosquito! What's a Mosquito? A mosquito (say: mus-KEE-toe) is an ...

  2. Hey! A Mosquito Bit Me!

    MedlinePlus

    ... What Happens in the Operating Room? Hey! A Mosquito Bit Me! KidsHealth > For Kids > Hey! A Mosquito ... español ¡Ay! ¡Me picó un mosquito! What's a Mosquito? A mosquito (say: mus-KEE-toe) is an ...

  3. Novel acetylcholinesterase target site for malaria mosquito control.

    PubMed

    Pang, Yuan-Ping

    2006-12-20

    Current anticholinesterase pesticides were developed during World War II and are toxic to mammals because they target a catalytic serine residue of acetylcholinesterases (AChEs) in insects and in mammals. A sequence analysis of AChEs from 73 species and a three-dimensional model of a malaria-carrying mosquito (Anopheles gambiae) AChE (AgAChE) reported here show that C286 and R339 of AgAChE are conserved at the opening of the active site of AChEs in 17 invertebrate and four insect species, respectively. Both residues are absent in the active site of AChEs of human, monkey, dog, cat, cattle, rabbit, rat, and mouse. The 17 invertebrates include house mosquito, Japanese encephalitis mosquito, African malaria mosquito, German cockroach, Florida lancelet, rice leaf beetle, African bollworm, beet armyworm, codling moth, diamondback moth, domestic silkworm, honey bee, oat or wheat aphid, the greenbug, melon or cotton aphid, green peach aphid, and English grain aphid. The four insects are house mosquito, Japanese encephalitis mosquito, African malaria mosquito, and German cockroach. The discovery of the two invertebrate-specific residues enables the development of effective and safer pesticides that target the residues present only in mosquito AChEs rather than the ubiquitous serine residue, thus potentially offering an effective control of mosquito-borne malaria. Anti-AgAChE pesticides can be designed to interact with R339 and subsequently covalently bond to C286. Such pesticides would be toxic to mosquitoes but not to mammals.

  4. Artificial Diets for Mosquitoes

    PubMed Central

    Gonzales, Kristina K.; Hansen, Immo A.

    2016-01-01

    Mosquito-borne diseases are responsible for more than a million human deaths every year. Modern mosquito control strategies such as sterile insect technique (SIT), release of insects carrying a dominant lethal (RIDL), population replacement strategies (PR), and Wolbachia-based strategies require the rearing of large numbers of mosquitoes in culture for continuous release over an extended period of time. Anautogenous mosquitoes require essential nutrients for egg production, which they obtain through the acquisition and digestion of a protein-rich blood meal. Therefore, mosquito mass production in laboratories and other facilities relies on vertebrate blood from live animal hosts. However, vertebrate blood is expensive to acquire and hard to store for longer times especially under field conditions. This review discusses older and recent studies that were aimed at the development of artificial diets for mosquitoes in order to replace vertebrate blood. PMID:28009851

  5. Tips to Prevent Mosquito Bites

    EPA Pesticide Factsheets

    Using the right insect repellent and other preventive actions can discourage mosquitoes from landing on you. Tips include removing mosquito habitats such as standing water, minimizing exposed skin, and staying indoors while mosquitoes are most active.

  6. House-to-house human movement drives dengue virus transmission.

    PubMed

    Stoddard, Steven T; Forshey, Brett M; Morrison, Amy C; Paz-Soldan, Valerie A; Vazquez-Prokopec, Gonzalo M; Astete, Helvio; Reiner, Robert C; Vilcarromero, Stalin; Elder, John P; Halsey, Eric S; Kochel, Tadeusz J; Kitron, Uriel; Scott, Thomas W

    2013-01-15

    Dengue is a mosquito-borne disease of growing global health importance. Prevention efforts focus on mosquito control, with limited success. New insights into the spatiotemporal drivers of dengue dynamics are needed to design improved disease-prevention strategies. Given the restricted range of movement of the primary mosquito vector, Aedes aegypti, local human movements may be an important driver of dengue virus (DENV) amplification and spread. Using contact-site cluster investigations in a case-control design, we demonstrate that, at an individual level, risk for human infection is defined by visits to places where contact with infected mosquitoes is likely, independent of distance from the home. Our data indicate that house-to-house human movements underlie spatial patterns of DENV incidence, causing marked heterogeneity in transmission rates. At a collective level, transmission appears to be shaped by social connections because routine movements among the same places, such as the homes of family and friends, are often similar for the infected individual and their contacts. Thus, routine, house-to-house human movements do play a key role in spread of this vector-borne pathogen at fine spatial scales. This finding has important implications for dengue prevention, challenging the appropriateness of current approaches to vector control. We argue that reexamination of existing paradigms regarding the spatiotemporal dynamics of DENV and other vector-borne pathogens, especially the importance of human movement, will lead to improvements in disease prevention.

  7. The Distribution of Circumsporozoite Protein (CS) in Anopheles Stephensi Mosquitoes Infected with Plasmodium Falciparum Malaria

    DTIC Science & Technology

    1990-01-01

    389 in differentiating oocysts, on remnant membranes left on the midgut Roitt IM, BrostoffJ, Male DK (1985): Immunology. St Louis, CV Mosby wall after...Plasmodium falciparum; Anopheles stephensi; Cir- on the mosquito midgut. As oocysts differentiated to ma- cumsporozoite protein; Fuchsin/naphthol AS-BI...and sporogony in the mosquito. During a blood meal, microscopy and an indirect fluorescent antibody test (IFAT). These the mosquito ingests the male

  8. A Survey of Knowledge, Attitudes, and Practices in Relation to Mosquitoes and Mosquito-Borne Disease in Western Australia

    PubMed Central

    Potter, Abbey; Jardine, Andrew; Neville, Peter J.

    2016-01-01

    On average, more than 1,000 individuals will acquire a mosquito-borne disease in Western Australia (WA) each year. Knowledge, attitudes, and practices (KAP) in relation to mosquitoes and mosquito-borne disease have not yet been investigated within Australia. A randomized telephone survey of 2,500 households across 12 regions in WA was undertaken between February and May 2014. The aim of the survey was to obtain baseline KAP data surrounding mosquitoes and mosquito-borne diseases in different regions of WA, across a range of age groups and between males and females. The results of this survey indicate that the majority of respondents are aware of the potential for mosquitoes in WA to transmit Ross River virus, while awareness of other endemic mosquito-borne diseases remains limited. Common misconceptions exist in relation to exotic mosquito-borne diseases, with respondents incorrectly identifying malaria and dengue as endemic diseases in WA. The survey also highlighted a range of important issues, such as limited awareness of the potential for backyard breeding in domestic containers, occupational exposure to mosquitoes in regions with a large employment base in the mining and resources sector, increased exposure to mosquitoes as a result of participation in outdoor recreational activities in the north of the State, and reduced awareness of mosquito-borne disease in individuals aged 18–34 years. The results of this study will be used to inform the development of a new communication strategy by the Department of Health, to further raise awareness of mosquito-borne disease in WA. The data will then provide a baseline against which to compare future survey results, facilitating the rigorous evaluation of new communication efforts. PMID:26973827

  9. Mosquito Immunity against Arboviruses

    PubMed Central

    Sim, Shuzhen; Jupatanakul, Natapong; Dimopoulos, George

    2014-01-01

    Arthropod-borne viruses (arboviruses) pose a significant threat to global health, causing human disease with increasing geographic range and severity. The recent availability of the genome sequences of medically important mosquito species has kick-started investigations into the molecular basis of how mosquito vectors control arbovirus infection. Here, we discuss recent findings concerning the role of the mosquito immune system in antiviral defense, interactions between arboviruses and fundamental cellular processes such as apoptosis and autophagy, and arboviral suppression of mosquito defense mechanisms. This knowledge provides insights into co-evolutionary processes between vector and virus and also lays the groundwork for the development of novel arbovirus control strategies that target the mosquito vector. PMID:25415198

  10. Swarming mechanisms in the yellow fever mosquito: aggregation pheromones involved in the mating behavior of Aedes aegypti

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mosquitoes of various species mate in swarms comprised of tens to thousands flying males. Yet little information is known about mosquito swarming mechanism. Discovering chemical cues involved in mosquito biology leads to better adaptation of disease control interventions. In this study, we aimed ...

  11. Natural and engineered mosquito immunity.

    PubMed

    Alphey, Luke

    2009-01-01

    A recent paper in BMC Microbiology shows how suppression of mosquito innate immunity against a virus that the mosquito can normally tolerate increases mosquito mortality. This is just one of several approaches that may soon bring genetics-based mosquito control methods from the laboratory into the field.

  12. Convergence between a mosquito-eating predator's natural diet and its prey-choice behaviour

    PubMed Central

    Jackson, Robert R.; Deng, Chan

    2016-01-01

    On the basis of 1115 records of Evarcha culicivora feeding in the field, we can characterize this East African jumping spider (Salticidae) as being distinctively stenophagic. We can also, on the basis of laboratory prey-choice experiments, characterize E. culicivora as having a specialized prey-classification system and a hierarchy of innate preferences for various categories of mosquitoes and other arthropods. Prey from the field belonged to 10 arthropod orders, but 94.5% of the prey records were dipterans. Mosquitoes were the dominant prey (80.2% of the records), with the majority (82.9%) of the mosquitoes being females, and thereafter midges were the most common prey (9.2% of the records). Preference profiles that were determined from experiments showed strong convergence with natural diet in some, but not all, instances. In experiments, E. culicivora adults appeared to distinguish between six prey categories and juveniles between seven, with blood-carrying anopheline female mosquitoes being ranked highest in preference. For adults, this was followed by blood-carrying culicine female mosquitoes and then anopheline female mosquitoes not carrying blood, but these two preferences were reversed for juveniles. Moreover, for juveniles, but not for adults, anopheline male mosquitoes seem to be a distinct prey category ranked in preference after blood-carrying culicine females and, for both adults and juveniles, preference for midges is evident when the alternatives are not mosquitoes. These findings illustrate the importance of going beyond simply specifying preferred prey categories when characterizing predators as ‘specialized’ and a need to make clear conceptual distinctions between a predator's natural diet, the prey categories that are relevant to the predator, and the predator's prey-choicebehaviour. PMID:28083103

  13. Zika mosquito vectors: the jury is still out.

    PubMed

    Leal, Walter S

    2016-01-01

    After a 40-year hiatus, the International Congress of Entomology (ICE 2016) convened in Orlando, Florida (September 25-30, 2016). One of the symposia at ICE 2016, the Zika Symposium, covered multiple aspects of the Zika epidemic, including epidemiology, sexual transmission, genetic tools for reducing transmission, and particularly vector competence. While there was a consensus among participants that the yellow fever mosquito, Aedes aegypti, is a vector of the Zika virus, there is growing evidence indicating that the range of mosquito vectors might be wider than anticipated. In particular, three independent groups from Canada, China, and Brazil presented and discussed laboratory and field data strongly suggesting that the southern house mosquito, Culex quinquefasciatus, also known as the common mosquito, is highly likely to be a vector in certain environments.

  14. Zika mosquito vectors: the jury is still out

    PubMed Central

    Leal, Walter S.

    2016-01-01

    After a 40-year hiatus, the International Congress of Entomology (ICE 2016) convened in Orlando, Florida (September 25-30, 2016). One of the symposia at ICE 2016, the Zika Symposium, covered multiple aspects of the Zika epidemic, including epidemiology, sexual transmission, genetic tools for reducing transmission, and particularly vector competence. While there was a consensus among participants that the yellow fever mosquito, Aedes aegypti, is a vector of the Zika virus, there is growing evidence indicating that the range of mosquito vectors might be wider than anticipated. In particular, three independent groups from Canada, China, and Brazil presented and discussed laboratory and field data strongly suggesting that the southern house mosquito, Culex quinquefasciatus, also known as the common mosquito, is highly likely to be a vector in certain environments. PMID:27853521

  15. Does Zika virus infection affect mosquito response to repellents?

    PubMed

    Leal, Walter S; Barbosa, Rosângela M R; Zeng, Fangfang; Faierstein, Gabriel B; Tan, Kaiming; Paiva, Marcelo H S; Guedes, Duschinka R D; Crespo, Mônica M; Ayres, Constância F J

    2017-02-16

    The World Health Organization (WHO) recommends that people travelling to or living in areas with Zika virus (ZIKV) outbreaks or epidemics adopt prophylactic measures to reduce or eliminate mosquito bites, including the use of insect repellents. It is, however, unknown whether repellents are effective against ZIKV-infected mosquitoes, in part because of the ethical concerns related to exposing a human subject's arm to infected mosquitoes in the standard arm-in-cage assay. We used a previously developed, human subject-free behavioural assay, which mimics a human subject to evaluate the top two recommended insect repellents. Our measurements showed that DEET provided significantly higher protection than picaridin provided against noninfected, host-seeking females of the southern house mosquito, Culex quinquefasciatus, and the yellow fever mosquito, Aedes aegypti. When tested at lower doses, we observed a significant reduction in DEET-elicited protection against ZIKV-infected yellow fever mosquitoes from old and recent laboratory colonies. The reduction in protection is more likely associated with aging than the virus infection and could be compensated by applying a 5x higher dose of DEET. A substantial protection against ZIKV-infected and old noninfected mosquitoes was achieved with 5% DEET, which corresponds approximately to a 30% dose in the conventional arm-in-cage assays.

  16. Does Zika virus infection affect mosquito response to repellents?

    PubMed Central

    Leal, Walter S.; Barbosa, Rosângela M. R.; Zeng, Fangfang; Faierstein, Gabriel B.; Tan, Kaiming; Paiva, Marcelo H. S.; Guedes, Duschinka R. D.; Crespo, Mônica M.; Ayres, Constância F. J.

    2017-01-01

    The World Health Organization (WHO) recommends that people travelling to or living in areas with Zika virus (ZIKV) outbreaks or epidemics adopt prophylactic measures to reduce or eliminate mosquito bites, including the use of insect repellents. It is, however, unknown whether repellents are effective against ZIKV-infected mosquitoes, in part because of the ethical concerns related to exposing a human subject’s arm to infected mosquitoes in the standard arm-in-cage assay. We used a previously developed, human subject-free behavioural assay, which mimics a human subject to evaluate the top two recommended insect repellents. Our measurements showed that DEET provided significantly higher protection than picaridin provided against noninfected, host-seeking females of the southern house mosquito, Culex quinquefasciatus, and the yellow fever mosquito, Aedes aegypti. When tested at lower doses, we observed a significant reduction in DEET-elicited protection against ZIKV-infected yellow fever mosquitoes from old and recent laboratory colonies. The reduction in protection is more likely associated with aging than the virus infection and could be compensated by applying a 5x higher dose of DEET. A substantial protection against ZIKV-infected and old noninfected mosquitoes was achieved with 5% DEET, which corresponds approximately to a 30% dose in the conventional arm-in-cage assays. PMID:28205633

  17. Comparison of three residential mosquito traps against riceland mosquitoes in southeast Arkansas.

    PubMed

    Allen, R A; Lewis, C N; Meisch, M V; Dame, D A

    2009-03-01

    Field trials were conducted at 3 locations in Arkansas County, AR, to compare the effectiveness of 3 residential mosquito traps, the Stinger Mosquito Vacuum, the Mosquito Magnet Defender, and the Mosquito Deleto 2500 Active System, against riceland mosquitoes, specifically Anopheles quadrimaculatus and Psorophora columbiae. Both the Stinger Mosquito Vacuum and the Mosquito Deleto captured significantly more An. quadrimaculatus and total mosquitoes than did the Mosquito Magnet Defender. The Mosquito Deleto captured significantly more Ps. columbiae than did either of the other 2 traps.

  18. Evaluation of a Stable Isotope Method to Mark Naturally-Breeding Larval Mosquitoes for Adult Dispersal Studies

    PubMed Central

    HAMER, GABRIEL L.; DONOVAN, DANIELLE J.; HOOD-NOWOTNY, REBECCA; KAUFMAN, MICHAEL G.; GOLDBERG, TONY L.; WALKER, EDWARD D.

    2014-01-01

    Understanding mosquito dispersal is critically important for vector-borne disease control and prevention. Mark–release–recapture methods using various marking techniques have made substantial contributions to the study of mosquito biology. However, the ability to mark naturally breeding mosquitoes noninvasively and with life-long retention has remained problematic. Here, we describe a method to mark naturally breeding mosquitoes with stable isotopes. Culexpipiens f. molestus mosquitoes were provisioned as larvae in laboratory experiments with 15N-labeled potassium nitrate and 13C-labeled glucose. Larval enrichment was sufficient to differentiate marked adult mosquitoes from unmarked control mosquitoes and the natural source population from Chicago Illinois, using either δ15N or δ13C. Isotopic retention lasted for at least 55 d for adult male and females mosquitoes. There were no consistent effects of isotopic enrichment on immature mosquito survival or adult mosquito body size. We then applied this marking technique to naturally breeding Culex pipiens mosquitoes in suburban Chicago, IL, and for the first time, report successful isotopic enrichment of mosquitoes in the field. This stable isotope marking technique will facilitate studies of mosquito dispersal. PMID:22308772

  19. Adult survivorship of the dengue mosquito Aedes aegypti varies seasonally in central Vietnam.

    PubMed

    Hugo, Leon E; Jeffery, Jason A L; Trewin, Brendan J; Wockner, Leesa F; Nguyen, Thi Yen; Nguyen, Hoang Le; Nghia, Le Trung; Hine, Emma; Ryan, Peter A; Kay, Brian H

    2014-02-01

    The survival characteristics of the mosquito Aedes aegypti affect transmission rates of dengue because transmission requires infected mosquitoes to survive long enough for the virus to infect the salivary glands. Mosquito survival is assumed to be high in tropical, dengue endemic, countries like Vietnam. However, the survival rates of wild populations of mosquitoes are seldom measured due the difficulty of predicting mosquito age. Hon Mieu Island in central Vietnam is the site of a pilot release of Ae. aegypti infected with a strain of Wolbachia pipientis bacteria (wMelPop) that induces virus interference and mosquito life-shortening. We used the most accurate mosquito age grading approach, transcriptional profiling, to establish the survival patterns of the mosquito population from the population age structure. Furthermore, estimations were validated on mosquitoes released into a large semi-field environment consisting of an enclosed house, garden and yard to incorporate natural environmental variability. Mosquito survival was highest during the dry/cool (January-April) and dry/hot (May-August) seasons, when 92 and 64% of Hon Mieu mosquitoes had survived to an age that they were able to transmit dengue (12 d), respectively. This was reduced to 29% during the wet/cool season from September to December. The presence of Ae. aegypti older than 12 d during each season is likely to facilitate the observed continuity of dengue transmission in the region. We provide season specific Ae. aegypti survival models for improved dengue epidemiology and evaluation of mosquito control strategies that aim to reduce mosquito survival to break the dengue transmission cycle.

  20. Mosquitoes, models, and dengue.

    PubMed

    Lifson, A R

    1996-05-04

    In the last 10 years dengue has spread markedly through Latin America and the Caribbean (Dominican Republic, Jamaica, Barbados, Mexico, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Ecuador, Colombia, Venezuela, and Brazil). The mosquito Aedes aegypti has taken advantage of increased urbanization and crowding to transmit the dengue virus. The mosquito infests tires, cans, and water jars near dwellings. The female mosquito practices multiple, interrupted feeding. Thus, mosquito infesting and feeding practices facilitate dengue transmission in crowded conditions. Factors contributing to the spread of dengue include numbers of infected and susceptible human hosts, strain of dengue virus, size of mosquito population, feeding habits, time from infection to ability to transmit virus for both vector and host, likelihood of virus transmission from human to mosquito to human, and temperature (which affects vector distribution, size, feeding habits, and extrinsic incubation period). Public health models may use simulation models to help them plan or evaluate the potential impact of different intervention strategies and/or of environmental changes (e.g., global warming). Other factors contributing to the dengue epidemic are international travel, urbanization, population growth, crowding, poverty, a weakened public health infrastructure, and limited support for sustained disease control programs. Molecular epidemiology by nucleic acid sequence analysis is another sophisticated technique used to study infectious diseases. It showed that dengue type 3 isolated from Panama and Nicaragua in 1994 was identical to that responsible for the major dengue hemorrhagic fever epidemics in Sri Lanka and India in the 1980s. Public health officials must remember three priorities relevant to dengue and other emerging infections: the need to strengthen surveillance efforts, dedicated and sustained involvement in prevention and control needs at the local level, and a strong

  1. Experiences and results of initial studies of RIDL® mosquitoes in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2009, staff from the Mosquito and Fly Research Unit (MFRU), Center for Medical, Agricultural, and Veterinary Entomology in Gainesville, Florida began collaborative studies involving male Aedes aegypti mosquitoes carrying a dominant lethal (RIDL®) gene that was developed by Oxitec, Ltd., in Oxford...

  2. Genetic elimination of dengue vector mosquitoes.

    PubMed

    Wise de Valdez, Megan R; Nimmo, Derric; Betz, John; Gong, Hong-Fei; James, Anthony A; Alphey, Luke; Black, William C

    2011-03-22

    An approach based on mosquitoes carrying a conditional dominant lethal gene (release of insects carrying a dominant lethal, RIDL) is being developed to control the transmission of dengue viruses by vector population suppression. A transgenic strain, designated OX3604C, of the major dengue vector, Aedes aegypti, was engineered to have a repressible female-specific flightless phenotype. This strain circumvents the need for radiation-induced sterilization, allows genetic sexing resulting in male-only releases, and permits the release of eggs instead of adult mosquitoes. OX3604C males introduced weekly into large laboratory cages containing stable target mosquito populations at initial ratios of 8.5-101 OX3604Ctarget eliminated the populations within 10-20 weeks. These data support the further testing of this strain in contained or confined field trials to evaluate mating competitiveness and environmental and other effects. Successful completion of the field trials should facilitate incorporation of this approach into area-wide dengue control or elimination efforts as a component of an integrated vector management strategy.

  3. General Information about Mosquitoes

    EPA Pesticide Factsheets

    There are about 200 different species of mosquitoes in the U. S., with varied habitats and behaviors. Bites can transmit diseases such as malaria and West Nile virus to humans, as well as diseases and parasites particularly harmful to dogs and horses.

  4. Procurement and persistence of GFP-expressing Escherichia coli and Salmonella Typhimurium in male and female house flies exposed to cattle manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: Adult house flies, Musca domestica L., are associated with animal manure and other microbe-rich substrates. Consequently, both sexes can acquire and potentially disseminate pathogenic bacteria to surrounding environments, including residential areas, via contaminated body parts and/or ...

  5. Landscape Ecology of Sylvatic Chikungunya Virus and Mosquito Vectors in Southeastern Senegal

    PubMed Central

    Diallo, Diawo; Sall, Amadou A.; Buenemann, Michaela; Chen, Rubing; Faye, Oumar; Diagne, Cheikh T.; Faye, Ousmane; Ba, Yamar; Dia, Ibrahima; Watts, Douglas; Weaver, Scott C.; Hanley, Kathryn A.; Diallo, Mawlouth

    2012-01-01

    The risk of human infection with sylvatic chikungunya (CHIKV) virus was assessed in a focus of sylvatic arbovirus circulation in Senegal by investigating distribution and abundance of anthropophilic Aedes mosquitoes, as well as the abundance and distribution of CHIKV in these mosquitoes. A 1650 km2 area was classified into five land cover classes: forest, barren, savanna, agriculture and village. A total of 39,799 mosquitoes was sampled from all classes using human landing collections between June 2009 and January 2010. Mosquito diversity was extremely high, and overall vector abundance peaked at the start of the rainy season. CHIKV was detected in 42 mosquito pools. Our data suggest that Aedes furcifer, which occurred abundantly in all land cover classes and landed frequently on humans in villages outside of houses, is probably the major bridge vector responsible for the spillover of sylvatic CHIKV to humans. PMID:22720097

  6. Insect bioacoustics: mosquitoes make an effort to listen to each other.

    PubMed

    Robert, Daniel

    2009-06-09

    As they encounter each other in flight, male and female mosquitoes alter their wing beat to bring their flight tones closer together. Two recent studies provide new insights into the complex auditory processing required for this behaviour.

  7. Control of mosquito-borne infectious diseases: Sex and gene drive

    PubMed Central

    Adelman, Zach N.; Tu, Zhijian

    2015-01-01

    Sterile male releases have successfully reduced local populations of the dengue vector, Aedes aegypti, but challenges remain in scale and in separating sexes prior to release. The recent discovery of the first mosquito male determining factor (M factor), will facilitate our understanding of the genetic programs that initiate sexual development in mosquitoes. Manipulation of the M-factor and possible intermediary factors may result in female-to-male conversion or female killing, enabling efficient sex-separation and effective reduction of target mosquito populations. Given recent breakthroughs in the development of CRISPR-Cas9 reagents as a source of gene drive, more advanced technologies at driving maleness, the ultimate disease refractory phenotype, become possible and may represent efficient and self-limiting methods to control mosquito populations. PMID:26897660

  8. Socioeconomic status affects mosquito (Diptera: Culicidae) larval habitat type availability and infestation level.

    PubMed

    Dowling, Zara; Ladeau, Shannon L; Armbruster, Peter; Biehler, Dawn; Leisnham, Paul T

    2013-07-01

    Mosquito populations are largely regulated by processes occurring at the larval stage. We sampled mosquito larval microhabitats (mostly water-holding containers) in six neighborhoods in the Washington, DC, area that varied in socioeconomic status (SES) and housing structure (row houses vs. stand-alone houses) to test associations among these neighborhood characteristics, microhabitat abundance and parameters, and mosquito occurrence and densities. Thirty-four percent (33.9%) of sampled microhabitats contained mosquito larvae, and 93.1% of larvae were Aedes albopictus Skuse or Culex pipiens L. Five specific container types (drains, corrugated flexible drainpipes, planters, garbage cans, and buckets) accounted for the majority of water-holding (56.0%) and mosquito-positive (50.6%) microhabitats sampled. We found no associations between SES or housing structure with total microhabitat abundance per yard, mosquito occurrence or mosquito densities per microhabitat. In contrast, container purpose varied with SES, with low SES neighborhoods having greater numbers of disused containers and lower numbers of functional containers than low and medium SES neighborhoods. Ae. albopictus were 83% more abundant in disused containers, whereas Cx. pipiens were more abundant in structural and functional containers, possibly owing to species-specific oviposition and development related to water quality. Ae. albopictus densities increased over the summer, whereas Cx. pipiens densities remained constant. Ae. albopictus is usually the dominant pest in urban areas in the eastern United States; therefore, integrated mosquito management programs should incorporate the elimination of disused containers to reduce its infestation and adult production, especially in low SES neighborhoods where they occur most frequently.

  9. Mechanical transmission of porcine reproductive and respiratory syndrome virus by mosquitoes, Aedes vexans (Meigen)

    PubMed Central

    Otake, Satoshi; Dee, Scott A.; Rossow, Kurt D.; Moon, Roger D.; Pijoan, Carlos

    2002-01-01

    The objective of this study was to determine whether porcine reproductive and respiratory syndrome virus (PRRSV) could be transmitted to naïve pigs by mosquitoes following feeding on infected pigs. During each of 4 replicates, mosquito-to-pig contact took place on days 5, 6, and 7 after PRRSV infection of the donor pig. A total of 300 mosquitoes [Aedes vexans (Meigen)] were allowed to feed on each viremic donor pig, housed in an isolation room. After 30 to 60 s, feeding was interrupted, and the mosquitoes were manually transferred in small plastic vials and allowed to feed to repletion on a naïve recipient pig housed in another isolation room. Prior to contact with the recipient pig, the mosquitoes were transferred to clean vials. Swabs were collected from the exterior surface of all vials, pooled, and tested for PRRSV. Separate personnel handled the donor pig, the recipient pig, and the vial-transfer procedure. Transmission of PRRSV from the donor to the recipient pig occurred in 2 out of 4 replicates. The PRRSV isolated from the infected recipient pigs was nucleic-acid-sequenced and found to be 100% homologous with the virus used to infect the donor pigs. Homogenates of mosquito tissues collected in all replicates were positive by either polymerase chain reaction or swine bioassay. All control pigs remained PRRSV negative, and PRRSV was not detected on the surface of the vials. This study indicates that mosquitoes (A. vexans) can serve as mechanical vectors of PRRSV. PMID:12146891

  10. Mechanical transmission of porcine reproductive and respiratory syndrome virus by mosquitoes, Aedes vexans (Meigen).

    PubMed

    Otake, Satoshi; Dee, Scott A; Rossow, Kurt D; Moon, Roger D; Pijoan, Carlos

    2002-07-01

    The objective of this study was to determine whether porcine reproductive and respiratory syndrome virus (PRRSV) could be transmitted to naive pigs by mosquitoes following feeding on infected pigs. During each of 4 replicates, mosquito-to-pig contact took place on days 5, 6, and 7 after PRRSV infection of the donor pig. A total of 300 mosquitoes [Aedes vexans (Meigen)] were allowed to feed on each viremic donor pig, housed in an isolation room. After 30 to 60 s, feeding was interrupted, and the mosquitoes were manually transferred in small plastic vials and allowed to feed to repletion on a naïve recipient pig housed in another isolation room. Prior to contact with the recipient pig, the mosquitoes were transferred to clean vials. Swabs were collected from the exterior surface of all vials, pooled, and tested for PRRSV. Separate personnel handled the donor pig, the recipient pig, and the vial-transfer procedure. Transmission of PRRSV from the donor to the recipient pig occurred in 2 out of 4 replicates. The PRRSV isolated from the infected recipient pigs was nucleic-acid-sequenced and found to be 100% homologous with the virus used to infect the donor pigs. Homogenates of mosquito tissues collected in all replicates were positive by either polymerase chain reaction or swine bioassay. All control pigs remained PRRSV negative, and PRRSV was not detected on the surface of the vials. This study indicates that mosquitoes (A. vexans) can serve as mechanical vectors of PRRSV.

  11. Mosquitoes of Middle America.

    DTIC Science & Technology

    1976-09-30

    survey of mosquitoes in Costa Rica, 197 1. Walsh , Robert D., Aedes aegypti Eradication Program, Public Health Service.—Collections in St. Croix...At least a start has been made in nearly every major group of medical importance in Middle America: Aedes , Anopheles, Culex. Deinocerites, Haemago~us...fauna in the area covered by the project. At least a start has been made in nearl y every major group of medical importance in Middle America: Aedes

  12. Identification of the sexually dimorphic gastrin-releasing peptide system in the lumbosacral spinal cord that controls male reproductive function in the mouse and Asian house musk shrew (Suncus murinus).

    PubMed

    Tamura, Kei; Kobayashi, Yasuhisa; Hirooka, Asuka; Takanami, Keiko; Oti, Takumi; Jogahara, Takamichi; Oda, Sen-Ichi; Sakamoto, Tatsuya; Sakamoto, Hirotaka

    2016-11-02

    Several regions of the brain and spinal cord control male reproductive function. We previously demonstrated that the gastrin-releasing peptide (GRP) system, located in the lumbosacral spinal cord of rats, controls spinal centers to promote penile reflexes during male copulatory behavior. However, little information exists on the male-specific spinal GRP system in animals other than rats. The objective of this study was to examine the functional generality of the spinal GRP system in mammals using the Asian house musk shrew (Suncus murinus; suncus named as the laboratory strain), a specialized placental mammal model. Mice are also used for a representative model of small laboratory animals. We first isolated complementary DNA encoding GRP in suncus. Phylogenetic analysis revealed that suncus preproGRP was clustered to an independent branch. Reverse transcription-PCR showed that GRP and its receptor mRNAs were both expressed in the lumbar spinal cord of suncus and mice. Immunohistochemistry for GRP demonstrated that the sexually dimorphic GRP system and male-specific expression/distribution patterns of GRP in the lumbosacral spinal cord in suncus are similar to those of mice. In suncus, we further found that most GRP-expressing neurons in males also express androgen receptors, suggesting that this male-dominant system in suncus is also androgen-dependent. Taken together, these results indicate that the sexually dimorphic spinal GRP system exists not only in mice but also in suncus, suggesting that this system is a conserved property in mammals. This article is protected by copyright. All rights reserved.

  13. Mosquito Lagoon environmental resources inventory

    NASA Technical Reports Server (NTRS)

    Provancha, Jane A.; Hall, Carlton R.; Oddy, Donna M.

    1992-01-01

    This document provides a synopsis of biotic and abiotic data collected in the Mosquito Lagoon area in relation to water quality. A holistic ecological approach was used in this review to allow for summaries of climate, land use, vegetation, geohydrology, water quality, fishes, sea turtles, wading birds, marine mammals, invertebrates, shellfish, and mosquito control. The document includes a bibliographic database list of 157 citations that have references to the Mosquito Lagoon, many of which were utilized in development of the text.

  14. Quantitative analysis of harmonic convergence in mosquito auditory interactions.

    PubMed

    Aldersley, Andrew; Champneys, Alan; Homer, Martin; Robert, Daniel

    2016-04-01

    This article analyses the hearing and behaviour of mosquitoes in the context of inter-individual acoustic interactions. The acoustic interactions of tethered live pairs of Aedes aegypti mosquitoes, from same and opposite sex mosquitoes of the species, are recorded on independent and unique audio channels, together with the response of tethered individual mosquitoes to playbacks of pre-recorded flight tones of lone or paired individuals. A time-dependent representation of each mosquito's non-stationary wing beat frequency signature is constructed, based on Hilbert spectral analysis. A range of algorithmic tools is developed to automatically analyse these data, and used to perform a robust quantitative identification of the 'harmonic convergence' phenomenon. The results suggest that harmonic convergence is an active phenomenon, which does not occur by chance. It occurs for live pairs, as well as for lone individuals responding to playback recordings, whether from the same or opposite sex. Male-female behaviour is dominated by frequency convergence at a wider range of harmonic combinations than previously reported, and requires participation from both partners in the duet. New evidence is found to show that male-male interactions are more varied than strict frequency avoidance. Rather, they can be divided into two groups: convergent pairs, typified by tightly bound wing beat frequencies, and divergent pairs, that remain widely spaced in the frequency domain. Overall, the results reveal that mosquito acoustic interaction is a delicate and intricate time-dependent active process that involves both individuals, takes place at many different frequencies, and which merits further enquiry.

  15. Swarming Mechanisms in the Yellow Fever Mosquito: Aggregation Pheromones are Involved in the Mating Behavior of Aedes aegypti

    DTIC Science & Technology

    2014-12-01

    Accepted 15 July 2014 ABSTRACT: Mosquitoes of various species mate in swarms comprised of tens of thousands of flying males . In this study, we examined...thousands of flying males (Yuval 2006, Cabrera and Jaffe 2007, Ng’habi et al. 2008). The great majority of researchers consider mosquito swarms as a...means to facilitate mating (Yuval et al. 1993). The female response to these swarms was proportionally related to the number of males participating

  16. Control of vector populations using genetically modified mosquitoes.

    PubMed

    Wilke, André Barreto Bruno; Gomes, Almério de Castro; Natal, Delsio; Marrelli, Mauro Toledo

    2009-10-01

    The ineffectiveness of current strategies for chemical control of mosquito vectors raises the need for developing novel approaches. Thus, we carried out a literature review of strategies for genetic control of mosquito populations based on the sterile insect technique. One of these strategies consists of releasing radiation-sterilized males into the population; another, of integrating a dominant lethal gene under the control of a specific promoter into immature females. Advantages of these approaches over other biological and chemical control strategies include: highly species-specific, environmentally safety, low production cost, and high efficacy. The use of this genetic modification technique will constitute an important tool for integrated vector management.

  17. Diversity of riceland mosquitoes and factors affecting their occurrence and distribution in Mwea, Kenya.

    PubMed

    Muturi, Ephantus J; Shililu, Josephat I; Jacob, Benjamin G; Mwangangi, Joseph M; Mbogo, Charles M; Githure, John I; Novak, Robert J

    2008-09-01

    Knowledge of mosquito species diversity, occurrence, and distribution is an essential component of vector ecology and a guiding principle to formulation and implementation of integrated vector management programs. A 12-month entomological survey was conducted to determine the diversity of riceland mosquitoes and factors affecting their occurrence and distribution at 3 sites targeted for malaria vector control in Mwea, Kenya. Adult mosquitoes were sampled indoors by pyrethrum spray catch and outdoors by the Centers for Disease Control and Prevention light traps. Mosquitoes were then morphologically identified to species using taxonomic keys. The characteristics of houses sampled for indoor resting mosquitoes, including number of people sleeping in each house the night preceding collection, presence of bed nets, location of the house, size of eaves, wall type, presence of cattle and distance of the house to the cowshed, and proximity to larval habitats, were recorded. Of the 191,378 mosquitoes collected, 95% were identified morphologically to species and comprised 25 species from 5 genera. Common species included Anopheles arabiensis (53.5%), Culex quinquefasciatus (35.5%), An. pharoensis (4.7%), An. coustani (2.5%), and An. funestus (1.6%). Shannon's species diversity and evenness indices did not differ significantly among the 3 study sites. There was a marked house-to-house variation in the average number of mosquitoes captured. The number of people sleeping in the house the night preceding collection, size of eaves, distance to the cowshed, and the nearest larval habitat were significant predictors of occurrence of either or both An. arabiensis and Cx. quinquefasciatus. The peak abundance of An. arabiensis coincided with land preparation and the first few weeks after transplanting of rice seedlings, and that of Cx. quinquefasciatus coincided with land preparation, late stage of rice development, and short rains. After transplanting of rice seedlings, the

  18. House calls.

    PubMed

    Unwin, Brian K; Tatum, Paul E

    2011-04-15

    House calls provide a unique perspective on patients' environment and health problems. The demand for house calls is expected to increase considerably in future decades as the U.S. population ages. Although study results have been inconsistent, house calls involving multidisciplinary teams may reduce hospital readmissions and long-term care facility stays. Common indications for house calls are management of acute or chronic illnesses, and palliative care. Medicare beneficiaries must meet specific criteria to be eligible for home health services. The INHOMESSS mnemonic provides a checklist for components of a comprehensive house call. In addition to performing a clinical assessment, house calls may involve observing the patient performing daily activities, reconciling medication discrepancies, and evaluating home safety. House calls can be integrated into practice with careful planning, including clustering house calls by geographic location and coordinating visits with other health care professionals and agencies.

  19. White House

    MedlinePlus

    ... to main content Jump to navigation the WHITE HOUSE President Donald J. Trump Get in Touch Home ... News Read the latest news from the White House Video Gallery View the most recent videos from ...

  20. Sexual chemoecology of mosquitoes (Diptera, Culicidae): Current knowledge and implications for vector control programs.

    PubMed

    Vaníčková, Lucie; Canale, Angelo; Benelli, Giovanni

    2017-04-01

    Mosquitoes (Diptera: Culicidae) act as vectors of medical and veterinary importance, due to their ability to transmit many pathogens and parasites. Renewed interest has been recently devoted to the potential of sterile insect technique (SIT) for mosquito suppression. However, the success of the SIT is mostly dependent on the ability of sterile males to compete for mates with the wild ones in the field. Nevertheless, little is known on the sexual chemical ecology of mosquitoes, with special reference to the role of chemical signals in males. We reviewed the current knowledge on mosquito sexual chemical ecology and other key cues affecting courtship and mating behavior. The information available on the aggregation and sex pheromones in mosquito males is rather limited. To the best of our knowledge, the components of the aggregation pheromone stimulating swarming mechanisms have been fully characterized only for Aedes aegypti, while evidence for aggregation pheromones in other mosquito species remains elusive. Further research on this issue is needed, as well as to dissect the relative importance of visual (with special reference to swarming landmarks), vibrational, olfactory and tactile cues perceived during swarming and mate. On the other hand, more knowledge is available for cuticular hydrocarbons, which modulate mating behavior in several species of economic importance. These compounds, coupled with volatile aggregation components, have potential interest for the development of monitoring and trapping systems. In addition, the analyses of cuticular hydrocarbons are essential for discrimination between closely related mosquito species and/or populations.

  1. Pair housing induced feeding suppression: individual housing not novelty.

    PubMed

    Lopak, V; Eikelboom, R

    Male rats that are moved from individual to pair housing suppress their feeding for a few days [O'Connor R, Eikelboom R. The effects of changes in housing on feeding and wheel running. Physiol Behav 2000;68:361-371]. The present study explored whether the suppression was a result of the period of individual housing or the novelty of the other animal. Two groups of 16 rats were pair-housed and one group of rats was individually housed for 21 days. The individually housed rats were then pair-housed (IP group) and rats in one of the pair-housed groups were re-housed with novel partners (NP group), while rats in the other pair-housed group remained with the same partner (SP group). Feeding was suppressed only for rats in the IP group, suggesting that the novelty of the partner did not suppress feeding, but rather, the change from individual to pair housing did. Water consumption was also measured, but was unaffected by the re-housing manipulation.

  2. Historic Houses.

    ERIC Educational Resources Information Center

    Curtis, Nancy

    1997-01-01

    Reviews some of the efforts of the Society for the Preservation of New England Antiquities (SPNEA) to preserve, conserve, and interpret historic houses to the public. Examines the history and some of the specific preservation problems concerning the Beauport Cottage, the Sayward-Wheeler House, and the Gropius House. (MJP)

  3. Substandard Housing.

    ERIC Educational Resources Information Center

    Milkove, Daniel L., Comp.

    1986-01-01

    Defines substandard housing and summarizes newly derived data from the 1980 Census showing that 7.5% of all rural occupied housing in the Nation was substandard. Points out regional and rural-urban differences. Notes effects on rural housing of poverty rates, percentage of nonwhite households, average household size, growth in county population,…

  4. De Havilland F-8 Mosquito

    NASA Technical Reports Server (NTRS)

    1944-01-01

    De Havilland F-8 Mosquito: Not a Royal Air Force de Havilland DH-98, but an Air Force de Havilland F-8 Mosquito. A pair of these Canadian built, U. S. Army Air Force procured aircraft were flown at Langley. The Americans used these aircraft as photo-reconnaissance and meteorological aircraft.

  5. De Havilland F-8 Mosquito

    NASA Technical Reports Server (NTRS)

    1945-01-01

    De Havilland F-8 Mosquito: This de Havilland F-8 Mosquito was flown at Langley by NACA pilot Bill Gray during longitudinal stability and control studies of the aircraft. This fast twin engine design was noteworthy for its wooden construction and its versatility.

  6. Genetic Control Of Malaria Mosquitoes.

    PubMed

    McLean, Kyle Jarrod; Jacobs-Lorena, Marcelo

    2016-03-01

    Experiments demonstrating the feasibility of genetically modifying mosquito vectors to impair their ability to transmit the malaria parasite have been known for well over a decade. However, means to spread resistance or population control genes into wild mosquito populations remains an unsolved challenge. Two recent reports give hope that CRISPR technology may allow such challenge to be overcome.

  7. Ultrastructural studies of mosquito ovogenesis.

    PubMed

    Soumaré, M L; Ndiaye, M

    2005-04-01

    The ovogenesis of four mosquito species belonging to the genera Aedes, Anopheles and Culex, are investigated using Electron microscopes. Three ovogenetic phases named previtellogenesis, vitellogenesis, postvitellogenesis and mature eggs are described using transmission electron and light microscopes. Egg ornamentations are described with scanning electron microscopy. The controversial nomenclature of the mosquito egg envelopes is discussed.

  8. Genetic Control Of Malaria Mosquitoes

    PubMed Central

    McLean, Kyle Jarrod; Jacobs-Lorena, Marcelo

    2016-01-01

    Experiments demonstrating the feasibility of genetically modifying mosquito vectors to impair their ability to transmit the malaria parasite have been known for well over a decade. However, means to spread resistance or population control genes into wild mosquito populations remains an unsolved challenge. Two recent reports give hope that CRISPR technology may allow such challenge to be overcome. PMID:26809567

  9. Zika Virus Emergence in Mosquitoes in Southeastern Senegal, 2011

    PubMed Central

    Diallo, Diawo; Sall, Amadou A.; Diagne, Cheikh T.; Faye, Oumar; Faye, Ousmane; Ba, Yamar; Hanley, Kathryn A.; Buenemann, Michaela; Weaver, Scott C.; Diallo, Mawlouth

    2014-01-01

    Background Zika virus (ZIKV; genus Flavivirus, family Flaviviridae) is maintained in a zoonotic cycle between arboreal Aedes spp. mosquitoes and nonhuman primates in African and Asian forests. Spillover into humans has been documented in both regions and the virus is currently responsible for a large outbreak in French Polynesia. ZIKV amplifications are frequent in southeastern Senegal but little is known about their seasonal and spatial dynamics. The aim of this paper is to describe the spatio-temporal patterns of the 2011 ZIKV amplification in southeastern Senegal. Methodology/Findings Mosquitoes were collected monthly from April to December 2011 except during July. Each evening from 18∶00 to 21∶00 hrs landing collections were performed by teams of 3 persons working simultaneously in forest (canopy and ground), savannah, agriculture, village (indoor and outdoor) and barren land cover sites. Mosquitoes were tested for virus infection by virus isolation and RT-PCR. ZIKV was detected in 31 of the 1,700 mosquito pools (11,247 mosquitoes) tested: Ae. furcifer (5), Ae. luteocephalus (5), Ae. africanus (5), Ae. vittatus (3), Ae. taylori, Ae. dalzieli, Ae. hirsutus and Ae. metallicus (2 each) and Ae. aegypti, Ae. unilinaetus, Ma. uniformis, Cx. perfuscus and An. coustani (1 pool each) collected in June (3), September (10), October (11), November (6) and December (1). ZIKV was detected from mosquitoes collected in all land cover classes except indoor locations within villages. The virus was detected in only one of the ten villages investigated. Conclusions/Significance This ZIKV amplification was widespread in the Kédougou area, involved several mosquito species as probable vectors, and encompassed all investigated land cover classes except indoor locations within villages. Aedes furcifer males and Aedes vittatus were found infected within a village, thus these species are probably involved in the transmission of Zika virus to humans in this environment. PMID

  10. Why housing?

    PubMed

    Aidala, Angela A; Sumartojo, Esther

    2007-11-01

    Housing/lack of housing and HIV are powerfully linked. Housing occupies an important place in the causal chains linking poverty and inequality, and HIV risk and outcomes of infection. The articles in this Special Supplement of AIDS and Behavior confirm the impact of homelessness, and poor or unstable housing, on HIV/AIDS, and challenge scientists to test and policy makers to implement the promise of housing as an innovative response to the epidemic. In order to influence the development of policies on housing to benefit at-risk or HIV-infected persons, however, proponents must justify why this association exists, and how housing can help end the epidemic as well as improve the care and health of persons living with HIV/AIDS. We introduce this supplement with a discussion of the "why" question.

  11. Mosquitoes: A Resource Book for the Classroom.

    ERIC Educational Resources Information Center

    Gillmor, Mary S.; And Others

    This booklet was written for anyone interested in growing mosquitoes and experimenting with them. There are three major sections: (1) rationale for studying mosquitoes, (2) raising mosquitoes, and (3) some scientific findings. The first section describes basic information about mosquitoes. The second section includes information about materials,…

  12. Effects of insect growth regulators on the mosquito-parasitic nematode Romanomermis iyengari.

    PubMed

    Suman, Devi Shankar; Brey, Christopher W; Wang, Yi; Sanad, Manar; Shamseldean, Muhammed S M; Gaugler, Randy

    2013-02-01

    Pyriproxyfen, a juvenile hormone analogue, diflubenzuron, a chitin synthesis inhibitor, and azadirachtin, an ecdysone agonist, are three insect growth regulators (IGRs) considered as selective and effective insecticides for mosquitoes. Romanomermis iyengari (Welch) is a mosquito-parasitic mermithid that can provide biological control against many medically important mosquito species. The compatibility of these two control tactics was tested by evaluating the sublethal effects of exposure to IGR on nematode developmental stages (preparasitic, parasitic, and preparasitic + parasitic) using Culex pipiens larvae as the host. Sublethal concentrations of IGRs were 90 % emergence inhibition of host mosquito. Preparasitic exposure to pyriproxyfen, azadirachtin, and diflurbenzuron had no effect on infectivity, parasite load, sex ratio, or male size but reduced nematode female length and increased male sex ratio at one parasite/larva. When IGRs treatments were made against the parasitic and preparasitic + parasitic stages, pyriproxyfen and azadirachtin reduced R. iyengari infectivity, parasite load, and male nematode length, whereas pyriproxyfen exposure increased male sex ratio and reduced the female R. iyengari length. Thus, IGRs have significant negative impacts on different stages of mosquito mermithid that can destabilize the balance of host-parasite population interaction. Therefore, IGRs should be used with caution in mosquito habitats where these parasites have established.

  13. Malaria parasite development in mosquitoes.

    PubMed

    Beier, J C

    1998-01-01

    Mosquitoes of the genus Anopheles transmit malaria parasites to humans. Anopheles mosquito species vary in their vector potential because of environmental conditions and factors affecting their abundance, blood-feeding behavior, survival, and ability to support malaria parasite development. In the complex life cycle of the parasite in female mosquitoes, a process termed sporogony, mosquitoes acquire gametocyte-stage parasites from blood-feeding on an infected host. The parasites carry out fertilization in the midgut, transform to ookinetes, then oocysts, which produce sporozoites. Sporozoites invade the salivary glands and are transmitted when the mosquito feeds on another host. Most individual mosquitoes that ingest gametocytes do not support development to the sporozoite stage. Bottle-necks occur at every stage of the cycle in the mosquito. Powerful new techniques and approaches exist for evaluating malaria parasite development and for identifying mechanisms regulating malaria parasite-vector interactions. This review focuses on those interactions that are important for the development of new approaches for evaluating and blocking transmission in nature.

  14. Dusk to dawn activity patterns of anopheline mosquitoes in West Timor and Java, Indonesia.

    PubMed

    Ndoen, Ermi; Wild, Clyde; Dale, Pat; Sipe, Neil; Dale, Mike

    2011-05-01

    Malaria is a serious health issue in Indonesia. We investigated the dusk to dawn anopheline mosquito activity patterns, host-seeking and resting locations in coastal plain, hilly and highland areas in West Timor and Java. Adult mosquitoes were captured landing on humans or resting in houses or animal barns. Data analyzed were: mosquito night-time activities; period of peak activity; night-time activity in specific periods of time and for mosquito resting locations. Eleven species were recorded; data were sparse for some species therefore detailed analyses were performed for four species only. In Java Anopheles vagus was common, with a bimodal pattern of high activity. In West Timor, its activity peaked around midnight. Other species with peak activity around the middle of the night were An. barbirostris and An. subpictus. Most species showed no biting and resting preference for indoors or outdoors, although An. barbirostris preferred indoors in West Timor, but outdoors in Java. An. aconitus and An. annularis preferred resting in human dwellings; An. subpictus and An. vagus preferred resting in animal barns. An. barbirostris preferred resting in human dwellings in West Timor and in animal barns in Java. The information is useful for planning the mosquito control aspect of malaria management. For example, where mosquito species have peak activity at night indoors, bednets and indoor residual spraying should reduce malaria risk, but where mosquitoes are most active outdoors, other options may be more effective.

  15. Mosquito odorant receptor for DEET and methyl jasmonate

    PubMed Central

    Xu, Pingxi; Choo, Young-Moo; De La Rosa, Alyssa; Leal, Walter S.

    2014-01-01

    Insect repellents are important prophylactic tools for travelers and populations living in endemic areas of malaria, dengue, encephalitis, and other vector-borne diseases. DEET (N,N-diethyl-3-methylbenzamide) is a 6-decade-old synthetic repellent, which is still considered the gold standard of mosquito repellents. Mosquitoes use their sense of smell to detect DEET, but there are currently two hypotheses regarding its mode of action: activation of ionotropic receptor IR40a vs. odorant receptor(s). Here, we demonstrate that DEET, picaridin, insect repellent 3535, and p-menthan-3,8-diol activate the odorant receptor CquiOR136 of the southern house mosquito, Culex quinquefasciatus. Electrophysiological and behavioral assays showed that CquiIR40a knockdown had no significant effect on DEET detection and repellency. By contrast, reduction of CquiOR136 transcript levels led to a significant decrease in electroantennographic responses to DEET and a complete lack of repellency. Thus, direct activation of an odorant receptor, not an ionotropic receptor, is necessary for DEET reception and repellency in Culex mosquitoes. Interestingly, methyl jasmonate, a repellent derived from the nonvolatile jasmonic acid in the signaling pathway of plant defenses, elicited robust responses in CquiOR136•CquiOrco-expressing Xenopus oocytes, thus suggesting a possible link between natural products with long insect–plant evolutionary history and synthetic repellents. PMID:25349401

  16. Midgut of the non-hematophagous mosquito Toxorhynchites theobaldi (Diptera, Culicidae).

    PubMed

    Godoy, Raquel S M; Fernandes, Kenner M; Martins, Gustavo F

    2015-10-30

    In most mosquito species, the females require a blood-feeding for complete egg development. However, in Toxorhynchites mosquitoes, the eggs develop without blood-feeding, and both females and males exclusively feed on sugary diets. The midgut is a well-understood organ in blood-feeding mosquitoes, but little is known about it in non-blood-feeding ones. In the present study, the detailed morphology of the midgut of Toxorhynchites theobaldi were investigated using histochemical and ultrastructural methods. The midgut of female and male T. theobaldi adults consists of a long, slender anterior midgut (AMG), and a short, dilated posterior midgut (PMG). The AMG is subdivided into AMG1 (short, with folds) and AMG2 (long, without folds). Nerve branches and enteroendocrine cells are present in AMG and PMG, respectively. Compared with the PMG of blood-feeding female mosquitoes, the PMG of T. theobaldi is smaller; however, in both mosquitoes, PMG seems be the main region of food digestion and absorption, and protein secretion. The epithelial folds present in the AMG of T. theobaldi have not been reported in other mosquitoes; however, the midgut muscle organization and endocrine control of the digestion process are conserved in both T. theobaldi and blood-feeding mosquitoes.

  17. Midgut of the non-hematophagous mosquito Toxorhynchites theobaldi (Diptera, Culicidae)

    PubMed Central

    Godoy, Raquel S. M.; Fernandes, Kenner M.; Martins, Gustavo F.

    2015-01-01

    In most mosquito species, the females require a blood-feeding for complete egg development. However, in Toxorhynchites mosquitoes, the eggs develop without blood-feeding, and both females and males exclusively feed on sugary diets. The midgut is a well-understood organ in blood-feeding mosquitoes, but little is known about it in non-blood-feeding ones. In the present study, the detailed morphology of the midgut of Toxorhynchites theobaldi were investigated using histochemical and ultrastructural methods. The midgut of female and male T. theobaldi adults consists of a long, slender anterior midgut (AMG), and a short, dilated posterior midgut (PMG). The AMG is subdivided into AMG1 (short, with folds) and AMG2 (long, without folds). Nerve branches and enteroendocrine cells are present in AMG and PMG, respectively. Compared with the PMG of blood-feeding female mosquitoes, the PMG of T. theobaldi is smaller; however, in both mosquitoes, PMG seems be the main region of food digestion and absorption, and protein secretion. The epithelial folds present in the AMG of T. theobaldi have not been reported in other mosquitoes; however, the midgut muscle organization and endocrine control of the digestion process are conserved in both T. theobaldi and blood-feeding mosquitoes. PMID:26514271

  18. Multitasking roles of mosquito labrum in oviposition and blood feeding

    PubMed Central

    Choo, Young-Moo; Buss, Garrison K.; Tan, Kaiming; Leal, Walter S.

    2015-01-01

    Reception of odorants by two main head appendages, antennae and maxillary palps, is essential for insects' survival and reproduction. There is growing evidence in the literature suggesting that the proboscis is also an olfactory appendage and its function as an additional “antenna” has been previously proposed. We surmised that movements of the labrum toward a blood vessel might be chemically oriented and, if so, there should be odorant receptors expressed in the labrum. To test this hypothesis, we first compared by quantitative PCR expression of odorant receptors (OR) from the Southern house mosquito, Culex quinquefasciatus in antennae and proboscis and, subsequently compared OR expression in various proboscis parts. Our data suggested that a receptor for the oviposition attractant, skatole, CquiOR21, was not expressed in proboscis, whereas a receptor for another oviposition attractant, 4EP (4-ethylphenol), CquiOR99, and a receptorf for the insect repellent DEET, CquiOR136, were expressed in the stylet of the proboscis, particularly in the tip of the labrum. In a dual-choice olfactometer, mosquitoes having the stylet coated with nail polish were attracted to 4EP in the same manner as the untreated mosquitoes. By contrast, in an oviposition assay, the stylet-treated mosquitoes did not discriminate 4EP from control oviposition cups, whereas the untreated mosquitoes (as well as mosquitoes having the labella coated) laid significantly more egg rafts in cups treated with 4EP. Ablation experiments confirmed that 4EP was sensed by the labrum where CquiOR99 is highly expressed. Stylet-coated, labella-coated, and untreated mosquitoes laid significantly more egg rafts in skatole-treated cups than in control cups. Likewise, coating of proboscis structures with nail polish had no effect on DEET-mediated oviposition deterrence. In a behavioral arena designed to mimic a human arm, mosquitoes showed significantly reduced probing time when blood was impregnated with 4EP, i

  19. RNA Interference for Mosquito and Mosquito-Borne Disease Control

    PubMed Central

    Airs, Paul M.; Bartholomay, Lyric C.

    2017-01-01

    RNA interference (RNAi) is a powerful tool to silence endogenous mosquito and mosquito-borne pathogen genes in vivo. As the number of studies utilizing RNAi in basic research grows, so too does the arsenal of physiological targets that can be developed into products that interrupt mosquito life cycles and behaviors and, thereby, relieve the burden of mosquitoes on human health and well-being. As this technology becomes more viable for use in beneficial and pest insect management in agricultural settings, it is exciting to consider its role in public health entomology. Existing and burgeoning strategies for insecticide delivery could be adapted to function as RNAi trigger delivery systems and thereby expedite transformation of RNAi from the lab to the field for mosquito control. Taken together, development of RNAi-based vector and pathogen management techniques & strategies are within reach. That said, tools for successful RNAi design, studies exploring RNAi in the context of vector control, and studies demonstrating field efficacy of RNAi trigger delivery have yet to be honed and/or developed for mosquito control. PMID:28067782

  20. RNA Interference for Mosquito and Mosquito-Borne Disease Control.

    PubMed

    Airs, Paul M; Bartholomay, Lyric C

    2017-01-05

    RNA interference (RNAi) is a powerful tool to silence endogenous mosquito and mosquito-borne pathogen genes in vivo. As the number of studies utilizing RNAi in basic research grows, so too does the arsenal of physiological targets that can be developed into products that interrupt mosquito life cycles and behaviors and, thereby, relieve the burden of mosquitoes on human health and well-being. As this technology becomes more viable for use in beneficial and pest insect management in agricultural settings, it is exciting to consider its role in public health entomology. Existing and burgeoning strategies for insecticide delivery could be adapted to function as RNAi trigger delivery systems and thereby expedite transformation of RNAi from the lab to the field for mosquito control. Taken together, development of RNAi-based vector and pathogen management techniques & strategies are within reach. That said, tools for successful RNAi design, studies exploring RNAi in the context of vector control, and studies demonstrating field efficacy of RNAi trigger delivery have yet to be honed and/or developed for mosquito control.

  1. Mathematical Modeling of Sterile Insect Technology for Control of Anopheles Mosquito

    NASA Astrophysics Data System (ADS)

    Anguelov, R.; Dumont, Y.; Lubuma, J.

    2011-11-01

    Sterile Insect Technology (SIT) is a nonpolluting method of insect control that relies on the release of sterile males. We study the effectiveness of the application of SIT for control of Anopheles mosquito via mathematical modeling. The theoretical analysis of the mathematical model as a dynamical system leads to the formulation of possible strategies for control of the Anopheles mosquito, also illustrated by numerical simulations.

  2. Synthesis and Bioassay of Improved Mosquito Repellents Predicted From Chemical Structure

    DTIC Science & Technology

    2008-05-27

    substituted n-alkanesulfonamides as repellents for the yellow fever mosquito and the German cockroach . J Econ Entomol 67:71–73. 15. McGovern TP... Cockroach repellents. US patent 6,625,329; (1985) Chem Abstr 102:144859. 34. House HO, Lee LF (1976) A new synthesis of 2-alkylpyrrolidines and 2

  3. Mosquito Bite Prevention For Travelers

    MedlinePlus

    ... is an insecticide that kills mosquitoes and other insects. - Do not wash bed nets or expose them ... for extra protection. Use only an EPA-registered insect repellent Consider bringing insect repellent with you. Always ...

  4. Rental Housing.

    ERIC Educational Resources Information Center

    American Association of Retired Persons, Washington, DC. Consumer Housing Information Service for Seniors.

    This is one of a series of booklets prepared as a resource for trained Housing Information Volunteers to provide impartial information to older people who have questions of concern about how to find safe, comfortable, affordable housing; how to cut household expenses or use their homes to earn extra income; home maintenance and home improvement;…

  5. Housing Deprivation

    ERIC Educational Resources Information Center

    Atkinson, Reilly

    1975-01-01

    This testimony, before a public hearing of the New York City Commission on Human Rights in May 1974, summarizes the implications of a study done at the Joint Center for Urban Studies of the number and characteristics of families that will buy a house, and what kind of housing problems they have, for the relative status of blacks or whites or other…

  6. Clay Houses

    ERIC Educational Resources Information Center

    Pedro, Cathy

    2011-01-01

    In this article, the author describes a project designed for fourth-graders that involves making clay relief sculptures of houses. Knowing the clay houses will become a family heirloom makes this lesson even more worth the time. It takes three classes to plan and form the clay, and another two to underglaze and glaze the final products.

  7. Heritability of Attractiveness to Mosquitoes

    PubMed Central

    Fernández-Grandon, G. Mandela; Gezan, Salvador A.; Armour, John A. L.; Pickett, John A.; Logan, James G.

    2015-01-01

    Female mosquitoes display preferences for certain individuals over others, which is determined by differences in volatile chemicals produced by the human body and detected by mosquitoes. Body odour can be controlled genetically but the existence of a genetic basis for differential attraction to insects has never been formally demonstrated. This study investigated heritability of attractiveness to mosquitoes by evaluating the response of Aedes aegypti (=Stegomyia aegypti) mosquitoes to odours from the hands of identical and non-identical twins in a dual-choice assay. Volatiles from individuals in an identical twin pair showed a high correlation in attractiveness to mosquitoes, while non-identical twin pairs showed a significantly lower correlation. Overall, there was a strong narrow-sense heritability of 0.62 (SE 0.124) for relative attraction and 0.67 (0.354) for flight activity based on the average of ten measurements. The results demonstrate an underlying genetic component detectable by mosquitoes through olfaction. Understanding the genetic basis for attractiveness could create a more informed approach to repellent development. PMID:25901606

  8. Environmentally friendly tool to control mosquito populations without risk of insecticide resistance: the Lehmann’s funnel entry trap

    PubMed Central

    2013-01-01

    Background Current malaria control strategies have cut down the malaria burden in many endemic areas, however the emergence and rapid spread of insecticide and drug resistance undermine the success of these efforts. There is growing concern that malaria eradication will not be achieved without the introduction of novel control tools. One approach that has been developed in the last few years is based on house screening to reduce indoor mosquito vector densities and consequently decrease malaria transmission. Here screening and trapping were combined in one tool to control mosquito populations. The trap does not require an insecticide or even an attractant, yet it effectively collects incoming resistant and susceptible mosquitoes and kills them. Results Performance of the funnel entry trap was tested in low and high malaria vector density areas. An overall reduction of 70 to 80% of mosquito density was seen in both. Species and molecular forms of Anopheles gambiae identification indicated no variation in the number of Anopheles arabiensis and the molecular forms of An. gambiae between houses and traps. Mosquitoes collected in the traps and in houses were highly resistant to pyrethroids (0.9 kdr-based mechanism). Conclusion There is a global consensus that new intervention tools are needed to cross the last miles in malaria elimination/eradication. The funnel entry trap showed excellent promise in suppressing mosquito densities even in area of high insecticide resistance. It requires no chemicals and is self-operated. PMID:23758904

  9. An annotated list of the mosquitoes (Diptera: Culicidae) of Mississippi.

    PubMed

    Goddard, Jerome; Varnado, Wendy C; Harrison, Bruce A

    2010-06-01

    There has been no previous systematic statewide study of mosquitoes in Mississippi. This survey, resulting in the collection of over 400,000 specimens, was conducted by the authors from 2003 to 2007 throughout much of the state using CO2-baited CDC light traps and larval dipping. In addition, a health department contract mosquito surveillance technician collected several thousand specimens from the state from 2001 to 2003. Lastly, specimens housed at the Mississippi State University Entomological Museum, obtained from previous surveys, were included as vouchers for species occurring in the state. The collection records and literature show 60 species as occurring or having occurred in Mississippi. Voucher specimens representing 57 of the 60 species discussed are deposited in the Mississippi Entomological Museum or in the U.S. National Museum of Natural History (USNM), Washington, D.C.

  10. Quantitative analysis of harmonic convergence in mosquito auditory interactions

    PubMed Central

    Aldersley, Andrew; Champneys, Alan; Robert, Daniel

    2016-01-01

    This article analyses the hearing and behaviour of mosquitoes in the context of inter-individual acoustic interactions. The acoustic interactions of tethered live pairs of Aedes aegypti mosquitoes, from same and opposite sex mosquitoes of the species, are recorded on independent and unique audio channels, together with the response of tethered individual mosquitoes to playbacks of pre-recorded flight tones of lone or paired individuals. A time-dependent representation of each mosquito's non-stationary wing beat frequency signature is constructed, based on Hilbert spectral analysis. A range of algorithmic tools is developed to automatically analyse these data, and used to perform a robust quantitative identification of the ‘harmonic convergence’ phenomenon. The results suggest that harmonic convergence is an active phenomenon, which does not occur by chance. It occurs for live pairs, as well as for lone individuals responding to playback recordings, whether from the same or opposite sex. Male–female behaviour is dominated by frequency convergence at a wider range of harmonic combinations than previously reported, and requires participation from both partners in the duet. New evidence is found to show that male–male interactions are more varied than strict frequency avoidance. Rather, they can be divided into two groups: convergent pairs, typified by tightly bound wing beat frequencies, and divergent pairs, that remain widely spaced in the frequency domain. Overall, the results reveal that mosquito acoustic interaction is a delicate and intricate time-dependent active process that involves both individuals, takes place at many different frequencies, and which merits further enquiry. PMID:27053654

  11. Host Reproductive Phenology Drives Seasonal Patterns of Host Use in Mosquitoes

    PubMed Central

    Burkett-Cadena, Nathan D.; McClure, Christopher J. W.; Ligon, Russell A.; Graham, Sean P.; Guyer, Craig; Hill, Geoffrey E.; Ditchkoff, Stephen S.; Eubanks, Micky D.; Hassan, Hassan K.; Unnasch, Thomas R.

    2011-01-01

    Seasonal shifts in host use by mosquitoes from birds to mammals drive the timing and intensity of annual epidemics of mosquito-borne viruses, such as West Nile virus, in North America. The biological mechanism underlying these shifts has been a matter of debate, with hypotheses falling into two camps: (1) the shift is driven by changes in host abundance, or (2) the shift is driven by seasonal changes in the foraging behavior of mosquitoes. Here we explored the idea that seasonal changes in host use by mosquitoes are driven by temporal patterns of host reproduction. We investigated the relationship between seasonal patterns of host use by mosquitoes and host reproductive phenology by examining a seven-year dataset of blood meal identifications from a site in Tuskegee National Forest, Alabama USA and data on reproduction from the most commonly utilized endothermic (white-tailed deer, great blue heron, yellow-crowned night heron) and ectothermic (frogs) hosts. Our analysis revealed that feeding on each host peaked during periods of reproductive activity. Specifically, mosquitoes utilized herons in the spring and early summer, during periods of peak nest occupancy, whereas deer were fed upon most during the late summer and fall, the period corresponding to the peak in births for deer. For frogs, however, feeding on early- and late-season breeders paralleled peaks in male vocalization. We demonstrate for the first time that seasonal patterns of host use by mosquitoes track the reproductive phenology of the hosts. Peaks in relative mosquito feeding on each host during reproductive phases are likely the result of increased tolerance and decreased vigilance to attacking mosquitoes by nestlings and brooding adults (avian hosts), quiescent young (avian and mammalian hosts), and mate-seeking males (frogs). PMID:21408172

  12. Mosquito defense strategies against viral infection

    PubMed Central

    Cheng, Gong; Liu, Yang; Wang, Penghua; Xiao, Xiaoping

    2015-01-01

    Mosquito-borne viral diseases are a major concern of global health and result in significant economic losses in many countries. As natural vectors, mosquitoes are very permissive to and allow systemic and persistent arbovirus infection. Intriguingly, persistent viral propagation in mosquito tissues neither results in dramatic pathological sequelae nor impairs the vectorial behavior or lifespan, indicating that mosquitoes have evolved mechanisms to tolerate persistent infection and developed efficient antiviral strategies to restrict viral replication to non-pathogenic levels. Here, we provide an overview of recent progress in understanding mosquito antiviral immunity and advances in the strategies by which mosquitoes control viral infection in specific tissues. PMID:26626596

  13. Mosquito Host Selection Varies Seasonally with Host Availability and Mosquito Density

    PubMed Central

    Thiemann, Tara C.; Wheeler, Sarah S.; Barker, Christopher M.; Reisen, William K.

    2011-01-01

    Host selection by vector mosquitoes is a critical component of virus proliferation, particularly for viruses such as West Nile (WNV) that are transmitted enzootically to a variety of avian hosts, and tangentially to dead-end hosts such as humans. Culex tarsalis is a principal vector of WNV in rural areas of western North America. Based on previous work, Cx. tarsalis utilizes a variety of avian and mammalian hosts and tends to feed more frequently on mammals in the late summer than during the rest of the year. To further explore this and other temporal changes in host selection, bloodfed females were collected at a rural farmstead and heron nesting site in Northern California from May 2008 through May 2009, and bloodmeal hosts identified using either a microsphere-based array or by sequencing of the mitochondrial cytochrome c oxidase I (COI) gene. Host composition during summer was dominated by four species of nesting Ardeidae. In addition, the site was populated with various passerine species as well as domestic farm animals and humans. When present, Cx. tarsalis fed predominantly (>80%) upon the ardeids, with Black-crowned Night-Herons, a highly competent WNV host, the most prevalent summer host. As the ardeids fledged and left the area and mosquito abundance increased in late summer, Cx. tarsalis feeding shifted to include more mammals, primarily cattle, and a high diversity of avian species. In the winter, Yellow-billed Magpies and House Sparrows were the predominant hosts, and Yellow-billed Magpies and American Robins were fed upon more frequently than expected given their relative abundance. These data demonstrated that host selection was likely based both on host availability and differences in utilization, that the shift of bloodfeeding to include more mammalian hosts was likely the result of both host availability and increased mosquito abundance, and that WNV-competent hosts were fed upon by Cx. tarsalis throughout the year. PMID:22206038

  14. Housing and health transition in Thailand.

    PubMed

    Friel, S; McMichael, A J; Kjellstrom, T; Prapamontol, T

    2004-01-01

    Over the past half-century, Thailand's health profile has been undergoing an epidemiologic transition in association with various fundamental societal changes, shifting from one with a predominant burden of communicable disease to one in which noncommunicable diseases and accidents now predominate. The primary question is why have the disease rates in the Thai population changed? Answering this question requires an examination of the underlying transitions in social and contextual factors. This paper explores, using published data, how housing conditions, as one set of environmental health risks, have undergone transition in recent years and how this change maps on the health-transition process. A combination of economic development, urbanization, modernization, and increased health literacy resulted in a range of health-protecting changes in housing design and materials. Pre-eminent among such changes are improvements in household sanitation and in equipment, ventilation, and fuel pertaining to indoor cooking and heating. In tropical countries like Thailand, gains have been made in mosquito-proofing houses and in minimizing open pools of water to combat the risks of malaria, dengue fever, and other mosquito-borne infections. Meanwhile, the growth in shantytown and slum housing around the urban fringe, often in precarious environmental settings, introduced a negative dimension to the evolving profile of housing-related health risks, whereas the urban sprawl of modern residences creates health risks that are due to traffic crashes and the lack of walking in daily transport.

  15. Towards mosquito sterile insect technique programmes: exploring genetic, molecular, mechanical and behavioural methods of sex separation in mosquitoes.

    PubMed

    Gilles, Jeremie R L; Schetelig, Marc F; Scolari, Francesca; Marec, František; Capurro, Margareth L; Franz, Gerald; Bourtzis, Kostas

    2014-04-01

    When considering a mosquito release programme, one of the first issues to be addressed is how to eliminate/separate the females. The greatest number of options might eventually be available for those who can use transgenic mosquitoes, but the inherent characteristics of the target species may also provide possibilities for interim measures until more efficient methods can be developed. Differences in intrinsic size, in behaviour and in development rate between females and males are often available and useful for sexing. Efficient species-specific systems for eliminating females at the embryo stage have been developed, but most have since been discarded due to lack of use. Ideal systems specifically kill female embryos using some treatment that can be manipulated during production. Such killing systems are far more efficient than using intrinsic sexual differences, but they systems require selectable genetic markers and sex-linkage created by rare random chromosomal rearrangements. While intrinsic sexual differences should not be considered as long-term candidates for the development of robust and efficient sexing approaches, in the absence of these, the accessibility and integration of less efficient systems can provide a stop-gap measure that allows rapid start up with a minimum of investment. The International Atomic Energy Agency is funding over a 5 year period (2013-2018) a new Coordinated Research Project on "Exploring Genetic, Molecular, Mechanical and Behavioural Methods of Sex Separation in Mosquitoes" to network researchers and to address the critical need of genetic sexing strains for the implementation of the sterile insect technique (using radiation-sterilised or transgenic male mosquitoes) and for insect incompatibility technique programmes against disease-transmitting mosquitoes.

  16. House Rules.

    ERIC Educational Resources Information Center

    Hammel, Bette

    2001-01-01

    Discusses the "house" concept architectural design at Albert Lea High School (Minnesota) and how the design addresses the community's 21st Century educational goals. Photos and a floor plan are included. (GR)

  17. Controlling Mosquitoes at the Larval Stage

    EPA Pesticide Factsheets

    Larvicides target larvae in the breeding habitat before they can mature into adult mosquitoes and disperse. Larvicide treatment of breeding habitats help reduce the adult mosquito population in nearby areas.

  18. Scientists Create Mosquitoes Resistant to Dengue Virus

    MedlinePlus

    ... fullstory_163019.html Scientists Create Mosquitoes Resistant to Dengue Virus Hope is to eventually make the bugs ... say they have created mosquitoes resistant to the dengue virus, which might eventually help control the spread ...

  19. The effect of the radio-protective agents ethanol, trimethylglycine, and beer on survival of X-ray-sterilized male Aedes aegypti

    PubMed Central

    2013-01-01

    Background Sterile Insect Technique (SIT) has been successfully implemented to control, and in some cases, eradicate, dipteran insect populations. SIT has great potential as a mosquito control method. Different sterilization methods have been used on mosquitoes ranging from chemosterilization to genetically modified sterile male mosquito strains; however, sterilization with ionizing radiation is the method of choice for effective sterilization of male insects for most species. The lack of gentle radiation methods has resulted in significant complications when SIT has been applied to mosquitoes. Several studies report that irradiating mosquitoes resulted in a decrease in longevity and mating success compared to unirradiated males. The present study explored new protocols for mosquito sterilization with ionizing radiation that minimized detrimental effects on the longevity of irradiated males. Methods We tested three compounds that have been shown to act as radioprotectors in the mouse model system - ethanol, trimethylglycine, and beer. Male Aedes aegypti were treated with one of three chosen potential radioprotectors and were subsequently irradiated with identical doses of long-wavelength X-rays. We evaluated the effect of these radioprotectors on the longevity of male mosquito after irradiation. Results We found that X-ray irradiation with an absorbed dose of 1.17 gy confers complete sterility. Irradiation with this dose significantly shortened the lifespan of male mosquitoes and all three radioprotectors tested significantly enhanced the lifespan of irradiated mosquito males. Conclusion Our results suggest that treatment with ethanol, beer, or trimethylglycine before irradiation can be used to enhance longevity in mosquitoes. PMID:23866939

  20. Mosquitoes on the Wing ``Tune In'' to Acoustic Distortion

    NASA Astrophysics Data System (ADS)

    Warren, Ben; Russell, Ian

    2011-11-01

    Our current understanding of the mating game for many mosquito species is that males aggregate in noisy mating swarms and listen with their Johnston's organs (JOs) for the deeper flight tones of approaching females, to which they are attracted. As has been demonstrated, at least for the most intensely studied vector species, the mechanical resonance of the flagellum and the frequency range of the female's JO is far below that of the male's flight tones. Therefore, it has been assumed that females do not use hearing to detect the presence of males. Here we reveal that this may not be the case, and that the JOs of female Culex quinquefasciatus are exquisitely tuned to low frequency distortion products in the vibrations of the antenna due to a nonlinear interaction between her own flight tones and those of a nearby male. She can hear male flight tones by virtue of, and not despite, hearing her own flight tones.

  1. A novel olfactory pathway is essential for fast and efficient blood-feeding in mosquitoes

    PubMed Central

    Won Jung, Je; Baeck, Seung-Jae; Perumalsamy, Haribalan; Hansson, Bill S.; Ahn, Young-Joon; Kwon, Hyung Wook

    2015-01-01

    In mosquitoes, precise and efficient finding of a host animal is crucial for survival. One of the poorly understood aspects of mosquito blood-feeding behavior is how these insects target an optimal site in order to penetrate the skin and blood vessels without alerting the host animal. Here we provide new findings that a piercing structure of the mouthpart of the mosquitoes, the stylet, is an essential apparatus for the stage in blood feeding. Indeed, the stylet possesses a number of sensory hairs located at the tip of the stylet. These hairs house olfactory receptor neurons that express two conventional olfactory receptors of Aedes aegypti (AaOrs), AaOr8 and AaOr49, together with the odorant co-receptor (AaOrco). In vivo calcium imaging using transfected cell lines demonstrated that AaOr8 and AaOr49 were activated by volatile compounds present in blood. Inhibition of gene expression of these AaOrs delayed blood feeding behaviors of the mosquito. Taken together, we identified olfactory receptor neurons in the stylet involved in mosquito blood feeding behaviors, which in turn indicates that olfactory perception in the stylet is necessary and sufficient for mosquitoes to find host blood in order to rapidly acquire blood meals from a host animal. PMID:26306800

  2. Complete Dosage Compensation in Anopheles stephensi and the Evolution of Sex-Biased Genes in Mosquitoes

    PubMed Central

    Jiang, Xiaofang; Biedler, James K.; Qi, Yumin; Hall, Andrew Brantley; Tu, Zhijian

    2015-01-01

    Complete dosage compensation refers to hyperexpression of the entire X or Z chromosome in organisms with heterogametic sex chromosomes (XY male or ZW female) in order to compensate for having only one copy of the X or Z chromosome. Recent analyses suggest that complete dosage compensation, as in Drosophila melanogaster, may not be the norm. There has been no systematic study focusing on dosage compensation in mosquitoes. However, analysis of dosage compensation in Anopheles mosquitoes provides opportunities for evolutionary insights, as the X chromosome of Anopheles and that of its Dipteran relative, D. melanogaster formed independently from the same ancestral chromosome. Furthermore, Culicinae mosquitoes, including the Aedes genus, have homomorphic sex-determining chromosomes, negating the need for dosage compensation. Thus, Culicinae genes provide a rare phylogenetic context to investigate dosage compensation in Anopheles mosquitoes. Here, we performed RNA-seq analysis of male and female samples of the Asian malaria mosquito Anopheles stephensi and the yellow fever mosquito Aedes aegypti. Autosomal and X-linked genes in An. stephensi showed very similar levels of expression in both males and females, indicating complete dosage compensation. The uniformity of average expression levels of autosomal and X-linked genes remained when An. stephensi gene expression was normalized by that of their Ae. aegypti orthologs, strengthening the finding of complete dosage compensation in Anopheles. In addition, we comparatively analyzed the differentially expressed genes between adult males and adult females in both species, investigated sex-biased gene chromosomal distribution patterns in An. stephensi and provided three examples where gene duplications may have enabled the acquisition of sex-specific expression during mosquito evolution. PMID:26078263

  3. Update on the American Mosquito Control Association

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The American Mosquito Control Association in a non-profit scientific organization dedicated to promoting the highest standard in professional mosquito control. It is comprised of more than 1300 members representing students, scientists, regulators, industry, mosquito control employees and many other...

  4. An insight into the sialotranscriptome of the non-blood feeding Toxorhynchites amboinensis mosquito

    PubMed Central

    Calvo, E.; Pham, V. M.; Ribeiro, J. M. C.

    2008-01-01

    All adult mosquitoes take sugar meals, and most adult females also take blood meals to develop eggs. Salivary glands (SG) of males are thus much smaller and do not contain many of the antihemostatic and antiinflammatory compounds found in females. In the past 5 years, transcriptome analyses have identified nearly 70 different genes expressed in adult female SG. For most of these, no function can be assigned in either blood or sugar feeding. Exceptionally, Toxorhynchites mosquitoes are unusual in that they never feed on blood, and the SG of adults are identical in both sexes. Transcriptome analysis of the adult SG of this mosquito was performed to increase knowledge of the evolution of blood feeding—and to identify polypeptide families associated with sugar feeding—in mosquitoes. PMID:18405828

  5. Artificial natural selection: can supplemental feeding domesticate mosquitoes and control mosquito-borne diseases?

    PubMed

    Egeth, Marc; Kurzban, Robert

    2012-08-29

    A new method is proposed for controlling mosquito-borne diseases. In particular, instead of trying to kill mosquitoes, we suggest provisioning them with food from artificial feeders. Because mosquito populations are frequently limited by ecological factors other than blood meals, such as the availability of egg-laying sites, feeding mosquitoes would not necessarily increase the total number of mosquitoes, but could reduce the number of human-drawn mosquito meals. Like mosquito traps, feeders could divert biting mosquitoes away from people by means of lures, but, after diversion, prevent subsequent human bites by satiating the mosquitoes instead of killing them. Mosquito feeders might reduce the problem of the evolution of resistance to control: in an ecology with mosquito feeders, which provide safe and abundant calories for adult female mosquitoes, there could be selection for preferring (rather than avoiding) feeders, which could eventually lead to a population of feeder-preferring mosquitoes. Artificial feeders also offer the chance to introduce novel elements into the mosquito diet, such as anti- malarial or other anti-parasitic agents. Feeders might directly reduce human bites and harnesses the power of natural selection by selectively favoring feeder-preferring (rather than trap-resistant) mosquitoes.

  6. Active auditory mechanics in mosquitoes.

    PubMed Central

    Göpfert, M. C.; Robert, D.

    2001-01-01

    In humans and other vertebrates, hearing is improved by active contractile properties of hair cells. Comparable active auditory mechanics is now demonstrated in insects. In mosquitoes, Johnston's organ transduces sound-induced vibrations of the antennal flagellum. A non-muscular 'motor' activity enhances the sensitivity and tuning of the flagellar mechanical response in physiologically intact animals. This motor is capable of driving the flagellum autonomously, amplifying sound-induced vibrations at specific frequencies and intensities. Motor-related electrical activity of Johnston's organ strongly suggests that mosquito hearing is improved by mechanoreceptor motility. PMID:11270428

  7. A quantitative mosquito survey of 7 villages in Punjab Province, Pakistan with notes on bionomics, sampling methodology and the effects of insecticides.

    PubMed

    Reisen, W K

    1978-12-01

    A total of 451,337 female and male mosquitoes comprising 43 species in 9 genera were collected during a quantitative survey of 7 suburban and rural villages in the Lahore area during 1976 and 1977 using larval, indoor resting, outdoor resting, biting and light trap collections at weekly intervals. Culex tritaeniorhynchus was the most abundant species collected comprising 51.8% of the total specimens, followed by Cx. quinquefasciatus (16.4%), Cx. pseudovishnui (6.8%), An. subpictus (4.8%) and An. culicifacies (4.7%). Bovid bait collections provided the greatest diversity and highest numbers of mosquitoes per unit of collection effort, while light traps provided the poorest diversity and lowest numbers of specimens. Most species exhibited a bimodal seasonal abundance pattern, with peaks occurring in late spring and after the cessation of the heavy monsoon rains. The spraying of houses and cattle sheds with organophosphorous insecticides was effective in controlling the endophilic resting vectors of human Plasmodia, An. culicifacies and An. stephensi, but had little effect on the partially or completely exophilic resting species.

  8. Looking Backward, Looking Forward: The Long, Torturous Struggle with Mosquitoes

    PubMed Central

    Patterson, Gordon M.

    2016-01-01

    The American anti-mosquito movement grew out of the discovery of the role of mosquitoes in transferring pathogens and public concern about pest and nuisance mosquitoes in the late 1800s. In the 20th century, organized mosquito control in the United States passed through three eras: mechanical, chemical, and integrated mosquito control. Mosquito control in the 21st century faces the challenge of emerging pathogens, invasive mosquito species, and balancing concerns about the environment with effective control strategies. PMID:27775554

  9. Exploiting mosquito sugar feeding to detect mosquito-borne pathogens

    PubMed Central

    Hall-Mendelin, Sonja; Ritchie, Scott A.; Johansen, Cheryl A.; Zborowski, Paul; Cortis, Giles; Dandridge, Scott; Hall, Roy A.; van den Hurk, Andrew F.

    2010-01-01

    Arthropod-borne viruses (arboviruses) represent a global public health problem, with dengue viruses causing millions of infections annually, while emerging arboviruses, such as West Nile, Japanese encephalitis, and chikungunya viruses have dramatically expanded their geographical ranges. Surveillance of arboviruses provides vital data regarding their prevalence and distribution that may be utilized for biosecurity measures and the implementation of disease control strategies. However, current surveillance methods that involve detection of virus in mosquito populations or sero-conversion in vertebrate hosts are laborious, expensive, and logistically problematic. We report a unique arbovirus surveillance system to detect arboviruses that exploits the process whereby mosquitoes expectorate virus in their saliva during sugar feeding. In this system, infected mosquitoes captured by CO2-baited updraft box traps are allowed to feed on honey-soaked nucleic acid preservation cards within the trap. The cards are then analyzed for expectorated virus using real-time reverse transcription-PCR. In field trials, this system detected the presence of Ross River and Barmah Forest viruses in multiple traps deployed at two locations in Australia. Viral RNA was preserved for at least seven days on the cards, allowing for long-term placement of traps and continuous collection of data documenting virus presence in mosquito populations. Furthermore no mosquito handling or processing was required and cards were conveniently shipped to the laboratory overnight. The simplicity and efficacy of this approach has the potential to transform current approaches to vector-borne disease surveillance by streamlining the monitoring of pathogens in vector populations. PMID:20534559

  10. Mosquito and Blackfly Category Manual.

    ERIC Educational Resources Information Center

    Bowman, James S.; And Others

    This manual provides information needed to meet the standards for pesticide applicator certification. Section one is concerned with the morphology, life cycle and breeding areas of mosquitoes and the diseases resulting from their presence. The second section covers similar categories in relation to the black fly population. Calculation methods and…

  11. Systematics of Aedes Mosquito Project

    DTIC Science & Technology

    1988-01-25

    viruses , six of which cause human illness (Chikungunya, dengue 1 and 2, Dugbe, Rift Valley Fever, yellow fever and Zika ). Chikungunya, dengue and...superficial and inadequate to accurately identify specimens that are critically needed for mosquito surveys, virus isolation and epidemiological

  12. Human and mosquito infections by dengue viruses during and after epidemics in a dengue-endemic region of Colombia.

    PubMed

    Méndez, Fabián; Barreto, Mauricio; Arias, Juan F; Rengifo, Graciela; Muñoz, Jaime; Burbano, María E; Parra, Beatriz

    2006-04-01

    We conducted a study in a dengue-endemic area of Colombia to evaluate the dynamics of transmission of dengue viruses during and after epidemics. Information was simultaneously gathered about occurrence of infection in humans and mosquitoes every three months in four cities with endemic transmission. Viral isolation was confirmed in 6.7% of the persons and most were asymptomatic. Adult mosquito and larvae house indexes were not found associated with increased burden of disease. The only entomologic indicator related to dengue infection in humans was the pooled infection rate of mosquitoes. Aedes aegypti infection rates showed significant differences between the epidemic (10.68, 95% confidence interval [CI] = 7.04-15.62) and after epidemic periods of the study (6.15, 95% CI = 3.46-10.19). In addition, Ae. albopictus were also infected with dengue viruses. Increases in mosquito infection rates were associated with increases in human infection rates in the following trimester.

  13. Housing Projects.

    ERIC Educational Resources Information Center

    Schmalz, Georgann

    1985-01-01

    Building specifications for birdhouses (nesting boxes) are given for 11 species (chickadee, titmouse, nuthatch, Carolina wren, house wren, downy woodpecker, hairy woodpecker, flicker, bluebird, screech owl, and wood duck) including length, width, depth, entrance diameter, and height above the ground. Pointers for construction, materials, and…

  14. Evaluation of a peridomestic mosquito trap for integration into an Aedes aegypti (Diptera: Culicidae) push-pull control strategy.

    PubMed

    Salazar, Ferdinand V; Achee, Nicole L; Grieco, John P; Prabaripai, Atchariya; Eisen, Lars; Shah, Pankhil; Chareonviriyaphap, Theeraphap

    2012-06-01

    We determined the feasibility of using the BG-Sentinel™ mosquito trap (BGS) as the pull component in a push-pull strategy to reduce indoor biting by Aedes aegypti. This included evaluating varying numbers of traps (1-4) and mosquito release numbers (10, 25, 50, 100, 150, 200, and 250) on recapture rates under screen house conditions. Based on these variations in trap and mosquito numbers, release intervals were rotated through a completely randomized design with environmental factors (temperature, relative humidity, and light intensity) and monitored throughout each experiment. Data from four sampling time points (05:30, 09:30, 13:30, and 17:30) indicate a recapture range among treatments of 66-98%. Furthermore, 2-3 traps were as effective in recapturing mosquitoes as 4 traps for all mosquito release numbers. Time trends indicate Day 1 (the day the mosquitoes were released) as the "impact period" for recapture with peak numbers of marked mosquitoes collected at 09:30 or 4 h post-release. Information from this study will be used to guide the configuration of the BGS trap component of a push-pull vector control strategy currently in the proof-of-concept stage of development in Thailand and Peru.

  15. Factors influencing infection and transmission of Anopheles gambiae densovirus (AgDNV) in mosquitoes

    PubMed Central

    2016-01-01

    Anopheles gambiae densovirus (AgDNV) is a potential microbial agent for paratransgenesis and gene transduction in An. gambiae, the major vector of human malaria in sub-Saharan Africa. Understanding the interaction between AgDNV and An. gambiae is critical for using AgDNV in a basic and applied manner for Anopheles gene manipulation. Here, we tested the effects of mosquito age, sex, blood feeding status, and potential for horizontal transmission using an enhanced green fluorescent protein (EGFP) reporter AgDNV system. Neither mosquito age at infection nor feeding regime affected viral titers. Female mosquitoes were more permissive to viral infection than males. Despite low viral titers, infected males were able to venereally transmit virus to females during mating, where the virus was localized with the transferred sperm in the spermathecae. These findings will be useful for designing AgDNV-based strategies to manipulate Anopheles gambiae. PMID:27867767

  16. Factors influencing infection and transmission of Anopheles gambiae densovirus (AgDNV) in mosquitoes.

    PubMed

    Barik, Tapan K; Suzuki, Yasutsugu; Rasgon, Jason L

    2016-01-01

    Anopheles gambiae densovirus (AgDNV) is a potential microbial agent for paratransgenesis and gene transduction in An. gambiae, the major vector of human malaria in sub-Saharan Africa. Understanding the interaction between AgDNV and An. gambiae is critical for using AgDNV in a basic and applied manner for Anopheles gene manipulation. Here, we tested the effects of mosquito age, sex, blood feeding status, and potential for horizontal transmission using an enhanced green fluorescent protein (EGFP) reporter AgDNV system. Neither mosquito age at infection nor feeding regime affected viral titers. Female mosquitoes were more permissive to viral infection than males. Despite low viral titers, infected males were able to venereally transmit virus to females during mating, where the virus was localized with the transferred sperm in the spermathecae. These findings will be useful for designing AgDNV-based strategies to manipulate Anopheles gambiae.

  17. First field evidence for natural vertical transmission of West Nile virus in Culex univittatus complex mosquitoes from Rift Valley province, Kenya.

    PubMed

    Miller, B R; Nasci, R S; Godsey, M S; Savage, H M; Lutwama, J J; Lanciotti, R S; Peters, C J

    2000-02-01

    West Nile virus is a mosquito borne flavivirus endemic over a large geographic area including Africa, Asia, and the Middle East. Although the virus generally causes a mild, self-limiting febrile illness in humans, it has sporadically caused central nervous system infections during epidemics. An isolate of West Nile virus was obtained from a pool of four male Culex univittatus complex mosquitoes while we were conducting an investigation of Rift Valley fever along the Kenya-Uganda border in February-March 1998. This represents the first field isolation of West Nile virus from male mosquitoes and strongly suggests that vertical transmission of the virus occurs in the primary maintenance mosquito vector in Kenya. A phylogenetic analysis of the complete amino acid sequence of the viral envelope glycoprotein demonstrated a sister relationship with a Culex pipiens mosquito isolate from Romania made in 1996. This unexpected finding probably reflects the role of migratory birds in disseminating West Nile virus between Africa and Europe.

  18. Eave Screening and Push-Pull Tactics to Reduce House Entry by Vectors of Malaria

    PubMed Central

    Menger, David J.; Omusula, Philemon; Wouters, Karlijn; Oketch, Charles; Carreira, Ana S.; Durka, Maxime; Derycke, Jean-Luc; Loy, Dorothy E.; Hahn, Beatrice H.; Mukabana, Wolfgang R.; Mweresa, Collins K.; van Loon, Joop J. A.; Takken, Willem; Hiscox, Alexandra

    2016-01-01

    Long-lasting insecticidal nets and indoor residual spraying have contributed to a decline in malaria over the last decade, but progress is threatened by the development of physiological and behavioral resistance of mosquitoes against insecticides. Acknowledging the need for alternative vector control tools, we quantified the effects of eave screening in combination with a push-pull system based on the simultaneous use of a repellent (push) and attractant-baited traps (pull). Field experiments in western Kenya showed that eave screening, whether used in combination with an attractant-baited trap or not, was highly effective in reducing house entry by malaria mosquitoes. The magnitude of the effect varied for different mosquito species and between two experiments, but the reduction in house entry was always considerable (between 61% and 99%). The use of outdoor, attractant-baited traps alone did not have a significant impact on mosquito house entry but the high number of mosquitoes trapped outdoors indicates that attractant-baited traps could be used for removal trapping, which would enhance outdoor as well as indoor protection against mosquito bites. As eave screening was effective by itself, addition of a repellent was of limited value. Nevertheless, repellents may play a role in reducing outdoor malaria transmission in the peridomestic area. PMID:26834195

  19. Smart Houses

    NASA Technical Reports Server (NTRS)

    1987-01-01

    GWS takes plans for a new home and subjects them to intensive computerized analysis that does 10,000 calculations relative to expected heat loss and heat gain, then provides specifications designed specifically for each structure as to heating, cooling, ventilation and insulation. As construction progresses, GWS inspects the work of the electrical, plumbing and insulation contractors and installs its own Smart House Radiant Barrier. On completion of the home, GWS technicians use a machine that creates a vacuum in the house and enables computer calculation of the air exchanged, a measure of energy efficiency. Key factor is the radiant barrier, borrowed from the Apollo program. This is an adaptation of a highly effective aluminized heat shield as a radiation barrier holding in or keeping out heat, cold air and water vapor.

  20. Mosquito and Drosophila entomobirnaviruses suppress dsRNA- and siRNA-induced RNAi.

    PubMed

    van Cleef, Koen W R; van Mierlo, Joël T; Miesen, Pascal; Overheul, Gijs J; Fros, Jelke J; Schuster, Susan; Marklewitz, Marco; Pijlman, Gorben P; Junglen, Sandra; van Rij, Ronald P

    2014-07-01

    RNA interference (RNAi) is a crucial antiviral defense mechanism in insects, including the major mosquito species that transmit important human viruses. To counteract the potent antiviral RNAi pathway, insect viruses encode RNAi suppressors. However, whether mosquito-specific viruses suppress RNAi remains unclear. We therefore set out to study RNAi suppression by Culex Y virus (CYV), a mosquito-specific virus of the Birnaviridae family that was recently isolated from Culex pipiens mosquitoes. We found that the Culex RNAi machinery processes CYV double-stranded RNA (dsRNA) into viral small interfering RNAs (vsiRNAs). Furthermore, we show that RNAi is suppressed in CYV-infected cells and that the viral VP3 protein is responsible for RNAi antagonism. We demonstrate that VP3 can functionally replace B2, the well-characterized RNAi suppressor of Flock House virus. VP3 was found to bind long dsRNA as well as siRNAs and interfered with Dicer-2-mediated cleavage of long dsRNA into siRNAs. Slicing of target RNAs by pre-assembled RNA-induced silencing complexes was not affected by VP3. Finally, we show that the RNAi-suppressive activity of VP3 is conserved in Drosophila X virus, a birnavirus that persistently infects Drosophila cell cultures. Together, our data indicate that mosquito-specific viruses may encode RNAi antagonists to suppress antiviral RNAi.

  1. Awareness and support of release of genetically modified "sterile" mosquitoes, Key West, Florida, USA.

    PubMed

    Ernst, Kacey C; Haenchen, Steven; Dickinson, Katherine; Doyle, Michael S; Walker, Kathleen; Monaghan, Andrew J; Hayden, Mary H

    2015-02-01

    After a dengue outbreak in Key West, Florida, during 2009-2010, authorities, considered conducting the first US release of male Aedes aegypti mosquitoes genetically modified to prevent reproduction. Despite outreach and media attention, only half of the community was aware of the proposal; half of those were supportive. Novel public health strategies require community engagement.

  2. Characterization of an Enantioselective Odorant Receptor in the Yellow Fever Mosquito Aedes aegypti

    DTIC Science & Technology

    2009-09-15

    Doolittle RE, Ladd TL, Proveaux AT (1977) Identification of the female Japanese beetle sex pheromone: Inhibition of male response by an enantiomer. Science...Characterization of an Enantioselective Odorant Receptor in the Yellow Fever Mosquito Aedes aegypti Jonathan D. Bohbot, Joseph C. Dickens* United...be differentially active at the physiological and behavioral levels. Only recently were enantioselective odorant receptors demonstrated in mammals

  3. Physiological bases of mosquito ecology.

    PubMed

    Briegel, Hans

    2003-06-01

    The research carried out during more than 30 years in the author's laboratory is briefly reviewed. Quantitative analyses of basic physiological processes, such as growth and development, digestion and excretion, oogenesis and fecundity, reserve synthesis and resulting flight-potentials of Aedes aegypti were summarized and compared with several other mosquito species, particularly with Anopheles. These studies led to the recognition of distinctly different physiological strategies, for which the term "physiotype" has been coined, providing a basis for understanding the different ecotypes.

  4. Systematics of Aedes Mosquito Project

    DTIC Science & Technology

    1991-03-27

    African species of stegmyia have been implicated as natural hosts, vectors, and/or reservoirs of 8 viruses , 6 of which cause human illness (Chikingunya...dengue 1 and 2, Duige, Rift Valley Fever, yellow fever and Zika ). Chikungunya, dengue and yellow fever are the most important arboviruses associated...accurately identify specimens of vector species for mosquito survey, virus -isolation studies and epidemiological studies. 3 This paper is part of a revision

  5. North American wetlands and mosquito control.

    PubMed

    Rey, Jorge R; Walton, William E; Wolfe, Roger J; Connelly, C Roxanne; O'Connell, Sheila M; Berg, Joe; Sakolsky-Hoopes, Gabrielle E; Laderman, Aimlee D

    2012-12-10

    Wetlands are valuable habitats that provide important social, economic, and ecological services such as flood control, water quality improvement, carbon sequestration, pollutant removal, and primary/secondary production export to terrestrial and aquatic food chains. There is disagreement about the need for mosquito control in wetlands and about the techniques utilized for mosquito abatement and their impacts upon wetlands ecosystems. Mosquito control in wetlands is a complex issue influenced by numerous factors, including many hard to quantify elements such as human perceptions, cultural predispositions, and political climate. In spite of considerable progress during the last decades, habitat protection and environmentally sound habitat management still remain inextricably tied to politics and economics. Furthermore, the connections are often complex, and occur at several levels, ranging from local businesses and politicians, to national governments and multinational institutions. Education is the key to lasting wetlands conservation. Integrated mosquito abatement strategies incorporate many approaches and practicable options, as described herein, and need to be well-defined, effective, and ecologically and economically sound for the wetland type and for the mosquito species of concern. The approach will certainly differ in response to disease outbreaks caused by mosquito-vectored pathogens versus quality of life issues caused by nuisance-biting mosquitoes. In this contribution, we provide an overview of the ecological setting and context for mosquito control in wetlands, present pertinent information on wetlands mosquitoes, review the mosquito abatement options available for current wetlands managers and mosquito control professionals, and outline some necessary considerations when devising mosquito control strategies. Although the emphasis is on North American wetlands, most of the material is applicable to wetlands everywhere.

  6. North American Wetlands and Mosquito Control

    PubMed Central

    Rey, Jorge R.; Walton, William E.; Wolfe, Roger J.; Connelly, Roxanne; O’Connell, Sheila M.; Berg, Joe; Sakolsky-Hoopes, Gabrielle E.; Laderman, Aimlee D.

    2012-01-01

    Wetlands are valuable habitats that provide important social, economic, and ecological services such as flood control, water quality improvement, carbon sequestration, pollutant removal, and primary/secondary production export to terrestrial and aquatic food chains. There is disagreement about the need for mosquito control in wetlands and about the techniques utilized for mosquito abatement and their impacts upon wetlands ecosystems. Mosquito control in wetlands is a complex issue influenced by numerous factors, including many hard to quantify elements such as human perceptions, cultural predispositions, and political climate. In spite of considerable progress during the last decades, habitat protection and environmentally sound habitat management still remain inextricably tied to politics and economics. Furthermore, the connections are often complex, and occur at several levels, ranging from local businesses and politicians, to national governments and multinational institutions. Education is the key to lasting wetlands conservation. Integrated mosquito abatement strategies incorporate many approaches and practicable options, as described herein, and need to be well-defined, effective, and ecologically and economically sound for the wetland type and for the mosquito species of concern. The approach will certainly differ in response to disease outbreaks caused by mosquito-vectored pathogens versus quality of life issues caused by nuisance-biting mosquitoes. In this contribution, we provide an overview of the ecological setting and context for mosquito control in wetlands, present pertinent information on wetlands mosquitoes, review the mosquito abatement options available for current wetlands managers and mosquito control professionals, and outline some necessary considerations when devising mosquito control strategies. Although the emphasis is on North American wetlands, most of the material is applicable to wetlands everywhere. PMID:23222252

  7. Volatile phytochemicals as mosquito semiochemicals

    PubMed Central

    Nyasembe, Vincent O.; Torto, Baldwyn

    2014-01-01

    Plant biochemical processes result in the release of an array of volatile chemical substances into the environment, some of which are known to play important plant fitness enhancing functions, such as attracting pollinators, thermal tolerance of photosynthesis, and defense against herbivores. Cunningly, phytophagous insects have evolved mechanisms to utilize these volatiles to their own advantage, either to colonize a suitable host for feeding, reproduction and oviposition or avoid an unsuitable one. The volatile compounds involved in plant–insect chemical interactions have been widely exploited in the management of agricultural pests. On the other hand, use of plant volatiles in the management of medically important insects is limited, mainly due to paucity of information on their role in disease vector–plant interactions. To date, a total of 29 plant volatile compounds from various chemical classes, including phenols, aldehydes, alcohols, ketones and terpenes, have been identified as mosquito semiochemicals. In this review, we present highlights of mosquito–plant interactions, the available evidence of nectar feeding, with particular emphasis on sources of plant attractants, methods of plant volatile collection and the candidate plant volatile compounds that attract mosquitoes to nectar sources. We also highlight the potential application of these phytochemical attractants in integrated mosquito management. PMID:25383131

  8. The impact of transgenic mosquitoes on dengue virulence to humans and mosquitoes.

    PubMed

    Medlock, Jan; Luz, Paula M; Struchiner, Claudio J; Galvani, Alison P

    2009-10-01

    Dengue is a major public health concern in the tropics and subtropics. Innovative transgenic strategies to render Aedes aegypti mosquitoes, the primary vector of dengue, incompetent for dengue transmission are under development. We modeled the evolutionary impact of different transgenic mosquito strategies on dengue-induced mortality, that is, dengue virulence, to both humans and mosquitoes. This model incorporates various evolutionary trade-offs in dengue virus epidemiological traits, for example, a trade-off between dengue transmission rate and its virulence to humans. Our results indicate that strategies that block transmission or reduce mosquito biting impose selection on dengue virulence in humans. This selection can be for either higher or lower virulence, depending on the interaction between the effect of the transgene and the trade-offs in epidemiological traits, highlighting the need for detailed quantitative data to understand more fully the impact of mosquito transgenesis on dengue virulence. Dengue virulence in mosquitoes can be selected on by transgenic strategies of blocking transmission, decreased mosquito biting, increased mosquito background mortality, and increased mosquito infection-induced mortality. Our results suggest that dengue control strategies that raise mosquito background mortality or mosquito infection-induced mortality pose less risk of causing increased virulence to humans than strategies that block transmission or reduce mosquito biting.

  9. Spatio-temporal Modeling of Mosquito Distribution

    NASA Astrophysics Data System (ADS)

    Dumont, Y.; Dufourd, C.

    2011-11-01

    We consider a quasilinear parabolic system to model mosquito displacement. In order to use efficiently vector control tools, like insecticides, and mechanical control, it is necessary to provide density estimates of mosquito populations, taking into account the environment and entomological knowledges. After a brief introduction to mosquito dispersal modeling, we present some theoretical results. Then, considering a compartmental approach, we get a quasilinear system of PDEs. Using the time splitting approach and appropriate numerical methods for each operator, we construct a reliable numerical scheme. Considering vector control scenarii, we show that the environment can have a strong influence on mosquito distribution and in the efficiency of vector control tools.

  10. Entomopathogenic fungi for mosquito control: A review

    PubMed Central

    Scholte, Ernst-Jan; Knols, Bart G.J.; Samson, Robert A.; Takken, Willem

    2004-01-01

    Fungal diseases in insects are common and widespread and can decimate their populations in spectacular epizootics. Virtually all insect orders are susceptible to fungal diseases, including Dipterans. Fungal pathogens such as Lagenidium, Coelomomyces and Culicinomyces are known to affect mosquito populations, and have been studied extensively. There are, however, many other fungi that infect and kill mosquitoes at the larval and/or adult stage. The discovery, in 1977, of the selective mosquito-pathogenic bacterium Bacillus thuringiensis Berliner israelensis (Bti) curtailed widespread interest in the search for other suitable biological control agents. In recent years interest in mosquito-killing fungi is reviving, mainly due to continuous and increasing levels of insecticide resistance and increasing global risk of mosquito-borne diseases. This review presents an update of published data on mosquito-pathogenic fungi and mosquito-pathogen interactions, covering 13 different fungal genera. Notwithstanding the potential of many fungi as mosquito control agents, only a handful have been commercialized and are marketed for use in abatement programs. We argue that entomopathogenic fungi, both new and existing ones with renewed/improved efficacies may contribute to an expansion of the limited arsenal of effective mosquito control tools, and that they may contribute in a significant and sustainable manner to the control of vector-borne diseases such as malaria, dengue and filariasis. PMID:15861235

  11. Susceptibility of adult mosquitoes to insecticides in aqueous sucrose baits.

    PubMed

    Allan, Sandra A

    2011-06-01

    Mosquitoes characteristically feed on plant-derived carbohydrates and honeydew just after emergence and intermittently during their lives. Development of toxic baits focusing on this carbohydrate-seeking behavior may potentially contribute to localized control. In the present study, ten insecticides were fed to female Culex quinquefasciatus, Anopheles quadrimaculatus, and Aedes taeniorhynchus in a 10% sucrose solution. Active ingredients representative of five classes of insecticides (pyrethroids, phenylpyroles, pyrroles, neonicotinoids, and macrocyclic lactones) were selected for comparison with commercial formulations used to facilitate incorporation of active ingredients into aqueous sucrose solutions. Sucrose as a phagostimulant significantly enhanced mortality to toxicants. In general, the most effective active ingredients were fipronil, deltamethrin and imidacloprid, followed by spinosad, thiamethoxam, bifenthrin, permethrin, and cyfluthrin. The least effective ingredients were chlorfenapyr and ivermectin. For some of the ingredients tested, Cx. quinquefasciatus was the least susceptible species. One-day-old male Cx. quinquefasciatus were more susceptible than females; however, no differences existed between one- and seven-day-old mosquitoes. There were no differences in susceptibility between unfed and gravid ten-day-old female Cx. quinquefasciatus to bifenthrin. In conclusion, several pesticides from different classes of compounds have potential for use in development of toxic baits for mosquitoes.

  12. Diel sugar feeding and reproductive behaviours of Aedes aegypti mosquitoes in Trinidad: with implications for mass release of sterile mosquitoes.

    PubMed

    Chadee, Dave D; Sutherland, Joan M; Gilles, Jeremie R L

    2014-04-01

    Studies on the diel sugar feeding periodicity of male and female Aedes aegypti were conducted under laboratory conditions and monitored in single cages using the polyphagometer device and examined every 2h. Males mosquitoes displayed two peaks in sugar feeding, a small morning peak at 06.00-08.00 h (16% of sugar feeding) and a significant evening peak at 16.00-18.00 h (40% of sugar feeding). A similar pattern was observed among females: a small early morning peak (18% of sugar feeding) and a significant peak in the evening 16.00-18.00 h (42% of sugar feeding). Studies on the effects of sugar feeding on the excitation of males showed 100% erect antennal fibrillae after 36 h. In contrast, only 15% of the water-fed males responded. Laboratory studies on the effects of sugar feeding on the insemination rates of A. aegypti females showed similar inseminations rates among sugar and water fed males but after 4 days all water fed males died while the sugar fed males continued to survive and inseminate females. The synchronization of the male and female diel sugar feeding periodicity is discussed in the context of sterile insect techniques or genetic control methods.

  13. Wyeomyia exallos, a new species of sylvatic mosquito (Diptera: Culicidae) from Brazil.

    PubMed

    Rocha, Glauber Pereira; Lourenço-de-Oliveira, Ricardo; Motta, Monique de Albuquerque

    2012-11-01

    Wyeomyia exallos, a new mosquito species from Atlantic Forest of southeastern Brazil, is described based on morphological characters of the adult female, male, male genitalia, pupa and fourth-instar larva. The morphological characters of Wy. exallos sp. nov. are compared with those of different subgenera of Wyeomyia as well as of species without subgeneric position. It is proposed that the new species should be placed in genus Wyeomyia Theobald without subgeneric assignment.

  14. Contributions to the Mosquito Fauna of Southeast Asia - II. The Genus Culex in Thailand (Diptera: Culicidae)

    DTIC Science & Technology

    1967-01-01

    on the internal margin. LARVA. Specimens not available for study; figure 9A, B is after Bar- raud (1924b). TYPE DATA. Lectotype male of tenuipalpis...have never been reported feeding on man. Larvae Figure 9. C. (Neoculex) tenuipalpis. A, B, dorsal view of the fourth stage larva ( after Barraud...lobe of the basimere. FEMALE. Unknown. MALE ( After Chu 1958). A small dark mosquito, closely related to C. flochthogenes) pluvzizlis Barraud, but

  15. Mathematical model to assess the control of Aedes aegypti mosquitoes by the sterile insect technique.

    PubMed

    Esteva, Lourdes; Mo Yang, Hyun

    2005-12-01

    We propose a mathematical model to assess the effects of irradiated (or transgenic) male insects introduction in a previously infested region. The release of sterile male insects aims to displace gradually the natural (wild) insect from the habitat. We discuss the suitability of this release technique when applied to peri-domestically adapted Aedes aegypti mosquitoes which are transmissors of Yellow Fever and Dengue disease.

  16. An aggregation pheromone modulates lekking behavior in the vector mosquito Aedes aegypti (Diptera: Culicidae).

    PubMed

    Cabrera, Maira; Jaffe, Klaus

    2007-03-01

    Males of Aedes aegypti mosquitoes formed swarms in the laboratory, triggered by the onset of the photophase or by the presence of odors from a rat (which is a potential host for females). The swarm attracted both males and females and increased mating activity. The number of copulas per mosquito was positively correlated with the number of mosquitoes in the swarm and with the duration of the swarm. Swarming and mating activity increased with the presence of a host for females. Young sexually immature males, less than 24 h old, flew but did not swarm nor copulate. Observations using an olfactometer showed that swarming males produced a volatile pheromone that stimulates the flying activity of females at a distance. Females also produce a volatile attractant. The results suggest that males, and possibly also females, produce an aggregation pheromone that attracts males and females towards the swarm. The characteristics of the pheromone-mediated swarm may be described as a 3-dimensional lek. Our results suggest that the development of pheromone-based control systems and/or pheromone traps for the monitoring of vector populations is feasible, adding a new tool to combat this vector of several human pathogens.

  17. Attractiveness of MM-X traps baited with human or synthetic odor to mosquitoes (Diptera: Culicidae) in The Gambia.

    PubMed

    Qiu, Yu Tong; Smallegange, Renate C; Ter, Braak Cajo J F; Spitzen, Jeroen; Van Loon, Joop J A; Jawara, Musa; Milligan, Paul; Galimard, Agnes M; Van Beek, Teris A; Knols, Bart G J; Takken, Willem

    2007-11-01

    Chemical cues play an important role in the host-seeking behavior of blood-feeding mosquitoes (Diptera: Culicidae). A field study was carried out in The Gambia to investigate the effects of human odor or synthetic odor blends on the attraction of mosquitoes. MM-X traps baited with 16 odor blends to which carbon dioxide (CO2) was added were tested in four sets of experiments. In a second series of experiments, MM-X traps with 14 odor blends without CO2 were tested. A blend of ammonia and L-lactic acid with or without CO2 was used as control odor in series 1 and 2, respectively. Centers for Disease Control and Prevention (CDC) traps were placed in a traditional house and an experimental house to monitor mosquito densities during the experiments. The MM-X traps caught a total number of 196,756 mosquitoes, with the most abundant species belonging to the genera Mansonia (70.6%), Anopheles (17.5%), and Culex (11.5%). The most abundant mosquito species caught by the CDC traps (56,290 in total) belonged to the genera Mansonia (59.4%), Anopheles (16.0% An. gambiae s.l. Giles, and 11.3% An. ziemanni Grünberg), and Culex (11.6%). MM-X traps baited with synthetic blends were in many cases more attractive than MM-X traps baited with human odors. Addition of CO2 to synthetic odors substantially increased the catch of all mosquito species in the MM-X traps. A blend of ammonia + L-lactic acid + CO, + 3-methylbutanoic acid was the most attractive odor for most mosquito species. The candidate odor blend shows the potential to enhance trap collections so that traps will provide better surveillance and possible control.

  18. A Modified Experimental Hut Design for Studying Responses of Disease-Transmitting Mosquitoes to Indoor Interventions: The Ifakara Experimental Huts

    PubMed Central

    Okumu, Fredros O.; Moore, Jason; Mbeyela, Edgar; Sherlock, Mark; Sangusangu, Robert; Ligamba, Godfrey; Russell, Tanya; Moore, Sarah J.

    2012-01-01

    Differences between individual human houses can confound results of studies aimed at evaluating indoor vector control interventions such as insecticide treated nets (ITNs) and indoor residual insecticide spraying (IRS). Specially designed and standardised experimental huts have historically provided a solution to this challenge, with an added advantage that they can be fitted with special interception traps to sample entering or exiting mosquitoes. However, many of these experimental hut designs have a number of limitations, for example: 1) inability to sample mosquitoes on all sides of huts, 2) increased likelihood of live mosquitoes flying out of the huts, leaving mainly dead ones, 3) difficulties of cleaning the huts when a new insecticide is to be tested, and 4) the generally small size of the experimental huts, which can misrepresent actual local house sizes or airflow dynamics in the local houses. Here, we describe a modified experimental hut design - The Ifakara Experimental Huts- and explain how these huts can be used to more realistically monitor behavioural and physiological responses of wild, free-flying disease-transmitting mosquitoes, including the African malaria vectors of the species complexes Anopheles gambiae and Anopheles funestus, to indoor vector control-technologies including ITNs and IRS. Important characteristics of the Ifakara experimental huts include: 1) interception traps fitted onto eave spaces and windows, 2) use of eave baffles (panels that direct mosquito movement) to control exit of live mosquitoes through the eave spaces, 3) use of replaceable wall panels and ceilings, which allow safe insecticide disposal and reuse of the huts to test different insecticides in successive periods, 4) the kit format of the huts allowing portability and 5) an improved suite of entomological procedures to maximise data quality. PMID:22347415

  19. Mosquito Surveillance Revealed Lagged Effects of Mosquito Abundance on Mosquito-Borne Disease Transmission: A Retrospective Study in Zhejiang, China

    PubMed Central

    Guo, Song; Ling, Feng; Hou, Juan; Wang, Jinna; Fu, Guiming; Gong, Zhenyu

    2014-01-01

    Mosquito-borne diseases (MBDs) are still threats to public health in Zhejiang. In this study, the associations between the time-lagged mosquito capture data and MBDs incidence over five years were used to examine the potential effects of mosquito abundance on patterns of MBDs epidemiology in Zhejiang during 2008–2012. Light traps were used to collect adult mosquitoes at 11 cities. Correlation tests with and without time lag were performed to investigate the correlations between MBDs incidence rates and mosquito abundance by month. Selected MBDs consisted of Japanese encephalitis (JE), dengue fever (DF) and malaria. A Poisson regression analysis was performed by using a generalized estimating equations (GEE) approach, and the most parsimonious model was selected based on the quasi-likelihood based information criterion (QICu). We identified five mosquito species and the constituent ratio of Culex pipiens pallens, Culex tritaeniorhynchus, Aedes albopictus, Anopheles sinensis and Armigeres subalbatus was 66.73%, 21.47%, 6.72%, 2.83% and 2.25%, respectively. The correlation analysis without and with time lag showed that Culex mosquito abundance at a lag of 0 or 1 month was positively correlated with JE incidence during 2008–2012, Ae. albopictus abundance at a lag of 1 month was positively correlated with DF incidence in 2009, and An. sinensis abundance at a lag of 0–2 months was positively correlated with malaria incidence during 2008–2010. The Poisson regression analysis showed each 0.1 rise of monthly mosquito abundance corresponded to a positive increase of MBD cases for the period of 2008–2012. The rise of mosquito abundance with a lag of 0–2 months increased the risk of human MBDs infection in Zhejiang. Our study provides evidence that mosquito monitoring could be a useful early warning tool for the occurrence and transmission of MBDs. PMID:25393834

  20. Microsporidian isolates from mosquitoes of Argentina

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microsporidia are among the most common and widely distributed microbial pathogens associated with mosquitoes in nature. Since 1980 studies of microsporidia in mosquitoes of Argentina were conducted at the Laboratory of Insect Vectors of CEPAVE. Eleven morphologically unique species of microsporidia...

  1. Neuropeptidomics of the mosquito Aedes aegypti

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Neuropeptidomic data were collected on the mosquito Ae. aegypti which is considered the most tractable mosquito species for physiological and endocrine studies. The data were solely obtained by direct mass spectrometric profiling, including tandem fragmentation, of selected tissues from single speci...

  2. An innovative mosquito trap for testing attractants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We describe a simple trap modification for testing or using attractants to collect flying mosquitoes. The trap also can test the effectiveness of spatial repellents. The proposed design may facilitate standardized testing of mosquito attractants and repellents. The trap uses a standard Centers f...

  3. History of Aedes mosquitoes in Hawaii.

    PubMed

    Winchester, Jonathan C; Kapan, Durrell D

    2013-06-01

    As a geographically isolated island chain with no native mosquitoes, Hawaii is a model for examining the mechanisms behind insect vector invasions and their subsequent interactions with each other and with human populations. The yellow fever mosquito, Aedes aegypti, and the Asian tiger mosquito, Ae. albopictus, have been responsible for epidemics of dengue in Hawaii. As one of the world's earliest locations to be invaded by both species, Hawaii's history is particularly relevant because both species are currently invading new areas worldwide and are implicated in outbreaks of emergent or reemergent pathogens such as dengue, chikungunya, and yellow fever. Here we analyze the historical records of mosquito introductions in order to understand the factors that have led to the current distribution of these 2 mosquitoes in the Hawaiian Islands.

  4. Asymptomatic humans transmit dengue virus to mosquitoes

    PubMed Central

    Duong, Veasna; Lambrechts, Louis; Paul, Richard E.; Ly, Sowath; Lay, Rath Srey; Long, Kanya C.; Huy, Rekol; Tarantola, Arnaud; Scott, Thomas W.; Sakuntabhai, Anavaj; Buchy, Philippe

    2015-01-01

    Three-quarters of the estimated 390 million dengue virus (DENV) infections each year are clinically inapparent. People with inapparent dengue virus infections are generally considered dead-end hosts for transmission because they do not reach sufficiently high viremia levels to infect mosquitoes. Here, we show that, despite their lower average level of viremia, asymptomatic people can be infectious to mosquitoes. Moreover, at a given level of viremia, DENV-infected people with no detectable symptoms or before the onset of symptoms are significantly more infectious to mosquitoes than people with symptomatic infections. Because DENV viremic people without clinical symptoms may be exposed to more mosquitoes through their undisrupted daily routines than sick people and represent the bulk of DENV infections, our data indicate that they have the potential to contribute significantly more to virus transmission to mosquitoes than previously recognized. PMID:26553981

  5. Reception of odors and repellents in mosquitoes

    PubMed Central

    Ray, Anandasankar

    2015-01-01

    Mosquitoes use their sense of smell to find hosts, nectar, and oviposition sites, and to avoid repellents. A small number of mosquito species are adapted to feed on humans and have a major impact on public health by transmitting malaria, dengue, filariasis, etc. The application of odorants for behavioral control has not been fully realized yet due to complexity of the mosquito olfactory system. Recent progress in molecular and computational tools has enabled rigorous investigations of the mosquito olfactory system function and has started to reveal how specific receptors contribute to attractive and aversive behaviors. Here we discuss recent advances in linking odors to receptors and in exploiting this knowledge in finding attractants and repellents for mosquitoes. PMID:26202080

  6. Genetic control of Aedes mosquitoes

    PubMed Central

    Alphey, Luke; McKemey, Andrew; Nimmo, Derric; Neira Oviedo, Marco; Lacroix, Renaud; Matzen, Kelly; Beech, Camilla

    2013-01-01

    Aedes mosquitoes include important vector species such as Aedes aegypti, the major vector of dengue. Genetic control methods are being developed for several of these species, stimulated by an urgent need owing to the poor effectiveness of current methods combined with an increase in chemical pesticide resistance. In this review we discuss the various genetic strategies that have been proposed, their present status, and future prospects. We focus particularly on those methods that are already being tested in the field, including RIDL and Wolbachia-based approaches. PMID:23816508

  7. Field testing of different chemical combinations as odour baits for trapping wild mosquitoes in The Gambia.

    PubMed

    Jawara, Musa; Awolola, Taiwo S; Pinder, Margaret; Jeffries, David; Smallegange, Renate C; Takken, Willem; Conway, David J

    2011-01-01

    Odour baited traps have potential use in population surveillance of insect vectors of disease, and in some cases for vector population reduction. Established attractants for human host-seeking mosquitoes include a combination of CO(2) with L-lactic acid and ammonia, on top of which additional candidate compounds are being tested. In this field study in rural Gambia, using Latin square experiments with thorough randomization and replication, we tested nine different leading candidate combinations of chemical odorants for attractiveness to wild mosquitoes including anthropophilic malaria vectors, using modified Mosquito Magnet-X (MM-X) counterflow traps outside experimental huts containing male human sleepers. Highest catches of female mosquitoes, particularly of An. gambiae s.l. and Mansonia species, were obtained by incorporation of tetradecanoic acid. As additional carboxylic acids did not increase the trap catches further, this 'reference blend' (tetradecanoic acid with L-lactic acid, ammonia and CO(2)) was used in subsequent experiments. MM-X traps with this blend caught similar numbers of An. gambiae s.l. and slightly more Mansonia and Culex mosquitoes than a standard CDC light trap, and these numbers were not significantly affected by the presence or absence of human sleepers in the huts. Experiments with CO(2) produced from overnight yeast cultures showed that this organic source was effective in enabling trap attractiveness for all mosquito species, although at a slightly lower efficiency than obtained with use of CO(2) gas cylinders. Although further studies are needed to discover additional chemicals that increase attractiveness, as well as to optimise trap design and CO(2) source for broader practical use, the odour-baited traps described here are safe and effective for sampling host-seeking mosquitoes outdoors and can be incorporated into studies of malaria vector ecology.

  8. Tools for delivering entomopathogenic fungi to malaria mosquitoes: effects of delivery surfaces on fungal efficacy and persistence

    PubMed Central

    2010-01-01

    Background Entomopathogenic fungi infection on malaria vectors increases daily mortality rates and thus represents a control measure that could be used in integrated programmes alongside insecticide-treated bed nets (ITNs) and indoor residual spraying (IRS). Before entomopathogenic fungi can be integrated into control programmes, an effective delivery system must be developed. Methods The efficacy of Metarhizium anisopliae ICIPE-30 and Beauveria bassiana I93-825 (IMI 391510) (2 × 1010 conidia m-2) applied on mud panels (simulating walls of traditional Tanzanian houses), black cotton cloth and polyester netting was evaluated against adult Anopheles gambiae sensu stricto. Mosquitoes were exposed to the treated surfaces 2, 14 and 28 d after conidia were applied. Survival of mosquitoes was monitored daily. Results All fungal treatments caused a significantly increased mortality in the exposed mosquitoes, descending with time since fungal application. Mosquitoes exposed to M. anisopliae conidia on mud panels had a greater daily risk of dying compared to those exposed to conidia on either netting or cotton cloth (p < 0.001). Mosquitoes exposed to B. bassiana conidia on mud panels or cotton cloth had similar daily risk of death (p = 0.14), and a higher risk than those exposed to treated polyester netting (p < 0.001). Residual activity of fungi declined over time; however, conidia remained pathogenic at 28 d post application, and were able to infect and kill 73 - 82% of mosquitoes within 14 d. Conclusion Both fungal isolates reduced mosquito survival on immediate exposure and up to 28 d after application. Conidia were more effective when applied on mud panels and cotton cloth compared with polyester netting. Cotton cloth and mud, therefore, represent potential substrates for delivering fungi to mosquitoes in the field. PMID:20799967

  9. Dosage Compensation in the African Malaria Mosquito Anopheles gambiae

    PubMed Central

    Rose, Graham; Krzywinska, Elzbieta; Kim, Jan; Revuelta, Loic; Ferretti, Luca; Krzywinski, Jaroslaw

    2016-01-01

    Dosage compensation is the fundamental process by which gene expression from the male monosomic X chromosome and from the diploid set of autosomes is equalized. Various molecular mechanisms have evolved in different organisms to achieve this task. In Drosophila, genes on the male X chromosome are upregulated to the levels of expression from the two X chromosomes in females. To test whether a similar mechanism is operating in immature stages of Anopheles mosquitoes, we analyzed global gene expression in the Anopheles gambiae fourth instar larvae and pupae using high-coverage RNA-seq data. In pupae of both sexes, the median expression ratios of X-linked to autosomal genes (X:A) were close to 1.0, and within the ranges of expression ratios between the autosomal pairs, consistent with complete compensation. Gene-by-gene comparisons of expression in males and females revealed mild female bias, likely attributable to a deficit of male-biased X-linked genes. In larvae, male to female ratios of the X chromosome expression levels were more female biased than in pupae, suggesting that compensation may not be complete. No compensation mechanism appears to operate in male germline of early pupae. Confirmation of the existence of dosage compensation in A. gambiae lays the foundation for research into the components of dosage compensation machinery in this important vector species. PMID:26782933

  10. Fitness aspects of transgenic Aedes fluviatilis mosquitoes expressing a Plasmodium-blocking molecule.

    PubMed

    Santos, Maíra N; Nogueira, Paula M; Dias, Fernando B S; Valle, Denise; Moreira, Luciano A

    2010-12-01

    Vector-born diseases cause millions of deaths every year globally. Alternatives for the control of diseases such as malaria and dengue fever are urgently needed and the use of transgenic mosquitoes that block parasite/virus is a sound strategy to be used within control programs. However, prior to use transgenic mosquitoes as control tools, it is important to study their fitness since different biological aspects might influence their ability to disseminate and compete with wild populations. We previously reported the construction of four transgenic Aedes fluviatilis mosquito lines expressing a Plasmodium- blocking molecule (mutated bee venom phospholipase A(2)-mPLA(2)). Presently we studied two aspects of their fitness: body size, that has been used as a fitness-related status, and the expression of major enzymes classes involved in the metabolism of xenobiotics, including insecticides. Body size analysis (recorded by geometric wing morphometrics) indicated that both male and female mosquitoes were larger than the non-transgenic counterparts, suggesting that this characteristic might have an impact on their overall fitness. By contrast, no significant difference in the activity of enzymes related to metabolic insecticide resistance was detected in transgenic mosquitoes. The implication on fitness advantage of these features, towards the implementation of this strategy, is further discussed.

  11. Green Nanoparticles for Mosquito Control

    PubMed Central

    Soni, Namita; Prakash, Soam

    2014-01-01

    Here, we have used the green method for synthesis of silver and gold nanoparticles. In the present study the silver (Ag) and gold (Au) nanoparticles (NPs) were synthesized by using the aqueous bark extract of Indian spice dalchini (Cinnamomum zeylanicum) (C. zyelanicum or C. verum J. Presl). Additionally, we have used these synthesized nanoparticles for mosquito control. The larvicidal activity has been tested against the malaria vector Anopheles stephensi and filariasis vector Culex quinquefasciatus. The results were obtained using UV-visible spectrophotometer and the images were recorded with a transmission electron microscope (TEM). The efficacy tests were then performed at different concentrations and varying numbers of hours by probit analysis. The synthesized AgNPs were in spherical shape and average sizes (11.77 nm AgNPs and 46.48 nm AuNPs). The larvae of An. stephensi were found highly susceptible to the synthesized AgNPs and AuNPs than the Cx. quinquefasciatus. These results suggest that the C. zeylanicum synthesized silver and gold nanoparticles have the potential to be used as an ideal ecofriendly approach for the control of mosquito. PMID:25243210

  12. Mosquito Oviposition Behavior and Vector Control.

    PubMed

    Day, Jonathan F

    2016-11-18

    The burden of gene transfer from one mosquito generation to the next falls on the female and her eggs. The selection of an oviposition site that guarantees egg and larval survival is a critical step in the reproductive process. The dangers associated with ephemeral aquatic habitats, lengthy droughts, freezing winters, and the absence of larval nutrition makes careful oviposition site selection by a female mosquito extremely important. Mosquito species exhibit a remarkable diversity of oviposition behaviors that ensure eggs are deposited into microenvironments conducive for successful larval development and the emergence of the next mosquito generation. An understanding of mosquito oviposition behavior is necessary for the development of surveillance and control opportunities directed against specific disease vectors. For example, Aedes aegypti Linnaeus is the vector of viruses causing important human diseases including yellow fever, dengue, chikungunya, and Zika. The preference of this species to oviposit in natural and artificial containers has facilitated the development of Ae. aegypti-specific surveillance and toxic oviposition traps designed to detect and control this important vector species in and around disease foci. A better understanding of the wide diversity of mosquito oviposition behavior will allow the development of new and innovative surveillance and control devices directed against other important mosquito vectors of human and animal disease.

  13. Plant extracts as potential mosquito larvicides

    PubMed Central

    Ghosh, Anupam; Chowdhury, Nandita; Chandra, Goutam

    2012-01-01

    Mosquitoes act as a vector for most of the life threatening diseases like malaria, yellow fever, dengue fever, chikungunya ferver, filariasis, encephalitis, West Nile Virus infection, etc. Under the Integrated Mosquito Management (IMM), emphasis was given on the application of alternative strategies in mosquito control. The continuous application of synthetic insecticides causes development of resistance in vector species, biological magnification of toxic substances through the food chain and adverse effects on environmental quality and non target organisms including human health. Application of active toxic agents from plant extracts as an alternative mosquito control strategy was available from ancient times. These are non-toxic, easily available at affordable prices, biodegradable and show broad-spectrum target-specific activities against different species of vector mosquitoes. In this article, the current state of knowledge on phytochemical sources and mosquitocidal activity, their mechanism of action on target population, variation of their larvicidal activity according to mosquito species, instar specificity, polarity of solvents used during extraction, nature of active ingredient and promising advances made in biological control of mosquitoes by plant derived secondary metabolites have been reviewed. PMID:22771587

  14. Mosquito Oviposition Behavior and Vector Control

    PubMed Central

    Day, Jonathan F.

    2016-01-01

    The burden of gene transfer from one mosquito generation to the next falls on the female and her eggs. The selection of an oviposition site that guarantees egg and larval survival is a critical step in the reproductive process. The dangers associated with ephemeral aquatic habitats, lengthy droughts, freezing winters, and the absence of larval nutrition makes careful oviposition site selection by a female mosquito extremely important. Mosquito species exhibit a remarkable diversity of oviposition behaviors that ensure eggs are deposited into microenvironments conducive for successful larval development and the emergence of the next mosquito generation. An understanding of mosquito oviposition behavior is necessary for the development of surveillance and control opportunities directed against specific disease vectors. For example, Aedes aegypti Linnaeus is the vector of viruses causing important human diseases including yellow fever, dengue, chikungunya, and Zika. The preference of this species to oviposit in natural and artificial containers has facilitated the development of Ae. aegypti-specific surveillance and toxic oviposition traps designed to detect and control this important vector species in and around disease foci. A better understanding of the wide diversity of mosquito oviposition behavior will allow the development of new and innovative surveillance and control devices directed against other important mosquito vectors of human and animal disease. PMID:27869724

  15. Attracting, trapping and killing disease-transmitting mosquitoes using odor-baited stations - The Ifakara Odor-Baited Stations

    PubMed Central

    2010-01-01

    Background To accelerate efforts towards control and possibly elimination of mosquito-borne diseases such as malaria and lymphatic filariasis, optimally located outdoor interventions could be used to complement existing intradomicilliary vector control methods such as house spraying with insecticides and insecticidal bednets. Methods We describe a new odor-baited station for trapping, contaminating and killing disease-transmitting mosquitoes. This device, named the 'Ifakara Odor-baited Station' (Ifakara OBS), is a 4 m3 hut-shaped canvas box with seven openings, two of which may be fitted with interception traps to catch exiting mosquitoes. It is baited with synthetic human odors and may be augmented with contaminants including toxic insecticides or biological agents. Results In field trials where panels of fabric were soaked in 1% pirimiphos-methyl solution and suspended inside the Ifakara OBS, at least 73.6% of Anopheles arabiensis, 78.7% of Culex and 60% of Mansonia mosquitoes sampled while exiting the OBS, died within 24 hours. When used simply as a trap and evaluated against two existing outdoor traps, Ifakara Tent trap and Mosquito Magnet-X®, the OBS proved more efficacious than the Ifakara Tent trap in catching all mosquito species found (P < 0.001). Compared to the Mosquito Magnet-X®, it was equally efficacious in catching An. arabiensis (P = 0.969), but was less efficacious against Culex (P < 0.001) or Mansonia species (P < 0.001). Conclusion The Ifakara OBS is efficacious against disease-carrying mosquitoes including the malaria vector, An. arabiensis and Culicine vectors of filarial worms and arboviruses. It can be used simultaneously as a trap and as a contamination or killing station, meaning most mosquitoes which escape trapping would leave when already contaminated and die shortly afterwards. This technique has potential to complement current vector control methods, by targeting mosquitoes in places other than human dwellings, but its effectiveness

  16. Mosquito populations dynamics associated with climate variations.

    PubMed

    Wilke, André Barretto Bruno; Medeiros-Sousa, Antônio Ralph; Ceretti-Junior, Walter; Marrelli, Mauro Toledo

    2017-02-01

    Mosquitoes are responsible for the transmission of numerous serious pathogens. Members of the Aedes and Culex genera, which include many important vectors of mosquito-borne diseases, are highly invasive and adapted to man-made environments. They are spread around the world involuntarily by humans and are highly adapted to urbanized environments, where they are exposed to climate-related abundance drivers. We investigated Culicidae fauna in two urban parks in the city of São Paulo to analyze the correlations between climatic variables and the population dynamics of mosquitoes in these urban areas. Mosquitoes were collected monthly over one year, and sampling sufficiency was evaluated after morphological identification of the specimens. The average monthly temperature and accumulated rainfall for the collection month and previous month were used to explain climate-related abundance drivers for the six most abundant species (Aedes aegypti, Aedes albopictus, Aedes fluviatilis, Aedes scapularis, Culex nigripalpus and Culex quinquefasciatus) and then analyzed using generalized linear statistical models and the Akaike Information Criteria corrected for small samples (AICc). The strength of evidence in favor of each model was evaluated using Akaike weights, and the explanatory model power was measured by McFadden's Pseudo-R(2). Associations between climate and mosquito abundance were found in both parks, indicating that predictive models based on climate variables can provide important information on mosquito population dynamics. We also found that this association is species-dependent. Urbanization processes increase the abundance of a few mosquito species that are well adapted to man-made environments and some of which are important vectors of pathogens. Predictive models for abundance based on climate variables may help elucidate the population dynamics of urban mosquitoes and their impact on the risk of disease transmission, allowing better predictive scenarios to be

  17. Dengue in Java, Indonesia: Relevance of Mosquito Indices as Risk Predictors

    PubMed Central

    Wijayanti, Siwi P. M.; Sunaryo, Sunaryo; Suprihatin, Suprihatin; McFarlane, Melanie; Rainey, Stephanie M.; Dietrich, Isabelle; Schnettler, Esther; Biek, Roman; Kohl, Alain

    2016-01-01

    Background No vaccine is currently available for dengue virus (DENV), therefore control programmes usually focus on managing mosquito vector populations. Entomological surveys provide the most common means of characterising vector populations and predicting the risk of local dengue virus transmission. Despite Indonesia being a country strongly affected by DENV, only limited information is available on the local factors affecting DENV transmission and the suitability of available survey methods for assessing risk. Methodology/principal findings We conducted entomological surveys in the Banyumas Regency (Central Java) where dengue cases occur on an annual basis. Four villages were sampled during the dry and rainy seasons: two villages where dengue was endemic, one where dengue cases occurred sporadically and one which was dengue-free. In addition to data for conventional larvae indices, we collected data on pupae indices, and collected adult mosquitoes for species identification in order to determine mosquito species composition and population density. Traditionally used larval indices (House indices, Container indices and Breteau indices) were found to be inadequate as indicators for DENV transmission risk. In contrast, species composition of adult mosquitoes revealed that competent vector species were dominant in dengue endemic and sporadic villages. Conclusions/significance Our data suggested that the utility of traditional larvae indices, which continue to be used in many dengue endemic countries, should be re-evaluated locally. The results highlight the need for validation of risk indicators and control strategies across DENV affected areas here and perhaps elsewhere in SE Asia. PMID:26967524

  18. Surveillance of Aedes aegypti: Comparison of House Index with Four Alternative Traps

    PubMed Central

    Codeço, Claudia T.; Lima, Arthur W. S.; Araújo, Simone C.; Lima, José Bento P.; Maciel-de-Freitas, Rafael; Honório, Nildimar A.; Galardo, Allan K. R.; Braga, Ima A.; Coelho, Giovanini E.; Valle, Denise

    2015-01-01

    Introduction The mosquito Aedes aegypti, vector of dengue, chikungunya and yellow fever viruses, is an important target of vector control programs in tropical countries. Most mosquito surveillance programs are still based on the traditional household larval surveys, despite the availability of new trapping devices. We report the results of a multicentric entomological survey using four types of traps, besides the larval survey, to compare the entomological indices generated by these different surveillance tools in terms of their sensitivity to detect mosquito density variation. Methods The study was conducted in five mid-sized cities, representing variations of tropical climate regimens. Surveillance schemes using traps for adults (BG-Sentinel, Adultrap and MosquiTRAP) or eggs (ovitraps) were applied monthly to three 1 km2 areas per city. Simultaneously, larval surveys were performed. Trap positivity and density indices in each area were calculated and regressed against meteorological variables to characterize the seasonal pattern of mosquito infestation in all cities, as measured by each of the four traps. Results The House Index was consistently low in most cities, with median always 0. Traps rarely produced null indices, pointing to their greater sensitivity in detecting the presence of Ae. aegypti in comparison to the larval survey. Trap positivity indices tend to plateau at high mosquito densities. Despite this, both indices, positivity and density, agreed on the seasonality of mosquito abundance in all cities. Mosquito seasonality associated preferentially with temperature than with precipitation even in areas where temperature variation is small. Conclusions All investigated traps performed better than the House Index in measuring the seasonal variation in mosquito abundance and should be considered as complements or alternatives to larval surveys. Choice between traps should further consider differences of cost and ease-of-use. PMID:25668559

  19. Pathogenesis of Dengue Vaccine Viruses in Mosquitoes.

    DTIC Science & Technology

    1980-01-01

    AD-A138 518 PATHOGENESIS OF DENGUE VACCINE YIRUSES IN MOSQUITOES 1/ (U) YALE UNIV NEW HAVEN CONN SCHOOL OF MEDICINE B J BEATY ET AL. 9i JAN 80 DRND7...34 ’ UNCLASSIFIED 0{) AD 0Pathogenesis of dengue vaccine viruses in mosquitoes -First Annual Report Barry I. Beaty, Ph.D. Thomas H. G...PATHOGENESIS OF DENGUE VACCINE VIRUSES ’ z Progress Report IN MOSQUITOES July 1, 1979-Jan 1, 1980 6. PERFORMING ORG. REPORT NUMBER 7. AUTHOR(@) S. CONTRACT

  20. The Influence of Antibodies to Selected Mosquito Immunogens on Mosquitoes Following Ingestion of Blood from an Immune Vertebrate Host.

    DTIC Science & Technology

    1992-08-05

    mosquito survivorship, the number of eggs deposited ( fecundity ), or the viability of eggs deposited. 14. SUBJECT TERMS IS. NUMBER OF PAGES Mosquitoes ... fecundity , and egg viability. Our results did not Indicate a deleterious effect of antibodies from an Immune mouse on mosquito survivorship, the...13 - 20. Mosquito fecundity as a function of immune status of blood source ............ 47 - 55 Figures 21 - 23. Mosquito egg viability as a function

  1. Use of Insecticide-Treated House Screens to Reduce Infestations of Dengue Virus Vectors, Mexico

    PubMed Central

    Manrique-Saide, Pablo; Che-Mendoza, Azael; Barrera-Perez, Mario; Guillermo-May, Guillermo; Herrera-Bojorquez, Josue; Dzul-Manzanilla, Felipe; Gutierrez-Castro, Cipriano; Lenhart, Audrey; Vazquez-Prokopec, Gonzalo; Sommerfeld, Johannes; McCall, Philip J.; Kroeger, Axel

    2015-01-01

    Dengue prevention efforts rely on control of virus vectors. We investigated use of insecticide-treated screens permanently affixed to windows and doors in Mexico and found that the screens significantly reduced infestations of Aedes aegypti mosquitoes in treated houses. Our findings demonstrate the value of this method for dengue virus vector control. PMID:25625483

  2. Wolbachia-Based Population Control Strategy Targeting Culex quinquefasciatus Mosquitoes Proves Efficient under Semi-Field Conditions

    PubMed Central

    Atyame, Célestine M.; Cattel, Julien; Lebon, Cyrille; Flores, Olivier; Dehecq, Jean-Sébastien; Weill, Mylène; Gouagna, Louis Clément; Tortosa, Pablo

    2015-01-01

    In mosquitoes, the maternally inherited bacterial Wolbachia induce a form of embryonic lethality called cytoplasmic incompatibility (CI). This property can be used to reduce the density of mosquito field populations through inundative releases of incompatible males in order to sterilize females (Incompatible Insect Technique, or IIT, strategy). We have previously constructed the LR[wPip(Is)] line representing a good candidate for controlling field populations of the Culex quinquefasciatus mosquito in the islands of the south-western Indian Ocean. The main purpose of the present study was to fill the gap between laboratory experiments and field implementation, i.e. assessing mating competitiveness of these incompatible males under semi-field conditions. In a first set of experiments, we analyzed crossing relationships between LR[wPip(Is)] males and La Réunion field females collected as larvae in 19 distinct localities throughout the island. This investigation revealed total embryonic mortality, confirming the strong sterilizing capacity of LR[wPip(Is)] males. Subsequently, mating competitiveness of LR[wPip(Is)] males was assessed under semi-field conditions in the presence of field males and females from La Réunion. Confrontations were carried out in April and December using different ratios of LR[wPip(Is)] to field males. The results indicated that the LR[wPip(Is)] males successfully compete with field males in mating with field females, displaying even higher competitiveness than field males in April. Our results support the implementation of small-scale field tests in order to assess the feasibility of IIT against Cx. quinquefasciatus in the islands of southwestern Indian Ocean where this mosquito species is a proven competent vector for human pathogens. PMID:25768841

  3. Fog spontaneously folds mosquito wings

    NASA Astrophysics Data System (ADS)

    Dickerson, Andrew K.; Liu, Xing; Zhu, Ting; Hu, David L.

    2015-02-01

    The flexibility of insect wings confers aerodynamic benefits, but can also present a hazard if exposed to fog or dew. Fog can cause water to accumulate on wings, bending them into tight taco shapes and rendering them useless for flight. In this combined experimental and theoretical study, we use high-speed video to film the spontaneous folding of isolated mosquito wings due to the evaporation of a water drop. We predict shapes of the deformed wing using two-dimensional elastica theory, considering both surface tension and Laplace pressure. We also recommend fold-resistant geometries for the wings of flapping micro-aerial vehicles. Our work reveals the mechanism of insect wing folding and provides a framework for further study of capillarity-driven folding in both natural and biomimetic systems at small scales.

  4. Spatial and temporal distribution of mosquitoes in underground storm drain systems in Orange County, California.

    PubMed

    Su, Tianyun; Webb, James P; Meyer, Richard P; Mulla, Mir S

    2003-06-01

    Underground storm drain systems in urban areas of Orange County include thousands of miles of gutters and underground pipelines, plus hundreds of thousands of catch basins and manhole chambers, all of which drain runoff water from residential, business and commercial establishments as well as highways and streets. These systems serve as major developmental and resting sites for anthropophilic and zoophilic mosquitoes. Investigations on spatial and temporal distribution of mosquitoes in these systems were conducted during November 1999 to October 2001. Immature mosquitoes were sampled by dipper or dipping net and adult mosquitoes by non-attractive CDC traps in manhole chambers, catch basins and a large drain. Culex quinquefasciatus Say prevailed at all 15 structures of the study in 4 cities of Orange County as the predominant species (> 99.9%). Larvae and pupae were present from April to October, peaking from May to September. The population density of adults was the lowest in February with 2 peaks of abundance occurring from May to July and from September to October. Manhole chambers and catch basins harbored more mosquitoes than did the large drain. Minimum and maximum temperatures during a 24 h sampling period was an important factor influencing adult mosquito activity and catches; more mosquitoes were caught in traps when it was warmer, especially when the minimum temperatures were higher. The proportion of females to males in general increased during winter and early spring an ddeclined during summer. The proportion of gravid females to empty females was higher during the winter than in summer. Other dipteran taxa such as psychodid moth flies and chironomid midges exhibited somewhat similar seasonal patterns as did mosquito populations. Average water temperature was relatively stable throughout the year, and water quality in underground drain systems was characterized by low dissolved oxygen, coupled with above normal electrical conductivity and salinity levels

  5. Mosquito, adult feeding on the skin (image)

    MedlinePlus

    There are many different species of mosquito, which can carry some of the world's most common and significant infectious diseases, including West Nile, Malaria, yellow fever, viral encephalitis, and ...

  6. Disproportionate mosquito feeding on aggregated hosts.

    PubMed

    Foppa, Ivo M; Moore, Jerrilynn; Caillouët, Kevin A; Wesson, Dawn M

    2011-11-01

    Despite the importance of per-capita feeding rates for mosquito-borne transmission dynamics, the relationship between host aggregation and per-capita feeding rates remains poorly characterized. We conducted indoor experiments to investigate how Culex quinquefasciatus (Say) mosquitoes distribute their blood feeding on variably aggregated domestic chickens (Callus gallus domesticus L.) (one chicken vs. a flock of seven to nine birds). Mosquitoes were always more likely to feed on the larger chicken group; yet, the single chicken tended to be fed on at a higher per-capita rate. When 10 chickens were available the feeding intensity was 4.5 times higher for the single chicken compared with the flock. We conclude that more highly aggregated hosts may experience lower exposure to mosquito bites than less aggregated hosts.

  7. Housing, Design, and Furnishings.

    ERIC Educational Resources Information Center

    Texas Tech Univ., Lubbock. Home Economics Curriculum Center.

    This document contains teacher's materials for a six-unit secondary education vocational home economics course on housing, design, and furnishings. The units cover: (1) the societal aspects of housing (including the relationship between housing and the economy, population trends, and culture-related housing characteristics); (2) family housing…

  8. Oviposition-Modifying Substances for Mosquitoes.

    DTIC Science & Technology

    1981-07-01

    preference may be due to the presence of oviposition pheromones or oviposition attractants and repellents in natural habitats. These oviposition -modifying...LfD-R125 421 OVIPOSITION -MODIFYING SUBSTANCES FOR MOSQUITOES(U) 11 I CALIFORNIA UNIV RIVERSIDE DEPT OF ENTOMOLOGY Y HWANG I 91 JUL 81 DANDi?7-79-C...STANDARDS- 1963-A ." !’, -b b’, -1 I- I 1. AD__ _ _ _ * N 3 OVIPOSITION -MODIFYING SUBSTANCES FOR MOSQUITOES Final Report Yih-Shen Hwang * July 1, 1981

  9. Oviposition-Modifying Substances for Mosquitoes.

    DTIC Science & Technology

    1980-09-01

    AD C: 2 OVIPOSITION -MODIFYING SUBSTANCES FOR MOSQUITOES Annual Summary Report YIH-SHEN HWANG * ’September 1, 1980 Supported by U.S. ARMY MEDICAL...NUMBER 2. GOVT ACCESSION NO. 3. RECIPIENT’S CATALOG NUMBER 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED OVIPOSITION -MODIFYING SUBSTANCES...nd identify by block number) MOSQUITOES/ OVIPOSITION -ATTRACTANTS/ OVIPOSITION -REPELLENTS/ OVIPOSITION - MODIFYING-SUBSTANCES/CARBOXYLIC-ACIDS/OCTANOIC

  10. Mosquito coil emissions and health implications.

    PubMed

    Liu, Weili; Zhang, Junfeng; Hashim, Jamal H; Jalaludin, Juliana; Hashim, Zailina; Goldstein, Bernard D

    2003-09-01

    Burning mosquito coils indoors generates smoke that can control mosquitoes effectively. This practice is currently used in numerous households in Asia, Africa, and South America. However, the smoke may contain pollutants of health concern. We conducted the present study to characterize the emissions from four common brands of mosquito coils from China and two common brands from Malaysia. We used mass balance equations to determine emission rates of fine particles (particulate matter < 2.5 microm in diameter; PM(2.5)), polycyclic aromatic hydrocarbons (PAHs), aldehydes, and ketones. Having applied these measured emission rates to predict indoor concentrations under realistic room conditions, we found that pollutant concentrations resulting from burning mosquito coils could substantially exceed health-based air quality standards or guidelines. Under the same combustion conditions, the tested Malaysian mosquito coils generated more measured pollutants than did the tested Chinese mosquito coils. We also identified a large suite of volatile organic compounds, including carcinogens and suspected carcinogens, in the coil smoke. In a set of experiments conducted in a room, we examined the size distribution of particulate matter contained in the coil smoke and found that the particles were ultrafine and fine. The findings from the present study suggest that exposure to the smoke of mosquito coils similar to the tested ones can pose significant acute and chronic health risks. For example, burning one mosquito coil would release the same amount of PM(2.5) mass as burning 75-137 cigarettes. The emission of formaldehyde from burning one coil can be as high as that released from burning 51 cigarettes.

  11. Engineering Plasmodium-refractory phenotypes in mosquitoes.

    PubMed

    Nirmala, Xavier; James, Anthony A

    2003-09-01

    A remarkable number of effector mechanisms have been developed for interfering with malaria parasite development in mosquitoes. These effector mechanisms affect different aspects of parasite biology and therefore could be targeted synergistically to reduce the probability of emergence of parasite resistance to any one mechanism. The use of these mechanisms will depend on how efficiently and safely they can be introduced into existing mosquito populations.

  12. Mosquito coil emissions and health implications.

    PubMed Central

    Liu, Weili; Zhang, Junfeng; Hashim, Jamal H; Jalaludin, Juliana; Hashim, Zailina; Goldstein, Bernard D

    2003-01-01

    Burning mosquito coils indoors generates smoke that can control mosquitoes effectively. This practice is currently used in numerous households in Asia, Africa, and South America. However, the smoke may contain pollutants of health concern. We conducted the present study to characterize the emissions from four common brands of mosquito coils from China and two common brands from Malaysia. We used mass balance equations to determine emission rates of fine particles (particulate matter < 2.5 microm in diameter; PM(2.5)), polycyclic aromatic hydrocarbons (PAHs), aldehydes, and ketones. Having applied these measured emission rates to predict indoor concentrations under realistic room conditions, we found that pollutant concentrations resulting from burning mosquito coils could substantially exceed health-based air quality standards or guidelines. Under the same combustion conditions, the tested Malaysian mosquito coils generated more measured pollutants than did the tested Chinese mosquito coils. We also identified a large suite of volatile organic compounds, including carcinogens and suspected carcinogens, in the coil smoke. In a set of experiments conducted in a room, we examined the size distribution of particulate matter contained in the coil smoke and found that the particles were ultrafine and fine. The findings from the present study suggest that exposure to the smoke of mosquito coils similar to the tested ones can pose significant acute and chronic health risks. For example, burning one mosquito coil would release the same amount of PM(2.5) mass as burning 75-137 cigarettes. The emission of formaldehyde from burning one coil can be as high as that released from burning 51 cigarettes. PMID:12948883

  13. Mosquito repellent activities of ocimum volatile oils.

    PubMed

    Chokechaijaroenporn, O; Bunyapraphatsara, N; Kongchuensin, S

    1994-09-01

    Essential oils obtained from Ocimum americanum, O. basilicum, O. basilicum fa. citratum, O. gratissimum and O. tenuiflorum, were tested for mosquito repellent and larvicidal activities. All the oils exhibited both activities. O. basilicum showed the strongest larvicidal activity (EC(50) = 81, EC(90) = 113 ppm), while O. gratissimum exhibited the longest duration of action for mosquito repellent activity (more than two hours). Gas chromatographic analysis indicated the presence of camphor, caryophyllene oxide, cineole, methyleugenol, limonene, myrcene, and thymol, all known insect repellents.

  14. Vector Competence of Mosquitoes for Arboviruses

    DTIC Science & Technology

    1989-07-30

    ml) on the titers of three alphaviruses , Sindbis(A), western equine encephalomyelitis (B), Venezuelan equine encephalomyelitis (C), and the...population have been delineated and discussed with reference to the mosquito, Culex tarsalis, and the alphavirus , western equine encephalomyelitis (WEE...mechanism that appears to control WEE viral replication (Hardy et al., 1983; Kramer et al., 1989; Ann. Prog. Rpt., 1988). The ability of a mosquito to

  15. Early-Life Social Isolation Influences Mouse Ultrasonic Vocalizations during Male-Male Social Encounters

    PubMed Central

    Finton, Caitlyn J.; Sell, Gabrielle L.; Hurley, Laura M.

    2017-01-01

    Early-life social isolation has profound effects on adult social competence. This is often expressed as increased aggression or inappropriate displays of courtship-related behaviors. The social incompetence exhibited by isolated animals could be in part due to an altered ability to participate in communicatory exchanges. House mice (Mus musculus) present an excellent model for exploring this idea, because social isolation has a well-established influence on their social behavior, and mice engage in communication via multiple sensory modalities. Here, we tested the prediction that social isolation during early life would influence ultrasonic vocalizations (USVs) emitted by adult male mice during same-sex social encounters. Starting at three weeks of age, male mice were housed individually or in social groups of four males for five weeks, after which they were placed in one of three types of paired social encounters. Pair types consisted of: two individually housed males, two socially housed males, or an individually housed and a socially housed male (“mixed” pairs). Vocal behavior (USVs) and non-vocal behaviors were recorded from these 15-minute social interactions. Pairs of mice consisting of at least one individually housed male emitted more and longer USVs, with a greater proportional use of USVs containing frequency jumps and 50-kHz components. Individually housed males in the mixed social pairs exhibited increased levels of mounting behavior towards the socially housed males. Mounting in these pairs was positively correlated with increased number and duration of USVs as well as increased proportional use of spectrally more complex USVs. These findings demonstrate that USVs are part of the suite of social behaviors influenced by early-life social isolation, and suggest that altered vocal communication following isolation reflects reduced social competence. PMID:28056078

  16. Modelling and analysis of impulsive releases of sterile mosquitoes.

    PubMed

    Huang, Mingzhan; Song, Xinyu; Li, Jia

    2017-12-01

    To study the impact of releasing sterile mosquitoes on mosquito-borne disease transmissions, we propose two mathematical models with impulsive releases of sterile mosquitoes. We consider periodic impulsive releases in the first model and obtain the existence, uniqueness, and globally stability of a wild-mosquito-eradication periodic solution. We also establish thresholds for the control of the wild mosquito population by selecting the release rate and the release period. In the second model, the impulsive releases are determined by the closely monitored wild mosquito density, or the state feedback. We prove the existence of an order one periodic solution and find a relatively small attraction region, which ensures the wild mosquito population is under control. We provide numerical analysis which shows that a smaller release rate and more frequent releases are more efficient in controlling the wild mosquito population for the periodic releases, but an early release of sterile mosquitoes is more effective for the state feedback releases.

  17. Diversity of culturable bacteria including Pantoea in wild mosquito Aedes albopictus

    PubMed Central

    2013-01-01

    Background The microbiota has been shown to play an important role in the biology of insects. In recent decades, significant efforts have been made to better understand the diversity of symbiotic bacteria associated with mosquitoes and assess their influence on pathogen transmission. Here, we report the bacterial composition found in field-caught Aedes albopictus populations by using culture-dependent methods. Results A total of 104 mosquito imagos (56 males and 48 females) were caught from four contrasting biotopes of Madagascar and their bacterial contents were screened by plating whole body homogenates on three different culture media. From 281 bacterial colony types obtained, amplified ribosomal DNA restriction analysis (ARDRA) showed they had 40 distinct ribotypes. Sequencing and BLAST analysis of the 16S rDNA genes responsible for each representative profile made it possible to identify 27 genera distributed in three major phyla. In female mosquitoes, bacterial isolates were mostly Proteobacteria (51.3%) followed by Firmicutes (30.3%) and Actinobacteria (18.4%). Conversely, Actinobacteria was the most abundant phylum in male mosquitoes (48%) followed by Proteobacteria (30.6%) and Firmicutes (20.4%). The relative abundance and composition of isolates also varied between sampling sites, ranging from 3 distinct families in Ankazobe to 8 in Tsimbazaza Park, and Toamasina and Ambohidratrimo. Pantoea was the most common genus in both females and males from all sampling sites, except for Ambohidratrimo. No differences in genome size were found between Pantoea isolates from mosquitoes and reference strains in pulse field gel electrophoresis. However, according to the numbers and sizes of plasmids, mosquito isolates clustered into three different groups with other strains isolated from insects but distinct from isolates from the environment. Conclusions The recent upsurge in research into the functional role of the insect microbiota prompts the interest to better

  18. Chikungunya virus and its mosquito vectors.

    PubMed

    Higgs, Stephen; Vanlandingham, Dana

    2015-04-01

    Chikungunya virus (CHIKV), a mosquito-borne alphavirus of increasing public health significance, has caused large epidemics in Africa and the Indian Ocean basin; now it is spreading throughout the Americas. The primary vectors of CHIKV are Aedes (Ae.) aegypti and, after the introduction of a mutation in the E1 envelope protein gene, the highly anthropophilic and geographically widespread Ae. albopictus mosquito. We review here research efforts to characterize the viral genetic basis of mosquito-vector interactions, the use of RNA interference and other strategies for the control of CHIKV in mosquitoes, and the potentiation of CHIKV infection by mosquito saliva. Over the past decade, CHIKV has emerged on a truly global scale. Since 2013, CHIKV transmission has been reported throughout the Caribbean region, in North America, and in Central and South American countries, including Brazil, Columbia, Costa Rica, El Salvador, French Guiana, Guatemala, Guyana, Nicaragua, Panama, Suriname, and Venezuela. Closing the gaps in our knowledge of driving factors behind the rapid geographic expansion of CHIKV should be considered a research priority. The abundance of multiple primate species in many of these countries, together with species of mosquito that have never been exposed to CHIKV, may provide opportunities for this highly adaptable virus to establish sylvatic cycles that to date have not been seen outside of Africa. The short-term and long-term ecological consequences of such transmission cycles, including the impact on wildlife and people living in these areas, are completely unknown.

  19. Filarial infection influences mosquito behaviour and fecundity

    PubMed Central

    Gleave, Katherine; Cook, Darren; Taylor, Mark J.; Reimer, Lisa J.

    2016-01-01

    Understanding vector-parasite interactions is increasingly important as we move towards the endpoint goals set by the Global Programme for the Elimination of Lymphatic Filariasis (GPELF), as interaction dynamics may change with reduced transmission pressure. Elimination models used to predict programmatic endpoints include parameters for vector-specific transmission dynamics, despite the fact that our knowledge of the host-seeking behaviour of filariasis infected mosquitoes is lacking. We observed a dynamic, stage-specific and density dependent change in Aedes aegypti behaviour towards host cues when exposed to Brugia malayi filarial parasites. Infected mosquitoes exhibited reduced activation and flight towards a host during the period of larval development (L1/L2), transitioning to a 5 fold increase in activation and flight towards a host when infective stage larvae (L3) were present (p < 0.001). In uninfected control mosquitoes, we observed a reduction in convergence towards a host during the same period. Furthermore, this behaviour was density dependent with non-activated mosquitoes harbouring a greater burden of L1 and L2 larvae while activated mosquitoes harboured a greater number of L3 (p < 0.001). Reductions in fecundity were also density-dependent, and extended to mosquitoes that were exposed to microfilariae but did not support larval development. PMID:27796352

  20. Distribution of Brugia malayi larvae and DNA in vector and non-vector mosquitoes: implications for molecular diagnostics

    PubMed Central

    2009-01-01

    Background The purpose of this study was to extend prior studies of molecular detection of Brugia malayi DNA in vector (Aedes aegypti- Liverpool) and non-vector (Culex pipiens) mosquitoes at different times after ingestion of infected blood. Results Parasite DNA was detected over a two week time course in 96% of pooled thoraces of vector mosquitoes. In contrast, parasite DNA was detected in only 24% of thorax pools from non-vectors; parasite DNA was detected in 56% of midgut pools and 47% of abdomen pools from non-vectors. Parasite DNA was detected in vectors in the head immediately after the blood meal and after 14 days. Parasite DNA was also detected in feces and excreta of the vector and non-vector mosquitoes which could potentially confound results obtained with field samples. However, co-housing experiments failed to demonstrate transfer of parasite DNA from infected to non-infected mosquitoes. Parasites were also visualized in mosquito tissues by immunohistololgy using an antibody to the recombinant filarial antigen Bm14. Parasite larvae were detected consistently after mf ingestion in Ae. aegypti- Liverpool. Infectious L3s were seen in the head, thorax and abdomen of vector mosquitoes 14 days after Mf ingestion. In contrast, parasites were only detected by histology shortly after the blood meal in Cx. pipiens, and these were not labeled by the antibody. Conclusion This study provides new information on the distribution of filarial parasites and parasite DNA in vector and non-vector mosquitoes. This information should be useful for those involved in designing and interpreting molecular xenomonitoring studies. PMID:19922607

  1. Laboratory selection for an accelerated mosquito sexual development rate

    PubMed Central

    2011-01-01

    Background Separating males and females at the early adult stage did not ensure the virginity of females of Anopheles arabiensis (Dongola laboratory strain), whereas two years earlier this method had been successful. In most mosquito species, newly emerged males and females are not able to mate successfully. For anopheline species, a period of 24 h post-emergence is generally required for the completion of sexual maturation, which in males includes a 180° rotation of the genitalia. In this study, the possibility of an unusually shortened sexual maturity period in the laboratory-reared colony was investigated. Methods The effect of two different sex-separation methods on the virginity of females was tested: females separated as pupae or less than 16 h post-emergence were mated with males subjected to various doses of radiation. T-tests were performed to compare the two sex-separation methods. The rate of genitalia rotation was compared for laboratory-reared and wild males collected as pupae in Dongola, Sudan, and analysed by Z-tests. Spermatheca dissections were performed on females mated with laboratory-reared males to determine their insemination status. Results When the sex-separation was performed when adults were less than 16 h post-emergence, expected sterility was never reached for females mated with radio-sterilized males. Expected sterility was accomplished only when sexes were separated at the pupal stage. Observation of genitalia rotation showed that some males from the laboratory strain Dongola were able to successfully mate only 11 h after emergence and 42% of the males had already completed rotation. A small proportion of the same age females were inseminated. Wild males showed a much slower genitalia rotation rate. At 17 h post-emergence, 96% of the laboratory-reared males had completed genitalia rotation whereas none of the wild males had. Conclusion This colony has been cultured in the laboratory for over one hundred generations, and now has

  2. Counseling Males.

    ERIC Educational Resources Information Center

    Scher, Murray, Ed.

    1981-01-01

    Contains 16 articles about counseling males including: (1) gender role conflict; (2) sex-role development; (3) counseling adolescent, adult, and gay males; (4) teenage fathers; (5) female therapists and male clients; (6) career development; (7) hypermasculinity; (8) counseling physically abusive men, uncoupling men; (9) group therapy, men's…

  3. A study on the resting preference of mosquito species in wells in Vellore in Tamilnadu, South India.

    PubMed

    Rajagopal, V; Elango, S; Jeykumar, K; Madhavan, J; Alamelu, M; Shanthi, S

    2010-03-01

    The resting preferences of mosquito species was investigated in domestic wells. In addition to the routine adult surveys in human dwellings, adult collections were also made in domestic wells using an innovated equipment operating on the principles of spray sheet collections. Above the water surface, wells provide humid and dark microclimate along the inner walls. It has been observed that this microclimate provides very congenial resting place for few mosquito species; specially for the males and for the females between their gonotropic cycles. Larval collections in the wells did not reveal breeding of majority of the mosquito species collected by this technique. Investigations were conducted in 87 wells in 11 localities during 2005. A total of 4969 mosquitos were collected of which 69.1% (3441) were males and 30.9% (1528) were females. From among the mosquitos collected 96.5% were Cu. quinquifasciatus, 0.26% All stephensi, 3.0% Aedes agypti and 0.24% Armegeres sp. The results of the analysis of the physical and chemical parameter of water samples of the study wells before and after the surveys endorsed the utility of this technique for entomological investigations in outbreak situations, for monitoring the liquidation of outbreak foci and for other research purposes.

  4. Using Stable Isotopes of Carbon and Nitrogen to Mark Wild Populations of Anopheles and Aedes Mosquitoes in South-Eastern Tanzania

    PubMed Central

    Opiyo, Mercy A.; Hamer, Gabriel L.; Lwetoijera, Dickson W.; Auckland, Lisa D.; Majambere, Silas; Okumu, Fredros O.

    2016-01-01

    Background Marking wild mosquitoes is important for understanding their ecology, behaviours and role in disease transmission. Traditional insect marking techniques include using fluorescent dyes, protein labels, radioactive labels and tags, but such techniques have various limitations; notably low marker retention and inability to mark wild mosquitoes at source. Stable isotopes are gaining wide spread use for non-invasive marking of arthropods, permitting greater understanding of mosquito dispersal and responses to interventions. We describe here a simple technique for marking naturally-breeding malaria and dengue vectors using stable isotopes of nitrogen (15N) and carbon (13C), and describe potential field applications. Methods We created man-made aquatic mosquito habitats and added either 15N-labelled potassium nitrate or 13C-labelled glucose, leaving non-adulterated habitats as controls. We then allowed wild mosquitoes to lay eggs in these habitats and monitored their development in situ. Pupae were collected promptly as they appeared and kept in netting cages. Emergent adults (in pools of ~4 mosquitoes/pool) and individually stored pupae were desiccated and analysed using Isotope Ratio Mass Spectrometry (IRMS). Findings Anopheles gambiae s.l and Aedes spp. from enriched 13C and enriched 15N larval habitats had significantly higher isotopic levels than controls (P = 0.005), and both isotopes produced sufficient distinction between marked and unmarked mosquitoes. Mean δ15N for enriched females and males were 275.6±65.1 and 248.0±54.6, while mean δ15N in controls were 2.1±0.1 and 3.9±1.7 respectively. Similarly, mean δ13C for enriched females and males were 36.08±5.28 and 38.5±6.86, compared to -4.3±0.2 and -7.9±3.6 in controls respectively. Mean δ15N and δ13C was significantly higher in any pool containing at least one enriched mosquito compared to pools with all unenriched mosquitoes, P<0.001. In all cases, there were variations in standardized

  5. Analysis and optimization of a synthetic milkweed floral attractant for mosquitoes.

    PubMed

    Otienoburu, Philip E; Ebrahimi, Babak; Phelan, P Larry; Foster, Woodbridge A

    2012-07-01

    A pentane extract of flowers of common milkweed, Asclepias syriaca (Asclepiadaceae), elicited significant orientation from both male and female Culex pipiens in a dual-port flight olfactometer. Analysis of the extract by gas chromatography-mass spectrometry revealed six major constituents in order of relative abundance: benzaldehyde, (E)-β-ocimene, phenylacetaldehyde, benzyl alcohol, nonanal, and (E)-2-nonenal. Although not all were collected from the headspace profile of live flowers, a synthetic blend of these six compounds, when presented to mosquitoes in the same levels and proportions that occur in the extract, elicited a response comparable to the extract. Subtractive behavioral bioassays demonstrated that a three-component blend consisting of benzaldehyde, phenylacetaldehyde, and (E)-2-nonenal was as attractive as the full blend. These findings suggest the potential use of synthetic floral-odor blends for monitoring or control of both male and female disease-vectoring mosquitoes.

  6. 2nd International Forum for Surveillance and Control of Mosquitoes and Mosquito-borne Diseases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Entomological Society of China (ESC) and Beijing Institute of Microbiology and Epidemiology (BIME) hosted the 2nd International Forum for Surveillance and Control of Mosquitoes and Mosquito-borne Diseases in Beijing, China, May 23-27, 2011. The theme of the Forum was “Impact of global climate ch...

  7. International forum for surveillance and control of mosquitoes and mosquito-borne diseases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This manuscript provides highlights of presentations given at the 1st International Forum for Surveillance and Control of Mosquitoes and Mosquito-borne Disease in Beijing, China. Topics covered in this 4-day forum included: diseases, surveillance, insecticides, physiology and ecology, behavior, inv...

  8. Research Contributing to Improvements in Controlling Florida's Mosquitoes and Mosquito-borne Diseases.

    PubMed

    Tabachnick, Walter J

    2016-09-28

    Research on mosquitoes and mosquito-borne diseases has contributed to improvements in providing effective, efficient, and environmentally proper mosquito control. Florida has benefitted from several research accomplishments that have increased the state's mosquito control capabilities. Research with Florida's mosquitoes has resulted in the development of ecologically sound management of mosquito impoundments on Florida's east coast. This strategy, called Rotational Impoundment Management (RIM), has improved the ability to target the delivery of pesticides and has helped to reduce non-target effects and environmental damage. Research has led to the development of an arbovirus surveillance system which includes sentinel chicken surveillance, real time use of environmental contributing factors like meteorology and hydrology to target mosquito control, as well as public health efforts to mitigate disease outbreaks to areas with risk of disease. These research driven improvements have provided substantial benefits to all of Florida. More research is needed to meet the future challenges to reduce emerging pathogens like Zika virus and the consequences of environmental changes like global climate change that are likely to influence the effects of mosquito-borne pathogens on human health and well-being.

  9. Research Contributing to Improvements in Controlling Florida’s Mosquitoes and Mosquito-Borne Diseases

    PubMed Central

    Tabachnick, Walter J.

    2016-01-01

    Research on mosquitoes and mosquito-borne diseases has contributed to improvements in providing effective, efficient, and environmentally proper mosquito control. Florida has benefitted from several research accomplishments that have increased the state’s mosquito control capabilities. Research with Florida’s mosquitoes has resulted in the development of ecologically sound management of mosquito impoundments on Florida’s east coast. This strategy, called Rotational Impoundment Management (RIM), has improved the ability to target the delivery of pesticides and has helped to reduce non-target effects and environmental damage. Research has led to the development of an arbovirus surveillance system which includes sentinel chicken surveillance, real time use of environmental contributing factors like meteorology and hydrology to target mosquito control, as well as public health efforts to mitigate disease outbreaks to areas with risk of disease. These research driven improvements have provided substantial benefits to all of Florida. More research is needed to meet the future challenges to reduce emerging pathogens like Zika virus and the consequences of environmental changes like global climate change that are likely to influence the effects of mosquito-borne pathogens on human health and well-being. PMID:27690112

  10. The discerning predator: decision rules underlying prey classification by a mosquito-eating jumping spider

    PubMed Central

    Nelson, Ximena J.; Jackson, Robert R.

    2012-01-01

    SUMMARY Evarcha culicivora is an East African jumping spider that feeds indirectly on vertebrate blood by choosing blood-fed female Anopheles mosquitoes as prey. Previous studies have shown that this predator can identify its preferred prey even when restricted to using only visual cues. Here, we used lures and virtual mosquitoes to investigate the optical cues underlying this predator's prey-choice behaviour. We made lures by dissecting and then reconstructing dead mosquitoes, combining the head plus thorax with different abdomens. Depending on the experiment, lures were either moving or motionless. Findings from the lure experiments suggested that, for E. culicivora, seeing a blood-fed female mosquito's abdomen on a lure was a necessary, but not sufficient, cue by which preferred prey was identified, as cues from the abdomen needed to be paired with cues from the head and thorax of a mosquito. Conversely, when abdomens were not visible or were identical, spiders based their decisions on the appearance of the head plus thorax of mosquitoes, choosing prey with female characteristics. Findings from a subsequent experiment using animated 3D virtual mosquitoes suggest that it is specifically the mosquito's antennae that influence E. culicivora's prey-choice decisions. Our results show that E. culicivora uses a complex process for prey classification. PMID:22675186

  11. Population Dynamics of Blood-Fed Female Mosquitoes and Comparative Efficacy of Resting Boxes in Collecting them from the Northwestern Part of Riverside County, California

    PubMed Central

    Sandhu, Tejbir S; Williams, Gregory W; Haynes, Bryan W; Dhillon, Major S

    2013-01-01

    Objectives: Testing of blood-fed mosquitoes plays an integral role in arbovirus surveillance and in understanding its interaction mechanisms between host, vector and reservoir. The present study was undertaken to evaluate the efficacy of two different traps (gravid and resting boxes) for collection of blood-fed mosquitoes in the northwestern part of Riverside County. Materials and Methods: Three trapping sites were selected in the Northwest Mosquito and Vector Control District of Riverside County, California. At each site resting boxes and gravid traps were set; and mosquitoes were collected on a weekly basis between July-December 2009. Mosquitoes were transported over blue ice, identified up to species level on chill table, and classified as male, female and blood-fed females. Results: During this study period, 3953 mosquitoes (826 blood-fed females) belonging to three different genera and eight species were collected; resting boxes collecting maximum number (seven) of mosquito species. Overall as well as individually in each trap kind, the most abundant mosquito species collected was Cx. quinquefasciatus. The proportion of blood-fed females of the Culex species collected in resting boxes was 28.8 times more, while of blood-fed females of Cx. quinquefasciatus was 32.2 times more than the proportion collected from gravid traps. Conclusions: Overall, the proportion of blood-fed female mosquitoes collected for each species trapped was highest in resting boxes. Additionally, resting boxes showed the advantage of extremely low running and maintenance cost; generation of no hazardous waste; quick turnaround time in terms of mosquito collection per man-hour spent; and they were less prone to vandalism or thefts. PMID:23599612

  12. Intriguing olfactory proteins from the yellow fever mosquito, Aedes aegypti

    NASA Astrophysics Data System (ADS)

    Ishida, Yuko; Chen, Angela M.; Tsuruda, Jennifer M.; Cornel, Anthon J.; Debboun, Mustapha; Leal, Walter S.

    2004-09-01

    Four antennae-specific proteins (AaegOBP1, AaegOBP2, AaegOBP3, and AaegASP1) were isolated from the yellow fever mosquito, Aedes aegypti and their full-length cDNAs were cloned. RT-PCR indicated that they are expressed in female and, to a lesser extent, in male antennae, but not in control tissues (legs). AaegOBP1 and AaegOBP3 showed significant similarity to previously identified mosquito odorant-binding proteins (OBPs) in cysteine spacing pattern and sequence. Two of the isolated proteins have a total of eight cysteine residues. The similarity of the spacing pattern of the cysteine residues and amino acid sequence to those of previously identified olfactory proteins suggests that one of the cysteine-rich proteins (AaegOBP2) is an OBP. The other (AaegASP1) did not belong to any group of known OBPs. Structural analyses indicate that six of the cysteine residues in AaegOBP2 are linked in a similar pattern to the previously known cysteine pairing in OBPs, i.e., Cys-24 Cys-55, Cys-51 Cys-104, Cys-95 Cys-113. The additional disulfide bridge, Cys-38 Cys-125, knits the extended C-terminal segment of the protein to a predicted α2-helix. As indicated by circular dichroism (CD) spectra, the extra rigidity seems to prevent the predicted formation of a C-terminal α-helix at low pH.

  13. Reintroduction of the invasive mosquito species Aedes albopictus in Belgium in July 2013.

    PubMed

    Boukraa, Slimane; Raharimalala, Fara N; Zimmer, Jean-Yves; Schaffner, Francis; Bawin, Thomas; Haubruge, Eric; Francis, Frédéric

    2013-01-01

    Since its first report in 2000, the invasive mosquito Aedes albopictus was not found any more during the different entomological inspections performed at its place of introduction in Belgium between 2001 and 2012. In July 2013, one adult male was captured at the same site (a platform of imported used tires located in Vrasene, Oost-Vlaanderen Province), during a monitoring using CO2-baited trap. This finding suggests the reintroduction of the species in Belgium via the used tire trade.

  14. DDT-resistant Culex quinquefasciatus: the effect of DDT on the mosquito's size, fecundity and survival.

    PubMed

    Kerdpibule, V; Sucharit, S; Deesin, T

    1981-03-01

    Resistant strains of Culex quinquefasciatus were selected in the larval stage by exposure to sublethal doses of DDT. The size, body weight and fecundity of DDT-resistant mosquitoes were significantly decreased. There was no significant difference between the longevity of females in the original strain and the DDT selected strains, however, there was a significant difference in the males of the DDT-resistant strains than those of the original strain.

  15. Reduced productivity in adult yellowfever mosquito (Diptera: Culicidae) populations

    SciTech Connect

    Rodriguez, P.H.; Hamm, W.J.; Garcia, F.; Garcia, M.; Schirf, V.

    1989-04-01

    Male and female Aedes aegypti (L.) mosquitoes of the laboratory strain ROCK were irradiated with 130 mw of argon 514.5 nm laser microbeams for 0.04, 0.25, 0.4, and 0.5 s, respectively. Egg production, percentage hatch, and productivity (average number of adults surviving after 3 wk) were used to assess mutagenic effects. Mortality was high for males in all laser radiation groups and increased with time of exposure. Except for the group treated for 0.25 s, significant reductions in total F1 progeny also were demonstrated for all other experimentals when male parents were exposed to laser radiation. Females showed a high mortality when subjected to 0.4- and 0.5-s laser radiation. No F1 progeny were produced when parental females were exposed for 0.25, 0.4, and 0.5 s. Numbers of F1 progeny from females exposed to 0.04 s of laser radiation were significantly reduced. A comparison of weekly mean number of progeny showed that the important differences in productivity occurred during the first and second week, respectively, when either male or female adult parents were subjected to laser radiation.

  16. Engineered mosquitoes to fight mosquito borne diseases: not a merely technical issue.

    PubMed

    Favia, Guido

    2015-01-01

    Malaria, dengue and other mosquito-borne diseases pose dramatic problems of public health, particularly in tropical and sub-tropical countries. Historically, vector control has been one of the most successfully strategies to eradicate some mosquito-borne diseases, as witnessed by malaria eradication in Mediterranean regions such as Italy and Greece. Vector control through insecticides has been used worldwide; unfortunately, it is losing effectiveness due to spread of resistances. Control of mosquito-borne diseases through field-releases of genetically engineered mosquitoes is an innovative and now feasible approach. Genetically modified mosquitoes have already been released into the wild in some regions, and protocols for this release are on hand in others. Local authorities are vigilant that transgenic insects in the field are safe for human and animal populations, and the public engagement in every control program is assuming a central role.

  17. Straightforward multi-object video tracking for quantification of mosquito flight activity.

    PubMed

    Wilkinson, David A; Lebon, Cyrille; Wood, Trevor; Rosser, Gabriel; Gouagna, Louis Clément

    2014-12-01

    Mosquito flight activity has been studied using a variety of different methodologies, and largely concentrates on female mosquito activity as vectors of disease. Video recording using standard commercially available hardware has limited accuracy for the measurement of flight activity due to the lack of depth-perception in two-dimensional images, but multi-camera observation for three dimensional trajectory reconstructions remain challenging and inaccessible to the majority of researchers. Here, in silico simulations were used to quantify the limitations of two-dimensional flight observation. We observed that, under the simulated conditions, two dimensional observation of flight was more than 90% accurate for the determination of population flight speeds and thus that two dimensional imaging can be used to provide accurate estimates of mosquito population flight speeds, and to measure flight activity over long periods of time. We optimized single camera video imaging to study male Aedes albopictus mosquitoes over a 30 h time period, and tested two different multi-object tracking algorithms for their efficiency in flight tracking. A. Albopictus males were observed to be most active at the start of the day period (06h00-08h00) with the longest period of activity in the evening (15h00-18h00) and that a single mosquito will fly more than 600 m over the course of 24 h. No activity was observed during the night period (18h00-06h00). Simplistic tracking methodologies, executable on standard computational hardware, are sufficient to produce reliable data when video imaging is optimized under laboratory conditions. As this methodology does not require overly-expensive equipment, complex calibration of equipment or extensive knowledge of computer programming, the technology should be accessible to the majority of computer-literate researchers.

  18. 24 CFR 982.618 - Shared housing: Housing quality standards.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false Shared housing: Housing quality standards. 982.618 Section 982.618 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING...

  19. 24 CFR 982.618 - Shared housing: Housing quality standards.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 4 2014-04-01 2014-04-01 false Shared housing: Housing quality standards. 982.618 Section 982.618 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING...

  20. 24 CFR 982.618 - Shared housing: Housing quality standards.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 4 2012-04-01 2012-04-01 false Shared housing: Housing quality standards. 982.618 Section 982.618 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING...

  1. 24 CFR 982.618 - Shared housing: Housing quality standards.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 4 2013-04-01 2013-04-01 false Shared housing: Housing quality standards. 982.618 Section 982.618 Housing and Urban Development REGULATIONS RELATING TO HOUSING AND URBAN DEVELOPMENT (CONTINUED) OFFICE OF ASSISTANT SECRETARY FOR PUBLIC AND INDIAN HOUSING, DEPARTMENT OF HOUSING...

  2. Mosquito Consumption by Insectivorous Bats: Does Size Matter?

    PubMed Central

    Gonsalves, Leroy; Bicknell, Brian; Law, Brad; Webb, Cameron; Monamy, Vaughan

    2013-01-01

    Insectivorous bats have often been touted as biological control for mosquito populations. However, mosquitoes generally represent only a small proportion of bat diet. Given the small size of mosquitoes, restrictions imposed on prey detectability by low frequency echolocation, and variable field metabolic rates (FMR), mosquitoes may not be available to or profitable for all bats. This study investigated whether consumption of mosquitoes was influenced by bat size, which is negatively correlated with echolocation frequency but positively correlated with bat FMR. To assess this, we investigated diets of five eastern Australian bat species (Vespadelus vulturnus Thomas, V. pumilus Gray, Miniopterus australis Tomes, Nyctophilus gouldi Tomes and Chalinolobus gouldii Gray) ranging in size from 4-14 g in coastal forest, using molecular analysis of fecal DNA. Abundances of potential mosquito and non-mosquito prey were concurrently measured to provide data on relative prey abundance. Aedes vigilax was locally the most abundant mosquito species, while Lepidoptera the most abundant insect order. A diverse range of prey was detected in bat feces, although members of Lepidoptera dominated, reflecting relative abundance at trap sites. Consumption of mosquitoes was restricted to V. vulturnus and V. pumilus, two smaller sized bats (4 and 4.5 g). Although mosquitoes were not commonly detected in feces of V. pumilus, they were present in feces of 55 % of V. vulturnus individuals. To meet nightly FMR requirements, Vespadelus spp. would need to consume ~600-660 mosquitoes on a mosquito-only diet, or ~160-180 similar sized moths on a moth-only diet. Lower relative profitability of mosquitoes may provide an explanation for the low level of mosquito consumption among these bats and the absence of mosquitoes in feces of larger bats. Smaller sized bats, especially V. vulturnus, are likely to be those most sensitive to reductions in mosquito abundance and should be monitored during mosquito

  3. Sexually dimorphic body size and development time plasticity in Aedes mosquitoes (Diptera: Culicidae)

    PubMed Central

    Wormington, Jillian D.; Juliano, Steven A.

    2015-01-01

    Background Sexual size dimorphism (SSD) in insects often accompanies a sexual difference in development time, sexual bimaturism (SBM). Goal To determine whether three Aedes mosquito species have similar plasticity in SSD, attain sexual dimorphism through similar strategies, and whether SSD and SBM are associated. Organisms Aedes albopictus, Aedes aegypti, and Aedes triseriatus (Diptera: Culicidae). Methods In four different food availability environments, we quantified plastic responses of relative growth rate (RGR), development time, and adult body size in individually reared males and females. Results Food availability affected RGR differently for the sexes for all three species. The RGR of males and females differed significantly in the 0.1 g/L food treatment. This difference did not account for observed SSD. Food levels over which the largest changes in RGR were observed differed among the species. Male and female adult mass and development time were jointly affected by food availability in a pattern that differed among the three species, so that degree of SSD and SBM changed differentially with food availability for all three species. Development time was generally less sexually dimorphic than mass, particularly in A. albopictus. At lower food levels, A. aegypti and A. triseriatus had accentuated dimorphism in development time. These results, combined with our knowledge of mosquito life history, suggest that a direct benefit of SBM is improbable for mosquitoes and that the observed intersexual differences in development time are more likely byproducts of selection for SSD. PMID:25663826

  4. Carbamate-resistance in mosquitos

    PubMed Central

    Georghiou, G. P.; Metcalf, R. L.; Gidden, Frances E.

    1966-01-01

    The authors investigated the rate of development and other characteristics of Baygon-resistance in Culex pipiens fatigans (=C. quinquefasciatus) recently colonized from Southern California. Selective pressure against the larvae (strain L) for 35 generations resulted in 25.4-fold resistance in larvae, but only 3-fold and 4.8-fold resistance in adults, as determined by contact and topical application, respectively. Conversely, selective pressure on adults (strain A) for 24 generations resulted in 8.4-fold (contact) and 5.3-fold (topical) resistance in adults, but only 2.7-fold resistance in larvae. About 10% of strain A adults survived 1-hour contact exposure even when the concentration of Baygon was increased 100-fold. This was not due to enhanced phototropism in this stage. Larvae of strain L metabolized 14C-labelled Baygon at a rate 2.5-fold greater than the non-selected strain. Cross-resistance in strain L to carbamates closely related to Baygon was high, but was extremely low to remotely related carbamates. The authors consider the relatively slow rate of development of resistance to Baygon, the reduced expressivity of the resistance character in adults, and its specificity for the selective agent and for closely related carbamates to be encouraging indications as to the usefulness of this class of compounds for mosquito control. PMID:5297803

  5. Does mosquito control have an effect on mosquito-borne disease? The case of Ross River virus disease and mosquito management in Queensland, Australia.

    PubMed

    Tomerini, Deanna M; Dale, Pat E; Sipe, Neil

    2011-03-01

    We examined the relationship between types of mosquito control programs and the mosquito-borne Ross River virus (RRV) disease in Queensland, Australia. Mosquito control information was collected through a survey of the responsible agencies (local governments), and RRV disease notification data were provided by the Queensland state health authority. The study developed a typology of mosquito control programs, based on the approaches used. Based on the analysis of data on RRV disease rates between mosquito control types within 4 climatic regions, each region had different combinations of mosquito control strategies in their programs; there were also general similarities in the relationship between program types and RRV rates between the regions. The long-term RRV disease rates were lower in areas where the mosquito control program included pre-emptive (rather than reactive) surveillance based on an extensive (rather than incomplete) knowledge of mosquito habitats, and where treatment of both saltwater and freshwater habitats (compared to only saltwater habitats, in coastal areas) occurred. The data indicate that mosquito control is an effective public health intervention to reduce mosquito-borne disease; hence, climate change adaptation strategies should ensure that adequate resources are available for effective vector control so as to manage the risk of mosquito-borne diseases.

  6. Mosquito vectors of West Nile virus during an epizootic outbreak in Puerto Rico.

    PubMed

    Barrera, R; MacKay, A; Amador, M; Vasquez, J; Smith, J; Díaz, A; Acevedo, V; Cabán, B; Hunsperger, E A; Muñoz-Jordán, J L

    2010-11-01

    The purpose of this investigation was to identify the mosquito (Diptera: Culicidae) vectors of West Nile virus (WNV; family Flaviviridae, genus Flavivirus) during an epizootic WNV outbreak in eastern Puerto Rico in 2007. In June 2006, 12 sentinel chicken pens with five chickens per pen were deployed in six types of habitats: herbaceous wetlands, mangrove forests, deciduous forests, evergreen forests, rural areas, and urban areas. Once WNV seroconversion in chickens was detected in June 2007, we began trapping mosquitoes using Centers for Disease Control and Prevention (CDC) miniature (light/CO2-baited) traps, CMT-20 collapsible mosquito (CO2- and ISCA SkinLure-baited) traps, and CDC gravid (hay infusion-baited) traps. We placed the CDC miniature traps both 2-4 m and >30 m from the chicken pens, the collapsible traps 2-4 m from the pens, and the gravid traps in backyards of houses with sentinel chicken pens and in a wetland adjacent to an urban area. We found numerous blood-engorged mosquitoes in the traps nearest to the sentinel chickens and reasoned that any such mosquitoes with a disseminated WNV infection likely served as vectors for the transmission of WNV to the sentinels. We used reverse transcriptase-polymerase chain reaction and isolation (C636) on pools of heads, thoraxes/ abdomens, and legs of collected blood-engorged mosquitoes to determine whether the mosquitoes carried WNV. We detected WNV-disseminated infections in and obtained WNV isolates from Culex nigripalpus Theo (minimum infection rate [MIR] 1.1-9.7/1,000), Culex bahamensis Dyar and Knab (MIR 1.8-6.0/1,000), and Aedes taeniorhynchus (Wied.) (MIR 0.34-0.36/1,000). WNV was also identified in and isolated from the pool of thoraxes and abdomens of Culex quinquefasciatus Say (4.17/1,000) and identified in one pool of thoraxes and abdomens of Culex habilitator Dyar and Knab (13.39/1,000). Accumulated evidence since 2002 suggests that WNV has not become endemic in Puerto Rico.

  7. Mayaro virus isolated from a Trinidadian mosquito, Mansonia venezuelensis.

    PubMed

    AITKEN, T H; DOWNS, W G; ANDERSON, C R; SPENCE, L; CASALS, J

    1960-04-01

    A strain of Mayaro virus has been isolated in Trinidad from the mosquito Mansonia venezuelensis. This is the first record of isolation of this agent from naturally infected mosquitoes, caught in the wild.

  8. Gustatory reception of chemicals affecting feeding in aedine mosquitoes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mosquitoes vector dangerous human diseases during blood feeding. Gustatory (taste) receptor neurons in the mosquito provide important chemical information including the nature and suitability of a potential host. Here we discuss the behavior, neurophysiology and molecular mechanisms associated wit...

  9. Not All Mosquitoes Need Standing Water to Breed

    MedlinePlus

    ... fullstory_164604.html Not All Mosquitoes Need Standing Water to Breed: Study Many of the critters lay ... curbing mosquitoes is to eliminate pools of standing water where they might breed. But new research on ...

  10. Genetically modified mosquito: the Malaysian public engagement experience.

    PubMed

    Subramaniam, T S Saraswathy; Lee, Han Lim; Ahmad, Nazni Wasi; Murad, Shahnaz

    2012-11-01

    On December 21, 2010, 6000 genetically modified (GM) mosquitoes were released in an uninhabited forest in Malaysia. The purpose of the deliberate release was a limited “marked release and recapture” (MRR) experiment, a standard ecological method in entomology, to evaluate under field conditions, the flight distance and longevity of the sterile male Aedes aegypti strain OX513A(My1), a GM strain. As with any other GM technologies, the release was received with mixed responses. As the scientific community debate over the public engagement strategies for similar GM releases, dengue incidence continues to rise with a heavy toll on morbidity, mortality and healthcare budgets. Meanwhile the wild female Aedes aegypti continues to breed offspring, surviving and evading conventional interventions for vector control.

  11. Vorticella sp: Prospective Mosquito Biocontrol Agent

    PubMed Central

    Patil, Chandrashekhar Devidas; Narkhede, Chandrakant Prakash; Suryawanshi, Rahul Khushal; Patil, Satish Vitthal

    2016-01-01

    Background: Considering the disadvantages of chemical insecticides, we aimed to evaluate Vorticella parasites for control of mosquito larvae of Anopheles stephensi and Aedes aegypti at different larval stages. Methods: Vorticella sp infected mosquito larvae were crushed in the 0.85% saline and homogenized well to get Vorticella in suspension. The effects of Vorticella sp infections on larval development were investigated by inoculating protozoan on different larval instars of An. stephensi and Ae. aegypti and observed under light microscope. Lethal time of the Vorticella infected larvae at different stages was calculated. Results: First and 2nd larval instars of both An. stephensi and Ae. aegypti did not show signs of infection by Vorticella sp., whereas 3rd instars of An. stephensi showed more Vorticella infection than those of Ae. aegypti. However, 4th larval instars of both mosquitoes were heavily infected with Vorticella parasite which was responsible for sluggish movements of larvae and eventually death. Moreover, parasites (Vorticella spp) were responsible for more than 90% reduction in adult emergence for both infected An. stephensi and Ae. aegypti. Conclusion: This study provides insights for mosquito larvicidal action of surface parasite Vorticella on different larval stages of An. stephensi and Ae. Aegypti. It could be suggested as a potential candidate in mosquito biocontrol programs. PMID:28032113

  12. Hyperparasitism of mosquitoes by water mite larvae.

    PubMed

    Werblow, Antje; Martin, Peter; Dörge, Dorian D; Koch, Lisa K; Mehlhorn, Heinz; Melaun, Christian; Klimpel, Sven

    2015-07-01

    Hyperparasitism of ectoparasitic water mite larvae on mosquitoes is still a neglected relationship and was investigated only in a few studies. We analysed 2313 female mosquitoes from six different sampling localities with regard to their degree of parasitism with water mite larvae. In total, we found 38 mosquito individuals parasitized by 93 water mite larvae, ranging from 1 to 12 larvae per mosquito. Water mite larvae detected are members of the two species Parathyas cf. barbigera (n = 92) and Arrenurus cf. globator (n = 1). Out of the analysed mosquitoes, individuals out of the species Aedes vexans, Anopheles claviger, Ochlerotatus communis, the Ochlerotatus cantans/annulipes group, Ochlerotatus cataphylla and Ochlerotatus sticticus were tested to be parasitized by water mite larvae. The highest prevalence was found within the species Oc. cataphylla (28.6 %) and Oc. cantans/annulipes (21.7 %). No water mite larvae were found, e.g. on individuals of Aedes cinereus, Coquillettidia richiardii, the Culex pipiens/torrentium group, Ochlerotatus caspius, Ochlerotatus dorsalis or Ochlerotatus punctor. All of the attachment sites were located between the neck and abdomen with the ventral thorax site being the most frequent one.

  13. Thule AB, Greenland, Mosquito Survey and Arbovirus Surveillance, 2012

    DTIC Science & Technology

    2013-11-21

    NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) USAF School of Aerospace Medicine Public Health and Preventive ...July 2012. One species of mosquitoes, Aedes impiger, was collected and more than 3000 were processed for virus testing. Active mosquito breeding...of mosquitoes, Aedes impiger, was collected and more than 3000 were processed for virus testing. Active mosquito breeding sites were located

  14. Student-Initiated Housing

    ERIC Educational Resources Information Center

    Feild, Robert M.

    1973-01-01

    Summarizes a report that describes housing where student groups lease, purchase, or even develop their own living quarters. Considers the birth of the movement, federal student housing programs, and a view to future programs. (Author/DN)

  15. Induced immunity against the mosquito Anopheles stephensi Liston (Diptera: Culicidae): effects on mosquito survival and fecundity.

    PubMed

    Almeida, A P; Billingsley, P F

    1998-11-01

    Mice were immunised three to five times with extracts of Anopheles stephensi heads, midguts, ovaries or fat bodies. At each immunisation the effects of feeding An. stephensi on the mice was determined, and changes in mosquito longevity and fecundity examined as the immune response developed. Although variability was common between control cages, significant and consistent reductions in mosquito longevity were observed when midguts were used as immunogens. Other extracts caused transient reductions in mortality. Fecundity was reduced significantly in mosquitoes fed upon mice immunised with each extract in at least one experiment. Mosquitoes fed upon fat-body-immunised mice showed delayed egg-laying as well as overall reduction in fecundity. The results confirm the feasibility of targeting mosquito antigens for novel vaccine development, but the "shotgun" approach used probably fails to successfully hit a suitable target antigen with any consistency. The natural variation in mosquito mortality can be countered by rigorous statistical analysis which can identify subtle effects in a very "noisy" experimental system. The midgut is the obvious target organ for anti-mosquito vaccine development and future work will focus on targeting components of this tissue for further immunisations.

  16. Development and optimization of the Suna trap as a tool for mosquito monitoring and control

    PubMed Central

    2014-01-01

    Background Monitoring of malaria vector populations provides information about disease transmission risk, as well as measures of the effectiveness of vector control. The Suna trap is introduced and evaluated with regard to its potential as a new, standardized, odour-baited tool for mosquito monitoring and control. Methods Dual-choice experiments with female Anopheles gambiae sensu lato in a laboratory room and semi-field enclosure, were used to compare catch rates of odour-baited Suna traps and MM-X traps. The relative performance of the Suna trap, CDC light trap and MM-X trap as monitoring tools was assessed inside a human-occupied experimental hut in a semi-field enclosure. Use of the Suna trap as a tool to prevent mosquito house entry was also evaluated in the semi-field enclosure. The optimal hanging height of Suna traps was determined by placing traps at heights ranging from 15 to 105 cm above ground outside houses in western Kenya. Results In the laboratory the mean proportion of An. gambiae s.l. caught in the Suna trap was 3.2 times greater than the MM-X trap (P < 0.001), but the traps performed equally in semi-field conditions (P = 0.615). As a monitoring tool , the Suna trap outperformed an unlit CDC light trap (P < 0.001), but trap performance was equal when the CDC light trap was illuminated (P = 0.127). Suspending a Suna trap outside an experimental hut reduced entry rates by 32.8% (P < 0.001). Under field conditions, suspending the trap at 30 cm above ground resulted in the greatest catch sizes (mean 25.8 An. gambiae s.l. per trap night). Conclusions The performance of the Suna trap equals that of the CDC light trap and MM-X trap when used to sample An. gambiae inside a human-occupied house under semi-field conditions. The trap is effective in sampling mosquitoes outside houses in the field, and the use of a synthetic blend of attractants negates the requirement of a human bait. Hanging a Suna trap outside a house can reduce An. gambiae house entry

  17. Wuchereria bancrofti infection in human and mosquito populations of a Polynesian village ten years after interruption of mass chemoprophylaxis with diethylcarbamazine.

    PubMed

    Cartel, J L; Nguyen, N L; Spiegel, A; Moulia-Pelat, J P; Plichart, R; Martin, P M; Manuellan, A B; Lardeux, F

    1992-01-01

    In 1991, a study on Wuchereria bancrofti microfilariae (mf) and infection rates was carried out in the human and mosquito populations of a Polynesian village where, 10 years before, the mf prevalence rate was 6.4% and twice-yearly mass treatment with 3 mg/kg of diethylcarbamazine (DEC) was interrupted. Venous blood samples were collected from 575 (97%) individuals aged 15 years or more, of whom 122 (21.4%) were mf positive. The mf carrier prevalence rate was 27.4% in males, significantly higher than that of 14% in females; it increased from 7-12% in the youngest age group (15-19 years) to 40-50% in the oldest (> or = 60 years) for both males and females. 387 mosquito collections were performed and 1748 female Aedes polynesiensis were dissected, of which 1176 were parous. Among the latter, 114 (9.7%) were infected with Wuchereria bancrofti larvae at L1, L2 or L3 stages. The mean number of larvae per mosquito was 2.46 (range 1-15). Of the 114 infected mosquitoes, 30 harboured L3 larvae, giving a 2.55% infective rate; the mean number of L3 larvae per mosquito was 1.15 (range 1-2). Such findings indicate that the interruption of systematic twice-yearly mass treatment with DEC (3 mg/kg) has resulted, after 10 years, in a substantial increase of microfilarial prevalence in humans, and in high infection rates in mosquitoes.

  18. Insulator for laser housing

    DOEpatents

    Duncan, D.B.

    1992-12-29

    The present invention provides a heat-resistant electrical insulator adapted for joining laser housing portions, which insulator comprises: an annulus; a channel in the annulus traversing the circumference and length of the housing; at least two ports, each communicating with the channel and an outer surface of the housing; and an attachment for securely attaching each end of the annulus to a laser housing member. 3 figs.

  19. Insulator for laser housing

    DOEpatents

    Duncan, David B.

    1992-01-01

    The present invention provides a heat-resistant electrical insulator adapted for joining laser housing portions, which insulator comprises: an annulus; a channel in the annulus traversing the circumference and length of the housing; at least two ports, each communicating with the channel and an outer surface of the housing; and an attachment for securely attaching each end of the annulus to a laser housing member.

  20. MosqTent: An individual portable protective double-chamber mosquito trap for anthropophilic mosquitoes.

    PubMed

    Lima, José Bento Pereira; Galardo, Allan Kardec Ribeiro; Bastos, Leonardo Soares; Lima, Arthur Weiss da Silva; Rosa-Freitas, Maria Goreti

    2017-03-01

    Here, we describe the development of the MosqTent, an innovative double-chamber mosquito trap in which a human being attracts mosquitoes while is protected from being bitten within the inner chamber of the trap, while mosquitoes are lured to enter an outer chamber where they are trapped. The MosqTent previously collected an average of 3,000 anophelines/man-hour compared to 240 anophelines/man-hour for the human landing catch (HLC), thereby providing high numbers of human host-seeking mosquitoes while protecting the collector from mosquito bites. The MosqTent performed well by collecting a high number of specimens of Anopheles marajoara, a local vector and anthropophilic mosquito species present in high density, but not so well in collecting An. darlingi, an anthropophilic mosquito species considered the main vector in Brazil but is present in low-density conditions in the area. The HLC showed a higher efficiency in collecting An. darlingi in these low-density conditions. The MosqTent is light (<1 kg), portable (comes as a bag with two handles), flexible (can be used with other attractants), adaptable (can be deployed in a variety of environmental settings and weather conditions), and it can be used in the intra-, peri-, and in the extradomicile. Also, the MosqTent collected similar portions of parous females and anthropophilic mosquito species and collects specimens suitable for downstream analysis. Further developments may include testing for other fabric colors, different mesh sizes and dimensions for other hematophagous insects and conditions, additional chemical mosquito attractants, and even the replacement of the human attractant in favor of other attractants. MosqTent modifications that would allow the trap to be applied as a vector control tool with killing action could also be explored.

  1. The Collection of Mosquito Eggs for Classroom and Field Investigations

    ERIC Educational Resources Information Center

    Steinly, Bruce A.

    2004-01-01

    A method for the collection of Aedes mosquito eggs is described whereby collection of mosquito eggs is used to monitor the intensity of egg deposition in urban and rural areas. The data is used to increase public awareness of the effect of human habitation and cultural practices on mosquito abundance.

  2. Zika Virus Vector Competency of Mosquitoes, Gulf Coast, United States

    PubMed Central

    Hart, Charles E.; Roundy, Christopher M.; Azar, Sasha R.; Huang, Jing H.; Yun, Ruimei; Reynolds, Erin; Leal, Grace; Nava, Martin R.; Vela, Jeremy; Stark, Pamela M.; Debboun, Mustapha; Rossi, Shannan; Vasilakis, Nikos

    2017-01-01

    Zika virus has recently spread throughout the Americas. Although Aedes aegypti mosquitoes are considered the primary vector, Culex quinquefasciatus and mosquitoes of other species may also be vectors. We tested Cx. quinquefasciatus and Ae. taeniorhynchus mosquitoes from the US Gulf Coast; both were refractory to infection and incapable of transmission. PMID:28005002

  3. Susceptibility of Adult Mosquitoes to Insecticides in Aqueous Sucrose Baits

    DTIC Science & Technology

    2011-06-01

    2010 ABSTRACT: Mosquitoes characteristically feed on plant-derived carbohydrates and honeydew just after emergence and intermittently during their...bait, Culex, Aedes, Anopheles. INTRODUCTION Plant-derived sugars and honeydew provide important components of mosquito nutrition and contribute to...unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Mosquitoes characteristically feed on plant-derived carbohydrates and honeydew just after emergence

  4. Evaluating the effects of mosquito control adulticides on honey bees

    Technology Transfer Automated Retrieval System (TEKTRAN)

    While mosquito control adulticides can be effective in rapidly reducing mosquito populations during times of high arbovirus transmission, the impacts of these control measures on pollinators has been of recent interest. The purpose of our study was to evaluate mosquito and honey bee mortality using ...

  5. Effect of collection method on estimates of adult mosquito density

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We made simultaneous comparison of the number of female mosquitoes captured by suction traps and portable light traps (augmented with CO2) in a Florida swamp with the landing rate of female mosquitoes on a human subject. Depending on the mosquito species, capture rates in light traps ranged between...

  6. Zika Virus Vector Competency of Mosquitoes, Gulf Coast, United States.

    PubMed

    Hart, Charles E; Roundy, Christopher M; Azar, Sasha R; Huang, Jing H; Yun, Ruimei; Reynolds, Erin; Leal, Grace; Nava, Martin R; Vela, Jeremy; Stark, Pamela M; Debboun, Mustapha; Rossi, Shannan; Vasilakis, Nikos; Thangamani, Saravanan; Weaver, Scott C

    2017-03-01

    Zika virus has recently spread throughout the Americas. Although Aedes aegypti mosquitoes are considered the primary vector, Culex quinquefasciatus and mosquitoes of other species may also be vectors. We tested Cx. quinquefasciatus and Ae. taeniorhynchus mosquitoes from the US Gulf Coast; both were refractory to infection and incapable of transmission.

  7. Measurement, analysis, and depiction of activity in adult mosquito populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Globalization, open trading practices, and climate change increase the likelihood of introduction of exotic mosquito species. These mosquitoes may harbor disease agents that threaten public and animal health. Successful containment and eradication of exotic mosquito species and (in the case of exo...

  8. A need for better housing to further reduce indoor malaria transmission in areas with high bed net coverage

    PubMed Central

    2013-01-01

    Background The suppression of indoor malaria transmission requires additional interventions that complement the use of insecticide treated nets (ITNs) and indoor residual spraying (IRS). Previous studies have examined the impact of house structure on malaria transmission in areas of low transmission. This study was conducted in a high transmission setting and presents further evidence about the association between specific house characteristics and the abundance of endophilic malaria vectors. Methods Mosquitoes were sampled using CDC light traps from 72 randomly selected houses in two villages on a monthly basis from 2008 to 2011 in rural Southern Tanzania. Generalized linear models using Poisson distributions were used to analyze the association of house characteristics (eave gaps, wall types, roof types, number of windows, rooms and doors, window screens, house size), number of occupants and ITN usage with mean catches of malaria vectors (An.gambiae s.l. and An. funestus). Results A total of 36490 female An. gambiae s.l. were collected in Namwawala village and 21266 in Idete village. As for An. funestus females, 2268 were collected in Namwawala and 3398 in Idete. Individually, each house factor had a statistically significant impact (p < 0.05) on the mean catches for An. gambiae s.l. but not An. funestus. A multivariate analysis indicated that the combined absence or presence of eaves, treated or untreated bed-nets, the number of house occupants, house size, netting over windows, and roof type were significantly related (p < 0.05) to An.gambiae s.l. and An. funestus house entry in both villages. Conclusions Despite significant reductions in vector density and malaria transmission caused by high coverage of ITNs, high numbers of host-seeking malaria vectors are still found indoors due to house designs that favour mosquito entry. In addition to ITNs and IRS, significant efforts should focus on improving house design to prevent mosquito entry and eliminate

  9. Radical remodeling of the Y chromosome in a recent radiation of malaria mosquitoes

    PubMed Central

    Hall, Andrew Brantley; Papathanos, Philippos-Aris; Sharma, Atashi; Cheng, Changde; Akbari, Omar S.; Assour, Lauren; Bergman, Nicholas H.; Cagnetti, Alessia; Crisanti, Andrea; Dottorini, Tania; Fiorentini, Elisa; Galizi, Roberto; Hnath, Jonathan; Jiang, Xiaofang; Koren, Sergey; Nolan, Tony; Radune, Diane; Sharakhova, Maria V.; Steele, Aaron; Timoshevskiy, Vladimir A.; Windbichler, Nikolai; Zhang, Simo; Emrich, Scott J.; Sharakhov, Igor V.; Tu, Zhijian Jake; Besansky, Nora J.

    2016-01-01

    Y chromosomes control essential male functions in many species, including sex determination and fertility. However, because of obstacles posed by repeat-rich heterochromatin, knowledge of Y chromosome sequences is limited to a handful of model organisms, constraining our understanding of Y biology across the tree of life. Here, we leverage long single-molecule sequencing to determine the content and structure of the nonrecombining Y chromosome of the primary African malaria mosquito, Anopheles gambiae. We find that the An. gambiae Y consists almost entirely of a few massively amplified, tandemly arrayed repeats, some of which can recombine with similar repeats on the X chromosome. Sex-specific genome resequencing in a recent species radiation, the An. gambiae complex, revealed rapid sequence turnover within An. gambiae and among species. Exploiting 52 sex-specific An. gambiae RNA-Seq datasets representing all developmental stages, we identified a small repertoire of Y-linked genes that lack X gametologs and are not Y-linked in any other species except An. gambiae, with the notable exception of YG2, a candidate male-determining gene. YG2 is the only gene conserved and exclusive to the Y in all species examined, yet sequence similarity to YG2 is not detectable in the genome of a more distant mosquito relative, suggesting rapid evolution of Y chromosome genes in this highly dynamic genus of malaria vectors. The extensive characterization of the An. gambiae Y provides a long-awaited foundation for studying male mosquito biology, and will inform novel mosquito control strategies based on the manipulation of Y chromosomes. PMID:27035980

  10. Radical remodeling of the Y chromosome in a recent radiation of malaria mosquitoes.

    PubMed

    Hall, Andrew Brantley; Papathanos, Philippos-Aris; Sharma, Atashi; Cheng, Changde; Akbari, Omar S; Assour, Lauren; Bergman, Nicholas H; Cagnetti, Alessia; Crisanti, Andrea; Dottorini, Tania; Fiorentini, Elisa; Galizi, Roberto; Hnath, Jonathan; Jiang, Xiaofang; Koren, Sergey; Nolan, Tony; Radune, Diane; Sharakhova, Maria V; Steele, Aaron; Timoshevskiy, Vladimir A; Windbichler, Nikolai; Zhang, Simo; Hahn, Matthew W; Phillippy, Adam M; Emrich, Scott J; Sharakhov, Igor V; Tu, Zhijian Jake; Besansky, Nora J

    2016-04-12

    Y chromosomes control essential male functions in many species, including sex determination and fertility. However, because of obstacles posed by repeat-rich heterochromatin, knowledge of Y chromosome sequences is limited to a handful of model organisms, constraining our understanding of Y biology across the tree of life. Here, we leverage long single-molecule sequencing to determine the content and structure of the nonrecombining Y chromosome of the primary African malaria mosquito, Anopheles gambiae We find that the An. gambiae Y consists almost entirely of a few massively amplified, tandemly arrayed repeats, some of which can recombine with similar repeats on the X chromosome. Sex-specific genome resequencing in a recent species radiation, the An. gambiae complex, revealed rapid sequence turnover within An. gambiae and among species. Exploiting 52 sex-specific An. gambiae RNA-Seq datasets representing all developmental stages, we identified a small repertoire of Y-linked genes that lack X gametologs and are not Y-linked in any other species except An. gambiae, with the notable exception of YG2, a candidate male-determining gene. YG2 is the only gene conserved and exclusive to the Y in all species examined, yet sequence similarity to YG2 is not detectable in the genome of a more distant mosquito relative, suggesting rapid evolution of Y chromosome genes in this highly dynamic genus of malaria vectors. The extensive characterization of the An. gambiae Y provides a long-awaited foundation for studying male mosquito biology, and will inform novel mosquito control strategies based on the manipulation of Y chromosomes.

  11. New State Records of Mosquitoes for Colorado.

    PubMed

    Rose, Dominic A; Kondratieff, B C; Weissmann, M J

    2015-06-01

    The 1967 treatment of the Mosquitoes of Colorado by Harmston and Lawson and subsequent publications have recorded 46 culicid species from Colorado. As part of a study to create an updated synopsis of the mosquitoes of Colorado, adult trapping at numerous localities was conducted in Colorado during the summers of 2013 and 2014. This review also included an examination of mosquito specimens in various relevant museum collections. Aedes (Ochlerotatus) niphadopsis and Ae. (Och.) spencerii spencerii were collected during the 2013 and 2014 field seasons. Records for Ae. (Och.) canadensis canadensis, Ae. (Stegomyia) aegypti, and Uranotaenia (Pseudoficalbia) anhydor syntheta were obtained from examination of museum specimens. These species constitute new state records for Colorado, with 51 species now known from the state.

  12. Behavioural responses of females of two anopheline mosquito species to human-occupied, insecticide-treated and untreated bed nets

    PubMed Central

    2014-01-01

    Background Insecticide-treated bed nets (ITNs), used extensively to reduce human exposure to malaria, work through physical and chemical means to block or deter host-seeking mosquitoes. Despite the importance of ITNs, very little is known about how host-seeking mosquitoes behave around occupied bed nets. As a result, evidence-based evaluations of the effects of physical damage on bed net effectiveness are not possible and there is a dearth of knowledge on which to base ITN design. Methods The dispersion of colony-raised female Anopheles gambiae and Anopheles albimanus was observed in 2-hr laboratory experiments in which up to 200 mosquitoes were released inside a mosquito-proof 3 m × 3 m tent housing a bed net arrayed with 18 30 cm × 30 cm sticky screen squares on the sides, ends and roof. Numbers of mosquitoes caught on the sticky squares were interpreted as the ‘mosquito pressure’ on that part of the net. Results Presence of a human subject in the bed net significantly increased total mosquito pressure on the net for both species and significantly re-oriented An. gambiae to the roof of the net. Anopheles albimanus pressure was greatest on the bed net roof in both host-present and no-host conditions. The effects of different human subjects in the bed net, of different ambient conditions (dry, cool conditions vs warm, humid conditions) and of bed net treatment (deltamethrin-treated or no insecticide) on mosquito pressure patterns were tested for both species. Species-specific pressure patterns did not vary greatly as a result of any of these factors though some differences were noted that may be due the size of the different human subjects. Conclusions As a result of the interaction between host-seeking responses and the convective plume from the net occupant, species-specific mosquito pressure patterns manifest more or less predictably on the bed net. This has implications for bed net design and suggests that current methods of assessing damaged

  13. The Hispanic Housing Crisis.

    ERIC Educational Resources Information Center

    Dolbeare, Cushing N.; Canales, Judith A.

    This report examines the housing characteristics and needs of Hispanic households in the United States, drawing on information from the 1980 Census and the 1983 Annual Housing Survey. Among the conclusions are the following: (1) housing quality is a major problem for more than one in six Hispanic families; (2) among Hispanic subgroups, Puerto…

  14. [Accessible Rural Housing.

    ERIC Educational Resources Information Center

    Baker, Nick, Ed.

    1995-01-01

    This issue of the quarterly newsletter "Rural Exchange" provides information and resources on accessible rural housing for the disabled. "Accessible Manufactured Housing Could Increase Rural Home Supply" (Nick Baker) suggests that incorporation of access features such as lever door handles and no-step entries into manufactured housing could help…

  15. Conspicuous Coloration in Males of the Damselfly Nehalennia irene (Zygoptera: Coenagrionidae): Do Males Signal Their Unprofitability to Other Males?

    PubMed Central

    Beatty, Christopher D.; Andrés, José A.; Sherratt, Thomas N.

    2015-01-01

    In damselflies, sexual colour dimorphism is commonly explained as a consequence of selection on traits that increase male attractiveness to females. However, while many species in the damselfly family Coenagrionidae (Insecta: Odonata) are sexually dimorphic, the males do not engage in displays, and male competition for mates resembles a “scramble”. An alternative explanation for the sexual differences in coloration within these species is that sexual dimorphism has evolved as a sex-related warning signal, with males signalling their uprofitability as mates to other males, thereby avoiding harassment from conspecifics. We evaluated an underlying assumption of the theory that male-male harassment rate is influenced by colour by comparing harassment of males of the species Nehalennia irene that had been painted to make them appear: (i) similar to an unaltered male (blue), (ii) different from a male (orange) and (iii) more similar to a female (black). When caged together we found that blue-painted males experienced significantly lower harassment than black-painted males. When unpainted males were caged with each type of painted male we found that blue-painted males and the unpainted males housed in the same cages experienced lower rates of harassment than males housed in cages where some males were painted black, suggesting that a single, reliable signal of unprofitability may benefit the individuals that carry it. While our results do not in themselves demonstrate that sexual colour dimorphism originally evolved as an intra-specific warning signal, they do show that harassment is influenced by coloration, and that such selection could conceivably maintain male coloration as a warning signal. PMID:26587979

  16. The dance of male Anopheles gambiae in wild mating swarms.

    PubMed

    Butail, Sachit; Manoukis, Nicholas C; Diallo, Moussa; Ribeiro, José M C; Paley, Derek A

    2013-05-01

    An important element of mating in the malaria vector Anopheles gambiae Giles in nature is the crepuscular mating aggregation (swarm) composed almost entirely of males, where most coupling and insemination is generally believed to occur. In this study, we mathematically characterize the oscillatory movement of male An. gambiae in terms of an established individual-based mechanistic model that parameterizes the attraction of a mosquito toward the center of the swarm using the natural frequency of oscillation and the resistance to its motion, characterized by the damping ratio. Using three-dimensional trajectory data of ten wild mosquito swarms filmed in Mali, Africa, we show two new results for low and moderate wind conditions, and indicate how these results may vary in high wind. First, we show that in low and moderate wind the vertical component of the mosquito motion has a lower frequency of oscillation and higher damping ratio than horizontal motion. In high wind, the vertical and horizontal motions are similar to one another and the natural frequencies are higher than in low and moderate wind. Second, we show that the predicted average disagreement in the direction of motion of swarming mosquitoes moving randomly is greater than the average disagreement we observed between each mosquito and its three closest neighbors, with the smallest level of disagreement occurring for the nearest neighbor in seven out of 10 swarms. The alignment of the direction of motion between nearest neighbors is the highest in high wind. This result provides evidence for flight-path coordination between swarming male mosquitoes.

  17. Effects of Habitat Complexity on Pair-Housed Zebrafish.

    PubMed

    Keck, Victoria A; Edgerton, Dale S; Hajizadeh, Susan; Swift, Larry L; Dupont, William D; Lawrence, Christian; Boyd, Kelli L

    2015-07-01

    Sexually mature zebrafish were housed as single male-female pairs with or without plastic vegetation for 1, 5, or 10 d for comparison of whole-body cortisol measured by radioimmunoassay. Individually housed male zebrafish were used as controls. In the fish that were pair-housed without vegetation (NVeg), one animal died in 5 of 24 pairs, and one animal was alive but wounded in an additional pair. No deaths or wounds occurred in the fish that were pair-housed with vegetation (Veg). Cortisol levels did not differ between the treatment groups on day 1. On day 5, cortisol values were higher in the Veg group than in the individually housed fish (P < 0.0005) and the NVeg fish (P = 0.004). On day 10, the relationships were inversed: cortisol levels had risen in the individually housed and NVeg groups and had fallen to baseline levels in the Veg group. Cortisol values on day 10 were lower in the Veg group than in the individually housed (P = 0.004) and NVeg (P = 0.05) groups. Cortisol levels in individually housed male zebrafish increased over time. Although this study did not demonstrate a reduction in cortisol levels associated with providing vegetation, this enrichment prevented injury and death from fighting. These findings show how commonly used housing situations may affect the wellbeing of laboratory zebrafish.

  18. Effects of Habitat Complexity on Pair-Housed Zebrafish

    PubMed Central

    Keck, Victoria A; Edgerton, Dale S; Hajizadeh, Susan; Swift, Larry L; Dupont, William D; Lawrence, Christian; Boyd, Kelli L

    2015-01-01

    Sexually mature zebrafish were housed as single male-female pairs with or without plastic vegetation for 1, 5, or 10 d for comparison of whole-body cortisol measured by radioimmunoassay. Individually housed male zebrafish were used as controls. In the fish that were pair-housed without vegetation (NVeg), one animal died in 5 of 24 pairs, and one animal was alive but wounded in an additional pair. No deaths or wounds occurred in the fish that were pair-housed with vegetation (Veg). Cortisol levels did not differ between the treatment groups on day 1. On day 5, cortisol values were higher in the Veg group than in the individually housed fish (P < 0.0005) and the NVeg fish (P = 0.004). On day 10, the relationships were inversed: cortisol levels had risen in the individually housed and NVeg groups and had fallen to baseline levels in the Veg group. Cortisol values on day 10 were lower in the Veg group than in the individually housed (P = 0.004) and NVeg (P = 0.05) groups. Cortisol levels in individually housed male zebrafish increased over time. Although this study did not demonstrate a reduction in cortisol levels associated with providing vegetation, this enrichment prevented injury and death from fighting. These findings show how commonly used housing situations may affect the wellbeing of laboratory zebrafish. PMID:26224437

  19. Genetically Modified (GM) Mosquito Use to Reduce Mosquito-Transmitted Disease in the US: A Community Opinion Survey

    PubMed Central

    Adalja, Amesh; Sell, Tara Kirk; McGinty, Meghan; Boddie, Crystal

    2016-01-01

    Introduction: Mosquito-borne infectious diseases such as dengue, chikungunya, and now Zika, pose a public health threat to the US, particularly Florida, the Gulf Coast states, and Hawaii. Recent autochthonous transmission of dengue and chikungunya in Florida, the recent dengue outbreak in Hawaii, and the potential for future local spread of Zika in the US, has led to the consideration of novel approaches to mosquito management. One such novel approach, the release of sterile genetically modified mosquitoes, has been proposed as a possible intervention, and a trial release of GM mosquitoes is being considered in one Florida community. However, this proposal has been controversial. The objective of this research was to increase understanding of community knowledge, attitudes, and beliefs regarding mosquito control and GM mosquitoes.   Methods: An 18-question self-administered survey was mailed to all households in the identified Key West, Florida neighborhood where a GM mosquito trial has been proposed. This survey was fielded between July 20, 2015 and November 1, 2015. The main outcome variable was opposition to the use of GM mosquitoes. Measures included demographic information and opinions on mosquitoes, mosquito control, and vector-borne diseases.   Results: A majority of survey respondents did not support use of GM mosquitoes as a mosquito control method. Discussion: Reasons for opposition included general fears about possible harmful impacts of this intervention, specific worries about human and animal health impacts from the GM mosquitoes, and environmental concerns about potential negative effects on the ecosystem. Residents were more likely to oppose GM mosquito use if they had a low perception of the potential risks posed by diseases like dengue and chikungunya, if they were female, and if they were less concerned about the need to control mosquitoes in general. These findings suggest a need for new approaches to risk communication, including

  20. Bioefficacy of crude extract of Cyperus aromaticus (Family: Cyperaceae ) cultured cells, against Aedes aegypti and Aedes albopictus mosquitoes

    PubMed Central

    Kamiabi, Fatemeh; Jaal, Zairi; Keng, Chan Lai

    2013-01-01

    ratio of the adult population either parental or F1 generation of the Aedes mosquito species was not significantly affected by the EI50 dosage of the crude extract of C. aromaticus cultured P4 cells. A significant decrease in the wing length of the treated adult (female and male) of Aedes aegypti as well as the treated female of Ae. albopictus were observed. Longevity of the adult female of the parental generation of both Aedes mosquitoes as well as females of F1 generation of Ae. albopictus were significantly decreased. Conclusions The present study revealed the potential of the crude extract of C. aromaticus cultured cells in controlling vector mosquito populations in the effort to reduce the transmission of vector borne diseases. PMID:24075340

  1. Pathogenesis of Dengue Vaccine Viruses in Mosquitoes.

    DTIC Science & Technology

    1982-07-01

    r AD Af29 019 PA I4OGENESIS OF DENGUE VACCINE VIRUSES IN MOSQITOES U) YALE UNIV NEW YIAVEN CONN SCHOOL OF MEDICINE B JBEAT ET AL 01 JUL 82 DAMD1779...1963-A ’UNCLASS IFIET) .AD.- PATHOGENESIS OF DENGUE VACCINE VIRUSES IN MOSQUITOES FINAL REPORT Barry J. Beaty, Ph.D. Thomas H. G. Aitken, Ph.D. July 1...NUMBER 4. TITLE (mid Subdl.) S. KVPE OF REPORT & PERIOD COVERED PATHOGENESIS OF DENGUE VACCINE VIRUSES Final Scientific Report IN MOSQUITOES 6/1/79 to 6

  2. Pathogenesis of Dengue Vaccine Viruses in Mosquitoes.

    DTIC Science & Technology

    1984-01-01

    IW AV wWW W N A A~~ Nq .. mcFILE COPY 0)0 AD PATHOGENESIS OF DENGUE VACCINE VIRUSES IN MOSQUITOES Annual Report Barry J. Beaty, Ph.D. D T IC ELECTE...TYPE OF REPORT & PERIOD COVERED Anhual Progress Report PATHOGENESIS OF DENGUE VACCINE VIRUSES 1/1/83 to 1/1/84 IN MOSQUITOES &. PERFORMING O1G. REPORT...19. KEY WORDS (Continue on reverse side if nec.eary nd Identify by block number) Dengue -i candidate vaccines; TP-56; 45AZ5; Dengue -i parent virus

  3. Pathogenesis of Dengue Vaccine Viruses in Mosquitoes.

    DTIC Science & Technology

    1981-01-01

    AD-AI30 52S PATHOGENESIS OF DENGUE VACCINE VIRUSES IN MOSQUITOES i/I (U) VALE UNIV NEW HAVEN CONN SCHOOL OF MEDICINE B J BEATY ET AL. 81 JAN 81 DAMDi...UNCLASSIFIED PATHOGENESIS OF DENGUE VACCINE VIRUSES IN MOSQUITOES Second Annual Report Barry J. Beaty, Ph.D. D T IC ; Thomas H.G. Aitken, Ph.D...REPORT NUMBER 2. GOVT ACCESSION NO. 3. RECIPIENT’S CATALOG NUMBER 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED PATHOMMSIS CF DENGUE

  4. Pathogenesis of Dengue Vaccine Viruses in Mosquitoes.

    DTIC Science & Technology

    1982-01-01

    AD-R38 519 PATHOGENESIS OF DENGUE VACCINE VIRUSES IN MOSQUITOES i/i (U) YALE UNIV NEW HAVEN CONN SCHOOL OF MEDICINE B J BEATY ET AL. 81 JAN 82 DAMDI...NATIONAL BUREAU OF STANDARDS 1963-A i UNCLASSIFIED ":’:" AD 2 0. PATHOGENESIS OF DENGUE VACCINE VIRUSES IN MOSQUITOES Third Annual Report Barry J. Beaty...SUPPLEMENTARY NOTES 1 7 Y NORDS (rontinue on reverq , side if necessary and identify by hlock numb-) Dengue -2 S-1 vaccine, PR-159 parent; IDenque-1

  5. 12 CFR 1807.401 - Affordable housing-rental housing.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 9 2012-01-01 2012-01-01 false Affordable housing-rental housing. 1807.401... TREASURY CAPITAL MAGNET FUND Qualification as Affordable Housing § 1807.401 Affordable housing—rental housing. To qualify as Affordable Housing, a rental Multi-family housing project financed with a CMF...

  6. 12 CFR 1807.401 - Affordable housing-rental housing.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 7 2011-01-01 2011-01-01 false Affordable housing-rental housing. 1807.401... TREASURY CAPITAL MAGNET FUND Qualification as Affordable Housing § 1807.401 Affordable housing—rental housing. To qualify as Affordable Housing, a rental Multi-family housing project financed with a CMF...

  7. 12 CFR 1807.401 - Affordable housing-rental housing.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 9 2013-01-01 2013-01-01 false Affordable housing-rental housing. 1807.401... TREASURY CAPITAL MAGNET FUND Qualification as Affordable Housing § 1807.401 Affordable housing—rental housing. To qualify as Affordable Housing, a rental Multi-family housing project financed with a CMF...

  8. 12 CFR 1807.401 - Affordable housing-rental housing.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 10 2014-01-01 2014-01-01 false Affordable housing-rental housing. 1807.401... TREASURY CAPITAL MAGNET FUND Qualification as Affordable Housing § 1807.401 Affordable housing—rental housing. To qualify as Affordable Housing, a rental Multi-family housing project financed with a CMF...

  9. Crowdsourcing Science to Promote Human Health: New Tools to Promote Sampling of Mosquito Populations by Citizen Scientists

    NASA Astrophysics Data System (ADS)

    Boger, R. A.; Low, R.; Jaroensutasinee, M.; Jaroensutasinee, K.; Sparrow, E. B.; Costosa, J. I.; Medina, J.; Randolph, G.

    2015-12-01

    GLOBE in Thailand and GLOBE in Africa independently developed citizen science protocols for collecting and analyzing mosquito larvae. These protocols have been piloted in several workshops and implemented in schools. Data collected have been used for several secondary, undergraduate and graduate student research studies. Over this past year, 2015, these protocols have been synthesized into one protocol that will be made available to the world-wide community through the GLOBE website (www.globe.gov). This new protocol is designed to be flexible in the mosquito species that can be collected and the types of environments sampled (e.g., containers in and around the house, ponds, irrigation ditches in a rice paddy field). Plans are underway to enable web-based data entry and mobile apps for data collection and submission. Once everything is finalized, a GLOBE field campaign will be initiated for citizen scientists to collect meaningful data on where different types of mosquito larvae are found and how the abundance and distribution is changing seasonally. To assist in the standardization of data collection and quality control, training slides are being developed and will be made available in early 2016. This will enable a wider participation of citizen scientists to participate in this effort to collect mosquito data by making it easier to become part of the GLOBE community. As with mosquito larvae, training slides are being created for hydrosphere, biosphere, atmosphere, and pedosphere GLOBE measurement protocols. The development of the mosquito protocol and the training slides are in direct response to the GLOBE community's desire to increase citizen science participation beyond primary and secondary schools, in observing and measuring environmental change.

  10. Mosquito species diversity and abundance in relation to land use in a riceland agroecosystem in Mwea, Kenya.

    PubMed

    Muturi, Ephantus J; Shililu, Josephat; Jacob, Benjamin; Gu, Weidong; Githure, John; Novak, Robert

    2006-06-01

    We conducted an entomological survey to determine the mosquito species diversity and abundance in relation to land use in the Mwea rice scheme, Kenya. Adult mosquitoes were collected by indoor spraying of houses and outdoors by CDC light traps in three villages representing planned (Mbuinjeru) and unplanned (Kiamachiri) rice agroecosystems and a non-irrigated agroecosystem (Murinduko). During the 12-month sampling period, a total of 98,708 mosquitoes belonging to five genera and 25 species were collected. The five most common species collected during this study were Anopheles arabiensis Patton (52.5%), Culex quinquefasciatus Say (36.7%), Anopheles pharoensis Theobald (5.2%), Anopheles coustani Laveran (1.4%), and Anopheles funestus Giles (1.3%). Anopheles arabiensis, Cx quinquefasciatus, and An. pharoensis were more abundant in rice agroecosystems than in the non-irrigated agroecosystem, and in planned than in the unplanned rice agroecosystems. In contrast, An. funestus was more abundant in the non-irrigated agroecosystem. The mosquito species diversity (H) and evenness (E(H)) in the non-irrigated agroecosystem (Shannon diversity Index, H = 1.507, EH = 0.503) was significantly higher than in the rice agroecosystems (H) = 0.968, E(H) = 0.313, unplanned; and H= 1.040, E(H) = 0.367 planned). Results of lag cross correlation analysis revealed a strong relationship between rainfall and the abundance of An. arabiensis, and C. quinquefasciatus in the non-irrigated agroecosystem but not in the rice agroecosystems. It is inferred from the data that different levels of habitat perturbations with regard to rice cultivation have different effects on mosquito diversity and abundance. This provides an understanding of how mosquito diversity is impacted by different habitat management and rice cropping strategies.

  11. Characterization of Carbonic Anhydrase 9 in the Alimentary Canal of Aedes aegypti and Its Relationship to Homologous Mosquito Carbonic Anhydrases

    PubMed Central

    Dixon, Daniel P.; Van Ekeris, Leslie; Linser, Paul J.

    2017-01-01

    In the mosquito midgut, luminal pH regulation and cellular ion transport processes are important for the digestion of food and maintenance of cellular homeostasis. pH regulation in the mosquito gut is affected by the vectorial movement of the principal ions including bicarbonate/carbonate and protons. As in all metazoans, mosquitoes employ the product of aerobic metabolism carbon dioxide in its bicarbonate/carbonate form as one of the major buffers of cellular and extracellular pH. The conversion of metabolic carbon dioxide to bicarbonate/carbonate is accomplished by a family of enzymes encoded by the carbonic anhydrase gene family. This study characterizes Aedes aegypti carbonic anhydrases using bioinformatic, molecular, and immunohistochemical methods. Our analyses show that there are fourteen Aedes aegypti carbonic anhydrase genes, two of which are expressed as splice variants. The carbonic anhydrases were classified as either integral membrane, peripheral membrane, mitochondrial, secreted, or soluble cytoplasmic proteins. Using polymerase chain reaction and Western blotting, one of the carbonic anhydrases, Aedes aegypti carbonic anhydrase 9, was analyzed and found in each life stage, male/female pupae, male/female adults, and in the female posterior midgut. Next, carbonic anhydrase 9 was analyzed in larvae and adults using confocal microscopy and was detected in the midgut regions. According to our analyses, carbonic anhydrase 9 is a soluble cytoplasmic enzyme found in the alimentary canal of larvae and adults and is expressed throughout the life cycle of the mosquito. Based on previous physiological analyses of adults and larvae, it appears AeCA9 is one of the major carbonic anhydrases involved in producing bicarbonate/carbonate which is involved in pH regulation and ion transport processes in the alimentary canal. Detailed understanding of the molecular bases of ion homeostasis in mosquitoes will provide targets for novel mosquito control strategies into the

  12. Characterization of Carbonic Anhydrase 9 in the Alimentary Canal of Aedes aegypti and Its Relationship to Homologous Mosquito Carbonic Anhydrases.

    PubMed

    Dixon, Daniel P; Van Ekeris, Leslie; Linser, Paul J

    2017-02-21

    In the mosquito midgut, luminal pH regulation and cellular ion transport processes are important for the digestion of food and maintenance of cellular homeostasis. pH regulation in the mosquito gut is affected by the vectorial movement of the principal ions including bicarbonate/carbonate and protons. As in all metazoans, mosquitoes employ the product of aerobic metabolism carbon dioxide in its bicarbonate/carbonate form as one of the major buffers of cellular and extracellular pH. The conversion of metabolic carbon dioxide to bicarbonate/carbonate is accomplished by a family of enzymes encoded by the carbonic anhydrase gene family. This study characterizes Aedes aegypti carbonic anhydrases using bioinformatic, molecular, and immunohistochemical methods. Our analyses show that there are fourteen Aedes aegypti carbonic anhydrase genes, two of which are expressed as splice variants. The carbonic anhydrases were classified as either integral membrane, peripheral membrane, mitochondrial, secreted, or soluble cytoplasmic proteins. Using polymerase chain reaction and Western blotting, one of the carbonic anhydrases, Aedes aegypti carbonic anhydrase 9, was analyzed and found in each life stage, male/female pupae, male/female adults, and in the female posterior midgut. Next, carbonic anhydrase 9 was analyzed in larvae and adults using confocal microscopy and was detected in the midgut regions. According to our analyses, carbonic anhydrase 9 is a soluble cytoplasmic enzyme found in the alimentary canal of larvae and adults and is expressed throughout the life cycle of the mosquito. Based on previous physiological analyses of adults and larvae, it appears AeCA9 is one of the major carbonic anhydrases involved in producing bicarbonate/carbonate which is involved in pH regulation and ion transport processes in the alimentary canal. Detailed understanding of the molecular bases of ion homeostasis in mosquitoes will provide targets for novel mosquito control strategies into the

  13. The interaction between a sexually transferred steroid hormone and a female protein regulates oogenesis in the malaria mosquito Anopheles gambiae.

    PubMed

    Baldini, Francesco; Gabrieli, Paolo; South, Adam; Valim, Clarissa; Mancini, Francesca; Catteruccia, Flaminia

    2013-10-01

    Molecular interactions between male and female factors during mating profoundly affect the reproductive behavior and physiology of female insects. In natural populations of the malaria mosquito Anopheles gambiae, blood-fed females direct nutritional resources towards oogenesis only when inseminated. Here we show that the mating-dependent pathway of egg development in these mosquitoes is regulated by the interaction between the steroid hormone 20-hydroxy-ecdysone (20E) transferred by males during copulation and a female Mating-Induced Stimulator of Oogenesis (MISO) protein. RNAi silencing of MISO abolishes the increase in oogenesis caused by mating in blood-fed females, causes a delay in oocyte development, and impairs the function of male-transferred 20E. Co-immunoprecipitation experiments show that MISO and 20E interact in the female reproductive tract. Moreover MISO expression after mating is induced by 20E via the Ecdysone Receptor, demonstrating a close cooperation between the two factors. Male-transferred 20E therefore acts as a mating signal that females translate into an increased investment in egg development via a MISO-dependent pathway. The identification of this male-female reproductive interaction offers novel opportunities for the control of mosquito populations that transmit malaria.

  14. Applications of a sugar-based surveillance system to track arboviruses in wild mosquito populations.

    PubMed

    van den Hurk, Andrew F; Hall-Mendelin, Sonja; Townsend, Michael; Kurucz, Nina; Edwards, Jim; Ehlers, Gerhard; Rodwell, Chris; Moore, Frederick A; McMahon, Jamie L; Northill, Judith A; Simmons, Russell J; Cortis, Giles; Melville, Lorna; Whelan, Peter I; Ritchie, Scott A

    2014-01-01

    Effective arbovirus surveillance is essential to ensure the implementation of control strategies, such as mosquito suppression, vaccination, or dissemination of public warnings. Traditional strategies employed for arbovirus surveillance, such as detection of virus or virus-specific antibodies in sentinel animals, or detection of virus in hematophagous arthropods, have limitations as an early-warning system. A system was recently developed that involves collecting mosquitoes in CO2-baited traps, where the insects expectorate virus on sugar-baited nucleic acid preservation cards. The cards are then submitted for virus detection using molecular assays. We report the application of this system for detecting flaviviruses and alphaviruses in wild mosquito populations in northern Australia. This study was the first to employ nonpowered passive box traps (PBTs) that were designed to house cards baited with honey as the sugar source. Overall, 20/144 (13.9%) of PBTs from different weeks contained at least one virus-positive card. West Nile virus Kunjin subtype (WNVKUN), Ross River virus (RRV), and Barmah Forest virus (BFV) were detected, being identified in 13/20, 5/20, and 2/20 of positive PBTs, respectively. Importantly, sentinel chickens deployed to detect flavivirus activity did not seroconvert at two Northern Territory sites where four PBTs yielded WNVKUN. Sufficient WNVKUN and RRV RNA was expectorated onto some of the honey-soaked cards to provide a template for gene sequencing, enhancing the utility of the sugar-bait surveillance system for investigating the ecology, emergence, and movement of arboviruses.

  15. Productivity and population density estimates of the dengue vector mosquito Aedes aegypti (Stegomyia aegypti) in Australia.

    PubMed

    Williams, C R; Johnson, P H; Ball, T S; Ritchie, S A

    2013-09-01

    New mosquito control strategies centred on the modifying of populations require knowledge of existing population densities at release sites and an understanding of breeding site ecology. Using a quantitative pupal survey method, we investigated production of the dengue vector Aedes aegypti (L.) (Stegomyia aegypti) (Diptera: Culicidae) in Cairns, Queensland, Australia, and found that garden accoutrements represented the most common container type. Deliberately placed 'sentinel' containers were set at seven houses and sampled for pupae over 10 weeks during the wet season. Pupal production was approximately constant; tyres and buckets represented the most productive container types. Sentinel tyres produced the largest female mosquitoes, but were relatively rare in the field survey. We then used field-collected data to make estimates of per premises population density using three different approaches. Estimates of female Ae. aegypti abundance per premises made using the container-inhabiting mosquito simulation (CIMSiM) model [95% confidence interval (CI) 18.5-29.1 females] concorded reasonably well with estimates obtained using a standing crop calculation based on pupal collections (95% CI 8.8-22.5) and using BG-Sentinel traps and a sampling rate correction factor (95% CI 6.2-35.2). By first describing local Ae. aegypti productivity, we were able to compare three separate population density estimates which provided similar results. We anticipate that this will provide researchers and health officials with several tools with which to make estimates of population densities.

  16. Merida virus, a putative novel rhabdovirus discovered in Culex and Ochlerotatus spp. mosquitoes in the Yucatan Peninsula of Mexico

    PubMed Central

    Charles, Jermilia; Firth, Andrew E.; Loroño-Pino, Maria A.; Garcia-Rejon, Julian E.; Farfan-Ale, Jose A.; Lipkin, W. Ian; Briese, Thomas

    2016-01-01

    Sequences corresponding to a putative, novel rhabdovirus [designated Merida virus (MERDV)] were initially detected in a pool of Culex quinquefasciatus collected in the Yucatan Peninsula of Mexico. The entire genome was sequenced, revealing 11 798 nt and five major ORFs, which encode the nucleoprotein (N), phosphoprotein (P), matrix protein (M), glycoprotein (G) and RNA-dependent RNA polymerase (L). The deduced amino acid sequences of the N, G and L proteins have no more than 24, 38 and 43 % identity, respectively, to the corresponding sequences of all other known rhabdoviruses, whereas those of the P and M proteins have no significant identity with any sequences in GenBank and their identity is only suggested based on their genome position. Using specific reverse transcription-PCR assays established from the genome sequence, 27 571 C. quinquefasciatus which had been sorted in 728 pools were screened to assess the prevalence of MERDV in nature and 25 pools were found positive. The minimal infection rate (calculated as the number of positive mosquito pools per 1000 mosquitoes tested) was 0.9, and similar for both females and males. Screening another 140 pools of 5484 mosquitoes belonging to four other genera identified positive pools of Ochlerotatus spp. mosquitoes, indicating that the host range is not restricted to C. quinquefasciatus. Attempts to isolate MERDV in C6/36 and Vero cells were unsuccessful. In summary, we provide evidence that a previously undescribed rhabdovirus occurs in mosquitoes in Mexico. PMID:26868915

  17. EFFECTS OF ELEVATED ATMOSPHERIC CO(2) ON WATER CHEMISTRY AND MOSQUITO (DIPTERA: CULICIDAE) GROWTH UNDER COMPETITIVE CONDITIONS IN CONTAINER HABITATS.

    PubMed

    Alto, Barry W; Yanoviak, Stephen P; Lounibos, L Philip; Drake, Bert G

    2005-01-01

    We investigated the direct and indirect effects of elevated atmospheric CO(2) on freshwater container habitats and their larval mosquito occupants. We predicted that a doubling of atmospheric CO(2) would (1) alter the chemical properties of water in this system, (2) slow degradation of leaf litter, and (3) decrease larval growth of Aedes albopictus (Skuse) mosquitoes raised on that litter under competitive conditions. Effects of elevated CO(2) on water quality parameters were not detected, but the presence of leaf litter significantly reduced pH and dissolved oxygen relative to water-filled containers without litter. Degradation rates of oak leaf litter from plants grown under elevated CO(2) atmospheres did not differ from breakdown rates of litter from ambient CO(2) conditions. Litter from plants grown in an elevated CO(2) atmospheres did not influence mosquito population growth, but mosquito production decreased significantly with increasing larval density. Differences among mosquito density treatments influenced survivorship most strongly among male Ae. albopictus and time to emergence most strongly among females, suggesting fundamental sex-determined differences in response to competition. Results of this and other studies indicate that direct and indirect effects of doubled atmospheric CO(2) are minimal in artificial containers with freshwater.

  18. Impact of mating behaviour on the success of malaria control through a single inundative release of transgenic mosquitoes.

    PubMed

    Boëte, C; Agusto, F B; Reeves, R G

    2014-04-21

    Transgenic mosquitoes are a potential tool for the control or eradication of insect-vectored diseases. For malaria, one possible strategy relies on the introduction of malaria-refractory transgenes into wild Anopheles mosquito populations that would limit their capacity to transmit the disease. The success of such an approach obviously depends on a variety of factors. By developing a model that integrates both population genetics and epidemiology, we explore how mosquito mating preferences and the cost and efficacy of refractoriness affects the long-term prevalence of malaria in humans subsequent to a single generation inundative release of male transgenic mosquitoes. As may be intuitively expected, mating discrimination by wild-type individuals against transgenic ones generally reduces the probability that transgenes become stably established at a high frequency in mosquito populations. We also show that in circumstances where transgenic individuals exhibit some degree of discrimination against wild-type individuals, this can favour the spread of refractory alleles and lead to a significant reduction in malaria prevalence in the human population (if the efficacy of a dominant refractory mechanism exceeds at least 75%). The existence of such a non-intuitive outcome highlights the practical value of increasing the understanding of Anopheles mating preferences in the wild as a means to harness them in the implementation of population replacement approaches. Potential strategies by which previously described mating preferences of Anopheles gambiae populations could be exploited to manipulate the mate choice of transgenic release stocks are discussed.

  19. Merida virus, a putative novel rhabdovirus discovered in Culex and Ochlerotatus spp. mosquitoes in the Yucatan Peninsula of Mexico.

    PubMed

    Charles, Jermilia; Firth, Andrew E; Loroño-Pino, Maria A; Garcia-Rejon, Julian E; Farfan-Ale, Jose A; Lipkin, W Ian; Blitvich, Bradley J; Briese, Thomas

    2016-04-01

    Sequences corresponding to a putative, novel rhabdovirus [designated Merida virus (MERDV)] were initially detected in a pool of Culex quinquefasciatus collected in the Yucatan Peninsula of Mexico. The entire genome was sequenced, revealing 11 798 nt and five major ORFs, which encode the nucleoprotein (N), phosphoprotein (P), matrix protein (M), glycoprotein (G) and RNA-dependent RNA polymerase (L). The deduced amino acid sequences of the N, G and L proteins have no more than 24, 38 and 43 % identity, respectively, to the corresponding sequences of all other known rhabdoviruses, whereas those of the P and M proteins have no significant identity with any sequences in GenBank and their identity is only suggested based on their genome position. Using specific reverse transcription-PCR assays established from the genome sequence, 27 571 C. quinquefasciatus which had been sorted in 728 pools were screened to assess the prevalence of MERDV in nature and 25 pools were found positive. The minimal infection rate (calculated as the number of positive mosquito pools per 1000 mosquitoes tested) was 0.9, and similar for both females and males. Screening another 140 pools of 5484 mosquitoes belonging to four other genera identified positive pools of Ochlerotatus spp. mosquitoes, indicating that the host range is not restricted to C. quinquefasciatus. Attempts to isolate MERDV in C6/36 and Vero cells were unsuccessful. In summary, we provide evidence that a previously undescribed rhabdovirus occurs in mosquitoes in Mexico.

  20. Spatial model for transmission of mosquito-borne diseases

    NASA Astrophysics Data System (ADS)

    Kon, Cynthia Mui Lian; Labadin, Jane

    2015-05-01

    In this paper, a generic model which takes into account spatial heterogeneity for the dynamics of mosquito-borne diseases is proposed. The dissemination of the disease is described by a system of reaction-diffusion partial differential equations. Host human and vector mosquito populations are divided into susceptible and infectious classes. Diffusion is considered to occur in all classes of both populations. Susceptible humans are infected when bitten by infectious mosquitoes. Susceptible mosquitoes bite infectious humans and become infected. The biting rate of mosquitoes is considered to be density dependent on the total human population in different locations. The system is solved numerically and results are shown.

  1. miRNA genes of an invasive vector mosquito, Aedes albopictus.

    PubMed

    Gu, Jinbao; Hu, Wanqi; Wu, Jinya; Zheng, Peiming; Chen, Maoshan; James, Anthony A; Chen, Xiaoguang; Tu, Zhijian

    2013-01-01

    Aedes albopictus, a vector of Dengue and Chikungunya viruses, is a robust invasive species in both tropical and temperate environments. MicroRNAs (miRNAs) regulate gene expression and biological processes including embryonic development, innate immunity and infection. While a number of miRNAs have been discovered in some mosquitoes, no comprehensive effort has been made to characterize them from different developmental stages from a single species. Systematic analysis of miRNAs in Ae. albopictus will improve our understanding of its basic biology and inform novel strategies to prevent virus transmission. Between 10-14 million Illumina sequencing reads per sample were obtained from embryos, larvae, pupae, adult males, sugar-fed and blood-fed adult females. A total of 119 miRNA genes represented by 215 miRNA or miRNA star (miRNA*) sequences were identified, 15 of which are novel. Eleven, two, and two of the newly-discovered miRNA genes appear specific to Aedes, Culicinae, and Culicidae, respectively. A number of miRNAs accumulate predominantly in one or two developmental stages and the large number that showed differences in abundance following a blood meal likely are important in blood-induced mosquito biology. Gene Ontology (GO) analysis of the targets of all Ae. albopictus miRNAs provides a useful starting point for the study of their functions in mosquitoes. This study is the first systematic analysis of miRNAs based on deep-sequencing of small RNA samples of all developmental stages of a mosquito species. A number of miRNAs are related to specific physiological states, most notably, pre- and post-blood feeding. The distribution of lineage-specific miRNAs is consistent with mosquito phylogeny and the presence of a number of Aedes-specific miRNAs likely reflects the divergence between the Aedes and Culex genera.

  2. Species interactions among larval mosquitoes: context dependence across habitat gradients.

    PubMed

    Juliano, Steven A

    2009-01-01

    Biotic interactions involving mosquito larvae are context dependent, with effects of interactions on populations altered by ecological conditions. Relative impacts of competition and predation change across a gradient of habitat size and permanence. Asymmetrical competition is common and ecological context changes competitive advantage, potentially facilitating landscape-level coexistence of competitors. Predator effects on mosquito populations sometimes depend on habitat structure and on emergent effects of multiple predators, particularly interference among predators. Nonlethal effects of predators on mosquito oviposition, foraging, and life history are common, and their consequences for populations and for mosquito-borne disease are poorly understood. Context-dependent beneficial effects of detritus shredders on mosquitoes occur in container habitats, but these interactions appear to involve more than simple resource modification by shredders. Investigations of context-dependent interactions among mosquito larvae will yield greater understanding of mosquito population dynamics and provide useful model systems for testing theories of context dependence in communities.

  3. Species Interactions Among Larval Mosquitoes: Context Dependence Across Habitat Gradients

    PubMed Central

    Juliano, Steven A.

    2009-01-01

    Biotic interactions involving mosquito larvae are context dependent, with effects of interactions on populations altered by ecological conditions. Relative impacts of competition and predation change across a gradient of habitat size and permanence. Asymmetrical competition is common and ecological context changes competitive advantage, potentially facilitating landscape-level coexistence of competitors. Predator effects on mosquito populations sometimes depend on habitat structure and on emergent effects of multiple predators, particularly interference among predators. Nonlethal effects of predators on mosquito oviposition, foraging, and life history are common, and their consequences for populations and for mosquito-borne disease are poorly understood. Context-dependent beneficial effects of detritus shredders on mosquitoes occur in container habitats, but these interactions appear to involve more than simple resource modification by shredders. Investigations of context-dependent interactions among mosquito larvae will yield greater understanding of mosquito population dynamics and provide useful model systems for testing theories of context dependence in communities. PMID:19067629

  4. Diversity and function of bacterial microbiota in the mosquito holobiont

    PubMed Central

    2013-01-01

    Mosquitoes (Diptera: Culicidae) have been shown to host diverse bacterial communities that vary depending on the sex of the mosquito, the developmental stage, and ecological factors. Some studies have suggested a potential role of microbiota in the nutritional, developmental and reproductive biology of mosquitoes. Here, we present a review of the diversity and functions of mosquito-associated bacteria across multiple variation factors, emphasizing recent findings. Mosquito microbiota is considered in the context of possible extended phenotypes conferred on the insect hosts that allow niche diversification and rapid adaptive evolution in other insects. These kinds of observations have prompted the recent development of new mosquito control methods based on the use of symbiotically-modified mosquitoes to interfere with pathogen transmission or reduce the host life span and reproduction. New opportunities for exploiting bacterial function for vector control are highlighted. PMID:23688194

  5. Condoms - male

    MedlinePlus

    Prophylactics; Rubbers; Male condoms; Contraceptive - condom; Contraception - condom; Barrier method - condom ... rubber Polyurethane Condoms are the only method of birth control for men that are not permanent. They can ...

  6. Biting patterns and seasonality of anopheles gambiae sensu lato and anopheles funestus mosquitoes in Kamuli District, Uganda

    PubMed Central

    2013-01-01

    Background We investigated the biting patterns and seasonal abundances of Anopheles gambiae s.l. and An. funestus mosquitoes in Kamuli District, Uganda. Methods Hourly indoor and outdoor catches of human biting mosquitoes were sampled from 19.00 to 07.00 hours for four consecutive nights each month using bed net traps in forty-eight houses randomly selected from Bugabula county where insecticide-treated bed nets (ITNs) had been used for at least five years and Budiope county where ITNs had not been used. The indoor and outdoor human-biting fractions, time of biting of the anophelines and climatic data were recorded from January to December 2010. Data were analysed using Multi-way analysis of variance, Kruskal-wallis rank sum test and Pearson correlation. The number of mosquitoes caught biting humans and resting indoors, the indoor and outdoor human biting densities and biting rates during different hours of the night, and mosquito abundances for a twelve-month sampling period in both zones are reported. Results Approximately four times more Anopheles mosquitoes were caught biting humans in Budiope County than in the Bugabula zone, with An. gambiae s. l. catches exceeding those of An. funestus. In both zones, peak night biting occurred between 23.00 and 05.00 hours. The majority of bites occurred between 03.00 and 06.00 hours for both Anopheles gambiae s. l. and funestus group. Outdoor biting densities of Anopheles gambiae s. l. exceeded the indoor biting densities throughout the night in both zones, while the indoor and outdoor human biting densities of An. funestus group were apparently equal. The outdoor and indoor human biting rates were similar in both zones. In Bugabula county, the abundance of An. gambiae s.l. was rainfall-dependent, while the An. funestus group could thrive with or without rain fall. In Budiope county, both An. gambiae s.l. and An. funestus mosquitoes thrived all year round regardless of the amount of rainfall. Conclusion Considering the

  7. Workbook on the Identification of Mosquito Larvae.

    ERIC Educational Resources Information Center

    Pratt, Harry D.; And Others

    This self-instructional booklet is designed to enable public health workers identify larvae of some important North American mosquito species. The morphological features of larvae of the various genera and species are illustrated in a programed booklet, which also contains illustrated taxonomic keys to the larvae of 11 North American genera and to…

  8. Mosquito repellency of novel Trifluoromethylphenyl amides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Human diseases caused by mosquito-transmitted pathogens include malaria, dengue and yellow fever and are responsible for several million human deaths every year, according to the World Health Organization (WHO). Our current research projects focus on the development of new insecticides and repellent...

  9. Mosquito proboscis: An elegant biomicroelectromechanical system

    NASA Astrophysics Data System (ADS)

    Kong, X. Q.; Wu, C. W.

    2010-07-01

    The mouthparts of female mosquitoes have evolved to form a special proboscis, a natural biomicroelectromechanical system (BMEMS), which is used for painlessly penetrating human skin and sucking blood. Scanning electron microscope observations show that the mosquito proboscis consists of a small bundle of long, tapering, and feeding stylets that are collectively called the fascicle, and a large scaly outer lower lip called the labium. During blood feeding, only the fascicle penetrates into the skin while the labium buckles back to remain on the surface of the skin. Here, we measured the dynamic force of penetration of the fascicle into human skin to reveal the mechanical principle underlying the painless process of penetration. High-speed video observations of movements associated with insertion of the fascicle indicate that the “smart” mosquito does not directly pierce its victim’s skin with the fascicle. Instead, it uses the two maxillas as variable frequency microsaws with nanosharp teeth to advance into the skin tissue. This elegant BMEMS enables the mosquito to insert its feeding fascicle into human skin using an exceedingly small force (average of 16.5μN ).

  10. Malaria Mosquitoes Attracted by Fatal Fungus

    PubMed Central

    George, Justin; Jenkins, Nina E.; Blanford, Simon; Thomas, Matthew B.; Baker, Thomas C.

    2013-01-01

    Insect-killing fungi such as Beauveria bassiana are being evaluated as possible active ingredients for use in novel biopesticides against mosquito vectors that transmit malaria. Fungal pathogens infect through contact and so applications of spores to surfaces such as walls, nets, or other resting sites provide possible routes to infect mosquitoes in and around domestic dwellings. However, some insects can detect and actively avoid fungal spores to reduce infection risk. If true for mosquitoes, such behavior could render the biopesticide approach ineffective. Here we find that the spores of B. bassiana are highly attractive to females of Anopheles stephensi, a major anopheline mosquito vector of human malaria in Asia. We further find that An. stephensi females are preferentially attracted to dead and dying caterpillars infected with B. bassiana, landing on them and subsequently becoming infected with the fungus. Females are also preferentially attracted to cloth sprayed with oil-formulated B. bassiana spores, with 95% of the attracted females becoming infected after a one-minute visit on the cloth. This is the first report of an insect being attracted to a lethal fungal pathogen. The exact mechanisms involved in this behavior remain unclear. Nonetheless, our results indicate that biopesticidal formulations comprising B. bassiana spores will be conducive to attraction and on-source visitation by malaria vectors. PMID:23658757

  11. 75 FR 4100 - Affirmative Fair Housing, Marketing (AFHM) Plan-Multifamily Housing, Affirmative Fair Housing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-26

    ... URBAN DEVELOPMENT Affirmative Fair Housing, Marketing (AFHM) Plan-Multifamily Housing, Affirmative Fair Housing Marketing (AFHM) Plan-Single Family Housing and Affirmative Fair Housing Marketing (AFHM) Plan... forms to describe their intent for marketing to ensure that they meet the Fair Housing...

  12. Bitter-sensitive gustatory receptor neuron responds to chemically diverse insect repellents in the common malaria mosquito Anopheles quadrimaculatus

    NASA Astrophysics Data System (ADS)

    Sparks, Jackson T.; Dickens, Joseph C.

    2016-06-01

    Female mosquitoes feed on blood from animal hosts to obtain nutritional resources used for egg production. These contacts facilitate the spread of harmful human diseases. Chemical repellents are used to disrupt mosquito host-seeking and blood-feeding behaviors; however, little is known about the gustatory sensitivity of mosquitoes to known repellents. Here, we recorded electrical responses from gustatory receptor neurons (GRNs) housed within the labellar sensilla of female Anopheles quadrimaculatus to N,N-diethyl-3-methylbenzamide (DEET), picaridin, IR3535, 2-undecanone, p-menthane-3,8-diol, geraniol, trans-2-hexen-1-ol, quinine, and quinidine. A bitter-sensitive GRN responded to all tested repellents and quinine, a known feeding deterrent. Responses of the bitter-sensitive neuron to quinine and an isomer, quinidine, did not differ. Delayed bursts of electrical activity were observed in response to continuous stimulation with synthetic repellents at high concentrations. Electrophysiological recordings from bitter-sensitive GRNs associated with mosquito gustatory sensilla represent a convenient model to evaluate candidate repellents.

  13. Site-directed mutagenesis of an acetylcholinesterase gene from the yellow fever mosquito Aedes aegypti confers insecticide insensitivity.

    PubMed

    Vaughan, A; Rocheleau, T; ffrench-Constant, R

    1997-11-01

    Insecticide resistance is a serious problem facing the effective control of insect vectors of disease. Insensitive acetylcholinesterase (AChE) confers resistance to organophosphorus (OP) and carbamate insecticides and is a widespread resistance mechanism in vector mosquitoes. Although the point mutations that underlie AChE insensitivity have been described from Drosophila, the Colorado potato beetle, and house flies, no resistance associated mutations have been documented from mosquitoes to date. We are therefore using a cloned acetylcholinesterase gene from the yellow fever mosquito Aedes aegypti as a model in which to perform site directed mutagenesis in order to understand the effects of potential resistance associated mutations. The same resistance associated amino-acid replacements as found in other insects also confer OP and carbamate resistance to the mosquito enzyme. Here we describe the levels of resistance conferred by different combinations of these mutations and the effects of these mutations on the kinetics of the AChE enzyme. Over-expression of these constructs in baculovirus will facilitate purification of each of the mutant enzymes and a more detailed analysis of their associated inhibition kinetics.

  14. Estimation of Aedes aegypti (Diptera: Culicidae) population size and adult male survival in an urban area in Panama.

    PubMed

    Neira, Marco; Lacroix, Renaud; Cáceres, Lorenzo; Kaiser, Paul E; Young, Josue; Pineda, Lleysa; Black, Isaac; Sosa, Nestor; Nimmo, Derric; Alphey, Luke; McKemey, Andrew

    2014-11-01

    Traditional mosquito control strategies rely heavily on the use of chemical insecticides. However, concerns about the efficiency of traditional control methods, environmental impact and emerging pesticide resistance have highlighted the necessity for developing innovative tools for mosquito control. Some novel strategies, including release of insects carrying a dominant lethal gene (RIDL®), rely on the sustained release of modified male mosquitoes and therefore benefit from a thorough understanding of the biology of the male of the species. In this report we present the results of a mark-release-recapture study aimed at: (i) establishing the survival in the field of laboratory-reared, wild-type male Aedes aegypti and (b) estimating the size of the local adult Ae. aegypti population. The study took place in Panama, a country where recent increases in the incidence and severity of dengue cases have prompted health authorities to evaluate alternative strategies for vector control. Results suggest a life expectancy of 2.3 days for released male mosquitoes (confidence interval: 1.78-2.86). Overall, the male mosquito population was estimated at 58 males/ha (range 12-81 males/ha), which can be extrapolated to an average of 0.64 pupae/person for the study area. The practical implications of these results are discussed.

  15. Estimation of Aedes aegypti (Diptera: Culicidae) population size and adult male survival in an urban area in Panama

    PubMed Central

    Neira, Marco; Lacroix, Renaud; Cáceres, Lorenzo; Kaiser, Paul E; Young, Josue; Pineda, Lleysa; Black, Isaac; Sosa, Nestor; Nimmo, Derric; Alphey, Luke; McKemey, Andrew

    2014-01-01

    Traditional mosquito control strategies rely heavily on the use of chemical insecticides. However, concerns about the efficiency of traditional control methods, environmental impact and emerging pesticide resistance have highlighted the necessity for developing innovative tools for mosquito control. Some novel strategies, including release of insects carrying a dominant lethal gene (RIDL®), rely on the sustained release of modified male mosquitoes and therefore benefit from a thorough understanding of the biology of the male of the species. In this report we present the results of a mark-release-recapture study aimed at: (i) establishing the survival in the field of laboratory-reared, wild-type male Aedes aegypti and (b) estimating the size of the local adult Ae. aegypti population. The study took place in Panama, a country where recent increases in the incidence and severity of dengue cases have prompted health authorities to evaluate alternative strategies for vector control. Results suggest a life expectancy of 2.3 days for released male mosquitoes (confidence interval: 1.78-2.86). Overall, the male mosquito population was estimated at 58 males/ha (range 12-81 males/ha), which can be extrapolated to an average of 0.64 pupae/person for the study area. The practical implications of these results are discussed. PMID:25410991

  16. Long-lasting insecticide-treated house screens and targeted treatment of productive breeding-sites for dengue vector control in Acapulco, Mexico

    PubMed Central

    Che-Mendoza, Azael; Guillermo-May, Guillermo; Herrera-Bojórquez, Josué; Barrera-Pérez, Mario; Dzul-Manzanilla, Felipe; Gutierrez-Castro, Cipriano; Arredondo-Jiménez, Juan I.; Sánchez-Tejeda, Gustavo; Vazquez-Prokopec, Gonzalo; Ranson, Hilary; Lenhart, Audrey; Sommerfeld, Johannes; McCall, Philip J.; Kroeger, Axel; Manrique-Saide, Pablo

    2015-01-01

    Background Long-lasting insecticidal net screens (LLIS) fitted to domestic windows and doors in combination with targeted treatment (TT) of the most productive Aedes aegypti breeding sites were evaluated for their impact on dengue vector indices in a cluster-randomised trial in Mexico between 2011 and 2013. Methods Sequentially over 2 years, LLIS and TT were deployed in 10 treatment clusters (100 houses/cluster) and followed up over 24 months. Cross-sectional surveys quantified infestations of adult mosquitoes, immature stages at baseline (pre-intervention) and in four post-intervention samples at 6-monthly intervals. Identical surveys were carried out in 10 control clusters that received no treatment. Results LLIS clusters had significantly lower infestations compared to control clusters at 5 and 12 months after installation, as measured by adult (male and female) and pupal-based vector indices. After addition of TT to the intervention houses in intervention clusters, indices remained significantly lower in the treated clusters until 18 (immature and adult stage indices) and 24 months (adult indices only) post-intervention. Conclusions These safe, simple affordable vector control tools were well-accepted by study participants and are potentially suitable in many regions at risk from dengue worldwide. PMID:25604761

  17. Mom Matters: Diapause Characteristics of Culex pipiens-Culex quinquefasciatus (Diptera: Culicidae) Hybrid Mosquitoes.

    PubMed

    Meuti, Megan E; Short, Clancy A; Denlinger, David L

    2015-03-01

    Females of the northern house mosquito, Culex pipiens L., are capable of entering an adult overwintering diapause characterized by arrested ovarian development, enhanced stress tolerance, and elevated lipid stores. In contrast, the southern house mosquito, Culex quinquefasciatus Say, lacks this capacity and is therefore unable to survive the harsh winters found in northern regions of North America. These two species are capable of forming fertile hybrids in the United States, yet the diapause characteristics of these hybrids have not been extensively investigated. We crossed Cx. pipiens from Columbus, OH, with Cx. quinquefasciatus from Vero Beach, FL, and reared F1 hybrids from all mothers separately under diapause-inducing, short-day conditions (a photoperiod of 8:16 [L:D] h) at 18°C. Egg follicle length and lipid content were used to assess the diapause status of hybrids. Diapause incidence of hybrids varied widely for progeny from different mothers of the same species, but hybrids with Cx. pipiens mothers were consistently more prone to enter diapause than hybrids that had Cx. quinquefasciatus mothers. Our results suggest a strong maternal influence on the diapause phenotype and that a high percentage (45-75%) of Cx. pipiens-Cx. quinquefasciatus hybrids are capable of entering diapause. This implies that many hybrids can successfully overwinter, leading to a possible widening of the hybrid zone of these two species in North America.

  18. Improved poultry house

    SciTech Connect

    1983-01-01

    The relationship of energy and poultry production was explored in three areas: methane production from litter, broiler house insulation, and broiler house HVAC systems. The findings show that while a methane plant would not be popular with individual American poultry producers; the pay back in fuel and fertilizer, if the plant was located in close proximinity to the processing plant, would be favorable. Broiler house insulation has been dramatically improved since the outset of this study. Presently, all new installations in the survey area are the Environmental houses which are fully insulated. HVAC systems have had to keep pace with the introduction of better insulation. The new Environmental houses HVAC systems are fully automated and operating on a positive atmosphere principal. Ammonia and other problems have been kept in check while reducing air changes per house from a high of 7 per hour to as little as 3 per hour.

  19. NASA Tech House

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The NASA Technology Utilization House, called Tech House, was designed and constructed at NASA's Langley Research Center in Hampton, Virginia, to demonstrate new technology that is available or will be available in the next several years and how the application of aerospace technology could help advance the homebuilding industry. Solar energy use, energy and water conservation, safety, security, and cost were major considerations in adapting the aerospace technology to the construction of Tech House.

  20. House Resolutions of Inquiry

    DTIC Science & Technology

    2003-05-12

    14 Two years later, the House made another change to its rules governing resolutions of inquiry, requiring not merely a day’s delay but also...of Government “does not necessarily belong to the province of legislation. It does not profess to be asked for that object.”42 Second, if the House ...recognized that the power of impeachment gives the House “the right to investigate the conduct of all public officers under the Government . This is

  1. Male contraception.

    PubMed

    Wang, Christina; Swerdloff, Ronald S

    2002-04-01

    Currently approved male-directed contraceptive methods include condoms and vas occlusion. Vas occlusion is very effective but is intended to be non-reversible. Condoms have a relatively high failure rate, at least partially due to compliance problems and are not accepted by many couples. The only other male-oriented methods in clinical trials utilize the administration of testosterone alone or its combination with another gonadotropin-suppressing agent such as a progestin or a gonadotropin-releasing hormone antagonist. Studies published in the 1990s demonstrated that a testosterone-containing hormonal contraceptive method suppressed spermatogenesis to azoospermia in most men and severe oligozoospermia in the remaining. The contraceptive efficacy after treatment with testosterone alone was comparable to that of female hormonal methods. Having proven that reversible male contraception is a reality, present trials are attempting to identify the best androgen delivery system and the most effective androgen plus progestin preparation. It is likely that the first marketed male hormonal contraceptive method will be a long-acting (injectable or implant) combination of an androgen plus a progestin. Research is continuing to identify other target areas for male contraceptive development, including agents with post-testicular and epididymal sites of action.

  2. The Interaction between a Sexually Transferred Steroid Hormone and a Female Protein Regulates Oogenesis in the Malaria Mosquito Anopheles gambiae

    PubMed Central

    Baldini, Francesco; Gabrieli, Paolo; South, Adam; Valim, Clarissa; Mancini, Francesca; Catteruccia, Flaminia

    2013-01-01

    Molecular interactions between male and female factors during mating profoundly affect the reproductive behavior and physiology of female insects. In natural populations of the malaria mosquito Anopheles gambiae, blood-fed females direct nutritional resources towards oogenesis only when inseminated. Here we show that the mating-dependent pathway of egg development in these mosquitoes is regulated by the interaction between the steroid hormone 20-hydroxy-ecdysone (20E) transferred by males during copulation and a female Mating-Induced Stimulator of Oogenesis (MISO) protein. RNAi silencing of MISO abolishes the increase in oogenesis caused by mating in blood-fed females, causes a delay in oocyte development, and impairs the function of male-transferred 20E. Co-immunoprecipitation experiments show that MISO and 20E interact in the female reproductive tract. Moreover MISO expression after mating is induced by 20E via the Ecdysone Receptor, demonstrating a close cooperation between the two factors. Male-transferred 20E therefore acts as a mating signal that females translate into an increased investment in egg development via a MISO-dependent pathway. The identification of this male–female reproductive interaction offers novel opportunities for the control of mosquito populations that transmit malaria. PMID:24204210

  3. Genotoxic effects of produced waters in mosquito fish (Gambusia affinis).

    PubMed

    Caliani, Ilaria; Porcelloni, Serena; Mori, Gabriele; Frenzilli, Giada; Ferraro, Maria; Marsili, Letizia; Casini, Silvia; Fossi, Maria Cristina

    2009-01-01

    The aim of this study was to assess the potential genotoxic effects of produced water (PW) from an Italian on-shore oil plant. Produced water is a complex mixture containing residual hydrocarbons, trace elements, naturally occurring radioactive material and potentially toxic treatment chemicals such as biocides, dispersants, detergents and scale inhibitors used in oil production. The test organism, mosquito fish (Gambusia affinis), was divided into male and female groups and exposed for 8 days in the laboratory to 50% concentrations of different produced waters: PW before treatment and after settling treatment. The fish were also exposed to lower concentrations (10%) of the same PW for 30 days. DNA damage was evaluated in erythrocytes by single cell gel electrophoresis (Comet assay) and micronucleus test, while an oxidative stress biomarker, was assessed. Polycyclic aromatic hydrocarbons (PAH) metabolites in bile were also evaluated. A higher sensitivity in biomarker responses was found in females in comparison to males. An increase in DNA strand breaks was observed in both genders after 30 days exposure and a statistically significant increase of micronucleated cells was found in females after 8 days exposure. A positive correlation between presence of micronucleated cells and PAH metabolites in bile was also observed.

  4. Comparative Transcriptomics of Malaria Mosquito Testes: Function, Evolution, and Linkage

    PubMed Central

    Cassone, Bryan J.; Kay, Raissa G. G.; Daugherty, Matthew P.; White, Bradley J.

    2017-01-01

    Testes-biased genes evolve rapidly and are important in the establishment, solidification, and maintenance of reproductive isolation between incipient species. The Anopheles gambiae complex, a group of at least eight isomorphic mosquito species endemic to Sub-Saharan Africa, is an excellent system to explore the evolution of testes-biased genes. Within this group, the testes are an important tissue in the diversification process because hybridization between species results in sterile hybrid males, but fully fertile females. We conducted RNA sequencing of A. gambiae and A. merus carcass and testes to explore tissue- and species-specific patterns of gene expression. Our data provides support for transcriptional repression of X-linked genes in the male germline, which likely drives demasculinization of the X chromosome. Testes-biased genes predominately function in cellular differentiation and show a number of interesting patterns indicative of their rapid evolution, including elevated dN/dS values, low evolutionary conservation, poor annotation in existing reference genomes, and a high likelihood of differential expression between species. PMID:28159865

  5. Exotic mosquito threats require strategic surveillance and response planning.

    PubMed

    Webb, Cameron E; Doggett, Stephen L

    2016-12-14

    Mosquito-borne diseases caused by endemic pathogens such as Ross River, Barmah Forest and Murray Valley encephalitis viruses are an annual concern in New South Wales (NSW), Australia. More than a dozen mosquito species have been implicated in the transmission of these pathogens, with each mosquito occupying a specialised ecological niche that influences their habitat associations, host feeding preferences and the environmental drivers of their abundance. The NSW Arbovirus Surveillance and Mosquito Monitoring Program provides an early warning system for potential outbreaks of mosquito-borne disease by tracking annual activity of these mosquitoes and their associated pathogens. Although the program will effectively track changes in local mosquito populations that may increase with a changing climate, urbanisation and wetland rehabilitation, it will be less effective with current surveillance methodologies at detecting or monitoring changes in exotic mosquito threats, where different surveillance strategies need to be used. Exotic container-inhabiting mosquitoes such as Aedes aegypti and Ae. albopictus pose a threat to NSW because they are nuisance-biting pests and vectors of pathogens such as dengue, chikungunya and Zika viruses. International movement of humans and their belongings have spread these mosquitoes to many regions of the world. In recent years, these two mosquitoes have been detected by the Australian Government Department of Agriculture and Water Resources at local airports and seaports. To target the detection of these exotic mosquitoes, new trapping technologies and networks of surveillance locations are required. Additionally, incursions of these mosquitoes into urban areas of the state will require strategic responses to minimise substantial public health and economic burdens to local communities.

  6. Paratransgenesis: a promising new strategy for mosquito vector control.

    PubMed

    Wilke, André Barretto Bruno; Marrelli, Mauro Toledo

    2015-06-24

    The three main mosquito genera, Anopheles, Aedes and Culex, transmit respectively malaria, dengue and lymphatic filariasis. Current mosquito control strategies have proved unsuccessful, and there still is a substantial number of morbidity and mortality from these diseases. Genetic control methods have now arisen as promising alternative strategies, based on two approaches: the replacement of a vector population by disease-refractory mosquitoes and the release of mosquitoes carrying a lethal gene to suppress target populations. However, substantial hurdles and limitations need to be overcome if these methods are to be used successfully, the most significant being that a transgenic mosquito strain is required for every target species, making genetically modified mosquito strategies inviable when there are multiple vector mosquitoes in the same area. Genetically modified bacteria capable of colonizing a wide range of mosquito species may be a solution to this problem and another option for the control of these diseases. In the paratransgenic approach, symbiotic bacteria are genetically modified and reintroduced in mosquitoes, where they express effector molecules. For this approach to be used in practice, however, requires a better understanding of mosquito microbiota and that symbiotic bacteria and effector molecules be identified. Paratransgenesis could prove very useful in mosquito species that are inherently difficult to transform or in sibling species complexes. In this approach, a genetic modified bacteria can act by: (a) causing pathogenic effects in the host; (b) interfering with the host's reproduction; (c) reducing the vector's competence; and (d) interfering with oogenesis and embryogenesis. It is a much more flexible and adaptable approach than the use of genetically modified mosquitoes because effector molecules and symbiotic bacteria can be replaced if they do not achieve the desired result. Paratransgenesis may therefore become an important integrated

  7. 4. View of houses from Port Ludlow, houses no. 69 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. View of houses from Port Ludlow, houses no. 69 and 70, facing southwest. House no. 69 in foreground, house no. 70 in background. - Houses Moved from Port Ludlow, Various Addresses (moved from Port Ludlow, WA), Port Gamble, Kitsap County, WA

  8. A low-cost mesocosm for the study of behaviour and reproductive potential in Afrotropical mosquito (Diptera: Culicidae) vectors of malaria.

    PubMed

    Jackson, B T; Stone, C M; Ebrahimi, B; Briët, O J T; Foster, W A

    2015-03-01

    A large-scale mesocosm was constructed and tested for its effectiveness for use in experiments on behaviour, reproduction and adult survivorship in the Afrotropical malaria vector Anopheles gambiae s.s. Giles (Diptera: Culicidae) in temperate climates. The large space (82.69 m(3) ) allowed for semi-natural experiments that increased demand on a mosquito's energetic reserves in an environment of widely distributed resources. A one-piece prefabricated enclosure, made with white netting and vinyl, prevented the ingress of predators and the egress of mosquitoes. Daylight and white materials prompted the mosquitoes to seclude themselves in restricted daytime resting sites and allowed the easy collection of dead bodies so that daily mortality could be assessed accurately using a method that accounts for the loss of a proportion of bodies. Here, daily, age-dependent mortality rates of males and females were estimated using Bayesian Markov chain Monte Carlo simulation. In overnight experiments, mosquitoes successfully located plants and took sugar meals. A 3-week survival trial with a single cohort demonstrated successful mating, blood feeding, oviposition and long life. The relatively low cost of the mesocosm and the performance of the mosquitoes in it make it a viable option for any behavioural or ecological study of tropical mosquitoes in which space and seasonal cold are constraining factors.

  9. Comparison of the efficacy of CO2-baited and unbaited light traps, gravid traps, backpack aspirators, and sweep net collections for sampling mosquitoes infected with Japanese encephalitis virus.

    PubMed

    Chen, Yu-Chen; Wang, Chih-Yuan; Teng, Hwa-Jen; Chen, Chien-Fu; Chang, Mi-Chun; Lu, Liang-Chen; Lin, Cheo; Jian, Shu-Wan; Wu, Ho-Sheng

    2011-06-01

    Two field studies were conducted to determine the efficacy of mosquito collection methods for species composition, species abundance, and Japanese encephalitis virus infection rates in Taiwan. Traps evaluated included John W. Hock (JH) model UD black light traps, JH model 1012 new standard miniature CDC light traps, JH model 1712 CDC gravid traps, and Taiwan-made Pest-O-Lite light traps. Backpack aspirators and sweep nets were also used to collect the resting population. Culex tritaeniorhynchus in all studies and Mansonia uniformis in the Taipei areas were the two most abundance species collected. Dry ice-baited UD black light traps were effective in regard to species diversity, species abundance, and Japanese encephalitis virus infection rates. The unbaited Pest-O-Lite light traps collected significantly more female mosquitoes than the UD black light traps but performed similarly with regard to species diversity and male mosquito collection. Most mosquitoes collected by Pest-O-Lite light traps were dried and not suitable for virus detection. Dry ice-baited CDC light traps collected significantly fewer mosquitoes than other light traps. Although CO(2) -baited UD black light traps with octenol attracted more mosquitoes, no statistical significance was found compared to CO(2) -baited UD black light traps without octenol. Japanese encephalitis viruses were isolated from half of the positive pools in UD black light traps and CDC light traps.

  10. Filarial Worms Reduce Plasmodium Infectivity in Mosquitoes

    PubMed Central

    Aliota, Matthew T.; Chen, Cheng-Chen; Dagoro, Henry; Fuchs, Jeremy F.; Christensen, Bruce M.

    2011-01-01

    Background Co-occurrence of malaria and filarial worm parasites has been reported, but little is known about the interaction between filarial worm and malaria parasites with the same Anopheles vector. Herein, we present data evaluating the interaction between Wuchereria bancrofti and Anopheles punctulatus in Papua New Guinea (PNG). Our field studies in PNG demonstrated that An. punctulatus utilizes the melanization immune response as a natural mechanism of filarial worm resistance against invading W. bancrofti microfilariae. We then conducted laboratory studies utilizing the mosquitoes Armigeres subalbatus and Aedes aegypti and the parasites Brugia malayi, Brugia pahangi, Dirofilaria immitis, and Plasmodium gallinaceum to evaluate the hypothesis that immune activation and/or development by filarial worms negatively impact Plasmodium development in co-infected mosquitoes. Ar. subalbatus used in this study are natural vectors of P. gallinaceum and B. pahangi and they are naturally refractory to B. malayi (melanization-based refractoriness). Methodology/Principal Findings Mosquitoes were dissected and Plasmodium development was analyzed six days after blood feeding on either P. gallinaceum alone or after taking a bloodmeal containing both P. gallinaceum and B. malayi or a bloodmeal containing both P. gallinaceum and B. pahangi. There was a significant reduction in the prevalence and mean intensity of Plasmodium infections in two species of mosquito that had dual infections as compared to those mosquitoes that were infected with Plasmodium alone, and was independent of whether the mosquito had a melanization immune response to the filarial worm or not. However, there was no reduction in Plasmodium development when filarial worms were present in the bloodmeal (D. immitis) but midgut penetration was absent, suggesting that factors associated with penetration of the midgut by filarial worms likely are responsible for the observed reduction in malaria parasite infections

  11. Predictors of mosquito net use in Ghana

    PubMed Central

    2011-01-01

    Background During the past decade the malaria control community has been successful in dramatically increasing the number of households that own mosquito nets. However, as many as half of nets already in households go unused. This study examines the factors associated with use of nets owned in Ghana. Methods The data come from an August 2008 survey in Ghana of households with a pregnant woman or a guardian of a child under five, conducted during the rainy season. 1796 households were included in this analysis, which generated a sample of 1,852 mosquito nets. Using each net owned as the unit of analysis, multivariate logistic regression was used to examine the relationship of net used last night with 23 potentially explanatory variables having to do with characteristics of the household, of the respondent, and of the net. Odds Ratios, p-values, and confidence intervals were calculated for each variable to develop an explanatory model. Results The final multivariate model consisted of 10 variables statistically associated with whether or not the net was used the prior night: rural location, lower SES, not using coils for mosquito control, fewer nets in the household, newer nets and those in better condition, light blue colour, higher level of education of the guardian of the child under five, knowing that mosquitoes transmit malaria, and paying for the net instead of obtaining it free of charge. Conclusions The results of this study suggest that net use would increase in Ghana if coloured nets were made available in mass distributions as well as in the commercial market; if programmes emphasize that malaria is caused only by night-biting mosquitoes, and that nets protect against mosquitoes better than coils and need to be used even if coils are burning; if donated nets are replaced more frequently so that households have nets that are in good condition; and if there were support for the commercial market so that those who can afford to purchase a net and want to

  12. Detection of West Nile virus RNA in mosquitoes and identification of mosquito blood meals collected at alligator farms in Louisiana.

    PubMed

    Unlu, Isik; Kramer, Wayne L; Roy, Alma F; Foil, Lane D

    2010-07-01

    Since 2001, alligator farms in the United States have sustained substantial economic losses because of West Nile virus (WNV) outbreaks in American alligators (Alligator mississippiensis). Once an initial infection is introduced into captive alligators, WNV can spread among animals by contaminative transmission. Some outbreaks have been linked to feeding on infected meat or the introduction of infected hatchlings, but the initial source of WNV infection has been uncertain in other outbreaks. We conducted a study to identify species composition and presence of WNV in mosquito populations associated with alligator farms in Louisiana. A second objective of this study was to identify the origin of mosquito blood meals collected at commercial alligator farms. Mosquitoes were collected from 2004 to 2006, using Centers for Disease Control light traps, gravid traps, backpack aspirators, and resting boxes. We collected a total of 58,975 mosquitoes representing 24 species. WNV was detected in 41 pools of females from 11 mosquito species: Anopheles crucians, Anopheles quadrimaculatus, Coquillettidia perturbans, Culex coronator, Culex erraticus, Culex nigripalpus, Culex quinquefasciatus, Mansonia titillans, Aedes sollicitans, Psorophora columbiae, and Uranotaenia lowii. The blood meal origins of 213 field-collected mosquitoes were identified based on cytochrome B sequence identity. Alligator blood was detected in 21 mosquitoes representing six species of mosquitoes, including Cx. quinquefasciatus and Cx. nigripalpus. Our results showed that mosquitoes of species that are known to be competent vectors of WNV fed regularly on captive alligators. Therefore, mosquitoes probably are important in the role of transmission of WNV at alligator farms.

  13. Sampling of adult mosquito vectors with Mosquito Magnet Pro in Panaji, Goa, India.

    PubMed

    Korgaonkar, Nandini S; Kumar, Ashwani; Yadav, Rajpal S; Kabadi, Dipak; Dash, Aditya P

    2008-12-01

    For mosquito vector population monitoring, a new commercial trap, Mosquito Magnet Pro (MM-PRO), was tested for its usefulness in Goa, India. Anopheles stephensi was tested for the presence of Plasmodium sporozoite infection in the salivary glands. Using the MM-PRO 24 h a day for 34 days, 2,329 mosquitoes belonging to 16 species were collected. These included 6 species each of the genera Anopheles and Culex, 2 species of Aedes, and 1 each of Mansonia and Armigeres. Most (91%) of the mosquitoes caught were females. Among these the number and percentage of each species were Anopheles stephensi 59 (2.78%), Culex quinquefasciatus 1013 (47.78%), Culex vishnui 551 (26.0%), Mansonia uniformis 216 (10.19%), and Aedes albopictus 1 (0.04%). Of the 54 An. stephensi females tested for the presence of circumsporozoite protein (CSP) by an ELISA technique, 1 was found to be Plasmodium falciparum CSP positive. The MM-PRO device was found useful for mosquito population sampling in the urban setting of Goa.

  14. Public perception of mosquito annoyance measured by a survey and simultaneous mosquito sampling.

    PubMed

    Read, N R; Rooker, J R; Gathman, J P

    1994-03-01

    For randomly chosen residents of the Minneapolis-St. Paul, Minnesota, metropolitan area, survey responses, reported bites, and observed defensive behaviors (e.g., brushing, swatting) for a 5-min period in their yard were compared with simultaneous mosquito counts from a human-baited drop-net trap 6 m from the resident. When mosquitoes trapped, reported bites, or observed behaviors per 5 min were 3 or more, the majority of respondents described the mosquito levels as greater than "moderate" and anticipated reduced outdoor time and/or possible repellent use. At 25 or more mosquitoes trapped, 11 or more reported bites, or 16 or more observed behaviors per 5 min, response was "bad", with most people anticipating a major reduction in outdoor time (without repellent), "probably" or "definitely" planning to use repellent, and anticipating some outdoor time loss even if using repellent. Levels of less than 3 mosquitoes trapped per 5 min were related to moderate annoyance in 20-45% of the population. Individual response was highly variable, and the personal and environmental covariates measured did not account for more than half the variability.

  15. Invasion of Wolbachia at the residential block level is associated with local abundance of Stegomyia aegypti, yellow fever mosquito, populations and property attributes.

    PubMed

    Hoffmann, A A; Goundar, A A; Long, S A; Johnson, P H; Ritchie, S A

    2014-08-01

    Wolbachia can suppress dengue and control mosquito populations and this depends on the successful invasion of Wolbachia-infected mosquitoes into local populations. Ovitrap data collected during the recent invasion of wMel-infected Stegomyia aegypti (Diptera: Culicidae) (Linnaeus) into Gordonvale near Cairns, Australia, were used to identify variables that help predict the success of localized invasion. Based on the variance in Wolbachia frequencies across Gordonvale as well as at another release site at Yorkeys Knob in comparison to simulations, it was estimated that on average 2-4 females contributed eggs to an ovitrap. By collating ovitrap data from two collection periods at the start of the release from residential blocks, it was found that uninfected mosquitoes had a patchy distribution across the release site. Residential blocks with relatively high uninfected mosquito numbers were less easily invaded by Wolbachia than blocks with low numbers. The numbers of uninfected mosquitoes in ovitraps were negatively correlated with the proportion of brick houses in a residential block, whereas local Wolbachia frequencies were correlated positively with this variable as well as negatively with the amount of shading in a yard and availability of breeding sites. These findings point to proxy measures for predicting the ease of localized invasion of Wolbachia.

  16. Housing Assistance Efficiency Act

    THOMAS, 113th Congress

    Rep. Peters, Scott H. [D-CA-52

    2013-07-23

    12/03/2014 Received in the Senate and Read twice and referred to the Committee on Banking, Housing, and Urban Affairs. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

  17. Special Report: College Housing.

    ERIC Educational Resources Information Center

    Abramson, Paul

    2003-01-01

    Responses of chief housing officers of 118 4-year colleges and universities to a survey focusing on costs, security, policies, and preferences provide a picture of college housing. More than 67% of respondents say that their colleges are planning to build more residential space. (SLD)

  18. Multiple pump housing

    DOEpatents

    Donoho, II, Michael R.; Elliott, Christopher M.

    2010-03-23

    A fluid delivery system includes a first pump having a first drive assembly, a second pump having a second drive assembly, and a pump housing. At least a portion of each of the first and second pumps are located in the housing.

  19. More Than a House.

    ERIC Educational Resources Information Center

    Simonelli, Richard

    1996-01-01

    For 14 years, Mountain Outreach, a program at Cumberland College (Williamsburg, Kentucky), has enabled college students to participate in community service projects. Recently, 35 students traveled to New Mexico to build a house for a Navajo elder who was unable to obtain adequate housing. Participants discuss their learning experiences and their…

  20. Ndebele Inspired Houses

    ERIC Educational Resources Information Center

    Rice, Nicole

    2012-01-01

    The house paintings of the South African Ndebele people are more than just an attempt to improve the aesthetics of a community; they are a source of identity and significance for Ndebele women. In this article, the author describes an art project wherein students use the tradition of Ndebele house painting as inspiration for creating their own…

  1. Male circumcision.

    PubMed

    2012-09-01

    Male circumcision consists of the surgical removal of some, or all, of the foreskin (or prepuce) from the penis. It is one of the most common procedures in the world. In the United States, the procedure is commonly performed during the newborn period. In 2007, the American Academy of Pediatrics (AAP) convened a multidisciplinary workgroup of AAP members and other stakeholders to evaluate the evidence regarding male circumcision and update the AAP's 1999 recommendations in this area. The Task Force included AAP representatives from specialty areas as well as members of the AAP Board of Directors and liaisons representing the American Academy of Family Physicians, the American College of Obstetricians and Gynecologists, and the Centers for Disease Control and Prevention. The Task Force members identified selected topics relevant to male circumcision and conducted a critical review of peer-reviewed literature by using the American Heart Association's template for evidence evaluation. Evaluation of current evidence indicates that the health benefits of newborn male circumcision outweigh the risks; furthermore, the benefits of newborn male circumcision justify access to this procedure for families who choose it. Specific benefits from male circumcision were identified for the prevention of urinary tract infections, acquisition of HIV, transmission of some sexually transmitted infections, and penile cancer. Male circumcision does not appear to adversely affect penile sexual function/sensitivity or sexual satisfaction. It is imperative that those providing circumcision are adequately trained and that both sterile techniques and effective pain management are used. Significant acute complications are rare. In general, untrained providers who perform circumcisions have more complications than well-trained providers who perform the procedure, regardless of whether the former are physicians, nurses, or traditional religious providers. Parents are entitled to factually correct

  2. Boltless Seal for Electronic Housings

    NASA Technical Reports Server (NTRS)

    Dawe, R. H.; Evans, J. T.

    1982-01-01

    Spring clips seal housings for electronic circuitry, preventing electromagnetic interference from entering or leaving housings. Clips also keep dust out of housing. Since no bolts are used, housing can be opened quickly; unlike bolts, clips can be used on thin-walled housing. Seal was developed for an X-band array amplifier.

  3. Metabolomic and ecdysteroid variations in Anopheles gambiae s.l. mosquitoes exposed to the stressful conditions of the dry season in Burkina Faso, West Africa.

    PubMed

    Mamai, W; Mouline, K; Blais, C; Larvor, V; Dabiré, K R; Ouedraogo, G A; Simard, F; Renault, D

    2014-01-01

    This study explored the metabolic adjustments prompted by a switch between the rainy and dry season conditions in the African malaria mosquitoes Anopheles gambiae (M and S molecular forms) and Anopheles arabiensis. Mosquitoes were reared in contrasted experimental conditions reflecting environmental variation in Burkina Faso. Thirty-five metabolites (including sugars, polyols, and amino acids) were monitored in newly emerged males and females, and their ecdysteroid titers were determined. Metabolomic signatures were remarkably similar across species, when specimens of same age and sex were reared under identical experimental conditions. In males and females, amino acids (including glycine, leucine, phenylanine, serine, threonine, and valine) were accumulated in 1-h-old mosquitoes, then decreased 24 h after emergence, probably reflecting adult maturation and the amino acid-consuming process of cuticle sclerotisation. In turn, elevated amounts of alanine and proline in 24-h-old mosquitoes may assist the development of flight ability. Lower concentration of tricarboxylic acid cycle intermediates and isoleucine characterized older females reared under dry season conditions, suggesting metabolic and reproduction depression. In all cases, ecdysteroid concentration was much higher in males than in females, with significant seasonal variation in males. This might reflect a unique role of these hormones in shaping reproductive strategies and population demography in the An. gambiae s.l. species complex, further contributing to local adaptation in a highly fluctuating environment.

  4. The Impact of Wolbachia on Virus Infection in Mosquitoes

    PubMed Central

    Johnson, Karyn N.

    2015-01-01

    Mosquito-borne viruses such as dengue, West Nile and chikungunya viruses cause significant morbidity and mortality in human populations. Since current methods are not sufficient to control disease occurrence, novel methods to control transmission of arboviruses would be beneficial. Recent studies have shown that virus infection and transmission in insects can be impeded by co-infection with the bacterium Wolbachia pipientis. Wolbachia is a maternally inherited endosymbiont that is commonly found in insects, including a number of mosquito vector species. In Drosophila, Wolbachia mediates antiviral protection against a broad range of RNA viruses. This discovery pointed to a potential strategy to interfere with mosquito transmission of arboviruses by artificially infecting mosquitoes with Wolbachia. This review outlines research on the prevalence of Wolbachia in mosquito vector species and the impact of antiviral effects in both naturally and artificially Wolbachia-infected mosquitoes. PMID:26556361

  5. Optimal control strategy of malaria vector using genetically modified mosquitoes.

    PubMed

    Rafikov, M; Bevilacqua, L; Wyse, A P P

    2009-06-07

    The development of transgenic mosquitoes that are resistant to diseases may provide a new and effective weapon of diseases control. Such an approach relies on transgenic mosquitoes being able to survive and compete with wild-type populations. These transgenic mosquitoes carry a specific code that inhibits the plasmodium evolution in its organism. It is said that this characteristic is hereditary and consequently the disease fades away after some time. Once transgenic mosquitoes are released, interactions between the two populations and inter-specific mating between the two types of mosquitoes take place. We present a mathematical model that considers the generation overlapping and variable environment factors. Based on this continuous model, the malaria vector control is formulated and solved as an optimal control problem, indicating how genetically modified mosquitoes should be introduced in the environment. Numerical simulations show the effectiveness of the proposed control.

  6. Spectral and spatial characterization of rice field mosquito habitat

    NASA Technical Reports Server (NTRS)

    Wood, Byron L.; Beck, Louisa R.; Washino, Robert K.; Palchick, Susan M.; Sebesta, Paul D.

    1991-01-01

    Irrigated rice provides an ideal breeding habitat for Anopheles free-borni, the western malaria mosquito, throughout California. In a 1985 study, it was determined that early-season rice canopy development, as monitored using remotely sensed data, could be used to distinguish between high and low mosquito producing rice fields. This distinction could be made over two months prior to peak mosquito production. It was found that high-producing fields were located in an area characterized by a diversity of land use, including livestock pastures, whereas the low-producing fields were in an area devoted almost exclusively to the cultivation of rice. The ability to distinguish between high and low mosquito producing fields prior to peak mosquito production is important in terms of mosquito habitat surveillance and control.

  7. Genetic approaches to interfere with malaria transmission by vector mosquitoes

    PubMed Central

    Wang, Sibao; Jacobs-Lorena, Marcelo

    2013-01-01

    Malaria remains one of the world’s most devastating diseases, causing over one million deaths every year. The most vulnerable stages of Plasmodium development in the vector mosquito occur in the midgut lumen, making the midgut a prime target for intervention. Mosquito transgenesis and paratransgenesis are two novel strategies that aim at rendering the vector incapable of sustaining Plasmodium development. Mosquito transgenesis involves direct genetic engineering of the mosquito itself for delivery of anti-Plasmodium effector molecules. Conversely, paratransgenesis involves the genetic modification of mosquito symbionts for expression of anti-pathogen effector molecules. Here we consider both genetic manipulation strategies for rendering mosquitoes refractory to Plasmodium infection, and discuss challenges for the translation of laboratory findings to field applications. PMID:23395485

  8. The Impact of Wolbachia on Virus Infection in Mosquitoes.

    PubMed

    Johnson, Karyn N

    2015-11-04

    Mosquito-borne viruses such as dengue, West Nile and chikungunya viruses cause significant morbidity and mortality in human populations. Since current methods are not sufficient to control disease occurrence, novel methods to control transmission of arboviruses would be beneficial. Recent studies have shown that virus infection and transmission in insects can be impeded by co-infection with the bacterium Wolbachia pipientis. Wolbachia is a maternally inherited endosymbiont that is commonly found in insects, including a number of mosquito vector species. In Drosophila, Wolbachia mediates antiviral protection against a broad range of RNA viruses. This discovery pointed to a potential strategy to interfere with mosquito transmission of arboviruses by artificially infecting mosquitoes with Wolbachia. This review outlines research on the prevalence of Wolbachia in mosquito vector species and the impact of antiviral effects in both naturally and artificially Wolbachia-infected mosquitoes.

  9. Genetic approaches to interfere with malaria transmission by vector mosquitoes.

    PubMed

    Wang, Sibao; Jacobs-Lorena, Marcelo

    2013-03-01

    Malaria remains one of the most devastating diseases worldwide, causing over 1 million deaths every year. The most vulnerable stages of Plasmodium development in the vector mosquito occur in the midgut lumen, making the midgut a prime target for intervention. Mosquito transgenesis and paratransgenesis are two novel strategies that aim at rendering the vector incapable of sustaining Plasmodium development. Mosquito transgenesis involves direct genetic engineering of the mosquito itself for delivery of anti-Plasmodium effector molecules. Conversely, paratransgenesis involves the genetic modification of mosquito symbionts for expression of anti-pathogen effector molecules. Here we consider both genetic manipulation strategies for rendering mosquitoes refractory to Plasmodium infection, and discuss challenges for the translation of laboratory findings to field applications.

  10. Bacterial associations reveal spatial population dynamics in Anopheles gambiae mosquitoes

    PubMed Central

    Buck, Moritz; Nilsson, Louise K. J.; Brunius, Carl; Dabiré, Roch K.; Hopkins, Richard; Terenius, Olle

    2016-01-01

    The intolerable burden of malaria has for too long plagued humanity and the prospect of eradicating malaria is an optimistic, but reachable, target in the 21st century. However, extensive knowledge is needed about the spatial structure of mosquito populations in order to develop effective interventions against malaria transmission. We hypothesized that the microbiota associated with a mosquito reflects acquisition of bacteria in different environments. By analyzing the whole-body bacterial flora of An. gambiae mosquitoes from Burkina Faso by 16 S amplicon sequencing, we found that the different environments gave each mosquito a specific bacterial profile. In addition, the bacterial profiles provided precise and predicting information on the spatial dynamics of the mosquito population as a whole and showed that the mosquitoes formed clear local populations within a meta-population network. We believe that using microbiotas as proxies for population structures will greatly aid improving the performance of vector interventions around the world. PMID:26960555

  11. Dissecting vectorial capacity for mosquito-borne viruses.

    PubMed

    Kramer, Laura D; Ciota, Alexander T

    2015-12-01

    The inter-relationship between mosquitoes and the viruses they transmit is complex. While previously understood barriers to infection and transmission remain valid, additional factors have been uncovered that suggest an 'arms race' between mosquito and virus. These include the mosquito microbiota and interplay between mosquito and viral genetics. Following an infectious blood meal, the mosquito mounts an immune and transcriptional response, leading to altered expression of multiple genes. These complex interactions, specific to vector and virus genotypes, combine with external influences, particularly temperature, to determine vector competence. The mosquito's response to the infecting agent may have consequences in terms of longevity, feeding behavior and/or fecundity. These factors, together with population density and the frequency of host contact determine vectorial capacity.

  12. Housing Survey. Campus Housing: Finding the Balance

    ERIC Educational Resources Information Center

    O'Connor, Shannon

    2016-01-01

    Depending on where you look for statistics, the number of students enrolling in colleges or universities is increasing, decreasing or remaining the about the same. Regardless of those trends, campus housing is a marketing tool for institutions looking to draw students to and keep them on campus. Schools need to offer sufficient beds and…

  13. Mosquito-borne viruses in Europe.

    PubMed

    Hubálek, Zdenek

    2008-12-01

    The number of mosquito-borne viruses ('moboviruses') occurring in Europe since the twentieth century now stands at ten; they belong to three families-Togaviridae (Sindbis, Chikungunya), Flaviviridae (West Nile, Usutu, Dengue), and Bunyaviridae (Batai, Tahyna, Snowshoe hare, Inkoo, Lednice). Several of them play a definite role in human or animal pathology (Sindbis, Chikungunya, Dengue, West Nile, Tahyna). Mobovirus outbreaks are strictly determined by the presence and/or import of particular competent vectors of the disease. Ecological variables affect moboviruses considerably; the main factors are population density of mosquito vectors and their vertebrate hosts, intense summer precipitations or floods, summer temperatures and drought, and presence of appropriate habitats, e.g., wetlands, small water pools, or intravillan sewage systems. A surveillance for moboviruses and the diseases they cause in Europe is recommendable, because the cases may often pass unnoticed or misdiagnosed not only in free-living vertebrates but also in domestic animals and even in humans.

  14. 1. HOUSE, VIEW TO NORTHEAST, SUMMER KITCHEN AND SMOKE HOUSE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. HOUSE, VIEW TO NORTHEAST, SUMMER KITCHEN AND SMOKE HOUSE ARE IN THE BACKGROUND - Kiel Farmstead, House, East side State Route 4, one half mile south of U.S. Route 64, Mascoutah, St. Clair County, IL

  15. Oviposition-Modifying Substances for Mosquitoes.

    DTIC Science & Technology

    1979-09-01

    high degree of pre- ference in selecting specific oviposition sites in the general area of their breeding sources. This preference may be due to the...7 -Ai5 419 OVIPOSITION -MODIFYING SUBSTANCES FOR MOSQUITOES(U) /7, CALIFORNIA UNIV RIVERSIDE DEPT OF ENTOMOLOGY Y HWANGICLRSFE 91 SEP 79 DAMD7-?9-C...9026 FO63 N - . L’. ! 1111112. MICROCOPY RESOLUTION TESr CHART NATIONAt BURAU Of S1ANDARDS 196J A -17 * 0) AD __ OVIPOSITION -MODIFYING SUBSTANCES FOR

  16. Pathogenesis of Dengue Vaccine Viruses in Mosquitoes.

    DTIC Science & Technology

    1985-07-01

    small percentage of engorging mosquitoes became infected. To determine if Fc receptors might be a determinate of virus infection of midgut cells, blood...somehow alter glycoprotein conformation rendering the virus less capable of interacting with midgut cell receptors , 2) virus in cells might be protected...virus preparations are known to be much less efficient than a viresic host in mediating midgut infection. The artificial meal must be several logs

  17. Changes in local mosquito fauna following beaver (Castor canadensis) activity--an update.

    PubMed

    Butts, W L

    1992-09-01

    Drastic reduction of populations of univoltine temporary pool mosquitoes followed impoundment of breeding areas by beavers. Mosquito populations persist at very low levels over a 10-year period with no evidence of mosquito development in the impoundment.

  18. [Highest mosquito records (Diptera: Culicidae) in Venezuela].

    PubMed

    Navarro, Juan-Carlos; Del Ventura, Fabiola; Zorrilla, Adriana; Liria, Jonathan

    2010-03-01

    Mosquitoes (Diptera: Culicidae) are holometabolous insects with aquatic immature stages, which use a broad variety of larval habitats, from ground water bodies to Phytothelmata (water deposits in plants) and artificial deposits. The availability of breeding sites often determines the upper limits of mosquito ranges. We built a database with 9,607 records with 432 localities, 19 genera and 254 species. The Andean mountains have 77% of the highest mosquito records including Aedes euris with record at 3,133 m, followed by three species of Anopheles--subgenera Kerteszia--with the upper limit of 2,680 m. Wyeomyia bicornis and Culex daumastocampa at 2,550 m were the highest records in the Central-Coastal cordillera, while the highest record in Pantepui was Wyeomyia zinzala at 2,252 m. The species associated with phytothelmata (Bromeliaceae and Sarraceniaceae) represent 60% of the records. The upper limits of Culex quinquefasciatus and Anopheles (Kerteszia) species could represent the theoretical limit for transmission of filariasis or arboviruses, by Culex, and malaria by Anopheles (Kerteszia) in Venezuela. Similarly, a vector of Dengue, Aedes aegypti, has not been not recorded above 2,000 m.

  19. Can we get AIDS from mosquito bites?

    PubMed

    Iqbal, M M

    1999-08-01

    Human immunodeficiency virus, or HIV, is a human retrovirus that infects lymphocytes and other cells bearing the CD4 surface marker. The virus is transmitted primarily by sexual and parental routes. There are two ways blood feeding arthropods can spread disease, mechanically, by simple transfer of virus between hosts by contaminated mouth parts, or, biologically, which would require virus replication in arthropod tissues (especially salivary glands). There are some important factors which have proven that AIDS is not transmitted by mosquito bite. These factors are: (1) AIDS virus can not replicate inside the mosquito, bed bug, flea, or other blood sucking insect and the lack of replication of HIV in arthropod cells due to lack of T4 antigen on cell surface, and (2) it is unlikely that HIV is transmitted by insects, given the low infectivity of HIV and the short survival of the virus in the mosquito. HIV appears to be much less easily transmitted probably due to lower titers of virus in body fluids. So, on the basis of experimental evidence and probability estimates, it has been concluded that the likelihood of mechanical or biological transmission of HIV by insects is virtually nonexistent.

  20. Forkhead transcription factors regulate mosquito reproduction

    PubMed Central

    Hansen, Immo A.; Sieglaff, Douglas H.; Munro, James B.; Shiao, Shin-Hong; Cruz, Josefa; Lee, Iris W.; Heraty, John M.; Raikhel, Alexander S.

    2007-01-01

    Forkhead box (Fox) genes encode a family of transcription factors defined by a ‘winged helix’ DNA-binding domain. In this study we aimed to identify Fox factors that are expressed within the fat body of the yellow fever mosquito Aedes aegypti, and determine whether any of these are involved in the regulation of mosquito yolk protein gene expression. The Ae. aegypti genome contains eighteen loci that encode putative Fox factors. Our stringent cladistic analysis has profound implications for the use of Fox genes as phylogenetic markers. Twelve Ae. aegypti Fox genes are expressed within various tissues of adult females, six of which are expressed within the fat body. All six Fox genes expressed in the fat body displayed dynamic expression profiles following a blood meal. We knocked down the ’fat body Foxes’ through RNAi to determine whether these “knockdowns” hindered amino acid-induced vitellogenin gene expression. We also determined the effect of these knockdowns on the number of eggs deposited following a blood meal. Knockdown of FoxN1, FoxN2, FoxL, and FoxO, had a negative effect on amino acid- induced vitellogenin gene expression and resulted in significantly fewer eggs laid. Our analysis stresses the importance of Fox transcription factors in regulating mosquito reproduction. PMID:17681238

  1. Species composition and habitat characterization of mosquito (Diptera: Culicidae) larvae in semi-urban areas of Dhaka, Bangladesh.

    PubMed

    Bashar, Kabirul; Rahman, Md Sayfur; Nodi, Ila Jahan; Howlader, Abdul Jabber

    2016-03-01

    Mosquito larvae are purely aquatic and develop in water bodies, the type of which is more or less specific to each species. Therefore, a study was carried out to identify the habitat characters of different mosquito species along with their species composition in semi-urban area of Dhaka in Bangladesh during the month of May and June 2012. A total of 6088 mosquito larvae belonging to 12 species (Aedes aegypti, Aedes albopictus, Anopheles barbirostris, Anopheles peditaeniatus, Anopheles vagus, Culex gelidus, Culex hutchinsoni, Culex quinquefasciatus, Culex tritaeniorhynchus, Mansonia annulifera, Mansonia uniformis, and Toxorhynchites splendens) under 5 genera were collected from 14 different types of habitats. Culex quinquefsciatus was the dominant (21.7/500 ml) species followed by Cx. tritaeniorhynchus (10.53/500 ml). Dissolved oxygen and chlorophyll a were the preeminent predictors for the abundance of all collected mosquito larvae except Ae. aegypti. Water temperature was positively associated with the breeding of An. vagus (r = 0.421, p = <0.001), An. barbirostris (r = 0.489, p = <0.001) and An. peditaeniatus (r = 0.375, p = <0.001). Water depth, distance from nearest house, emergent plant coverage, and alkalinity were found as the basis of larval abundance. Every Culex species and Tx. splendens (r = 0.359, p = 0.001) were found positively associated with chemical oxygen demand, while Mn. annulifera showed negative association (r = -0.115, p = 0.0297). This study also highlighted that various physicochemical factors affect the presence or abundance of mosquito larvae.

  2. Species composition and habitat characterization of mosquito (Diptera: Culicidae) larvae in semi-urban areas of Dhaka, Bangladesh

    PubMed Central

    Bashar, Kabirul; Rahman, Md. Sayfur; Nodi, Ila Jahan; Howlader, Abdul Jabber

    2016-01-01

    Mosquito larvae are purely aquatic and develop in water bodies, the type of which is more or less specific to each species. Therefore, a study was carried out to identify the habitat characters of different mosquito species along with their species composition in semi-urban area of Dhaka in Bangladesh during the month of May and June 2012. A total of 6088 mosquito larvae belonging to 12 species (Aedes aegypti, Aedes albopictus, Anopheles barbirostris, Anopheles peditaeniatus, Anopheles vagus, Culex gelidus, Culex hutchinsoni, Culex quinquefasciatus, Culex tritaeniorhynchus, Mansonia annulifera, Mansonia uniformis, and Toxorhynchites splendens) under 5 genera were collected from 14 different types of habitats. Culex quinquefsciatus was the dominant (21.7/500 ml) species followed by Cx. tritaeniorhynchus (10.53/500 ml). Dissolved oxygen and chlorophyll a were the preeminent predictors for the abundance of all collected mosquito larvae except Ae. aegypti. Water temperature was positively associated with the breeding of An. vagus (r = 0.421, p = <0.001), An. barbirostris (r = 0.489, p = <0.001) and An. peditaeniatus (r = 0.375, p = <0.001). Water depth, distance from nearest house, emergent plant coverage, and alkalinity were found as the basis of larval abundance. Every Culex species and Tx. splendens (r = 0.359, p = 0.001) were found positively associated with chemical oxygen demand, while Mn. annulifera showed negative association (r = −0.115, p = 0.0297). This study also highlighted that various physicochemical factors affect the presence or abundance of mosquito larvae. PMID:27241953

  3. The roles of mosquito and bird communities on the prevalence of West Nile virus in urban wetland and residential habitats.

    PubMed

    Johnson, Brian J; Munafo, Kristin; Shappell, Laura; Tsipoura, Nellie; Robson, Mark; Ehrenfeld, Joan; Sukhdeo, Michael V K

    2012-09-01

    This study investigated the impacts of urban wetlands and their adjacent residential environments on the transmission dynamics of West Nile virus (WNV) within the state of New Jersey (USA). A working hypothesis was that urban wetlands decrease the local prevalence of WNV through the dilution effect from increased bird diversity, and through relative reductions in the numbers of competent avian host and mosquito species commonly associated with WNV. Surveys of mosquito and bird communities were undertaken at six urban wetlands and their adjacent residential environments over two seasons (2009, 2010). The community compositions of both avian and mosquito species differed significantly across habitats, and over relatively short geographical distances. Residential areas contained significantly higher proportions of WNV-competent mosquito species (31.25±5.3 %; e.g. Culex pipiens and Culex restuans), and WNV-competent avian host species (62.8±2.3 %, e.g. House Sparrow and American Robin) when compared to adjacent urban wetlands (13.5±2.1 %; 35.4±2.1 % respectively). Correspondingly, WNV infection rates within local Culex spp. populations indicate that WNV was more prevalent within residential areas (28.53/1000) compared to wetlands (16.77/1000). Large urban wetlands (>100 ha) produced significantly lower weekly WNV infection rates in local Culex spp. (6.67±2.84/1000) compared to small (<15 ha) wet-lands (22.57±6.23/1000). Avian species richness was also influenced by patch size. Large urban wetlands contained significantly more species than small wetland patches. These results confirm that the community compositions of mosquito and avian hosts are important drivers in WNV infections, and that the ecological conditions that favor transmission are more strongly associated with urban residential environments than with adjacent urban wetlands.

  4. The roles of mosquito and bird communities on the prevalence of West Nile virus in urban wetland and residential habitats

    PubMed Central

    Johnson, Brian J.; Munafo, Kristin; Shappell, Laura; Tsipoura, Nellie; Robson, Mark; Ehrenfeld, Joan; Sukhdeo, Michael V. K.

    2014-01-01

    This study investigated the impacts of urban wetlands and their adjacent residential environments on the transmission dynamics of West Nile virus (WNV) within the state of New Jersey (USA). A working hypothesis was that urban wetlands decrease the local prevalence of WNV through the dilution effect from increased bird diversity, and through relative reductions in the numbers of competent avian host and mosquito species commonly associated with WNV. Surveys of mosquito and bird communities were undertaken at six urban wetlands and their adjacent residential environments over two seasons (2009, 2010). The community compositions of both avian and mosquito species differed significantly across habitats, and over relatively short geographical distances. Residential areas contained significantly higher proportions of WNV-competent mosquito species (31.25±5.3 %; e.g. Culex pipiens and Culex restuans), and WNV-competent avian host species (62.8±2.3 %, e.g. House Sparrow and American Robin) when compared to adjacent urban wetlands (13.5±2.1 %; 35.4±2.1 % respectively). Correspondingly, WNV infection rates within local Culex spp. populations indicate that WNV was more prevalent within residential areas (28.53/1000) compared to wetlands (16.77/1000). Large urban wetlands (>100 ha) produced significantly lower weekly WNV infection rates in local Culex spp. (6.67±2.84/1000) compared to small (<15 ha) wet-lands (22.57±6.23/1000). Avian species richness was also influenced by patch size. Large urban wetlands contained significantly more species than small wetland patches. These results confirm that the community compositions of mosquito and avian hosts are important drivers in WNV infections, and that the ecological conditions that favor transmission are more strongly associated with urban residential environments than with adjacent urban wetlands. PMID:25484570

  5. Mosquito Records from Mexico: The Mosquitoes (Diptera: Culicidae) of Tamaulipas State.

    PubMed

    Ortega-Morales, Aldo I; Zavortink, Thomas J; Huerta-Jiménez, Herón; Sánchez-Rámos, Francisco J; Valdés-Perezgasga, Ma Teresa; Reyes-Villanueva, Filiberto; Siller-Rodríguez, Quetzaly K; Fernandez-Salas, Ildefonso

    2015-03-01

    To document the diversity and distribution of mosquito species inhabiting the Mexican state of Tamaulipas, collection trips were conducted to all physiographic regions (Grand Northamerican Plains, Coastal Plain of North Gulf, and Sierra Madre Oriental) and subregions across the state. Additionally, we re-examined mosquito specimens in two Mexican entomological collections: the Collection of Insects and Mites of Medical Importance and the Collection of Arthropods of Medical Importance. In total, 3,931 specimens were collected. These represent the two Culicidae subfamilies Anophelinae and Culicinae, 10 tribes, 17 genera, 27 subgenera, 80 named species, and 2 undescribed species. Of these, 3 tribes, 6 genera, 7 subgenera, and 20 species are new records for the mosquito fauna of Tamaulipas. Fourteen species recorded in the historical records were not found in collections made for this study. Taxonomic notes, new distribution limits, and comments about the medical importance of some of the species collected are reported.

  6. DsRed2 transient expression in Culex quinquefasciatus mosquitoes.

    PubMed

    Wilke, André Barretto Bruno; Scaife, Sarah; Alphey, Luke; Marrelli, Mauro Toledo

    2013-06-01

    Culex quinquefasciatus mosquitoes have been successfully genetically modified only once, despite the efforts of several laboratories to transform and establish a stable strain. We have developed a transient gene expression method, in Culex, that delivers plasmid DNA directly to the mosquito haemolymph and additional tissues. We were able to express DsRed2 fluorescent protein in adult Cx. quinquefasciatus mosquitoes by injecting plasmids directly into their thorax. The expression of DsRed2 in adult Cx. quinquefasciatus mosquitoes is an important stepping stone to genetic transformation and the potential use of new control strategies and genetic interactions.

  7. Vector competence of Anopheles and Culex mosquitoes for Zika virus.

    PubMed

    Dodson, Brittany L; Rasgon, Jason L

    2017-01-01

    Zika virus is a newly emergent mosquito-borne flavivirus that has caused recent large outbreaks in the new world, leading to dramatic increases in serious disease pathology including Guillain-Barre syndrome, newborn microcephaly, and infant brain damage. Although Aedes mosquitoes are thought to be the primary mosquito species driving infection, the virus has been isolated from dozens of mosquito species, including Culex and Anopheles species, and we lack a thorough understanding of which mosquito species to target for vector control. We exposed Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes to blood meals supplemented with two Zika virus strains. Mosquito bodies, legs, and saliva were collected five, seven, and 14 days post blood meal and tested for infectious virus by plaque assay. Regardless of titer, virus strain, or timepoint, Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes were refractory to Zika virus infection. We conclude that Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes likely do not contribute significantly to Zika virus transmission to humans. However, future studies should continue to explore the potential for other novel potential vectors to transmit the virus.

  8. Vector competence of Anopheles and Culex mosquitoes for Zika virus

    PubMed Central

    Dodson, Brittany L.

    2017-01-01

    Zika virus is a newly emergent mosquito-borne flavivirus that has caused recent large outbreaks in the new world, leading to dramatic increases in serious disease pathology including Guillain-Barre syndrome, newborn microcephaly, and infant brain damage. Although Aedes mosquitoes are thought to be the primary mosquito species driving infection, the virus has been isolated from dozens of mosquito species, including Culex and Anopheles species, and we lack a thorough understanding of which mosquito species to target for vector control. We exposed Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes to blood meals supplemented with two Zika virus strains. Mosquito bodies, legs, and saliva were collected five, seven, and 14 days post blood meal and tested for infectious virus by plaque assay. Regardless of titer, virus strain, or timepoint, Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes were refractory to Zika virus infection. We conclude that Anopheles gambiae, Anopheles stephensi, and Culex quinquefasciatus mosquitoes likely do not contribute significantly to Zika virus transmission to humans. However, future studies should continue to explore the potential for other novel potential vectors to transmit the virus. PMID:28316896

  9. Beer Consumption Increases Human Attractiveness to Malaria Mosquitoes

    PubMed Central

    Lefèvre, Thierry; Gouagna, Louis-Clément; Dabiré, Kounbobr Roch; Elguero, Eric; Fontenille, Didier; Renaud, François; Costantini, Carlo; Thomas, Frédéric

    2010-01-01

    Background Malaria and alcohol consumption both represent major public health problems. Alcohol consumption is rising in developing countries and, as efforts to manage malaria are expanded, understanding the links between malaria and alcohol consumption becomes crucial. Our aim was to ascertain the effect of beer consumption on human attractiveness to malaria mosquitoes in semi field conditions in Burkina Faso. Methodology/Principal Findings We used a Y tube-olfactometer designed to take advantage of the whole body odour (breath and skin emanations) as a stimulus to gauge human attractiveness to Anopheles gambiae (the primary African malaria vector) before and after volunteers consumed either beer (n = 25 volunteers and a total of 2500 mosquitoes tested) or water (n = 18 volunteers and a total of 1800 mosquitoes). Water consumption had no effect on human attractiveness to An. gambiae mosquitoes, but beer consumption increased volunteer attractiveness. Body odours of volunteers who consumed beer increased mosquito activation (proportion of mosquitoes engaging in take-off and up-wind flight) and orientation (proportion of mosquitoes flying towards volunteers' odours). The level of exhaled carbon dioxide and body temperature had no effect on human attractiveness to mosquitoes. Despite individual volunteer variation, beer consumption consistently increased attractiveness to mosquitoes. Conclusions/Significance These results suggest that beer consumption is a risk factor for malaria and needs to be integrated into public health policies for the design of control measures. PMID:20209056

  10. The Plasmodium bottleneck: malaria parasite losses in the mosquito vector

    PubMed Central

    Smith, Ryan C; Vega-Rodríguez, Joel; Jacobs-Lorena, Marcelo

    2014-01-01

    Nearly one million people are killed every year by the malaria parasite Plasmodium. Although the disease-causing forms of the parasite exist only in the human blood, mosquitoes of the genus Anopheles are the obligate vector for transmission. Here, we review the parasite life cycle in the vector and highlight the human and mosquito contributions that limit malaria parasite development in the mosquito host. We address parasite killing in its mosquito host and bottlenecks in parasite numbers that might guide intervention strategies to prevent transmission. PMID:25185005

  11. Isolation of Jamestown Canyon virus from boreal Aedes mosquitoes from the Sierra Nevada of California.

    PubMed

    Campbell, G L; Eldridge, B F; Reeves, W C; Hardy, J L

    1991-03-01

    More than 28,000 mosquitoes in four genera were collected from high elevation (greater than or equal to 1,000 m) areas of California during 1988-89 and tested for virus by plaque assay in Vero cells. Viruses were serogrouped by enzyme immunoassay and serotyped by cross-neutralization. Six strains of Jamestown Canyon virus in the California serogroup were isolated from three species of boreal Aedes in the Aedes communis group of the subgenus Ochlerotatus. All isolates were from mosquitoes collected in Alpine County at approximately 2,300 m elevation in the Sierra Nevada. These included one virus from a pool of male Aedes cataphylla collected in immature stages, which is evidence for vertical transmission; four viruses from adult female Ae. communis (sens. lat.); and one virus from adult female Aedes hexodontus. These are the first isolations of viruses from boreal Aedes mosquitoes in California and the first reported isolations of Jamestown Canyon virus from Ae. cataphylla or Ae. hexodontus.

  12. Housing And Mounting Structure

    DOEpatents

    Anderson, Gene R.; Armendariz, Marcelino G.; Baca, Johnny R.F.; Bryan, Robert P.; Carson, Richard F.; Duckett, III, Edwin B.; McCormick, Frederick B.; Miller, Gregory V.; Peterson, David W.; Smith, Terrance T.

    2005-03-08

    This invention relates to an optical transmitter, receiver or transceiver module, and more particularly, to an apparatus for connecting a first optical connector to a second optical connector. The apparatus comprises: (1) a housing having at least a first end and at least a second end, the first end of the housing capable of receiving the first optical connector, and the second end of the housing capable of receiving the second optical connector; (2) a longitudinal cavity extending from the first end of the housing to the second end of the housing; and (3) an electromagnetic shield comprising at least a portion of the housing. This invention also relates to an apparatus for housing a flexible printed circuit board, and this apparatus comprises: (1) a mounting structure having at least a first surface and a second surface; (2) alignment ridges along the first and second surfaces of the mounting structure, the alignment ridges functioning to align and secure a flexible printed circuit board that is wrapped around and attached to the first and second surfaces of the mounting structure; and (3) a series of heat sink ridges adapted to the mounting structure, the heat sink ridges functioning to dissipate heat that is generated from the flexible printed circuit board.

  13. Mosquito (Aedes aegypti) flight tones: Frequency, harmonicity, spherical spreading, and phase relationships

    PubMed Central

    Arthur, Benjamin J.; Emr, Kevin S.; Wyttenbach, Robert A.; Hoy, Ronald R.

    2014-01-01

    Mosquito flight produces a tone as a side effect of wing movement; this tone is also a communication signal that is frequency-modulated during courtship. Recordings of tones produced by tethered flying male and female Aedes aegypti were undertaken using pairs of pressure-gradient microphones above and below, ahead and behind, and to the left and right over a range of distances. Fundamental frequencies were close to those previously reported, although amplitudes were lower. The male fundamental frequency was higher than that of the female and males modulated it over a wider range. Analysis of harmonics shows that the first six partials were nearly always within 1 Hz of integer multiples of the fundamental, even when the fundamental was being modulated. Along the front-back axis, amplitude attenuated as a function of distance raised to the power 2.3. Front and back recordings were out of phase, as were above and below, while left and right were in phase. Recordings from ahead and behind showed quadratic phase coupling, while others did not. Finally, two methods are presented for separating simultaneous flight tones in a single recording and enhancing their frequency resolution. Implications for mosquito behavior are discussed. PMID:25234901

  14. Universal design in housing.

    PubMed

    Mace, R L

    1998-01-01

    Universal design in housing is a growing and beneficial concept. It is subtle in its differences from barrier-free, accessible, and industry standard housing. Accessibility standards and codes have not mandated universal design and do not apply to most housing. Universal design exceeds their minimum specifications for accessible design and results in homes that are usable by and marketable to almost everyone. Universal homes avoid use of special assistive technology devices and, instead, incorporate consumer products and design features that are easily usable and commonly available.

  15. Household-Level Expenditure on Protective Measures Against Mosquitoes on the Island of La Réunion, France

    PubMed Central

    Thuilliez, Josselin; Bellia, Claire; Dehecq, Jean-Sébastien; Reilhes, Olivier

    2014-01-01

    Background For decades La Réunion has experienced a number of epidemics that have resulted in efforts to control the density of Aedes species on this Island. This study was conducted to assess household-level expenditure on protective measures against mosquito nuisance on the Island of La Réunion in 2012. Methodology/Principal Findings Data was collected during a cross-sectional survey of 1024 households and used to determine the relationship between the use of chemically-based protective measures and subjective and objective indicators of the density of Aedes albopictus. The average household expenditure in July 2012 was USD 9.86 and the total household-level expenditure over a one-year period was extrapolated to USD 28.05million (range: USD 25.58 million to USD 30.76 million). Much of this money was spent on measures thought to be relatively ineffective against Aedes mosquitoes. Expenditure on protective measures was not influenced by the level of knowledge on mosquitoes or by the visual nuisance they generated at home, but rather by the perception of risk related to a future epidemic of chikungunya and socioeconomic factors. Most importantly, household spending on protective measures was found to be influenced by a measure of zone-level mosquito density (the Breteau index), but not by objective indicators of the presence of mosquitoes within or around the house. Conclusions/Significance Household-level expenditure on chemically-based protective measures is high when compared to the investment made by public entities to achieve vector control, and it is differentially influenced by subjective and objective measures of mosquito density. The current situation could be improved, firstly by ensuring that the public is well-informed about mosquitoes and the effectiveness of various protective measures, and secondly by implementing interventions that could either complement current vector-control strategies and improve their effectiveness on a country-level, or that

  16. [The recurring necessity of mosquito surveillance and research].

    PubMed

    Kampen, Helge; Werner, Doreen

    2015-10-01

    Hematophagous arthropods and the diseases associated with them represent a growing threat to human and animal health in Europe. After the eradication of endemic malaria from Europe in the middle of the last century, there has been a resurgence of mosquitoes as significant vectors of disease agents under the influence of continuing globalisation, as exotic species and mosquito-borne pathogens are being introduced with increasing frequency. At present, southern Europe is particularly affected by disease outbreaks and cases, but invasive mosquito species, including efficient vectors, have also emerged in Germany. While there is considerable knowledge on the vector potential of many tropical and subtropical mosquito species, corresponding data on the indigenous mosquito species are scarce. Exceptions are the Anopheles species, which were already vectors of malaria parasites in historic Europe. It must be assumed, however, that many further indigenous species are able to transmit pathogens under certain conditions and will by all means gain vector competence under a scenario of climate warming. Thus, the permanent surveillance of mosquitoes and mosquito-borne disease agents is paramount for the purposes of conducting risk analyses and modelling, in addition to research work addressing the conditions of the spread of vectors and pathogens and of pathogen transmission. Only ample data can facilitate taking appropriate prophylactic action and designing control strategies. International health organizations have realised this and started to promote data collection on mosquitoes and mosquito-borne diseases in the EU. At a national levels, authorities are more reluctant, although, similar to other fields of health, it has been shown for mosquito-borne diseases that preventive measures are more cost-saving than disease case management and the coverage of follow-up costs. The present article is intended to illustrate the necessity of the re-intensification of mosquito

  17. [Male contraception].

    PubMed

    Demery, A

    1987-05-01

    Except for condoms, male contraception is very slightly utilized in France. Several male experimental methods are under study. A synthetic luteinizing hormone-releasing hormone (LHRH) analog has been used successfully in women and offers promise in men of blocking LHRH and thus blocking spermatogenesis. Several nonsteroid substances such an hypertensives and adrenaline would suppress follicle stimulating hormone and luteinizing hormone release, but are too toxic for use. The combination of 40 mcg ethinyl estradiol and 20 mg of methyltestosterone inhibits gonadotropin release and produces azoospermia in men, but at the risk of loss of libido, constant gynecomastia, and testicular atrophy. Several combinations of androgens and progestins have been evaluated. Percutaneous testosterone and medroxyprogesterone acetate appears to be the most effective, with good metabolic tolerance and maintenance of libido and sexual performance. Injections of inhibine, a testicular factor that controls secretion of follicle stimulating hormone by feedback, offer promise of suppressing spermatogenesis without affecting other systems. Numerous substances are known to inhibit spermatogenesis but are to toxic for use or entail an unacceptable loss of libido. Gossypol has been employed as a contraceptive by the Chinese for its action in inhibiting protein synthesis, but it is known to have serious secondary effects. Among male methods currently in use, the condom had a Pearl index of .4-1.6 in the most recent British studies. Coitus interruptus can seriously interfere with sexual pleasure and has a failure rate of 25-30%. Vasectomy is safe, effective, and easy to perform, but is not a reversible method. The combination of 20 mg of medroxyprogesterone acetate in 2 daily doses and 100 mg of testosterone applied in an abdominal spray has given very promising results in 2 small studies in France and merits further development and diffusion.

  18. Mitochondrial ATP synthase is dispensable in blood-stage Plasmodium berghei rodent malaria but essential in the mosquito phase

    PubMed Central

    Sturm, Angelika; Mollard, Vanessa; Cozijnsen, Anton; Goodman, Christopher D.; McFadden, Geoffrey I.

    2015-01-01

    Mitochondrial ATP synthase is driven by chemiosmotic oxidation of pyruvate derived from glycolysis. Blood-stage malaria parasites eschew chemiosmosis, instead relying almost solely on glycolysis for their ATP generation, which begs the question of whether mitochondrial ATP synthase is necessary during the blood stage of the parasite life cycle. We knocked out the mitochondrial ATP synthase β subunit gene in the rodent malaria parasite, Plasmodium berghei, ablating the protein that converts ADP to ATP. Disruption of the β subunit gene of the ATP synthase only marginally reduced asexual blood-stage parasite growth but completely blocked mouse-to-mouse transmission via Anopheles stephensi mosquitoes. Parasites lacking the β subunit gene of the ATP synthase generated viable gametes that fuse and form ookinetes but cannot progress beyond this stage. Ookinetes lacking the β subunit gene of the ATP synthase had normal motility but were not viable in the mosquito midgut and never made oocysts or sporozoites, thereby abrogating transmission to naive mice via mosquito bite. We crossed the self-infertile ATP synthase β subunit knockout parasites with a male-deficient, self-infertile strain of P. berghei, which restored fertility and production of oocysts and sporozoites, which demonstrates that mitochondrial ATP synthase is essential for ongoing viability through the female, mitochondrion-carrying line of sexual reproduction in P. berghei malaria. Perturbation of ATP synthase completely blocks transmission to the mosquito vector and could potentially be targeted for disease control. PMID:25831536

  19. Diversity of Cultivable Midgut Microbiota at Different Stages of the Asian Tiger Mosquito, Aedes albopictus from Tezpur, India.

    PubMed

    Yadav, Kamlesh K; Datta, Sibnarayan; Naglot, Ashok; Bora, Ajitabh; Hmuaka, Vanlal; Bhagyawant, Sameer; Gogoi, Hemanta K; Veer, Vijay; Raju, P Srinivas

    2016-01-01

    Aedes aegypti and Ae. albopictus are among the most important vectors of arboviral diseases, worldwide. Recent studies indicate that diverse midgut microbiota of mosquitoes significantly affect development, digestion, metabolism, and immunity of their hosts. Midgut microbiota has also been suggested to modulate the competency of mosquitoes to transmit arboviruses, malaria parasites etc. Interestingly, the midgut microbial flora is dynamic and the diversity changes with the development of vectors, in addition to other factors such as species, sex, life-stage, feeding behavior and geographical origin. The aim of the present study was to investigate the midgut bacterial diversity among larva, adult male, sugar fed female and blood fed female Ae. albopictus collected from Tezpur, Northeastern India. Based on colony morphological characteristics, we selected 113 cultivable bacterial isolates for 16S rRNA gene sequence based molecular identification. Of the 113 isolates, we could identify 35 bacterial species belonging to 18 distinct genera under four major phyla, namely Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes. Phyla Proteobacteria and Firmicutes accounted for majority (80%) of the species, while phylum Actinobacteria constituted 17% of the species. Bacteroidetes was the least represented phylum, characterized by a single species- Chryseobacterium rhizoplanae, isolated from blood fed individuals. Dissection of midgut microbiota diversity at different developmental stages of Ae. albopictus will be helpful in better understanding mosquito-borne diseases, and for designing effective strategies to manage mosquito-borne diseases.

  20. Swarming mechanisms in the yellow fever mosquito: aggregation pheromones are involved in the mating behavior of Aedes aegypti.

    PubMed

    Fawaz, Emadeldin Y; Allan, Sandra A; Bernier, Ulrich R; Obenauer, Peter J; Diclaro, Joseph W

    2014-12-01

    Mosquitoes of various species mate in swarms comprised of tens of thousands of flying males. In this study, we examined Aedes aegypti swarming behavior and identified associated chemical cues. Novel evidence is provided that Ae. aegypti females aggregate by means of olfactory cues, such as aggregation pheromones. Isolation of Ae. aegypti aggregation pheromones was achieved by aeration of confined mosquitoes and collection of associated volatiles by glass filters. The collected volatiles were identified through gas chromatography mass spectrometry (GCMS). Three aggregation pheromones were collected and identified as 2,6,6-trimethylcyclohex-2-ene-1,4-dione (ketoisophorone) (CAS# 1125-21-9, t(R) = 18.75), 2,2,6-trimethylcyclohexane-1,4-dione (the saturated analog of ketoisophorone) (CAS# 20547-99-3, t(R) = 20.05), and 1-(4-ethylphenyl) ethanone (CAS# 937-30-4, t(R) = 24.22). Our biological studies revealed that the identified compounds stimulated mosquito behavior under laboratory conditions. The mechanism of mosquito swarm formation is discussed in light of our behavioral study findings. A preliminary field trial demonstrated the potential application of the isolated aggregation pheromones in controlling Ae. aegypti.

  1. Diversity of Cultivable Midgut Microbiota at Different Stages of the Asian Tiger Mosquito, Aedes albopictus from Tezpur, India

    PubMed Central

    Datta, Sibnarayan; Naglot, Ashok; Bora, Ajitabh; Hmuaka, Vanlal; Bhagyawant, Sameer; Gogoi, Hemanta K.; Veer, Vijay; Raju, P. Srinivas

    2016-01-01

    Aedes aegypti and Ae. albopictus are among the most important vectors of arboviral diseases, worldwide. Recent studies indicate that diverse midgut microbiota of mosquitoes significantly affect development, digestion, metabolism, and immunity of their hosts. Midgut microbiota has also been suggested to modulate the competency of mosquitoes to transmit arboviruses, malaria parasites etc. Interestingly, the midgut microbial flora is dynamic and the diversity changes with the development of vectors, in addition to other factors such as species, sex, life-stage, feeding behavior and geographical origin. The aim of the present study was to investigate the midgut bacterial diversity among larva, adult male, sugar fed female and blood fed female Ae. albopictus collected from Tezpur, Northeastern India. Based on colony morphological characteristics, we selected 113 cultivable bacterial isolates for 16S rRNA gene sequence based molecular identification. Of the 113 isolates, we could identify 35 bacterial species belonging to 18 distinct genera under four major phyla, namely Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes. Phyla Proteobacteria and Firmicutes accounted for majority (80%) of the species, while phylum Actinobacteria constituted 17% of the species. Bacteroidetes was the least represented phylum, characterized by a single species- Chryseobacterium rhizoplanae, isolated from blood fed individuals. Dissection of midgut microbiota diversity at different developmental stages of Ae. albopictus will be helpful in better understanding mosquito-borne diseases, and for designing effective strategies to manage mosquito-borne diseases. PMID:27941985

  2. Hood River Passive House

    SciTech Connect

    Hales, D.

    2013-03-01

    The Hood River Passive Project was developed by Root Design Build of Hood River Oregon using the Passive House Planning Package (PHPP) to meet all of the requirements for certification under the European Passive House standards. The Passive House design approach has been gaining momentum among residential designers for custom homes and BEopt modeling indicates that these designs may actually exceed the goal of the U.S. Department of Energy's (DOE) Building America program to reduce home energy use by 30%-50% (compared to 2009 energy codes for new homes). This report documents the short term test results of the Shift House and compares the results of PHPP and BEopt modeling of the project.

  3. Cinemicrographic specimen housing

    NASA Technical Reports Server (NTRS)

    Wilkins, J. R.

    1979-01-01

    Housing used to observe gravitation effects on specimens embedded in support media, such as agar, supports microbial specimens vertically for time-lapsed cinemicrographic studies. Procedure cannot be performed with conventional microscopes which see specimens in horizontal plane only.

  4. Gingerbread-House Geometry.

    ERIC Educational Resources Information Center

    Emenaker, Charles E.

    1999-01-01

    Describes a sixth-grade interdisciplinary geometry unit based on Charles Dickens's "A Christmas Carol". Focuses on finding area, volume, and perimeter, and working with estimation, decimals, and fractions in the context of making gingerbread houses. (ASK)

  5. Effects of Parental Status on Male Body Mass in the Monogamous, Biparental California Mouse

    PubMed Central

    Saltzman, Wendy; Harris, Breanna N.; de Jong, Trynke R.; Nguyen, Pauline P.; Cho, Julia T.; Hernandez, Mindy; Perea-Rodriguez, Juan P.

    2014-01-01

    Studies of biparental mammals demonstrate that males may undergo systematic changes in body mass as a consequence of changes in reproductive status; however, these studies typically have not teased apart effects of specific social and reproductive factors, such as cohabitation with a female per se, cohabitation with a breeding female specifically, and engagement in paternal care. We aimed to determine whether California mouse (Peromyscus californicus) fathers undergo systematic changes in body mass and if so, which specific social/reproductive factor(s) might contribute to these changes. We compared mean weekly body masses over a 5-week period in 1) males housed with another male vs. males housed with a non-reproductive (tubally ligated) female; 2) males housed with a tubally ligated female vs. males housed with a female that was undergoing her first pregnancy; and 3) experienced fathers housed with vs. without pups during their mate’s subsequent pregnancy. Body mass did not differ between males housed with another male and those housed with a non-reproductive female; however, males housed with a non-reproductive female were significantly heavier than those housed with a primiparous female. Among experienced fathers, those housed with pups from their previous litter underwent significant increases in body mass across their mates’ pregnancy, whereas fathers housed without pups did not. These results suggest that male body mass is reduced by cohabitation with a breeding (pregnant) female, but not by cohabitation with a non-reproductive female, and that increases in body mass across the mate’s pregnancy are associated with concurrent care of offspring rather than cohabitation with a pregnant female. Additional work is needed to determine the mechanisms and functional significance, if any, of these changes in male body mass with reproductive condition. PMID:26005292

  6. Rotating housing turbine

    DOEpatents

    Allouche, Erez; Jaganathan, Arun P.

    2016-10-11

    The invention is a new turbine structure having a housing that rotates. The housing has a sidewall, and turbine blades are attached to a sidewall portion. The turbine may be completely open in the center, allowing space for solids and debris to be directed out of the turbine without jamming the spinning blades/sidewall. The turbine may be placed in a generator for generation of electrical current.

  7. 2. Keeper's house, light tower and oil house, view north, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Keeper's house, light tower and oil house, view north, south and east sides of keeper's house, south side of tower and oil house - Owl's Head Light Station, Off State Highway 73 just east of Rockland on Owl's Head Bay, Owls Head, Knox County, ME

  8. 12. Fuel house and fog signal house, view northeast, southwest ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Fuel house and fog signal house, view northeast, southwest side of fuel house, west and south sides of fog signal house - Cape Elizabeth Light Station, Near Two Lights State Park at end of Two Lights Road, off State Highway 77, Cape Elizabeth, Cumberland County, ME

  9. 7. Keeper's house, fog signal house and light tower, view ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Keeper's house, fog signal house and light tower, view north northeast, west and south sides of keeper's house and tower, southwest and southeast sides of fog signal house - West Quoddy Head Light Station, At eastern tip of West Quaddy Head, Lubec, Washington County, ME

  10. 3. Bell house, light tower and keeper's house, view west, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Bell house, light tower and keeper's house, view west, southeast side and northeast front of bell house, southeast sides of tower and keeper's house - Burnt Coat Harbor Light Station, At Hackamock Head on Swan's Island opposite Harbor Island at entrance to Burnt Coat Harbor, Swans Island, Hancock County, ME

  11. 1. General view, twoandahalf story house at left. (The house ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. General view, two-and-a-half story house at left. (The house next door is George McCraig House, HABS No. PA-1593). Photocopied from December 1957 photograph on file at Philadelphia Historical Commission - Henry Elwell House, 812 South Front Street, Philadelphia, Philadelphia County, PA

  12. Housing in Los Angeles: Affordable Housing for the Future.

    ERIC Educational Resources Information Center

    Los Angeles Blue Ribbon Committee for Affordable Housing, CA.

    A 1988 mayoral committee assessed the seriousness of Los Angeles (California) housing problems and found that the city's housing efforts were sufficient in the 1960s, when the Federal Government took primary responsibility for housing and the average wage was adequate to support the cost of the average house or apartment. However, the following…

  13. 91. VIEW NORTHWEST OF SCRAP HOUSE AND CAST HOUSE, BUILDINGS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    91. VIEW NORTHWEST OF SCRAP HOUSE AND CAST HOUSE, BUILDINGS 101 AND 72; BUILDING 101 IN THE CENTER OF THE PHOTOGRAPH HOUSED SCRAP METAL CLEANING AND PROCESSING FACILITIES; BUILDING 72 AT RIGHT CENTER HOUSED MELTING FURNACES AND CONTINUOUS CASTING MACHINERY - Scovill Brass Works, 59 Mill Street, Waterbury, New Haven County, CT

  14. Male catheterization.

    PubMed

    Hadfield-Law, L

    2001-10-01

    The insertion of catheters into male emergency patients is fairly common practice and is associated with a worryingly high rate of infection. Everyday pressures within the department, along with the added stress of resuscitation can result in inappropriately trained or skilled staff undertaking this procedure. The issue of gender and whether female nurses should catheterize male patients may also affect this vulnerable group of patients. Acquiring the psychomotor skills of inserting a urethral catheter is only one part of preparation for practice. Emergency nurses must know when and when not to resort to catheterization. Choosing the type and size of catheter requires careful judgment. What will you do if insertion proves difficult? Prevention of infection is of paramount importance and there are an increasing number of evidence-based sources of information, which are crucial to formulating procedures and informing every day practice. In the pressured surroundings of A&E departments, it is easy to ignore the vulnerability of men requiring catheterization, both from a physical and psychological point of view. Making the effort to explain the procedure, listen to questions and concerns and record relevant details in the notes, will take only a few extra moments. There is no doubt that urinary catheterization is not without complications. It is associated with significant morbidity and occasionally, mortality.

  15. Housing and child health.

    PubMed

    Weitzman, Michael; Baten, Ahmareen; Rosenthal, David G; Hoshino, Risa; Tohn, Ellen; Jacobs, David E

    2013-09-01

    The connection between housing and health is well established. Physical, chemical, and biological aspects of the child's home, such as cleanliness, moisture, pests, noise, accessibility, injury risks, and other forms of housing environmental quality, all have the potential to influence multiple aspects of the health and development of children. Basic sanitation, reduced household crowding, other improvements in housing and expanded, and improved housing regulations have led to advances in children's health. For example, lead poisoning prevention policies have profoundly reduced childhood lead exposure in the United States. This and many other successes highlight the health benefits for families, particularly children, by targeting interventions that reduce or eliminate harmful exposures in the home. Additionally, parental mental health problems, food insecurity, domestic violence, and the presence of guns in children's homes all are largely experienced by children in their homes, which are not as yet considered part of the Healthy Homes agenda. There is a large movement and now a regulatory structure being put in place for healthy housing, which is becoming closely wedded with environmental health, public health, and the practice of pediatrics. The importance of homes in children's lives, history of healthy homes, asthma, and exposures to lead, carbon monoxide, secondhand/thirdhand smoke, radon, allergy triggers is discussed, as well as how changes in ambient temperature, increased humidity, poor ventilation, water quality, infectious diseases, housing structure, guns, electronic media, family structure, and domestic violence all affect children's health.

  16. Mosquitoes of field and forest: the scale of habitat segregation in a diverse mosquito assemblage.

    PubMed

    Reiskind, M H; Griffin, R H; Janairo, M S; Hopperstad, K A

    2017-03-01

    Knowledge of the distribution of arthropod vectors across a landscape is important in determining the risk for vector-borne disease. This has been well explored for ticks, but not for mosquitoes, despite their importance in the transmission of a variety of pathogens. This study examined the importance of habitat, habitat edges, and the scale at which mosquito abundance and diversity vary in a rural landscape by trapping along transects from grassland areas into forest patches. Significant patterns of vector diversity and distinct mosquito assemblages across habitats were found. The scale of individual species' responses to habitat edges was often dramatic, with several species rarely straying even 10 m from the edge. The present results suggest blood-seeking mosquito species are faithful to certain habitats, which has consequences for patterns of vector diversity and risk for pathogen transmission. This implies that analysts of risk for pathogen transmission and foci of control, and developers of land management strategies should assess habitat at a finer scale than previously considered.

  17. Mosquito-Borne Diseases and Omics: Salivary Gland Proteome of the Female Aedes aegypti Mosquito.

    PubMed

    Dhawan, Rakhi; Kumar, Manish; Mohanty, Ajeet Kumar; Dey, Gourav; Advani, Jayshree; Prasad, T S Keshava; Kumar, Ashwani

    2017-01-01

    The female Aedes aegypti mosquito is an important vector for several tropical and subtropical diseases such as dengue, chikungunya, and Zika and yellow fever. The disease viruses infect the mosquito and subsequently spread to the salivary glands after which the viruses can be transmitted to humans with probing or feeding by the mosquito. Omics systems sciences offer the opportunity to characterize vectors and can inform disease surveillance, vector control and development of innovative diagnostics, personalized medicines, vaccines, and insecticide targets. Using high-resolution mass spectrometry, we performed an analysis of the A. aegypti salivary gland proteome. The A. aegypti proteome resulted in acquisition of 83,836 spectra. Upon searches against the protein database of the A. aegypti, these spectra were assigned to 5417 unique peptides, belonging to 1208 proteins. To the best of our knowledge, this is the largest set of proteins identified in the A. aegypti salivary gland. Of note, 29 proteins were involved in immunity-related pathways in salivary glands. A subset of these proteins is known to interact with disease viruses. Another 15 proteins with signal cleavage site were found to be secretory in nature, and thus possibly playing critical roles in blood meal ingestion. These findings provide a baseline to advance our understanding of vector-borne diseases and vector-pathogen interactions before virus transmission in global health, and might therefore enable future design and development of virus-blocking strategies and novel molecular targets in the mosquito vector A. aegypti.

  18. Understanding Housing Delays and Relocations Within the Housing First Model.

    PubMed

    Zerger, Suzanne; Pridham, Katherine Francombe; Jeyaratnam, Jeyagobi; Hwang, Stephen W; O'Campo, Patricia; Kohli, Jaipreet; Stergiopoulos, Vicky

    2016-01-01

    This study explores factors contributing to delays and relocations during the implementation of the Housing First model in Toronto, Ontario. While interruptions in housing tenure are expected en route to recovery and housing stability, consumer and service provider views on finding and keeping housing remain largely unknown. In-person interviews and focus groups were conducted with 48 study participants, including 23 case managers or housing workers and 25 consumers. The following three factors contributed to housing delays and transfers: (1) the effectiveness of communication and collaboration among consumers and service providers, (2) consumer-driven preferences and ambivalence, and (3) provider prioritization of consumer choice over immediate housing access. Two strategies--targeted communications and consumer engagement in housing searches--supported the housing process. Several factors affect the timing and stability of housing. Communication between and among providers and consumers, and a shared understanding of consumer choice, can further support choice and recovery.

  19. Changes in local mosquito fauna following beaver (Castor canadensis) activity.

    PubMed

    Butts, W L

    1986-09-01

    A marked decrease in anthropophilic temporary water mosquito populations subsequent to impoundment of extensive areas of larval development by beavers is documented. Absence to date of development of other mosquito species in the permanent water thus established is noted and discussed relative to current characteristics of the site.

  20. Insect Repellents: Modulators of mosquito odorant receptor activity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mosquitoes vector numerous pathogens that cause diseases including malaria, yellow fever, dengue fever and chikungunya. DEET, IR3535, Picaridin and 2-undecanone are insect repellents that are used to prevent interactions between humans and a broad array of disease vectors including mosquitoes. While...

  1. Extensive genetic diversity of Rickettsiales bacteria in multiple mosquito species

    PubMed Central

    Guo, Wen-Ping; Tian, Jun-Hua; Lin, Xian-Dan; Ni, Xue-Bing; Chen, Xiao-Ping; Liao, Yong; Yang, Si-Yuan; Dumler, J. Stephen; Holmes, Edward C.; Zhang, Yong-Zhen

    2016-01-01

    Rickettsiales are important zoonotic pathogens, causing severe disease in humans globally. Although mosquitoes are an important vector for diverse pathogens, with the exception of members of the genus Wolbachia little is known about their role in the transmission of Rickettsiales. Herein, Rickettsiales were identified by PCR in five species of mosquitoes (Anopheles sinensis, Armigeres subalbatus, Aedes albopictus, Culex quinquefasciatus and Cu. tritaeniorhynchus) collected from three Chinese provinces during 2014–2015. Subsequent phylogenetic analyses of the rrs, groEL and gltA genes revealed the presence of Anaplasma, Ehrlichia, Candidatus Neoehrlichia, and Rickettsia bacteria in mosquitoes, comprising nine documented and five tentative species bacteria, as well as three symbionts/endosybionts. In addition, bacteria were identified in mosquito eggs, larvae, and pupae sampled from aquatic environments. Hence, these data suggest that Rickettsiales circulate widely in mosquitoes in nature. Also of note was that Ehrlichia and Rickettsia bacteria were detected in each life stage of laboratory cultured mosquitoes, suggesting that Rickettsiales may be maintained in mosquitoes through both transstadial and transovarial transmission. In sum, these data indicate that mosquitoes may have played an important role in the transmission and evolution of Rickettsiales in nature. PMID:27934910

  2. Crowdsourcing for large-scale mosquito (Diptera: Culicidae) sampling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sampling a cosmopolitan mosquito (Diptera: Culicidae) species throughout its range is logistically challenging and extremely resource intensive. Mosquito control programmes and regional networks operate at the local level and often conduct sampling activities across much of North America. A method f...

  3. Do capture data from mosquito traps represent reality?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Collectively, the effects of mechanical trap style, the method of trap placement in the field, mosquito activity phase, and other biological phenomena are manifest as sample bias that leads to vector detection failure(s) and/or erroneous predictions of mosquito activity. The goal of this research i...

  4. Stop the biting: targeting a mosquito's sense of smell.

    PubMed

    Potter, Christopher J

    2014-02-27

    Mosquitoes are a great threat to human health. Fortunately, they have a weakness: they utilize their sense of smell to target a human host. Recent studies examine the effectiveness of protecting humans from attack by ablating or odorant targeting mosquito olfactory receptors. The results are both promising and alarming.

  5. Isolation and molecular characterization of Banna virus from mosquitoes, Vietnam.

    PubMed

    Nabeshima, Takeshi; Thi Nga, Phan; Guillermo, Posadas; Parquet, Maria del Carmen; Yu, Fuxun; Thanh Thuy, Nguyen; Minh Trang, Bui; Tran Hien, Nguyen; Sinh Nam, Vu; Inoue, Shingo; Hasebe, Futoshi; Morita, Kouichi

    2008-08-01

    We isolated and characterized a Banna virus from mosquitoes in Vietnam; 5 strains were isolated from field-caught mosquitoes at various locations; Banna virus was previously isolated from encephalitis patients in Yunnan, China, in 1987. Together, these findings suggest widespread distribution of this virus throughout Southeast Asia.

  6. Quantifying impact of mosquitoes on quality of life

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New Jersey, like many eastern states, has a persistent problem of the Asian tiger mosquito. This and other mosquitoes reduce residents’ quality of life from discomfort and possible risk of disease. To guide a comprehensive area-wide pest management project to control Aedes albopictus in two counties...

  7. GUARD HOUSE AND SOUTH FIRE HOUSE, VICINITY MAP. (Shows the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    GUARD HOUSE AND SOUTH FIRE HOUSE, VICINITY MAP. (Shows the Guard House and Barracks, and South Fire House in relation to nearby roads, railroad tracks, and the piers). Navy Yard, Mare Island, California. P.W. Drawing No. C-1899, approved 1941; file no. 930-C-1. Scale one inch to forty feet. 72 cn x 97 cm. Ink on vellum - Mare Island Naval Shipyard, Guard House & Barracks, Railroad Avenue near Eighteenth Street, Vallejo, Solano County, CA

  8. Binding of a fluorescence reporter and a ligand to an odorant-binding protein of the yellow fever mosquito, Aedes aegypti.

    PubMed

    Leal, Gabriel M; Leal, Walter S

    2014-01-01

    Odorant-binding proteins (OBPs), also named pheromone-binding proteins when the odorant is a pheromone, are essential for insect olfaction. They solubilize odorants that reach the port of entry of the olfactory system, the pore tubules in antennae and other olfactory appendages. Then, OBPs transport these hydrophobic compounds through an aqueous sensillar lymph to receptors embedded on dendritic membranes of olfactory receptor neurons. Structures of OBPs from mosquito species have shed new light on the mechanism of transport, although there is considerable debate on how they deliver odorant to receptors. An OBP from the southern house mosquito, Culex quinquefasciatus, binds the hydrophobic moiety of a mosquito oviposition pheromone (MOP) on the edge of its binding cavity. Likewise, it has been demonstrated that the orthologous protein from the malaria mosquito binds the insect repellent DEET on a similar edge of its binding pocket. A high school research project was aimed at testing whether the orthologous protein from the yellow fever mosquito, AaegOBP1, binds DEET and other insect repellents, and MOP was used as a positive control. Binding assays using the fluorescence reporter N-phenyl-1-naphtylamine (NPN) were inconclusive. However, titration of NPN fluorescence emission in AaegOBP1 solution with MOP led to unexpected and intriguing results. Quenching was observed in the initial phase of titration, but addition of higher doses of MOP led to a stepwise increase in fluorescence emission coupled with a blue shift, which can be explained at least in part by formation of MOP micelles to house stray NPN molecules.

  9. High efficiency germ-line transformation of mosquitoes.

    PubMed

    Lobo, Neil F; Clayton, John R; Fraser, Malcolm J; Kafatos, Fotis C; Collins, Frank H

    2006-01-01

    The ability to manipulate the mosquito genome through germ-line transformation provides us with a powerful tool for investigating gene structure and function. It is also a valuable method for the development of novel approaches to combating the spread of mosquito-vectored diseases. To date, germ-line transformation has been demonstrated in several mosquito species. Transgenes are introduced into pre-blastocyst mosquito embryos using microinjection techniques that take a few hours, and progeny are screened for the presence of a marker gene. The microinjection protocol presented here can be applied to most mosquitoes and contains several improvements over other published methods that increase the survival of injected embryos and, therefore, the number of transformants. Transgenic lines can be established in approximately 1 month using this technique.

  10. Variation in Aedes aegypti Mosquito Competence for Zika Virus Transmission.

    PubMed

    Roundy, Christopher M; Azar, Sasha R; Rossi, Shannan L; Huang, Jing H; Leal, Grace; Yun, Ruimei; Fernandez-Salas, Ildefonso; Vitek, Christopher J; Paploski, Igor A D; Kitron, Uriel; Ribeiro, Guilherme S; Hanley, Kathryn A; Weaver, Scott C; Vasilakis, Nikos

    2017-04-01

    To test whether Zika virus has adapted for more efficient transmission by Aedes aegypti mosquitoes, leading to recent urban outbreaks, we fed mosquitoes from Brazil, the Dominican Republic, and the United States artificial blood meals containing 1 of 3 Zika virus strains (Senegal, Cambodia, Mexico) and monitored infection, dissemination, and virus in saliva. Contrary to our hypothesis, Cambodia and Mexica strains were less infectious than the Senegal strain. Only mosquitoes from the Dominican Republic transmitted the Cambodia and Mexica strains. However, blood meals from viremic mice were more infectious than artificial blood meals of comparable doses; the Cambodia strain was not transmitted by mosquitoes from Brazil after artificial blood meals, whereas 61% transmission occurred after a murine blood meal (saliva titers up to 4 log 10 infectious units/collection). Although regional origins of vector populations and virus strain influence transmission efficiency, Ae. aegypti mosquitoes appear to be competent vectors of Zika virus in several regions of the Americas.

  11. Variation in Aedes aegypti Mosquito Competence for Zika Virus Transmission

    PubMed Central

    Roundy, Christopher M.; Azar, Sasha R.; Rossi, Shannan L.; Huang, Jing H.; Leal, Grace; Yun, Ruimei; Fernandez-Salas, Ildefonso; Vitek, Christopher J.; Paploski, Igor A.D.; Kitron, Uriel; Ribeiro, Guilherme S.; Hanley, Kathryn A.

    2017-01-01

    To test whether Zika virus has adapted for more efficient transmission by Aedes aegypti mosquitoes, leading to recent urban outbreaks, we fed mosquitoes from Brazil, the Dominican Republic, and the United States artificial blood meals containing 1 of 3 Zika virus strains (Senegal, Cambodia, Mexico) and monitored infection, dissemination, and virus in saliva. Contrary to our hypothesis, Cambodia and Mexica strains were less infectious than the Senegal strain. Only mosquitoes from the Dominican Republic transmitted the Cambodia and Mexica strains. However, blood meals from viremic mice were more infectious than artificial blood meals of comparable doses; the Cambodia strain was not transmitted by mosquitoes from Brazil after artificial blood meals, whereas 61% transmission occurred after a murine blood meal (saliva titers up to 4 log10 infectious units/collection). Although regional origins of vector populations and virus strain influence transmission efficiency, Ae. aegypti mosquitoes appear to be competent vectors of Zika virus in several regions of the Americas. PMID:28287375

  12. Mosquito Vectors and the Globalization of Plasmodium falciparum Malaria.

    PubMed

    Molina-Cruz, Alvaro; Zilversmit, Martine M; Neafsey, Daniel E; Hartl, Daniel L; Barillas-Mury, Carolina

    2016-11-23

    Plasmodium falciparum malaria remains a devastating public health problem. Recent discoveries have shed light on the origin and evolution of Plasmodium parasites and their interactions with their vertebrate and mosquito hosts. P. falciparum malaria originated in Africa from a single horizontal transfer between an infected gorilla and a human, and became global as the result of human migration. Today, P. falciparum malaria is transmitted worldwide by more than 70 different anopheline mosquito species. Recent studies indicate that the mosquito immune system can be a barrier to malaria transmission and that the P. falciparum Pfs47 gene allows the parasite to evade mosquito immune detection. Here, we review the origin and globalization of P. falciparum and integrate this history with analysis of the biology, evolution, and dispersal of the main mosquito vectors. This new perspective broadens our understanding of P. falciparum population structure and the dispersal of important parasite genetic traits.

  13. Dissecting vectorial capacity for mosquito-borne viruses

    PubMed Central

    Kramer, Laura D.; Ciota, Alexander T.

    2015-01-01

    The inter-relationship between mosquitoes and the viruses they transmit is complex. While previously understood barriers to infection and transmission remain valid, additional factors have been uncovered that suggest an “arms race” between mosquito and virus. These include the mosquito microbiota and interplay between mosquito and viral genetics. Following an infectious blood meal, the mosquito mounts an immune and transcriptional response, leading to altered expression of multiple genes. These complex interactions, specific to vector and virus genotypes, combine with external influences, particularly temperature, to determine vector competence. The mosquito’s response to the infecting agent may have consequences in terms of longevity, feeding behavior and/or fecundity. These factors, together with population density and the frequency of host contact determine vectorial capacity. PMID:26569343

  14. Climate change and mosquito-borne disease.

    PubMed Central

    Reiter, P

    2001-01-01

    Global atmospheric temperatures are presently in a warming phase that began 250--300 years ago. Speculations on the potential impact of continued warming on human health often focus on mosquito-borne diseases. Elementary models suggest that higher global temperatures will enhance their transmission rates and extend their geographic ranges. However, the histories of three such diseases--malaria, yellow fever, and dengue--reveal that climate has rarely been the principal determinant of their prevalence or range; human activities and their impact on local ecology have generally been much more significant. It is therefore inappropriate to use climate-based models to predict future prevalence. PMID:11250812

  15. New records of mosquitoes from northwestern Argentina.

    PubMed

    Dantur Juri, María J; Stein, Marina; Rossi, Gustavo C; Navarro, Juan Carlos; Zaidenberg, Mario; Sallum, María A Mureb

    2012-06-01

    Eleven mosquito species, namely Aedes hastatus, Ae. fulvus, Coquillettidia albicosta, Cq. juxtamansonia, Culex aliciae, Cx. delpontei, Cx. oedipus, Cx. pedroi, Mansonia flaveola, Uranotaenia leucoptera, and Wyeomyia oblita, are recorded for the first time from northwestern Argentina. In addition, 3 species, Cx. brethesi, Limatus durhami, and Ur. nataliae, are reported for the first time from Salta Province. These records extend the geographical distribution of these 3 species to Salta Province. This study also extends the geographical distributions of Cq. nigricans, Cx. chidesteri, and Ma. humeralis to Jujuy Province and of Ae. meprai, Ae. milleri, Ae. oligopistus, Cx. brethesi, Cx. fernandezi, and Cx. tatoi to Tucumán Province.

  16. Diversification of Wolbachia endosymbiont in the Culex pipiens mosquito.

    PubMed

    Atyame, Célestine M; Delsuc, Frédéric; Pasteur, Nicole; Weill, Mylène; Duron, Olivier

    2011-10-01

    The α-proteobacteria Wolbachia are among the most common intracellular bacteria and have recently emerged as important drivers of arthropod biology. Wolbachia commonly act as reproductive parasites in arthropods by inducing cytoplasmic incompatibility (CI), a type of conditional sterility between hosts harboring incompatible infections. In this study, we examined the evolutionary histories of Wolbachia infections, known as wPip, in the common house mosquito Culex pipiens, which exhibits the greatest variation in CI crossing patterns observed in any insect. We first investigated a panel of 20 wPip strains for their genetic diversity through a multilocus scheme combining 13 Wolbachia genes. Because Wolbachia depend primarily on maternal transmission for spreading within arthropod populations, we also studied the variability in the coinherited Cx. pipiens mitochondria. In total, we identified 14 wPip haplotypes, which all share a monophyletic origin and clearly cluster into five distinct wPip groups. The diversity of Cx. pipiens mitochondria was extremely reduced, which is likely a consequence of cytoplasmic hitchhiking driven by a unique and recent Wolbachia invasion. Phylogenetic evidence indicates that wPip infections and mitochondrial DNA have codiverged through stable cotransmission within the cytoplasm and shows that a rapid diversification of wPip has occurred. The observed pattern demonstrates that a considerable degree of Wolbachia diversity can evolve within a single host species over short evolutionary periods. In addition, multiple signatures of recombination were found in most wPip genomic regions, leading us to conclude that the mosaic nature of wPip genomes may play a key role in their evolution.

  17. Ethnobotanical knowledge on botanical repellents employed in the African region against mosquito vectors - A review.

    PubMed

    Pavela, Roman; Benelli, Giovanni

    2016-08-01

    Mosquitoes (Diptera: Culicidae) represent a huge threat for millions of humans and animals worldwide, since they act as vectors for important parasites and pathogens, including malaria, filariasis and important arboviruses, such as dengue, West Nile and Zika virus. No vaccines or other specific treatments are available against the arboviruses transmitted by mosquitoes, and avoidance of mosquito bites remains the best strategy. African regions are usually hit most whose inhabitants are poor, and the use of repellent plants is the only efficient protection against vectors they have. Ethnobotanical knowledge of such plants and their use is usually passed on orally from one generation to another. However, it is also important to preserve this information in a written form, as well. Ethnobotanical research projects carried out in the regions of today's Ethiopia, South Africa, Nigeria, Kenya, and Tanzania indicate that the native inhabitants of the African study regions traditionally use 64 plant species, belonging to 30 families. Aromatic plants (i.e., Citrus spp., Eucalyptus spp., Lantana camara, Ocimum spp. and Lippia javanica) the most commonly used in all the study regions. Native people know three major methods of using repellent plants: (i) production of repellent smoke from burning plants, (ii) hanging plants inside the house or sprinkling leaves on the floor, (iii) the use of plant oils, juices from crushed fresh parts of the plants, or various prepared extracts applied on uncovered body parts. Overall, this review covers studies conducted only in a limited part of the African continent, highlighting the importance to undertake further research efforts to preserve the unique knowledge and traditions of the native tribes.

  18. Nationwide investigation of the pyrethroid susceptibility of mosquito larvae collected from used tires in Vietnam.

    PubMed

    Kawada, Hitoshi; Higa, Yukiko; Nguyen, Yen T; Tran, Son H; Nguyen, Hoa T; Takagi, Masahiro

    2009-01-01

    Pyrethroid resistance is envisioned to be a major problem for the vector control program since, at present, there are no suitable chemical substitutes for pyrethroids. Cross-resistance to knockdown agents, which are mainly used in mosquito coils and related products as spatial repellents, is the most serious concern. Since cross-resistance is a global phenomenon, we have started to monitor the distribution of mosquito resistance to pyrethroids. The first pilot study was carried out in Vietnam. We periodically drove along the national road from the north end to the Mekong Delta in Vietnam and collected mosquito larvae from used tires. Simplified susceptibility tests were performed using the fourth instar larvae of Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus. Compared with the other species, Ae. aegypti demonstrated the most prominent reduction in susceptibility. For Ae. aegypti, significant increases in the susceptibility indices with a decrease in the latitude of collection points were observed, indicating that the susceptibility of Ae. aegypti against d-allethrin was lower in the southern part, including mountainous areas, as compared to that in the northern part of Vietnam. There was a significant correlation between the susceptibility indices in Ae. aegypti and the sum of annual pyrethroid use for malaria control (1998-2002). This might explain that the use of pyrethroids as residual treatment inside houses and pyrethroid-impregnated bed nets for malaria control is attributable to low pyrethroid susceptibility in Ae. aegypti. Such insecticide treatment appeared to have been intensively administered in the interior and along the periphery of human habitation areas where, incidentally, the breeding and resting sites of Ae. aegypti are located. This might account for the strong selection pressure toward Ae. aegypti and not Ae. albopictus.

  19. Associative learning in the dengue vector mosquito, Aedes aegypti: avoidance of a previously attractive odor or surface color that is paired with an aversive stimulus

    PubMed Central

    Menda, Gil; Uhr, Joshua H.; Wyttenbach, Robert A.; Vermeylen, Françoise M.; Smith, David M.; Harrington, Laura C.; Hoy, Ronald R.

    2013-01-01

    SUMMARY Associative learning has been shown in a variety of insects, including the mosquitoes Culex quinquefasciatus and Anopheles gambiae. This study demonstrates associative learning for the first time in Aedes aegypti, an important vector of dengue, yellow fever and chikungunya viruses. This species prefers to rest on dark surfaces and is attracted to the odor of 1-octen-3-ol. After training in which a dark surface alone or a dark surface with odor was paired with electric shock, mosquitoes avoided the previously attractive area. The association was stronger when odor was included in training, was retained for at least 60 min but not for 24 h, and was equal for males and females. These results demonstrate the utility of a bulk-training paradigm for mosquitoes similar to that used with Drosophila melanogaster. PMID:22996441

  20. Attitude Survey of Military Family Housing Residents, Hawaii 1987.

    DTIC Science & Technology

    1987-09-01

    service member. I. Male 2. Female 6. Marital status. 1. Married 2. Separated , divorced or widowed 3. Single, never married 7. Is spouse living with...C) Attitude Suvyof Military Family HousingUP Residents, OlIG- Ha ai18 . ...... .. . .. . -’le 88I C DEPARTMENT OF THE NAVY NAVY P9RSONN r L RESrARC14...ATTITUDE SURVEY OF MILITARY FAMILY HOUSING RESIDENTS, HAWAII, 1937 Enc: (1) NPRDC TN 87-48 I. This survey of residents of military family housing in

  1. Interspecific competition of a new invasive mosquito, Culex coronator, and two container mosquitoes, Aedes albopictus and Cx. quinquefasciatus (Diptera: Culicidae), across different detritus environments.

    PubMed

    Yee, D A; Skiff, J F

    2014-01-01

    The mosquito Culex coronator (Dyar and Knab) (Diptera: Culicidae) has undergone rapid range expansion in the United States since 2003, with its historical distribution in the southwest expanding eastward to the Atlantic coast. Although Cx. coronator nominally use small natural aquatic habitats for development, the use of containers (e.g., tires) makes it potentially important as container invasive. To determine the potential ecological effects of Cx. coronator on resident container species, we conducted a laboratory experiment to assess its competitive ability with two common tire-inhabiting species, Aedes albopictus (Skuse) and Culex quinquefasciatus (Say) (Diptera: Culicidae). Larvae were reared under a factorial design with each species alone and in combination (Cx. coronator + Ae. albopictus, Cx. coronator + Cx. quinquefasciatus) across three different resource environments (leaf detritus only, animal detritus only, animal + leaf). Mosquito performance (survival, adult male and female mass, and development time) was measured for each species across treatments. Female Cx. coronator developed slowest when grown with Ae. albopictus, or when grown with leaves only regardless of species combinations; similar patterns emerged for males although species effects were restricted to mass. Few differences were evident in performance for male and female Cx. coronator across detritus environments when grown with Cx. quinquefasciatus. Cx. quinquefasciatus did not vary in mass or development time in the presence of Cx. coronator compared with when grown alone. Ae. albopictus female mass was 15% lower in the presence of Cx. coronator. Survival of Cx. coronator was highest in animal and leaf detritus containers, although survival was generally lower when larvae were grown with Ae. albopictus. These findings suggest that the performance of Cx. coronator is similar to that of Cx. quinquefasciatus but it suffers in the presence of Ae. albopictus under some resource environments.

  2. Interspecific Competition of a New Invasive Mosquito, Culex coronator, and Two Container Mosquitoes, Aedes albopictus and Cx. quinquefasciatus (Diptera: Culicidae), Across Different Detritus Environments

    PubMed Central

    YEE, D. A.; SKIFF, J. F.

    2014-01-01

    The mosquito Culex coronator (Dyar and Knab) (Diptera: Culicidae) has undergone rapid range expansion in the United States since 2003, with its historical distribution in the southwest expanding eastward to the Atlantic coast. Although Cx. coronator nominally use small natural aquatic habitats for development, the use of containers (e.g., tires) makes it potentially important as container invasive. To determine the potential ecological effects of Cx. coronator on resident container species, we conducted a laboratory experiment to assess its competitive ability with two common tire-inhabiting species, Aedes albopictus (Skuse) and Culex quinquefasciatus (Say) (Diptera: Culicidae). Larvae were reared under a factorial design with each species alone and in combination (Cx. coronator + Ae. albopictus, Cx. coronator + Cx. quinquefasciatus) across three different resource environments (leaf detritus only, animal detritus only, animal + leaf). Mosquito performance (survival, adult male and female mass, and development time) was measured for each species across treatments. Female Cx. coronator developed slowest when grown with Ae. albopictus, or when grown with leaves only regardless of species combinations; similar patterns emerged for males although species effects were restricted to mass. Few differences were evident in performance for male and female Cx. coronator across detritus environments when grown with Cx. quinquefasciatus. Cx. quinquefasciatus did not vary in mass or development time in the presence of Cx. coronator compared with when grown alone. Ae. albopictus female mass was 15% lower in the presence of Cx. coronator. Survival of Cx. coronator was highest in animal and leaf detritus containers, although survival was generally lower when larvae were grown with Ae. albopictus. These findings suggest that the performance of Cx. coronator is similar to that of Cx. quinquefasciatus but it suffers in the presence of Ae. albopictus under some resource environments

  3. Anthropogenic Habitat Disturbance and Ecological Divergence between Incipient Species of the Malaria Mosquito Anopheles gambiae

    PubMed Central

    Kamdem, Colince; Tene Fossog, Billy; Simard, Frédéric; Etouna, Joachim; Ndo, Cyrille; Kengne, Pierre; Boussès, Philippe; Etoa, François-Xavier; Awono-Ambene, Parfait; Fontenille, Didier; Antonio-Nkondjio, Christophe; Besansky, Nora J.; Costantini, Carlo

    2012-01-01

    Background Anthropogenic habitat disturbance is a prime cause in the current trend of the Earth’s reduction in biodiversity. Here we show that the human footprint on the Central African rainforest, which is resulting in deforestation and growth of densely populated urban agglomerates, is associated to ecological divergence and cryptic speciation leading to adaptive radiation within the major malaria mosquito Anopheles gambiae. Methodology/Principal Findings In southern Cameroon, the frequency of two molecular forms–M and S–among which reproductive isolation is strong but still incomplete, was correlated to an index of urbanisation extracted from remotely sensed data, expressed as the proportion of built-up surface in each sampling unit. The two forms markedly segregated along an urbanisation gradient forming a bimodal cline of ∼6-km width: the S form was exclusive to the rural habitat, whereas only the M form was present in the core of densely urbanised settings, co-occurring at times in the same polluted larval habitats of the southern house mosquito Culex quinquefasciatus–a species association that was not historically recorded before. Conclusions/Significance Our results indicate that when humans create novel habitats and ecological heterogeneities, they can provide evolutionary opportunities for rapid adaptive niche shifts associated with lineage divergence, whose consequences upon malaria transmission might be significant. PMID:22745756

  4. Host-feeding preference of the mosquito, Culex quinquefasciatus, in Yucatan State, Mexico.

    PubMed

    Garcia-Rejon, Julian E; Blitvich, Bradley J; Farfan-Ale, Jose A; Loroño-Pino, Maria A; Chi Chim, Wilberth A; Flores-Flores, Luis F; Rosado-Paredes, Elsy; Baak-Baak, Carlos; Perez-Mutul, Jose; Suarez-Solis, Victor; Fernandez-Salas, Ildefonso; Beaty, Barry J

    2010-01-01

    Studies were conducted to determine the host-feeding preference of Culex quinquefasciatus Say (Diptera: Culicidae) in relation to the availability of human and domestic animals in the city of Merida, Yucatan State, Mexico. Mosquitoes were collected in the backyards of houses using resting wooden boxes. Collections were made five times per week from January to December 2005. DNA was extracted from engorged females and tested by PCR using universal avian- and mammalian-specific primers. DNA extracted from avian-derived blood was further analyzed by PCR using primers that differentiate among the birds of three avian orders: Passeriformes, Columbiformes and Galliformes. PCR products obtained from mammalian-derived blood were subjected to restriction enzyme digestion to differentiate between human-, dog-, cat-, pig-, and horse-derived blood meals. Overall, 82% of engorged mosquitoes had fed on birds, and 18% had fed on mammals. The most frequent vertebrate hosts were Galliformes (47.1%), Passeriformes (23.8%), Columbiformes (11.2%) birds, and dogs (8.8%). The overall human blood index was 6.7%. The overall forage ratio for humans was 0.1, indicating that humans were not a preferred host for Cx. quinquefasciatus in Merida.

  5. Host-Feeding Preference of the Mosquito, Culex quinquefasciatus, in Yucatan State, Mexico

    PubMed Central

    Garcia-Rejon, Julian E.; Blitvich, Bradley J.; Farfan-Ale, Jose A.; Loroño-Pino, Maria A.; Chi Chim, Wilberth A.; Flores-Flores, Luis F.; Rosado-Paredes, Elsy; Baak-Baak, Carlos; Perez-Mutul, Jose; Suarez-Solis, Victor; Fernandez-Salas, Ildefonso; Beaty, Barry J.

    2010-01-01

    Studies were conducted to determine the host-feeding preference of Culex quinquefasciatus Say (Diptera: Culicidae) in relation to the availability of human and domestic animals in the city of Merida, Yucatan State, Mexico. Mosquitoes were collected in the backyards of houses using resting wooden boxes. Collections were made five times per week from January to December 2005. DNA was extracted from engorged females and tested by PCR using universal avian- and mammalian-specific primers. DNA extracted from avian-derived blood was further analyzed by PCR using primers that differentiate among the birds of three avian orders: Passeriformes, Columbiformes and Galliformes. PCR products obtained from mammalian-derived blood were subjected to restriction enzyme digestion to differentiate between human-, dog-, cat-, pig-, and horse-derived blood meals. Overall, 82% of engorged mosquitoes had fed on birds, and 18% had fed on mammals. The most frequent vertebrate hosts were Galliformes (47.1%), Passeriformes (23.8%), Columbiformes (11.2%) birds, and dogs (8.8%). The overall human blood index was 6.7%. The overall forage ratio for humans was 0.1, indicating that humans were not a preferred host for Cx. quinquefasciatus in Merida. PMID:20578953

  6. Domotics Project Housing Block

    PubMed Central

    Morón, Carlos; Payán, Alejandro; García, Alfonso; Bosquet, Francisco

    2016-01-01

    This document develops the study of an implementation project of a home automation system in a housing placed in the town of Galapagar, Madrid. This house, which is going to be occupied by a four-member family, consists of 67 constructed square meters distributed in lounge, kitchen, three bedrooms, bath, bathroom and terrace, this being a common arrangement in Spain. Thus, this study will allow extracting conclusions about the adequacy of the home automation in a wide percentage of housing in Spain. In this document, three house automation proposals are developed based on the requirements of the client and the different home automation levels that the Spanish House and Building Automation Association has established, besides two parallel proposals relating to the safety and the technical alarms. The mentioned proposed systems are described by means of product datasheets and descriptions, distribution plans, measurements, budgets and flow charts that describe the functioning of the system in every case. An evaluation of each system is included, based on other studies conclusions on this matter, where expected energy savings from each design, depending on the current cost of lighting, water and gas, as well as the expected economic amortization period is evaluated. PMID:27223285

  7. Domotics Project Housing Block.

    PubMed

    Morón, Carlos; Payán, Alejandro; García, Alfonso; Bosquet, Francisco

    2016-05-23

    This document develops the study of an implementation project of a home automation system in a housing placed in the town of Galapagar, Madrid. This house, which is going to be occupied by a four-member family, consists of 67 constructed square meters distributed in lounge, kitchen, three bedrooms, bath, bathroom and terrace, this being a common arrangement in Spain. Thus, this study will allow extracting conclusions about the adequacy of the home automation in a wide percentage of housing in Spain. In this document, three house automation proposals are developed based on the requirements of the client and the different home automation levels that the Spanish House and Building Automation Association has established, besides two parallel proposals relating to the safety and the technical alarms. The mentioned proposed systems are described by means of product datasheets and descriptions, distribution plans, measurements, budgets and flow charts that describe the functioning of the system in every case. An evaluation of each system is included, based on other studies conclusions on this matter, where expected energy savings from each design, depending on the current cost of lighting, water and gas, as well as the expected economic amortization period is evaluated.

  8. A low-cost mesocosm for the study of behaviour and reproductive potential of Afrotropical mosquito (Diptera: Culicidae) vectors of malaria

    PubMed Central

    Jackson, Bryan T.; Stone, Christopher M.; Ebrahimi, Babak; Briët, Olivier J.T.; Foster, Woodbridge A.

    2014-01-01

    A large-scale mesocosm was constructed and tested for its effectiveness for experiments on behaviour, reproduction, and adult survivorship of the Afrotropical malaria vector Anopheles gambiae s.s. Giles (Diptera: Culicidae) in temperate climates. The large space (82.69 m3) allowed for semi-natural experiments that increased demand on a mosquito’s energetic reserves in an environment of widely distributed resources. A one-piece prefabricated enclosure, made with white netting and vinyl, prevented the ingress of predators and the egress of mosquitoes. Daylight and white materials prompted the mosquitoes to seclude themselves in restricted daytime resting sites and allowed easy collection of dead bodies so that daily mortality could be assessed accurately, using a method that accounts for a proportion of bodies being lost. Here, daily, age-dependent mortality rates of males and females were estimated using Bayesian Markov Chain Monte Carlo simulation. In overnight experiments, mosquitoes successfully located plants and took sugar meals. A 3-week survival trial with a single-cohort demonstrated successful mating, blood feeding, oviposition, and long life. The relatively low cost of the mesocosm and the performance of the mosquitoes in it make it a viable option for any behavioural or ecological study of tropical mosquitoes where space and seasonal cold are constraining factors. PMID:25294339

  9. Laser induced mortality of Anopheles stephensi mosquitoes

    PubMed Central

    Keller, Matthew D.; Leahy, David J.; Norton, Bryan J.; Johanson, Threeric; Mullen, Emma R.; Marvit, Maclen; Makagon, Arty

    2016-01-01

    Small, flying insects continue to pose great risks to both human health and agricultural production throughout the world, so there remains a compelling need to develop new vector and pest control approaches. Here, we examined the use of short (<25 ms) laser pulses to kill or disable anesthetized female Anopheles stephensi mosquitoes, which were chosen as a representative species. The mortality of mosquitoes exposed to laser pulses of various wavelength, power, pulse duration, and spot size combinations was assessed 24 hours after exposure. For otherwise comparable conditions, green and far-infrared wavelengths were found to be more effective than near- and mid-infrared wavelengths. Pulses with larger laser spot sizes required lower lethal energy densities, or fluence, but more pulse energy than for smaller spot sizes with greater fluence. Pulse duration had to be reduced by several orders of magnitude to significantly lower the lethal pulse energy or fluence required. These results identified the most promising candidates for the lethal laser component in a system being designed to identify, track, and shoot down flying insects in the wild. PMID:26887786

  10. Laser induced mortality of Anopheles stephensi mosquitoes

    NASA Astrophysics Data System (ADS)

    Keller, Matthew D.; Leahy, David J.; Norton, Bryan J.; Johanson, Threeric; Mullen, Emma R.; Marvit, Maclen; Makagon, Arty

    2016-02-01

    Small, flying insects continue to pose great risks to both human health and agricultural production throughout the world, so there remains a compelling need to develop new vector and pest control approaches. Here, we examined the use of short (<25 ms) laser pulses to kill or disable anesthetized female Anopheles stephensi mosquitoes, which were chosen as a representative species. The mortality of mosquitoes exposed to laser pulses of various wavelength, power, pulse duration, and spot size combinations was assessed 24 hours after exposure. For otherwise comparable conditions, green and far-infrared wavelengths were found to be more effective than near- and mid-infrared wavelengths. Pulses with larger laser spot sizes required lower lethal energy densities, or fluence, but more pulse energy than for smaller spot sizes with greater fluence. Pulse duration had to be reduced by several orders of magnitude to significantly lower the lethal pulse energy or fluence required. These results identified the most promising candidates for the lethal laser component in a system being designed to identify, track, and shoot down flying insects in the wild.

  11. Transglutaminase-mediated semen coagulation controls sperm storage in the malaria mosquito.

    PubMed

    Rogers, David W; Baldini, Francesco; Battaglia, Francesca; Panico, Maria; Dell, Anne; Morris, Howard R; Catteruccia, Flaminia

    2009-12-01

    Insect seminal fluid proteins are powerful modulators of many aspects of female physiology and behaviour including longevity, egg production, sperm storage, and remating. The crucial role of these proteins in reproduction makes them promising targets for developing tools aimed at reducing the population sizes of vectors of disease. In the malaria mosquito Anopheles gambiae, seminal secretions produced by the male accessory glands (MAGs) are transferred to females in the form of a coagulated mass called the mating plug. The potential of seminal fluid proteins as tools for mosquito control demands that we improve our limited understanding of the composition and function of the plug. Here, we show that the plug is a key determinant of An. gambiae reproductive success. We uncover the composition of the plug and demonstrate it is formed through the cross-linking of seminal proteins mediated by a MAG-specific transglutaminase (TGase), a mechanism remarkably similar to mammalian semen coagulation. Interfering with TGase expression in males inhibits plug formation and transfer, and prevents females from storing sperm with obvious consequences for fertility. Moreover, we show that the MAG-specific TGase is restricted to the anopheline lineage, where it functions to promote sperm storage rather than as a mechanical barrier to re-insemination. Taken together, these data represent a major advance in our understanding of the factors shaping Anopheles reproductive biology.

  12. Sugar-source preference, sugar intake and relative nutritional benefits in Anopheles arabiensis males.

    PubMed

    Gouagna, Louis Clément; Kerampran, Renaud; Lebon, Cyrille; Brengues, Cecile; Toty, Celine; Wilkinson, David A; Boyer, Sébastien; Fontenille, Didier

    2014-04-01

    Plant-derived sugar is the only source of dietary carbohydrate for males of most mosquito species. Male resource acquisition and utilization remain an under-researched area of behavior in vectors of human diseases. However, the renewed interest in the use of sterile males against disease vector mosquitoes reinforces the urgent need for studies on the behavioral and ecological processes that underpin male fitness and reproductive success. Here an attempt was made first to characterize the conditions and modes of resource acquisition (plant derived sugar meals) early in the life of An. arabiensis males, and second to test the hypothesis that the plants chosen for their sugar meals are those which maximize their fitness in terms of energy gains (i.e. amount of lipids, proteins, glycogen and glucose). Olfactometry assays demonstrated the ability of An. arabiensis males to discriminate among a sample of ten abundant flowering plants present in their natural habitats. In further experiments, we observed significant variations in the sugar intake rates that matched their olfactory preferences, with the most attractive plants eliciting significantly higher sugar intake rates. Consistent with our expectations, analyses of the whole-body free sugars, lipids and glycogen unequivocally showed that the energy reserve accumulated post-feeding is dependent on the diet of the adult males, with the preferred plants providing more energy reserves than the less preferred ones, despite mosquitoes actively feeding on both. Taken together, these results show that An. Arabiensis males are able to discern between food sources, preferentially feeding on those species of plant that provide the highest metabolic payoff. Ensuring or somehow heightening the ability to detect and obtain rewarding sugar meals by male mosquitoes reared for field release could enhance their competitive ability in the field.

  13. Aquaporin water channel AgAQP1 in the malaria vector mosquito Anopheles gambiae during blood feeding and humidity adaptation

    PubMed Central

    Liu, Kun; Tsujimoto, Hitoshi; Cha, Sung-Jae; Agre, Peter; Rasgon, Jason L.

    2011-01-01

    Altered patterns of malaria endemicity reflect, in part, changes in feeding behavior and climate adaptation of mosquito vectors. Aquaporin (AQP) water channels are found throughout nature and confer high-capacity water flow through cell membranes. The genome of the major malaria vector mosquito Anopheles gambiae contains at least seven putative AQP sequences. Anticipating that transmembrane water movements are important during the life cycle of A. gambiae, we identified and characterized the A. gambiae aquaporin 1 (AgAQP1) protein that is homologous to AQPs known in humans, Drosophila, and sap-sucking insects. When expressed in Xenopus laevis oocytes, AgAQP1 transports water but not glycerol. Similar to mammalian AQPs, water permeation of AgAQP1 is inhibited by HgCl2 and tetraethylammonium, with Tyr185 conferring tetraethylammonium sensitivity. AgAQP1 is more highly expressed in adult female A. gambiae mosquitoes than in males. Expression is high in gut, ovaries, and Malpighian tubules where immunofluorescence microscopy reveals that AgAQP1 resides in stellate cells but not principal cells. AgAQP1 expression is up-regulated in fat body and ovary by blood feeding but not by sugar feeding, and it is reduced by exposure to a dehydrating environment (42% relative humidity). RNA interference reduces AgAQP1 mRNA and protein levels. In a desiccating environment (<20% relative humidity), mosquitoes with reduced AgAQP1 protein survive significantly longer than controls. These studies support a role for AgAQP1 in water homeostasis during blood feeding and humidity adaptation of A. gambiae, a major mosquito vector of human malaria in sub-Saharan Africa. PMID:21444767

  14. Aquaporin water channel AgAQP1 in the malaria vector mosquito Anopheles gambiae during blood feeding and humidity adaptation.

    PubMed

    Liu, Kun; Tsujimoto, Hitoshi; Cha, Sung-Jae; Agre, Peter; Rasgon, Jason L

    2011-04-12

    Altered patterns of malaria endemicity reflect, in part, changes in feeding behavior and climate adaptation of mosquito vectors. Aquaporin (AQP) water channels are found throughout nature and confer high-capacity water flow through cell membranes. The genome of the major malaria vector mosquito Anopheles gambiae contains at least seven putative AQP sequences. Anticipating that transmembrane water movements are important during the life cycle of A. gambiae, we identified and characterized the A. gambiae aquaporin 1 (AgAQP1) protein that is homologous to AQPs known in humans, Drosophila, and sap-sucking insects. When expressed in Xenopus laevis oocytes, AgAQP1 transports water but not glycerol. Similar to mammalian AQPs, water permeation of AgAQP1 is inhibited by HgCl(2) and tetraethylammonium, with Tyr185 conferring tetraethylammonium sensitivity. AgAQP1 is more highly expressed in adult female A. gambiae mosquitoes than in males. Expression is high in gut, ovaries, and Malpighian tubules where immunofluorescence microscopy reveals that AgAQP1 resides in stellate cells but not principal cells. AgAQP1 expression is up-regulated in fat body and ovary by blood feeding but not by sugar feeding, and it is reduced by exposure to a dehydrating environment (42% relative humidity). RNA interference reduces AgAQP1 mRNA and protein levels. In a desiccating environment (<20% relative humidity), mosquitoes with reduced AgAQP1 protein survive significantly longer than controls. These studies support a role for AgAQP1 in water homeostasis during blood feeding and humidity adaptation of A. gambiae, a major mosquito vector of human malaria in sub-Saharan Africa.

  15. Towards a sterile insect technique field release of Anopheles arabiensis mosquitoes in Sudan: Irradiation, transportation, and field cage experimentation

    PubMed Central

    Helinski, Michelle EH; Hassan, Mo'awia M; El-Motasim, Waleed M; Malcolm, Colin A; Knols, Bart GJ; El-Sayed, Badria

    2008-01-01

    Background The work described in this article forms part of a study to suppress a population of the malaria vector Anopheles arabiensis in Northern State, Sudan, with the Sterile Insect Technique. No data have previously been collected on the irradiation and transportation of anopheline mosquitoes in Africa, and the first series of attempts to do this in Sudan are reported here. In addition, experiments in a large field cage under near-natural conditions are described. Methods Mosquitoes were irradiated in Khartoum and transported as adults by air to the field site earmarked for future releases (400 km from the laboratory). The field cage was prepared for experiments by creating resting sites with favourable conditions. The mating and survival of (irradiated) laboratory males and field-collected males was studied in the field cage, and two small-scale competition experiments were performed. Results Minor problems were experienced with the irradiation of insects, mostly associated with the absence of a rearing facility in close proximity to the irradiation source. The small-scale transportation of adult mosquitoes to the release site resulted in minimal mortality (< 6%). Experiments in the field cage showed that mating occurred in high frequencies (i.e. an average of 60% insemination of females after one or two nights of mating), and laboratory reared males (i.e. sixty generations) were able to inseminate wild females at rates comparable to wild males. Based on wing length data, there was no size preference of males for mates. Survival of mosquitoes from the cage, based on recapture after mating, was satisfactory and approximately 60% of the insects were recaptured after one night. Only limited information on male competitiveness was obtained due to problems associated with individual egg laying of small numbers of wild females. Conclusion It is concluded that although conditions are challenging, there are no major obstacles associated with the small

  16. Infertility resulting from transgenic I-PpoI male Anopheles gambiae in large cage trials

    PubMed Central

    Klein, T A; Windbichler, N; Deredec, A; Burt, A; Benedict, M Q

    2012-01-01

    Objectives Anopheles gambiae is the primary vector of malaria in sub-Saharan Africa and is a potential target of genetic control programs. We determined the capacity of male A. gambiae created by germline transformation to introduce infertility into stable age-distribution populations. We also determined effects of the transgenes on life history. Methods Stable age-distribution populations of A. gambiae mosquitoes were established in large indoor cages. Male mosquitoes carrying an I-PpoI homing endonuclease gene were introduced at ×5 and ×10 release rates where they competed with target male mosquitoes for matings. Similar trials were conducted in small cages with an additional ×1 release level. Results Infertility was successfully introduced into all target populations. In supporting experiments, complete female infertility was observed in all strains and species of the A. gambiae complex to which transgenic males were mated. Life history experiments demonstrated that reductions in I-PpoI male vigor exist in the form of reduced adult male emergence, longevity and competitiveness. Discussion A. gambiae I-PpoI males are capable of introducing high levels of infertility in target populations in indoor cage trials. This was accomplished despite losses of vigor resulting from the HEG transgene. These results motivate further trials of sexually I-PpoI A. gambiae in outdoor cage and field trials. PMID:22595271

  17. Effects of landscape anthropization on mosquito community composition and abundance

    NASA Astrophysics Data System (ADS)

    Ferraguti, Martina; Martínez-de La Puente, Josué; Roiz, David; Ruiz, Santiago; Soriguer, Ramón; Figuerola, Jordi

    2016-07-01

    Anthropogenic landscape transformation has an important effect on vector-borne pathogen transmission. However, the effects of urbanization on mosquito communities are still only poorly known. Here, we evaluate how land-use characteristics are related to the abundance and community composition of mosquitoes in an area with endemic circulation of numerous mosquito-borne pathogens. We collected 340 829 female mosquitoes belonging to 13 species at 45 localities spatially grouped in 15 trios formed by 1 urban, 1 rural and 1 natural area. Mosquito abundance and species richness were greater in natural and rural areas than in urban areas. Environmental factors including land use, vegetation and hydrological characteristics were related to mosquito abundance and community composition. Given the differing competences of each species in pathogen transmission, these results provide valuable information on the transmission potential of mosquito-borne pathogens that will be of great use in public and animal health management by allowing, for instance, the identification of the priority areas for pathogen surveillance and vector control.

  18. Mosquito repellent activity of volatile oils from selected aromatic plants.

    PubMed

    Lalthazuali; Mathew, Nisha

    2017-02-01

    Essential oils from fresh leaves of four aromatic plants viz., Ocimum sanctum, Mentha piperita, Eucalyptus globulus and Plectranthus amboinicus were extracted by hydrodistillation. The test solutions were prepared as 20% essential oil in ethanol and positive control as 20% DEET in ethanol. Essential oil blend was prepared as 5% concentration. Nulliparous, 3-5-day-old female adult Aedes aegypti mosquitoes were used for repellency screening as per ICMR protocol. The study showed that the repellency of 20% essential oil of O. sanctum, M. piperita and P. amboinicus were comparable with that of the standard DEET (20%) as no mosquito landing on the test was observed up to 6 h. The E. globulus oil exhibited mosquito repellency only upto 1½ h. Considerable mosquito landing and feeding was displayed in negative control. In the case of the oil blend, no landing of mosquitoes was seen up to 6 h as that of positive control. The results showed that the essential oil blend from O. sanctum, M. piperita, E. globulus and P. amboinicus could repel Ae. aegypti mosquitoes or prevent from feeding as in the case of DEET even at a lower concentration of 5%. This study demonstrates the potential of essential oils from O. sanctum, M. piperita, E. globulus and P. amboinicus and their blend as mosquito repellents against Ae. aegypti, the vector of dengue, chikungunya and yellow fever.

  19. [Applications of bacterial pathogens to the mosquito control].

    PubMed

    Lu, K H; Hou, R F

    1990-07-01

    Both Bacillus thuringiensis subsp. isrealensis (Bti) and Bacillus sphaericus are common bacteria found in a variety of soil and aquatic habitats. Some strains of them can produce a protein crystal, called parasporal body (or crystal) beside the spore in the cell during sporulation, and it is toxic if eaten by mosquito larvae. As the parasporal bodies are ingested into a mosquito digestive tract, they will be digested and activated by certain enzymes in alkaline digestive juice. The activated toxins can destroy midgut epithelium and other tissues, and then the mosquitoes will be intoxicated and killed. There are some factors affecting efficiency of the toxins produced by these two mosquitocidal bacteria. First, the toxicity of the toxins will decrease as larval age and density increase. Second, difference in mosquito species will demonstrate a different tolerance to both toxins. However, larvae of Anopheles are more tolerant to Bti than those of Aedes and Culex; whereas larvae of Aedes are more tolerant to B. sphaericus than Culex and Anopheles. Environmental factors are as important as the mosquito hosts in influencing the efficiency of the toxins. For examples, raising temperature under suitable ranges may increase the toxicity of the toxins. The UV light of sunlight could inhibit activity of the toxins and therefore decrease their efficiency. Quality and depth of the water are also important environmental factors affecting toxicity of the toxins to the mosquito larvae. The precipitation of the crystal and organic materials absorbing the toxins decreases their toxicity to the mosquito larvae as well.

  20. EPA-Registered Repellents for Mosquitoes Transmitting Emerging Viral Disease.

    PubMed

    Patel, Radha V; Shaeer, Kristy M; Patel, Pooja; Garmaza, Aleksey; Wiangkham, Kornwalee; Franks, Rachel B; Pane, Olivia; Carris, Nicholas W

    2016-12-01

    In many parts of the United States, mosquitoes were previously nuisance pests. However, they now represent a potential threat in the spread of viral diseases. The Aedes aegypti, Aedes albopictus, and Culex species mosquitoes are endemic to the United States and together may transmit a variety of viral diseases of growing concern, including West Nile virus, chikungunya, dengue fever, and Zika virus. The Centers for Disease Control and Prevention and the Environmental Protection Agency (EPA) recommend N,N-diethyl-meta-toluamide (DEET) as a first-line mosquito repellent, but for patients refusing to use DEET or other conventional repellents, guidance is limited to any EPA-registered product. Therefore, we conducted a systematic review of the literature to identify which EPA-registered personal mosquito repellent provides the best protection from A. aegypti, A. albopictus, and Culex spp. mosquitoes. We abstracted data from 62 published reports of EPA-registered mosquito repellents. The conventional repellent picaridin has the strongest data to support its use as a second-line agent, while IR3535 and oil of lemon eucalyptus are reasonably effective natural products. Citronella, catnip, and 2-undecanone offer limited protection or have limited data. These results can be used by pharmacists and other health care professionals to advise patients on the selection of an EPA-registered mosquito repellent. Regardless of the repellent chosen, it is vital for patients to follow all instructions/precautions in the product labeling to ensure safe and effective use.