Feeding preference of the South American endemic anomuran Aegla platensis (Decapoda, Anomura, Aeglidae)

NASA Astrophysics Data System (ADS)

Colpo, Karine Delevati; Ribeiro, Liara Colpo; Wesz, Bruna; Ribeiro, Ludmilla Oliveira

2012-04-01

In order to determine the feeding preference of Aegla platensis in streams and the importance of microorganisms in its detritivore diet, we carried out two experiments designed to evaluate the food preferences of A. platensis (1) among leaves with different levels of microbial colonization and (2) among insect larvae (Chironomidae, Simuliidae, Hydropsychidae) and microbially conditioned leaves. A. platensis preferred animal over plant food items; when only leaves were offered, this aeglid preferred the leaves with higher levels of microorganism conditioning.

Effects of Reservoir Releases on Water Quality, Macroinvertebrates, and Fish in Tailwaters: Field Study Results.

DTIC Science & Technology

1983-02-01

abundant at station 1 included Simuliidae, Culicidae, and Trichoptera. Organisms more common to natural streams, such as Ephemeroptera, Plecoptera ...20 4 Culicidae 65 36 Ceratopogonidae 4 2 Trichoptera 56 25 Ephemeroptera 10 180 Plecoptera 1 10 Coleoptera 13 2 Lepidoptera 9 0 Hydracarima. 2 24... Plecoptera 0 0 25 Coleoptera 18 0 27 Odonata 86 43 156 Hydracarina 670 258 204 Oligochaeta 3,929 612 854 Hirudinea 97 2 22 Nema toda 208 74 44 Amphipoda

Phylogeography and population diversity of Simulium hirtipupa Lutz (Diptera: Simuliidae) based on mitochondrial COI sequences

PubMed Central

Silva, Janisete G.; Hamada, Neusa

2017-01-01

High morphological homogeneity and cryptic speciation may cause the diversity within Simuliidae to be underestimated. Recent molecular studies on population genetics and phylogeography have contributed to reveal which factors influenced the diversity within this group. This study aimed at examining the genetic diversity of Simulium hirtipupa Lutz, 1910 in populations from the biomes Caatinga, Cerrado, and Atlantic Forest. In this study, we carried out phylogeographic and population genetic analyses using a fragment of the mitochondrial gene COI. The 19 populations studied were clustered into seven groups, most of which are associated with geography indicating certain genetic structure. The northern region of the state of Minas Gerais is most likely the center of origin of this species. The average intergroup genetic distance was 3.7%, indicating the presence of cryptic species. The species tree as well as the haplotype network recovered all groups forming two major groups: the first comprises groups Gr-Bahia (in which the São Francisco river has not acted as geographical barrier), Gr-Pernambuco, and Gr-Mato Grosso do Sul. The second included groups comprising populations of the states of Goiás, Tocantins, Minas Gerais, Bahia, São Paulo, and Espírito Santo. The mismatch distribution for groups was consistent with the model of demographic expansion, except for the Gr-Central-East_1 group. The diversification in this group occurred about 1.19 Mya during the Pleistocene, influenced by paleoclimatic oscillations during the Quaternary glacial cycles. PMID:29281704

Water pollution and distribution of the black fly (Diptera: Simuliidae) in the Atlantic Forest, Brazil.

PubMed

Docile, Tatiana N; Figueiró, Ronaldo; Gil-Azevedo, Leonardo H; Nessimian, Jorge L

2015-09-01

Black flies have medical importance because some species are vectors of the unenocerciasis and Mansonelosis, nevertheless, their ecology and potential use as bioindicators is still poorly studied in the Neotropical Region. In Brazil, bioindicators use is strongly focused in a multimetrical ecological index approach; this way, we investigated the black fly spatial distribution, in relation to abiotic factors correlated to water quality, to provide baseline information for their utilization as standalone indicators of lotic systems integrity. We have tested the hypothesis that environmental changes related to urbanization, lead to decreased abundance and loss in the number of species of the black fly fauna. The sampling was conducted in 10 urban and 10 preserved streams during the dry season (August-September) of 2012, in the mountainous region of Teres6polis, State of Rio de Janeiro, Brazil. The streams were characterized for their environmental integrity conditions and physico-chemical properties of water. In each stream, five different rapid points were sampled in a section of 50 meters, 10 meters apart from each other. The black flies were sampled with a kick-net sampler on rocky substrates. The material was separated and the larvae were sorted in morphotypes, and later, the final instar specimens were dissected and identified with the help of taxonomical literature at species level. A total abundance of 488 larvae from nine species were collected, 5 (1.02 %) in extremely impacted streams, 470 (96.31 %) in intermediate streams and 13 (2.66 %) in preserved streams. The visual evaluation (HII) differed in relation to the water physico-chemical evaluation, in which more variation in the characterization of the sampling sites was observed. In Canonical Correspondence Analysis Simulium subpallidum, S. inscrustatum and S. pertinax were significantly associated with intermediate values of most of the variables, and then to intermediate impacted sites. On the other hand, Lutzsimulium hirticosta, S. subnigrzm and Simulium sp. A were associated to low values of chemical variables, and then to more preserved sites. Most studies on the bioindicator potential of Simuliidae have suggested an approach to agricultural impacts, while our results, on the other hand, showed that Simuliidae species were present in streams with intermediate urban pollution impacts, but absent in heavily impacted sites. Thus, our data suggested that some species are associated to more pristine breeding sites, such as L. hirticosta and Simulium sp. A, while others may be good bioindicators of moderately impacted streams, such as S. nertinax. S. subnigrum and S. subpallidum.

Molecular analyses on host-seeking black flies (Diptera: Simuliidae) reveal a diverse assemblage of Leucocytozoon (Apicomplexa: Haemospororida) parasites in an alpine ecosystem.

PubMed

Murdock, Courtney C; Adler, Peter H; Frank, Jared; Perkins, Susan L

2015-06-25

Molecular studies have suggested that the true diversity of Leucocytozoon (Apicomplexa: Haemospororida) species well exceeds the approximately 35 currently described taxa. Further, the degree of host-specificity may vary substantially among lineages. Parasite distribution can be influenced by the ability of the parasite to infect a host, vector preferences for certain avian hosts, or other factors such as microhabitat requirements that increase the probability that vertebrate hosts and vectors are in frequent contact with each other. Whereas most studies of haemosporidians have focused on passerine hosts, sampling vectors in the same habitats may allow the detection of other lineages affecting other hosts. We sampled abundant, ornithophilic black flies (Simuliidae) across a variety of sites and habitats in the Colorado Rocky Mountains throughout the summer of 2007. Black flies were screened with PCR using Leucocytozoon-specific primers that amplify a portion of the cytochrome b gene, and the sequences were compared to the haplotypes in the MalAvi database. Infections of Leucocytozoon from birds sampled in the same area were also included. We recovered 33 unique haplotypes from the black flies in this study area, which represented a large phylogenetic diversity of Leucocytozoon parasites. However, there were no clear patterns of avian host species or geography for the distribution of Leucocytozoon haplotypes in the phylogeny. Sampling host-seeking vectors is a useful way to obtain a wide variety of avian haemosporidian haplotypes from a given area and may prove useful for understanding the global patterns of host, parasite, and vector associations of these ubiquitous and diverse parasites.

A New Anthropophilic Species of Simulium (Trichodagmia) (Diptera: Simuliidae) From Amazonia: Morphology, Chromosomes, and DNA Sequences.

PubMed

Nascimento, Jeane Marcelle Cavalcante Do; Hamada, Neusa; Andrade-Souza, Vanderly; Adler, Peter H

2018-01-10

The black fly Simulium (Trichodagmia) hirtipupa Lutz (Diptera: Simuliidae) is widely distributed in southern Brazil, with one report from Amapá state in the northern region of Brazilian Amazonia. Morphological comparison of northern and southern populations revealed differences in all life stages, corroborated by chromosomal and molecular analyses, and indicated that the population previously identified as S. hirtipupa from Amapá state represents an undescribed species. This new species is described based on all life stages above the egg, and its chromosomal and molecular divergence from S. hirtipupa is highlighted. Simulium criniferum n. sp. can be diagnosed by the deeply concave male ventral plate with a prominent median projection bearing a ventral keel; female anal lobe in lateral view with a broadly rounded, distal membranous area about as long as wide; pupa with a boot-shaped cocoon bearing a minutely bubbled surface, cephalic plate and thorax with abundant hair-like tubercles, and gill of 12 translucent filaments with darkly sclerotized, acuminate tips; and larva with the body cuticle bearing spiniform setae, abdomen truncated posteriorly, and gill histoblast in situ with the filament tips directed ventrally. Chromosomally, the new species has five unique fixed inversions and uniquely shares three additional fixed inversions with its nearest relative, S. hirtipupa. Partial COI sequences indicate a genetic distance of ~9% between the new species and S. hirtipupa. Females of the new species are anthropophilic. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Chromosomal Translocations in Black Flies (Diptera: Simuliidae)-Facilitators of Adaptive Radiation?

PubMed

Adler, Peter H; Yadamsuren, Oyunchuluun; Procunier, William S

2016-01-01

A macrogenomic investigation of a Holarctic clade of black flies-the Simulium cholodkovskii lineage-provided a platform to explore the implications of a unique, synapomorphic whole-arm interchange in the evolution of black flies. Nearly 60 structural rearrangements were discovered in the polytene complement of the lineage, including 15 common to all 138 analyzed individuals, relative to the central sequence for the entire subgenus Simulium. Three species were represented, of which two Palearctic entities (Simulium cholodkovskii and S. decimatum) were sympatric; an absence of hybrids confirmed their reproductive isolation. A third (Nearctic) entity had nonhomologous sex chromosomes, relative to the other species, and is considered a separate species, for which the name Simulium nigricoxum is revalidated. A cytophylogeny is inferred and indicates that the two Palearctic taxa are sister species and these, in turn, are the sister group of the Nearctic species. The rise of the S. cholodkovskii lineage encompassed complex chromosomal and genomic restructuring phenomena associated with speciation in black flies, viz. expression of one and the same rearrangement as polymorphic, fixed, or sex linked in different species; taxon-specific differentiation of sex chromosomes; and reciprocal translocation of chromosome arms. The translocation is hypothesized to have occurred early in male spermatogonia, with the translocated chromosomal complement being transmitted to the X- and Y-bearing sperm during spermatogenesis, resulting in alternate disjunction of viable F1 translocation heterozygotes and the eventual formation of more viable and selectable F2 translocation homozygous progeny. Of 11 or 12 independently derived whole-arm interchanges known in the family Simuliidae, at least six are associated with subsequent speciation events, suggesting a facilitating role of translocations in adaptive radiations. The findings are discussed in the context of potential structural and functional interactions for future genomic research.

A new species of Simulium (Simulium) (Diptera: Simuliidae) from Genting Highlands, Malaysia.

PubMed

Ya'cob, Zubaidah; Takaoka, Hiroyuki; Low, Van Lun; Sofian-Azirun, Mohd

2018-06-01

Simulium (Simulium) rasuli sp. nov. is described from two females collected by a Malaise trap in Genting Highlands, Peninsular Malaysia. This new species is placed in the Simulium christophersi species-group of the subgenus Simulium. The female of this new specie is characterized by the scutum with three longitudinal vittae, dark legs, claw with a small subbasal tooth, and ovipositor valve triangular with its inner margin nearly straight. This new species is distinguished in the female from all the six named species of the species-group by the entirely brownish-black femora and tibiae. Copyright © 2018 Elsevier B.V. All rights reserved.

[Adolpho Lutz's collection of black flies (Diptera - Simuliidae), its history and importance].

PubMed

Ribeiro do Amaral-Calvão, Ana Margarida; Maia-Herzog, Marilza

2003-01-01

This is part of a master's thesis currently being written under the auspices of the Post-Graduate Program in Animal Biology of the Federal University of Rio de Janeiro, with support from CAPES. It presents the species of black flies in Adolpho Lutz's collection, held at the Laboratory of Black Flies and Oncocercosis of the Department of Entomology of the Instituto Oswaldo Cruz. A pioneer in the study of these dipterons, Lutz described about 25 species from different places in Brazil. A vector of round worm, the black fly's importance to public health was recognized at the end of the 1920s.

Description of male, pupa and larva of Simulium (Asiosimulium) wanchaii (Diptera: Simuliidae) from Thailand, with keys to identify four species of the subgenus Asiosimulium.

PubMed

Srisuka, W; Takaoka, H; Saeung, A

2015-09-01

The male, pupa and mature larva of Simulium (Asiosimulium) wanchaii Takaoka & Choochote, one of the four species of the small Oriental black fly subgenus Asiosimulium, are described for the first time based on samples collected from Thailand. The male S. (A.) wanchaii is characterized based on the enlarged hind basitarsus and the ventral plate which is much wider than long. The pupa and larva are characterized by the gill with 19 filaments and the deep postgenal cleft, respectively. Keys are provided to identify all the four species of the subgenus Asiosimulium for females, males, pupae and mature larvae.

Insights into the epidemiological link between biting flies and pemphigus foliaceus in southeastern Brazil.

PubMed

Vernal, Sebastian; Pepinelli, Mateus; Casanova, Claudio; Goulart, Thais M; Kim, Olivia; De Paula, Natalia A; Pinto, Mara C; Sá-Nunes, Anderson; Roselino, Ana Maria

2017-12-01

Black fly and sandfly bites are related to the endemicity of pemphigus foliaceus (PF); however, an immune reaction against the salivary proteins from these flies still requires confirmation in the case of PF patients living in southeastern Brazil. To georeference the distribution of Simuliidae (Diptera: Simuliidae) and Phlebotominae (Diptera: Psychodidae) and of PF cases in the northeastern region of São Paulo State, and to assess the humoral immune response against salivary gland extracts (SGEs) from biting flies in PF patients, relatives, and neighbours. PF patients' medical information recorded between 1965 and 2014 were obtained from the database of the University Hospital. Data on the distribution of fly species were collected from scientific reports and epidemiological databases. Spatial maps relating the distribution of biting flies with PF cases were plotted. Serum IgG antibodies against the SGEs from Simulium nigrimanum, Nyssomyia neivai, and Aedes aegypti (as control) were determined by ELISA. Two hundred and eighty-five PF cases were distributed in 60 municipalities with a prevalence of 57.5 per million inhabitants, revealing well-defined geographical clusters. S. nigrimanum and N. neivai specimens were registered in eight (13.3%) and 26 (43.3%) of these municipalities, respectively. PF patients, and their relatives presented higher levels of IgG against the SGEs of S. nigrimanum and N. neivai (P<0.001 for both), but not against the SGE from A. aegypti (P=0.115 and P=0.552, respectively), as compared to controls. IgG against the SGEs from S. nigrimanum and N. neivai but not against the SGE from A. aegypti correlated with levels of anti-Desmoglein 1 in PF patients (r=0.3848, P=0.039; and r=0.416, P=0.022, respectively). An epidemiological link between biting flies and PF in southeastern Brazil is proposed, implying a possible role of the salivary proteins from these flies in PF etiopathogenesis. Copyright © 2017 Elsevier B.V. All rights reserved.

Distribution of larval and pupal stages of Simulium (Diptera: Simuliidae) flies in the Nilgiris hills of Tamil Nadu.

PubMed

Soundararajan, C; Nagarajan, K; Arul Prakash, M

2017-09-01

Endemicity of onchocerciasis (river blindness) in humans is linked to the location of Simulium spp. (black fly). The distribution of immature stages of Simulium in Sholur, Pykara, Gudalur, Coonoor and Kotagiri streams of the Nilgiris hills of Tamil Nadu was investigated during the months of May and July 2012. Out of these five streams, only Sholur was infested with larval and pupal stages of Simulium spp. Out of six plants collected from various water bodies, larval and pupal stages were found on the leaves and stems of an aquatic plant Nasturtium officinale and on the roots and leaves of Pennisetum glandulosum. The stages of Simulium were observed only during the summer month of May.

New records of the black fly fauna (Diptera: Simuliidae) in two rivers of the western Amazonia, Brazil.

PubMed

Nascimento, Erika S; Marchon-Silva, Verônica; Maia-Herzog, Marilza

2009-01-01

Our goal was to verify the presence and the composition of black floy species in the Antimari and Acre rivers, located in the end of Western Amazonia, where this entomological inquiry was accomplished. Along the Antimari and Acre rivers, 19 localities were studied and 133 larvae and 197 pupae were collected, totalizing 330 black floy immatures. The following species are recorded for the first time in this area: Simulium (Psaroniocompsa) amazonicum Goeldi, Simulium (Psaroniocompsa) oyapockense Floch & Abonnenc, Simulium (Psaroniocompsa) quadrifidum Lutz, Simulium (Psilopelmia) lutzianum Pinto, Simulium (Psilopelmia) perfloavum Roubaud and Simulium (Notolepria) exiguum Roubaud. Our data suggest that S. amazonicum, S. oyapockense and S. quadrifidum have a wide geographical distribution as well as population density.

Simulium (Gomphostilbia) merapiense sp. nov. (Diptera: Simuliidae) from Java, Indonesia.

PubMed

Takaoka, Hiroyuki; Sofian-Azirun, Mohd; Ya'cob, Zubaidah; Chen, Chee Dhang; Low, Van Lun; Zaid, Adnan

2016-01-01

Simulium (Gomphostilbia) merapiense sp. nov. is described based on females, males, pupae, and mature larvae from Yagyakarta, Java, Indonesia. This new species is placed in the Simulium epistum species-group, and is characterized by the pupal gill with eight short filaments all arising at the same level from a short stalk, somewhat enlarged basal fenestra, entirely bare pupal head and thoracic integument, and small and short larval postgenal cleft. These characters rarely are found in the subgenus. Taxonomic notes are given to separate this new species from related species of the S. epistum species-group. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Characterization of Simulium (Simulium) hackeri Edwards (Diptera: Simuliidae) from Malaysia: Morphological description of the pupa and larva, and DNA barcoding.

PubMed

Ya'cob, Zubaidah; Takaoka, Hiroyuki; Low, Van Lun; Sofian-Azirun, Mohd

2018-04-27

Simulium (Simulium) hackeri Edwards, 1928 of the Simulium variegatum species-group from Malaysia was described initially based on the female specimen from Cameron Highlands, Pahang. In the present study, the pupa and larva of this species are described for the first time. Their morphological characters resemble those of the Simulium variegatum species-group by having six gill filaments per side, abdomen with dorsal spine-combs at least on segments 7 and 8, cocoon with wall-pocket shaped and with or without an anterodorsal projection. Postgenal cleft of the larva medium-sized, rarely small, ventral papillae small or absent. The DNA barcode of this species is also reported herein. Copyright © 2018 Elsevier B.V. All rights reserved.

Insects as vectors: systematics and biology.

PubMed

Rodhain, F

2015-04-01

Among the many complex relationships between insects and microorganisms such as viruses, bacteria and parasites, some have resulted in the establishment of biological systems within which the insects act as a biological vector for infectious agents. It is therefore advisable to understand the identity and biology of these vectors in depth, in order to define procedures for epidemiological surveillance and anti-vector control. The following are successively reviewed in this article: Anoplura (lice), Siphonaptera (fleas), Heteroptera (bugs: Cimicidae, Triatoma, Belostomatidae), Psychodidae (sandflies), Simuliidae (black flies), Ceratopogonidae (biting midges), Culicidae (mosquitoes), Tabanidae (horseflies) and Muscidae (tsetse flies, stable flies and pupipara). The authors provide a rapid overview of the morphology, systematics, development cycle and bio-ecology of each of these groups of vectors. Finally, their medical and veterinary importance is briefly reviewed.

Two new Species of Simulium (Simulium) (Diptera: Simuliidae) From Mount Murud, Sarawak, Malaysia.

PubMed

Takaoka, Hiroyuki; Ya'cob, Zubaidah; Sofian-Azirun, Mohd

2015-01-01

Two new species of black flies, Simulium (Simulium) murudense and Simulium (Simulium) cheedhangi, are described on the basis of females, males, pupae, and larvae collected in Mount Murud, Sarawak, Malaysia. Both species belong to the Simulium melanopus Edwards species group. S. (S.) murudense sp. nov. is distinguished from most known species by a combination of the haired basal portion of the radial vein and the darkened fore coxae, and S. (S.) cheedhangi sp. nov. is characterized in the female by having a medium-sized claw tooth and in the pupa by six somewhat inflated gill filaments. Notes are given on the S. melanopus species-group in Sarawak and Sabah. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Two New Species of the Simulium (Simulium) variegatum Species-Group of Black Flies (Diptera: Simuliidae) From Thailand.

PubMed

Takaoka, Hiroyuki; Srisuka, Wichai; Saeung, Atiporn

2017-09-01

Two new species of black flies, Simulium (Simulium) srisukai and S. (S.) kiewmaepanense, are described from specimens collected in Thailand. Both species are assigned to the Simulium variegatum species-group of the subgenus Simulium (Simulium) Latreille. They are characterized by the darkened female femora and tibiae and six inflated pupal gill filaments, and the darkened female tibiae and six ordinary thread-like pupal gill filaments, respectively. Taxonomic notes are given to separate these new species from 10 related species among the group. These new species represent the third and fourth species of the S. variegatum species-group from Thailand. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com Version of Record, first published online May 15, 2017 with fixed content and layout in compliance with Art. 8.1.3.2 ICZN.

Effects of sea lamprey (Petromyzon marinus) control in the Great Lakes on aquatic plants, invertebrates and amphibians

USGS Publications Warehouse

Gilderhus, P.A.; Johnson, B.G.H.

1980-01-01

The chemicals 3-trifluoromethyl-4-nitrophenol (TFM) or a combination of TFM and 2a??,5-dichloro-4a??-nitrosalicylanilide (Bayer 73) have been used to control the sea lamprey (Petromyzon marinus) in the Great Lakes for about 20 yr. These chemicals cause some mortalities of Oligochaeta and Hirudinea, immature forms of Ephemeroptera (Hexagenia sp.), and certain Trichoptera, Simuliidae, and Amphibia (Necturus sp.). The combination of TFM and Bayer 73 may affect some Pelecypoda and Gastropoda, but its overall effects on invertebrates are probably less than those of TFM alone. Granular Bayer 73 is likely to induce mortalities among oligochaetes, microcrustaceans, chironomids, and pelecypods. No evidence exists that the lampricides have caused the catastrophic decline or disappearance of any species. The overall impact of chemical control of sea lampreys on aquatic communities has been minor compared with the benefits derived.

Nondestructive DNA extraction from blackflies (Diptera: Simuliidae): retaining voucher specimens for DNA barcoding projects.

PubMed

Hunter, Stephanie J; Goodall, Tim I; Walsh, Kerry A; Owen, Richard; Day, John C

2008-01-01

A nondestructive, chemical-free method is presented for the extraction of DNA from small insects. Blackflies were submerged in sterile, distilled water and sonicated for varying lengths of time to provide DNA which was assessed in terms of quantity, purity and amplification efficiency. A verified DNA barcode was produced from DNA extracted from blackfly larvae, pupae and adult specimens. A 60-second sonication period was found to release the highest quality and quantity of DNA although the amplification efficiency was found to be similar regardless of sonication time. Overall, a 66% amplification efficiency was observed. Examination of post-sonicated material confirmed retention of morphological characters. Sonication was found to be a reliable DNA extraction approach for barcoding, providing sufficient quality template for polymerase chain reaction amplification as well as retaining the voucher specimen for post-barcoding morphological evaluation. © 2007 The Authors.

[New public health challenges in vector management: black flies in Murcia (Spain)].

PubMed

Sánchez-López, Pedro F; Ruiz-Arrondo, Ignacio; Kotter, Heiko; Pacheco Martínez, Francisco; Segovia Hernández, Manuel; Gómez Campoy, M Elisa

Historically, no black fly (Diptera: Simuliidae) nuisance has been reported in the Murcia Region. Back in September 2016 the Ojós City Council has contacted the Regional Public Health General Directorate for help regarding a local insect nuisance, most probably based on mosquitoes. After sampling with a BG-sentinel 2 trap, collecting adult specimens with an entomological aspirator, and collect larvae and pupae on submerged giant cane stalks at the river, it turned out that Simulium sergenti was the insect species causing the nuisance. This species is not considered particularly anthropophilic; therefore, a low vector risk for human health was considered. However, the high fly density impaired the life quality of the people at the village. A management plan was recommended, treating the river with Bacillus thuringiensis var israelensis. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Three Taxa in One: Cryptic Diversity in the Black Fly Simulium nobile (Diptera: Simuliidae) in Southeast Asia.

PubMed

Low, Van Lun; Takaoka, Hiroyuki; Pramual, Pairot; Adler, Peter H; Ya'cob, Zubaidah; Chen, Chee Dhang; Yotopranoto, Subagyo; Zaid, Adnan; Hadi, Upik Kesumawati; Lardizabal, Maria Lourdes; Nasruddin-Roshidi, Affan; Sofian-Azirun, Mohd

2016-07-01

We access the molecular diversity of the black fly Simulium nobile De Mejiere, using the universal cytochrome c oxidase subunit I (COI) barcoding gene, across its distributional range in Southeast Asia. Our phylogenetic analyses recovered three well-supported mitochondrial lineages of S. nobile, suggesting the presence of cryptic species. Lineage A is composed of a population from Sabah, East Malaysia (Borneo); lineage B represents the type population from Java, Indonesia; and lineage C includes populations from the mainland of Southeast Asia (Peninsular Malaysia and Thailand). The genetic variation of lineage C on the mainland is greater than that of lineages A and B on the islands of Borneo and Java. Our study highlights the value of a molecular approach in assessing species status of simuliids in geographically distinct regions. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The lack of effect of low temperature and high turbidity on operational Bacillus thuringiensis subsp. israelensis activity against larval black flies (Diptera: Simuliidae).

PubMed

Gray, Elmer W; Wyatt, Roger D; Adler, Peter H; Smink, John; Cox, Julie E; Noblet, Ray

2012-06-01

Black fly suppression programs are conducted across a wide range of environmental conditions, targeting a variety of pest species with diverse life histories. Operational applications of Vectobac 12AS (Bacillus thuringiensis subsp. israelensis) were conducted during times characterized by water temperature and turbidity extremes. Applications were conducted in the Yellow River in central Wisconsin targeting Simulium annulus and S. johannseni when water temperatures were 1-2 degrees C. Applications were conducted in the Green River in western North Carolina targeting the S. jenningsi group after a rain event, when portions of the treatment zone experienced turbidities of 276 nephelometric turbidity units. Excellent larvicidal activity was observed in both programs, with 97% mortality or greater being observed at distances over 5 km downstream of a treatment site. Mortality data for larval black flies in 2 operational suppression programs conducted in 2011 demonstrated a negligible effect of near-freezing water temperatures and exceptionally high turbidity on Bti activity.

Descriptions of the female and larva of Simulium (Gomphostilbia) udomi (Diptera: Simuliidae) from Thailand, and its transfer to the Simulium asakoae species-group.

PubMed

Saeung, Atiporn; Srisuka, Wichai; Low, Van Lun; Maleewong, Wanchai; Takaoka, Hiroyuki

2017-08-01

The female and larva of Simulium (Gomphostilbia) udomi Takaoka & Choochote from Thailand are described for the first time. The female of this species is similar to those of S. (G.) asakoae Takaoka & Davies from Peninsular Malaysia, Thailand, Hong Kong and Vietnam, and S. (G.) chiangdaoense Takaoka & Srisuka from Thailand. The larva of this species is similar to S. (G.) curtatum Jitklang et al. and S. (G.) nr. asakoae 2 from Thailand in having a medium-long postgenal cleft. Taxonomic notes are given to separate this species from these related species. The COI gene sequence of S. (G.) udomi is compared with those of eight species of the S. asakoae species-group and three species of the S. ceylonicum species-group. This species is transferred from the S. ceylonicum species-group to the S. asakoae species-group based on the adult female and male morphological characters, comparisons of the genetic distances and phylogenetic relationships inferred from the COI gene sequences. Copyright © 2017 Elsevier B.V. All rights reserved.

A New Human-Biting Black Fly Species of Simulium (Simulium) (Diptera: Simuliidae) From Thailand.

PubMed

Takaoka, Hiroyuki; Srisuka, Wichai; Saeung, Atiporn

2017-07-01

Simulium (Simulium) umphangense, a new human-biting species of black fly, is described based on females captured while attacking humans in western and central Thailand. The female of this new species is similar to those of S. (S.) indicum Becher, S. (S.) nigrogilvum Summers, and S. (S.) vanellum Huang et al. in the Simulium griseifrons species-group of the subgenus Simulium Latreille in having the frons densely covered with golden-yellow short hairs, a character rarely found in the subgenus Simulium. This new species is readily distinguished from the three related species by having a darkened fore tibia, a bare subcosta (or rarely with a few hairs), and an ovipositor valve not protruded posteriorly. Additional diagnostic characters of this new species are noted. This is the seventh human-biting species of black fly in Thailand. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com Version of Record, first published online April 7, 2017 with fixed content and layout in compliance with Art. 8.1.3.2 ICZN.

Simulium maleewongae, a New Species of Simulium (Gomphostilbia) (Diptera: Simuliidae) From Thailand.

PubMed

Takaoka, Hiroyuki; Srisuka, Wichai; Saeung, Atiporn

2017-01-01

Simulium (Gomphostilbia) maleewongae sp. nov. is described based on the adult males and females, their pupal exuviae, and larvae from Thailand. This new species is placed in the Simulium gombakense species-group of Simulium (Gomphostilbia). It is characterized by the female cibarium with a cup-like appendage, male ventral plate deeply depressed ventromedially, pupal gill composed of an inflated structure and eight slender filaments, cone-shaped pupal terminal hooks, and cocoon with an anterodorsal projection. Taxonomic notes are given to separate this new species from 10 other species of the same species-group known from China, India, Malaysia, Thailand, Nepal, and Vietnam. Keys to identify all 11 species of the S. gombakense species-group are provided for females, males, pupae, and larvae. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com Version of Record, first published online October 20, 2016 with fixed content and layout in compliance with Art. 8.1.3.2 ICZN.

A New Species of Simulium (Gomphostilbia) (Diptera: Simuliidae) From Kalimantan, Indonesia, With Keys to Identify 19 Bornean Species of the Subgenus Gomphostilbia.

PubMed

Takaoka, Hiroyuki; Sofian-Azirun, Mohd; Ya'cob, Zubaidah; Chen, Chee Dhang; Low, Van Lun; Harmonis

2016-07-01

A new simuliid species, Simulium kalimantanense sp. nov., is described on the basis of females, males, pupae, and mature larvae from East Kalimantan, Indonesia, and is assigned to the Simulium banauense species-group of Simulium (Gomphostilbia). This new species has close similarities to S alienigenum Takaoka from the Philippines, in many characters including the adult antennal color pattern and pupal gill with four long filaments arranged in two pairs each bearing a long stalk, but is distinguished from the latter in the female by the longer sensory vesicle and in the pupa by the gill with an elongate common basal stalk. Simulium kalimantanense sp. nov. is the first member of the S. banauense group in Borneo, and marks the most southerly distribution of the group. Keys to identify 19 Bornean species of the subgenus Gomphostilbia are provided. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Identification of semiochemicals attractive to Simulium vittatum (IS-7).

PubMed

Verocai, G G; McGAHA, T W; Iburg, J P; Katholi, C R; Cupp, E W; Noblet, R; Unnasch, T R

2017-06-01

Many blackfly species (Diptera: Simuliidae) are economically important insect pests, both as nuisance biters and as vectors of pathogens of medical and veterinary relevance. Among the important blackfly pest species in North America is Simulium vittatum Zetterstedt sensu lato. The objective of this study was to identify compounds excreted by mammalian hosts that are attractive to host-seeking S. vittatum females. The attractiveness of putative compounds to colonized S. vittatum was tested through electrophysiological (electroantennography; n = 58 compounds) and behavioural (Y-tube assays; n = 7 compounds in three concentrations) bioassays. Five compounds were significantly attractive to host-seeking S. vittatum females: 1-octen-3-ol; 2-heptanone; acetophenone; 1-octanol, and naphthalene. These candidate compounds might be useful as attractants in traps that could be developed for use in alternative or complementary management tactics in programmes to suppress nuisance blackfly populations, or for the collection of samples in which to study the transmission ecology of pathogens transmitted by blackflies of the S. vittatum complex. © 2016 The Royal Entomological Society.

Effects of sea lamprey substrate modification and carcass nutrients on macroinvertebrate assemblages in a small Atlantic coastal stream

USGS Publications Warehouse

Weaver, Daniel M.; Coghlan, Stephen M.; Zydlewski, Joseph D.

2018-01-01

Aquatic macroinvertebrates respond to patch dynamics arising from interactions of physical and chemical disturbances across space and time. Anadromous fish, such as sea lamprey, Petromyzon marinus, migrate from the ocean and alter physical and chemical properties of recipient spawning streams. Sea lamprey disturb stream benthos physically through nest construction and spawning, and enrich food webs through nutrient deposition from decomposing carcasses. Sea lamprey spawning nests support greater macroinvertebrate abundance than adjacent reference areas, but concurrent effects of stream bed modification and nutrient supplementation have not been examined sequentially. We added carcasses and cleared substrate experimentally to mimic the physical disturbance and nutrient enrichment associated with lamprey spawning, and characterized effects on macroinvertebrate assemblage structure. We found that areas receiving cleared substrate and carcass nutrients were colonized largely by Simuliidae compared to upstream and downstream control areas that were colonized largely by Hydropsychidae, Philopotamidae, and Chironomidae. Environmental factors such as stream flow likely shape assemblages by physically constraining macroinvertebrate establishment and feeding. Our results indicate potential changes in macroinvertebrate assemblages from the physical and chemical changes to streams brought by spawning populations of sea lamprey.

DNA barcoding as an aid for species identification in austral black flies (Insecta: Diptera: Simuliidae).

PubMed

Hernández-Triana, Luis M; Montes De Oca, Fernanda; Prosser, Sean W J; Hebert, Paul D N; Gregory, T Ryan; McMurtrie, Shelley

2017-04-01

In this paper, the utility of a partial sequence of the COI gene, the DNA barcoding region, for the identification of species of black flies in the austral region was assessed. Twenty-eight morphospecies were analyzed: eight of the genus Austrosimulium (four species in the subgenus Austrosimulium s. str., three species in the subgenus Novaustrosimulium, and one species unassigned to subgenus), two of the genus Cnesia, eight of Gigantodax, three of Paracnephia, one of Paraustrosimulium, and six of Simulium (subgenera Morops, Nevermannia, and Pternaspatha). The neighbour-joining tree derived from the DNA barcode sequences grouped most specimens according to species or species groups recognized by morphotaxonomic studies. Intraspecific sequence divergences within morphologically distinct species ranged from 0% to 1.8%, while higher divergences (2%-4.2%) in certain species suggested the presence of cryptic diversity. The existence of well-defined groups within S. simile revealed the likely inclusion of cryptic diversity. DNA barcodes also showed that specimens identified as C. dissimilis, C. nr. pussilla, and C. ornata might be conspecific, suggesting possible synonymy. DNA barcoding combined with a sound morphotaxonomic framework would provide an effective approach for the identification of black flies in the region.

Evolution, epidemiology, and population genetics of black flies (Diptera: Simuliidae).

PubMed

Adler, Peter H; Cheke, Robert A; Post, Rory J

2010-10-01

More than 2000 species of black flies feed on vertebrate blood; 1.5% of all species are vectors of pathogens that cause human diseases. Of nine simuliid-borne animal diseases, only two, mansonellosis and onchocerciasis, afflict humans. Onchocerciasis is a debilitating disease infecting an estimated 40 million people in Africa, Latin America, and Yemen, whereas mansonellosis is a mild disease in the Neotropics. Cytogenetic studies of natural populations of more than 500 species of black flies have revealed that the classic morphospecies of taxonomists is typically a complex of two or more reproductively isolated entities, or sibling (cryptic) species. Most vectors of human pathogens are sibling species, each ecologically unique in traits such as breeding habitats, dispersal capabilities, and degree of vector competence. We review the evolution of black flies, the cytogenetics that have revealed about 260 cytologically distinct entities, the molecular studies that continue to expose additional hidden biodiversity, and a case study of the epidemiology of the Simulium damnosum complex, the largest species complex of blood-feeding arthropods on Earth and the premier group of black flies responsible for human onchocerciasis. Copyright 2010 Elsevier B.V. All rights reserved.

A new species of Simulium (Chirostilbia) (Diptera: Simuliidae) from Mantiqueira mountain range, southeastern Brazil.

PubMed

Hamada, Neusa; Nascimento, Jeane Marcelle Cavalcante; Pepinelli, Mateus

2015-10-01

Simulium (Chirostilbia) vitribasi n. sp. from the Mantiqueira mountain range, in São Paulo and Minas Gerais states, southeastern Brazil, is described and illustrated based on male, female, pupal and larval morphologies. The pupae of the new species is similar to the one of Simulium pertinax Kollar, one of the most voracious black fly species in the South and Southeast regions of Brazil and a target of control programs in these regions. But the pupa of the new species has a large basal fenestra in the gills that distinguishes it from all other S. (Chirostilibia) species. The other life stages of the new species also have morphological characters that distinguish it from the other species in the subgenus: male has scutum black, with patches of thick, golden hairs; female has scutum similar to that of the male, without banding or other markers, abdominal tergites I and II whitish and sternite VIII dark, heavily sclerotized; anal lobe almost as wide as long, with thin, long hairs on its outer margin; larva body cuticle has wide scale-like setae, with lobulated distal margins. Females were not observed biting humans during the fieldwork. Copyright © 2015 Elsevier B.V. All rights reserved.

[Incidence and damages inflicted by simuliid flies in the GDR district of Schwerin].

PubMed

Gräfner, G; Zimmermann, H; Karge, E; Münch, J; Ribbeck, R; Hiepe, T

1976-03-01

Systematic faunal studies in the district Schwerin showed at the present time there are 3 more or less damage-biotopes existing in the districts of Perleberg, Ludwigslust and Parchim; 5 river sources can be considered as potential sources, 5 are temporary and 2 are ephemeral whilst in 3 further areas environmental influences such as effluent impairs the flow of the river and the developmental stages of Simuliidae were not observed.--The following species were found: Boophthora erythrocephala, Wilhelmia salopiensis, Wilhelmia equina, Odagmia ornata, Eusimulium aureum and Eusimulium lundstroemi.--The damage statistics covering the period 1966--1971 showed in the district of Schwerin, due to Simuliid attacks, 38 cattle died, 170 were seriously ill; in 1967 5 horses were seriously ill; in 1971, 3 pigs died and 27 were seriously ill.--The symptoms were manifested by pathological petechiae, scabs and oedema, also by insufficiency of the heart and circulatory system, diminished performance and growth disturbance. In severe cases heart and circulation failure occurred, paresis, coma and death followed.--The real economic significance of the Simuliid attacks rest with its strong and prolonged distrubance in young animals, as well as in pronounced irreparable diminished performance in diseased dairy cattle.

[Ecological safety of mosquitocidal biocides based on Bacillus thuringiensis israelensis].

PubMed

Rydzanicz, Katarzyna; Lonc, Elzbieta

2010-01-01

Bacillus thuringiensis israelensis (Bti) has been developed into many products for the biological control of dipteran larvae, including mosquitoes (Culicidae), black flies (Simuliidae), and midges (Chironomidae) in various parts of the World. Bti appears to pose significantly less of a risk than other chemical pesticides used for mosquito control and eradication programs. Bioproducts based on Bti are highly selective with short environmental persistence, and thus they have very little potential to cause damage to populations of non-target organisms. So far, no example of an unexpected pathogenic organism being developed in the field as well as no examples of resistance to Bti both laboratory and field populations of mosquitoes have been documented. There are some indications that large declines in insect biomass can occur after long-term use of Bti in freshwater wetlands. However, no evidence for permanent damage to ecosystem function has been found. Organisms that utilized insects for food, adapted to the declines and either switched to other food sources or migrate (birds) outside of the treated zones to acquire insects. Even though over 40 tons of Bti have been applied in West Africa alone, no indications of human health or non-target effects have been reported.

An Insight into the Sialome of the Black Fly, Simulium vittatum

PubMed Central

Andersen, John F.; Pham, Van M.; Meng, Zhaojing; Champagne, Donald E.; Ribeiro, José M. C.

2009-01-01

Adaptation to vertebrate blood feeding includes development of a salivary ‘magic potion’ that can disarm host hemostasis and inflammatory reactions. Within the lower Diptera, a vertebrate blood-sucking mode evolved in the Psychodidae (sand flies), Culicidae (mosquitoes), Ceratopogonidae (biting midges), Simuliidae (black flies), and in the frog-feeding Corethrellidae. Sialotranscriptome analyses from several species of mosquitoes and sand flies and from one biting midge indicate divergence in the evolution of the blood-sucking salivary potion, manifested in the finding of many unique proteins within each insect family, and even genus. Gene duplication and divergence events are highly prevalent, possibly driven by vertebrate host immune pressure. Within this framework, we describe the sialome (from Greek sialo, saliva) of the black fly Simulium vittatum and discuss the findings within the context of the protein families found in other blood-sucking Diptera. Sequences and results of Blast searches against several protein family databases are given in Supplemental Tables S1 and S2, which can be obtained from http://exon.niaid.nih.gov/transcriptome/S_vittatum/T1/SV-tb1.zip and http://exon.niaid.nih.gov/transcriptome/S_vittatum/T2/SV-tb2.zip. PMID:19166301

Outstanding insecurities concerning the use of an Ov16-based ELISA in the Amazonia onchocerciasis focus.

PubMed

Luz, Sérgio Luiz Bessa; Crainey, James Lee; Shelley, Anthony John; Rubio, Miguel

2014-07-01

In a recent issue of Memórias do Instituto Oswaldo Cruz, published in Rio de Janeiro in February 2014 (109: 87-92), Adami et al. have published a survey reporting Mansonella parasite prevalence in the Amazon Region. This report makes a useful contribution to the existing knowledge of filarial parasite distribution within the Amazon area, parasite prevalence rates in relation to age and occupation and provides observations on the possible clinical impact of Mansonella ozzardi. Their publication also provides an account of what appears to be a novel ELISA that has recently been used in the Simuliidae and Onchocerciasis Laboratory of the Oswaldo Cruz Institute, Rio de Janeiro, Brazil. We are concerned that the publication of this ELISA may have created an excessively positive impression of the effectiveness of the onchocerciasis recrudescence serological surveillance tools that are presently available for use in the Amazonia onchocerciasis focus. In this letter we have, thus, sought to highlight some of the limitations of this ELISA and suggest how continuing insecurities concerning the detection of antibodies to Onchocerca volvulus within the Amazonia onchocerciasis focus might be minimised.

The black flies (Diptera: Simuliidae) of Vietnam.

PubMed

Takaoka, Hiroyuki; Sofian-Azirun, Mohd; Ya'cob, Zubaidah; Chen, Chee Dhang; Lau, Koon Weng; Low, VAN Lun; Pham, Xuan DA; Adler, Peter H

2017-05-05

The biodiversity of black flies (Diptera: Simuliidae), which are biting insects of medical and veterinary importance, is strikingly high in Southeast Asian countries, such as Indonesia, Malaysia, Philippines and Thailand. In 2013, we began to explore the fauna of black flies in Vietnam, which has so far been poorly studied. In this monograph, the wealth of the biodiversity of black flies in Vietnam is also confirmed on the basis of the results of our recent investigations, though limited to five provinces in the country.      Morphotaxonomic studies of black flies obtained from Sapa, Lao Cai Province, northern Vietnam, in 2014 and Nghe An Province, northern Vietnam, in 2015, and reexaminations of black flies collected from Tam Dao, Vinh Phuc Province, northern Vietnam, in 2013, Thua Thien Hue Province, central Vietnam, in 2014, and Lam Dong Province, southern Vietnam, in 2014, were conducted. A total of 22 species are described as new, including one in the newly recorded subgenus Montisimulium Rubtsov, and three species are recognized as new records from Vietnam. This investigation brings the number of species of black flies known in Vietnam to 70, all of which are assigned to the genus Simulium Latreille, and are placed in four subgenera (25 in Gomphostilbia Enderlein, one in Montisimulium, seven in Nevermannia Enderlein, and 37 in Simulium Latreille s. str.). The numbers of species-groups recognized include seven in Gomphostilbia, three in Nevermannia and nine in Simulium, indicating a high diversity of putative phylogenetic lineages. New species include S. (G.) sanchayense sp. nov. (= the species formerly regarded as S. (G.) brinchangense Takaoka, Sofian-Azirun & Hashim), S. (S.) lowi sp. nov. (= the species formerly regarded as S. (S.) brevipar Takaoka & Davies), S. (S.) fuscicoxae sp. nov. [= the species formerly regarded as S. (S.) rufibasis Brunetti (in part)], S. (S.) suoivangense sp. nov. [= morphoform 'b' of the S. (S.) tani Takaoka & Davies (complex)]. Newly recorded species are S. (G.) parahiyangum Takaoka & Sigit, S. (N.) maeaiense Takaoka & Srisuka, and S. (S.) doipuiense Takaoka & Choochote (complex) [= the species formerly regarded as S. (S.) rufibasis Brunetti (in part)]. The substitute name, S. (S.) huense, is given for the species that was described under the name of S. (S.) cavum from southern Vietnam. A redescription of the female, male, pupa and larva of S. (G.) asakoae Takaoka & Davies is presented, and the female and larva of S. (G.) hongthaii Takaoka, Sofian-Azirun & Ya'cob are described for the first time. Keys to 10 subgenera in the Oriental Region and all 70 species recorded from Vietnam are provided for females, males, pupae and mature larvae.      As investigations extend nationwide in all the provinces in Vietnam, more new species and records are expected to be discovered. It is hoped that this monograph will be useful as a baseline taxonomic reference for future studies of black flies in Vietnam and neighbouring countries.

Leucocytozoon Diversity and Possible Vectors in the Neotropical highlands of Colombia.

PubMed

Lotta, Ingrid A; Pacheco, M Andreína; Escalante, Ananias A; González, Angie D; Mantilla, Juan S; Moncada, Ligia I; Adler, Peter H; Matta, Nubia E

2016-04-01

Studies of the lowland avifauna in the Neotropical Region have shown a paucity of Leucocytozoon species. However, surveys conducted in the Colombian highlands revealed a great diversity of these parasites infecting resident birds. To further investigate the relationship between Leucocytozoon diversity, the potential vectors, and altitudinal distribution, birds from 41 families were sampled at low and high elevations in Colombia. Blood samples were screened by microscopy, and a fragment of cytochrome b was amplified from Leucocytozoon-positive samples. The complete mitochondrial genome was also obtained for each morphospecies of Leucocytozoon. Leucocytozoon species were detected in resident birds, with various degrees of host specificity, at elevations from 2,400 to 3,950 meters above sea level, where five new host-parasite associations were discovered. Phylogenetic analysis based on the cytochrome b fragment suggested that two nominal taxa, L. fringillinarum and L. majoris, are species complexes. Blood sources of Simuliidae revealed generalist-feeding habits that included avian and mammalian hosts. Molecular analysis of parasites in black flies indicated a close relationship with the parasites found in birds. Our investigation provides further evidence that the distribution and transmission of Leucocytozoon species in the Neotropics are influenced by elevation, with the highest prevalence between 2,400 and 3,200 m asl. Copyright © 2016 Elsevier GmbH. All rights reserved.

Population genetic structure and demographic history of the black fly vector, Simulium nodosum in Thailand.

PubMed

Chaiyasan, P; Pramual, P

2016-09-01

An understanding of the genetic structure and diversity of vector species is crucial for effective control and management. In this study, mitochondrial DNA sequences were used to examine the genetic structure, diversity and demographic history of a black fly vector, Simulium nodosum Puri (Diptera: Simuliidae), in Thailand. A total of 145 sequences were obtained from 10 sampling locations collected across geographical ranges in the country. Low genetic diversity was found in populations of S. nodosum that could be explained by the recent population history of this species. Demographic history analysis revealed a signature of demographic expansion dating back to only 2600-5200 years ago. Recent population expansion in S. nodosum possibly followed an increase in agriculture that enabled its hosts', humans and domestic animals, densities to increase. Alternatively, the Thai populations could be a derivative of an older expansion event in the more northern populations. Mitochondrial DNA genealogy revealed no genetically divergent lineages, which agrees with the previous cytogenetic study. Genetic structure analyses found that only 27% of the pairwise comparisons were significantly different. The most likely explanation for the pattern of genetic structuring is the effect of genetic drift because of recent colonization. © 2016 The Royal Entomological Society.

Morphotaxonomic revision of species-groups of Simulium (Simulium) (Diptera: Simuliidae) in the Oriental Region.

PubMed

Takaoka, Hiroyuki

2017-11-24

Species of eight species-groups (seven named and one unnamed) of Simulium (Simulium) Latreille are revised chiefly based on the adult female and male genitalia. Four species-groups are each divided into more than two groups. Thus, the S. christophersi species-group is divided into two (S. christophersi and S. nebulicola species-groups), the S. griseifrons species-group into six (S. griseifrons, S. grossifilum, S. chungi, S. crocinum, S. indicum and S. yadongense species-groups), the S. malyschevi species-group into two (S. malyschevi and S. pavlovskii species-groups), and the S. melanopus species-group into three (S. melanopus, S. dumogaense and S. iridescens species-groups). The S. crassifilum species-group is merged with the S. variegatum species-group. Simulium fulvipes (Ono) of the former S. malyschevi species-group and S. dentastylum Yang, Chen & Luo of Simulium s. str. species unplaced to species-group are removed from the subgenus Simulium because their male styles are subequal in length to the coxites. A revised classification of species of the 15 species-groups including eight new species-groups of Simulium (Simulium) is presented. Keys to 20 species-groups of Simulium (Simulium) in the Oriental Region are provided for adult females and males.

New species and first records of trichomycetes from immature aquatic insects in Idaho.

PubMed

Bench, Molly E; White, Merlin M

2012-01-01

Trichomycetes, or gut fungi, are currently recognized as an ecological group of fungi and protists that inhabit the guts of immature insects or other stages and types of arthropods. The geographic distribution of these endosymbionts is worldwide. However trichomycete data from the Pacific Northwest are limited and this is the first account of gut fungi in Idaho. We report on the trichomycetes from a single site, Cottonwood Creek at Military Reserve Park, Boise, Idaho, where periodic surveys for more than a year resulted in the discovery of four newly named, three probably new but unnamed and 15 previously known species. Among the Harpellales three new species, Capniomyces sasquatchoides, Harpella torus and Lancisporomyces lampetriformis, are described, with two possibly new species of Smittium detailed but unnamed at this time pending further collections. A Genistelloides cf. hibernus also is included as a possible new species. One new species of Amoebidiales, Paramoebidium hamatum, is described as well. Hosts in which the gut fungi were recovered include larvae or nymphs of Diptera (Chironomidae and Simuliidae), Ephemeroptera (Baetidae) and Plecoptera (Capniidae and Taeniopterygidae). We hope to demonstrate that future surveys or bioprospecting investigations into the biodiversity of these early-diverging fungi in this region and worldwide remain promising.

ASSESSING THE POTENTIAL EFFECTS OF FUNGICIDES ON NONTARGET GUT FUNGI (TRICHOMYCETES) AND THEIR ASSOCIATED LARVAL BLACK FLY HOSTS

PubMed Central

Wilson, Emma R.; Smalling, Kelly L.; Reilly, Timothy J.; Gray, Elmer; Bond, Laura; Steele, Lance; Kandel, Prasanna; Chamberlin, Alison; Gause, Justin; Reynolds, Nicole; Robertson, Ian; Novak, Stephen; Feris, Kevin; White, Merlin M.

2015-01-01

Fungicides are moderately hydrophobic and have been detected in water and sediment, particularly in agricultural watersheds, but typically are not included in routine water quality monitoring efforts. This is despite their widespread use and frequent application to combat fungal pathogens. Whereas the efficacy of these compounds on fungal pathogens is well documented, little is known about their effects on nontarget fungi. This pilot study, a field survey in southwestern Idaho from April to December 2010 on four streams with varying pesticide inputs (two agricultural and two reference sites), was conducted to assess nontarget impact of fungicides on gut fungi, or trichomycetes. Tissues of larval black flies (Diptera: Simuliidae), hosts of gut fungi, were analyzed for pesticide accumulation. Fungicides were detected in hosts from streams within agricultural watersheds but were not detected in hosts from reference streams. Gut fungi from agricultural sites exhibited decreased percent infestation, density within the gut, and sporulation, and black fly tissues had elevated pesticide concentrations. Differences observed between the sites demonstrate a potential effect on this symbiotic system. Future research is needed to parse out the details of the complex biotic and abiotic relationships; however, these preliminary results indicate that impacts to nontarget organisms could have far-reaching consequences within aquatic ecosystems. PMID:26380545

Macroinvertebrate community response to pulse exposure with the insecticide lambda-cyhalothrin using in-stream mesocosms.

PubMed

Heckmann, Lars-Henrik; Friberg, Nikolai

2005-03-01

Pesticides are constantly being applied to agricultural catchments, but little is known about their impact on aquatic biota during natural exposure. In the present study, the impact of the pyrethroid lambda-cyhalothrin was studied in an in-stream mesocosm setup. Twice during the summer of 2002, the natural macroinvertebrate community was exposed in situ to a 30-min pulse of lambda-cyhalothrin. Pyrethroid doses were released through a modified drip set with nominal concentrations of 0.10, 1.00, and 10.0 microg L(-1) during the first exposure and 0.05, 0.50, and 5.00 microg L(-1) in the second exposure. Before, during, and after exposure, drifting macroinvertebrates were caught in nets. Quantitative benthic samples were taken both before and on two occasions after exposure. Macroinvertebrate drift increased immediately after the pulse exposure, with total drift being significantly higher at all concentrations. Gammarus pulex, various Ephemeroptera, Leuctra sp., and Simuliidae were some of the taxa showing the most pronounced drift response. Structural change in the community was found only at 5.00 and 10.0 microg L(-1), and recovery occurred within approximately two weeks. The present study may be valuable in assessing extrapolations based on laboratory results as well as in evaluating pyrethroid impact on natural freshwater environments.

Endophagy of biting midges attacking cavity-nesting birds.

PubMed

Votýpka, J; Synek, P; Svobodová, M

2009-09-01

Feeding behaviour, host preferences and the spectrum of available hosts determine the role of vectors in pathogen transmission. Feeding preferences of blood-feeding Diptera depend on, among others factors, the willingness of flies to attack their hosts either in the open (exophagy) or in enclosed places (endophagy). As far as ornithophilic blood-feeding Diptera are concerned, the biting midges (Diptera: Ceratopogonidae) and blackflies (Diptera: Simuliidae) are generally considered to be strictly exophagous. We determined which blood-sucking Diptera enter nest cavities and feed on birds by placing sticky foil traps inside artificial nest boxes. A total of 667 females of eight species of biting midges of the genus Culicoides (Latreille, 1809) were captured on traps during 2006-2007, with Culicoides truncorum (Edwards, 1939) being the dominant species. DNA blood analyses of blood-engorged females proved that midges actually fed on birds nesting in the boxes. Three species were identified as endophagous: Culicoides truncorum, Culicoides pictipennis (Staeger, 1839), and Culicoides minutissimus (Zetterstedt, 1855). Our study represents the first evidence that ornithophilic biting midges are endophagous. The fact that we caught no blackflies in the bird boxes supports the exophagy of blackflies. We believe that our findings are important for surveillance programmes focusing on Diptera that transmit various bird pathogens.

Assessing the potential effects of fungicides on nontarget gut fungi (trichomycetes) and their associated larval black fly hosts

USGS Publications Warehouse

Wilson, Emma R.; Smalling, Kelly L.; Reilly, Timothy J.; Gray, Elmer; Bond, Laura; Steele, Lance; Kandel, Prasanna; Chamberlin, Alison; Gause, Justin; Reynolds, Nicole; Robertson, Ian; Novak, Stephen; Feris, Kevin; White, Merlin M.

2014-01-01

Fungicides are moderately hydrophobic and have been detected in water and sediment, particularly in agricultural watersheds, but typically are not included in routine water quality monitoring efforts. This is despite their widespread use and frequent application to combat fungal pathogens. Although the efficacy of these compounds on fungal pathogens is well documented, little is known about their effects on nontarget fungi. This pilot study, a field survey in southwestern Idaho from April to December 2010 on four streams with varying pesticide inputs (two agricultural and two reference sites), was conducted to assess nontarget impact of fungicides on gut fungi, or trichomycetes. Tissues of larval black flies (Diptera: Simuliidae), hosts of gut fungi, were analyzed for pesticide accumulation. Fungicides were detected in hosts from streams within agricultural watersheds but were not detected in hosts from reference streams. Gut fungi from agricultural sites exhibited decreased percent infestation, density and sporulation within the gut, and black fly tissues had elevated pesticide concentrations. Differences observed between the sites demonstrate a potential effect on this symbiotic system. Future research is needed to parse out the details of the complex biotic and abiotic relationships; however, these preliminary results indicate that impacts to nontarget organisms could have far-reaching consequences within aquatic ecosystems.

River-specific macrogenomic diversity in Simulium guianense s. l. (Diptera: Simuliidae), a complex of tropical American vectors associated with human onchocerciasis

PubMed Central

Hamada, Neusa; Cavalcante do Nascimento, Jeane Marcelle; Grillet, Maria Eugenia

2017-01-01

Simulium guianense Wise is a Latin American vector complex of black flies associated with transmission of the causal agent of human onchocerciasis (river blindness). An analysis of the chromosomal banding patterns of 607 larvae of S. guianense s. l. revealed a high level of variation involving 83 macrogenomic rearrangements across 25 populations in Brazil, French Guiana, and Venezuela. The 25 populations were assigned to 13 cytoforms (A1, A2, B1–B4, C, D, E1–E4, and F), some of which are probably valid species. Based on geographical proximity, a member of the B group of cytoforms probably represents the name-bearing type specimen of S. guianense and the primary vector in the last-remaining onchocerciasis foci in the Western Hemisphere. Cytoform B3 in Amapá State is implicated as an anthropophilic simuliid in an area currently and historically free of onchocerciasis. Distributions of cytoforms are associated with geography, elevation, and drainage basin, and are largely congruent with ecoregions. Despite extraordinarily large larval populations of S. guianense s. l. in big rivers and consequent production of female flies for dispersal, the cytoforms maintain their chromosomal distinction within individual rivers, suggesting a high degree of fidelity to the specialized breeding habitats—rocky shoals—of the natal rivers. PMID:28727841

River-specific macrogenomic diversity in Simulium guianense s. l. (Diptera: Simuliidae), a complex of tropical American vectors associated with human onchocerciasis.

PubMed

Adler, Peter H; Hamada, Neusa; Cavalcante do Nascimento, Jeane Marcelle; Grillet, Maria Eugenia

2017-01-01

Simulium guianense Wise is a Latin American vector complex of black flies associated with transmission of the causal agent of human onchocerciasis (river blindness). An analysis of the chromosomal banding patterns of 607 larvae of S. guianense s. l. revealed a high level of variation involving 83 macrogenomic rearrangements across 25 populations in Brazil, French Guiana, and Venezuela. The 25 populations were assigned to 13 cytoforms (A1, A2, B1-B4, C, D, E1-E4, and F), some of which are probably valid species. Based on geographical proximity, a member of the B group of cytoforms probably represents the name-bearing type specimen of S. guianense and the primary vector in the last-remaining onchocerciasis foci in the Western Hemisphere. Cytoform B3 in Amapá State is implicated as an anthropophilic simuliid in an area currently and historically free of onchocerciasis. Distributions of cytoforms are associated with geography, elevation, and drainage basin, and are largely congruent with ecoregions. Despite extraordinarily large larval populations of S. guianense s. l. in big rivers and consequent production of female flies for dispersal, the cytoforms maintain their chromosomal distinction within individual rivers, suggesting a high degree of fidelity to the specialized breeding habitats-rocky shoals-of the natal rivers.

Five new species of the Simulium decuplum subgroup of the Simulium (Gomphostilbia) batoense species-group (Diptera: Simuliidae) from Thailand and their phylogenetic relationships.

PubMed

Takaoka, Hiroyuki; Srisuka, Wichai; Van Lun Low; Saeung, Atiporn

2018-06-01

Five new species of black flies, Simulium (Gomphostilbia) chiangraiense, S. (G.) huaikaeoense, S. (G.) khaokhoense, S. (G.) maeklangense, and S. (G.) pamiangense, are described based on adults, pupae and mature larvae from Thailand. These five species are similar to one another and are placed in the S. decuplum subgroup of the S. batoense species-group by having the male fore coxae darkened, ventral plate flat and transverse; pupal gill with 10 short filaments; and larval postgenal cleft deep approaching or reaching the posterior margin of the hypostoma. Simulium (G.) chiangraiense sp. nov. and S. (G.) pamiangense sp. nov. differ from the three other new species by the much longer pupal gill filaments and darkened dorsal surface of abdominal segments 1 and 2. Taxonomic notes are provided to distinguish these five new species from five other related species. The phylogenetic positions of these new species in the S. decuplum subgroup are presented based on the mitochondrial COI gene. Simulium (G.) pamiangense sp. nov. and S. (G.) huaikaeoense sp. nov. are highly similar to each other genetically, showing a sister relationship, though they are clearly different morphologically. On the contrary, S. (G.) khaokhoense sp. nov. is distantly positioned from S. (G.) huaikaeoense nov., though it is almost indistinguishable morphologically from the latter. Copyright © 2018 Elsevier B.V. All rights reserved.

Passage of ingested Mansonella ozzardi (Spirurida: Onchocercidae) microfilariae through the midgut of Aedes aegypti (Diptera: Culicidae).

PubMed

Vaughan, Jefferson A; Bell, Jeffrey A; Turell, Michael J; Chadee, Dave D

2007-01-01

When virus and microfilariae are ingested concurrently by a mosquito, microfilariae (mf) may penetrate the mosquito midgut and introduce virus directly into the mosquito hemocoel, allowing mosquitoes to become infectious much sooner than normal and enhancing transmission of viruses by mosquitoes. Mansonella ozzardi (Manson) is a benign filarial nematode parasite of humans in Latin America and is transmitted by black flies (Diptera: Simuliidae) and biting midges (Diptera: Ceratopogonidae). Because M. ozzardi and dengue are sympatric, we wanted to know whether M. ozzardi mf had the ability to penetrate the midgut of Aedes aegypti (L.) (Diptera: Culicidae) and thus play a potential role in the enhancement of dengue transmission. To test this, the F1 progeny from locally collected Ae. aegypti were fed on M. ozzardi-infected human males in an endemic village in northern Trinidad. Mosquitoes were dissected at various times after feeding and examined for mf in the midguts and thoraces. Microfilariae penetrated the midguts of 43% of 63 mosquitoes that ingested mf. Overall, 11% of mf penetrated the midgut by 17 h after being ingested. The intensity of midgut penetration was positively correlated to the numbers of mf ingested. Because midgut penetration is a key requirement for mf enhancement to occur, the potential exists that M. ozzardi could be involved in the enhancement of dengue virus transmission.

Incorporation of bacterial extracellular polysaccharide by black fly larvae (Simuliidae)

USGS Publications Warehouse

Couch, C.A.; Meyer, J.L.; Hall, R.O.

1996-01-01

Black fly larvae (Simulium) assimilated, with high efficiency (80-90%), bacterial extracellular polysaccharide (EPS) extracted from laboratory cultures of a pseudomonad isolated from the Ogeechee River. Incorporation was traced using 13C-labelled EPS offered to larvae as a coating on a mixture of 1-??m latex beads and kaolin particles. These EPS-coated particles were used to simulate natural particles, both living and dead. Solubility, protein, and nitrogen content of the EPS suggested it was a slime rather than a capsular polysaccharide. Glycosyl composition of the EPS was glucose and galactose in ?? and ?? linkages, with pyruvate, succinate, and possibly malonate constituent groups. To evaluate the incorporation of C derived from protein associated with the EPS matrix, feeding experiments were conducted using EPS with and without proteins extracted. Black fly larvae incorporated 7.2 ??g EPS C larva-1 d-1 from EPS that did not have proteins extracted, and 19.5 ??g EPS C larva-1 d-1 from EPS with proteins extracted. Carbon in protein that is typically associated with EPS was not solely or selectively incorporated. EPS incorporation rates are similar to rates of cellular bacterial carbon incorporation previously estimated for Ogeechee River black fly larvae. If EPS is generally available as a food resource, the importance of bacteria in detrital food webs may be underestimated by studies that examine only the consumption of bacterial cells.

Diurnal biting periodicity of parous Simulium (Diptera: Simuliidae) vectors in the onchocerciasis Amazonian focus.

PubMed

Grillet, M-E; Villamizar, N J; Cortez, J; Frontado, H L; Escalona, M; Vivas-Martínez, S; Basáñez, M-G

2005-05-01

We describe the hourly patterns of parous biting activity of the three main simuliid vectors of human onchocerciasis in the Amazonian focus straddling between Venezuela and Brazil, namely, Simulium guianense s.l. Wise; S. incrustatum Lutz, and S. oyapockense s.l. Floch and Abonnenc. Time series of the hourly numbers of host-seeking parous flies caught in five Yanomami villages during dry, rainy, and their transition periods from 1995 to 2001 were investigated using harmonic analysis (assuming an underlying circadian rhythm) and periodic correlation (based on Spearman's r). Parous S guianense s.l. showed a bimodal activity pattern, with a minor peak in mid-morning and a major peak at 16:00 h. S. incrustatum exhibited mainly unimodal activity during either early morning or midday according to locality. S. oyapockense s.l. bit humans throughout the day mainly between 10:00 and 16:00 h but also showed bimodal periodicity in some localities. Superimposed on the endogenous, species-specific daily cycles, parous activity showed variation according to locality, season, air temperature and relative humidity, with biting being promoted by warmer and drier hours during wet seasons/periods and reduced during hotter times in dry seasons or transitions. The results are discussed in terms of their implications for blackfly biology and ecology as well as onchocerciasis epidemiology and control.

Evolution of insecticide resistance in non-target black flies (Diptera: Simuliidae) from Argentina.

PubMed

Montagna, Cristina Mónica; Gauna, Lidia Ester; D'Angelo, Ana Pechen de; Anguiano, Olga Liliana

2012-06-01

Black flies, a non-target species of the insecticides used in fruit production, represent a severe medical and veterinary problem. Large increases in the level of resistance to the pyrethroids fenvalerate (more than 355-fold) and deltamethrin (162-fold) and a small increase in resistance to the organophosphate azinphos methyl (2-fold) were observed between 1996-2008 in black fly larvae under insecticide pressure. Eventually, no change or a slight variation in insecticide resistance was followed by a subsequent increase in resistance. The evolution of pesticide resistance in a field population is a complex and stepwise process that is influenced by several factors, the most significant of which is the insecticide selection pressure, such as the dose and frequency of application. The variation in insecticide susceptibility within a black fly population in the productive area may be related to changes in fruit-pest control. The frequency of individuals with esterase activities higher than the maximum value determined in the susceptible population increased consistently over the sampling period. However, the insecticide resistance was not attributed to glutathione S-transferase activity. In conclusion, esterase activity in black flies from the productive area is one mechanism underlying the high levels of resistance to pyrethroids, which have been recently used infrequently. These enzymes may be reselected by currently used pesticides and enhance the resistance to these insecticides.

Determinants of abundance and effects of blood-sucking flying insects in the nest of a hole-nesting bird.

PubMed

Tomás, Gustavo; Merino, Santiago; Martínez-de la Puente, Josué; Moreno, Juan; Morales, Judith; Lobato, Elisa

2008-05-01

Compared to non-flying nest-dwelling ectoparasites, the biology of most species of flying ectoparasites and its potential impact on avian hosts is poorly known and rarely, if ever, reported. In this study we explore for the first time the factors that may affect biting midge (Diptera: Ceratopogonidae) and black fly (Diptera: Simuliidae) abundances in the nest cavity of a bird, the hole-nesting blue tit Cyanistes caeruleus, and report their effects on adults and nestlings during reproduction. The abundance of biting midges was positively associated with nest mass, parental provisioning effort and abundance of blowflies and black flies, while negatively associated with nestling condition. Furthermore, a medication treatment to reduce blood parasitaemias in adult birds revealed that biting midges were more abundant in nests of females whose blood parasitaemias were experimentally reduced. This finding would be in accordance with these insect vectors attacking preferentially uninfected or less infected hosts to increase their own survival. The abundance of black flies in the population was lower than that of biting midges and increased in nests with later hatching dates. No significant effect of black fly abundance on adult or nestling condition was detected. Blood-sucking flying insects may impose specific, particular selection pressures on their hosts and more research is needed to better understand these host-parasite associations.

Prevalence of River Epilepsy in the Orientale Province in the Democratic Republic of the Congo

PubMed Central

Colebunders, Robert; Tepage, Floribert; Rood, Ente; Mandro, Michel; Abatih, Emmanuel Nji; Musinya, Gisele; Mambandu, Germain; Kabeya, José; Komba, Michel; Levick, Bethany; Mokili, John L; Laudisoit, Anne

2016-01-01

Background An increased prevalence of epilepsy has been reported in many onchocerciasis endemic areas. Objective To determine the prevalence and distribution of epilepsy in an onchocerciasis endemic region in the Democratic Republic of the Congo (DRC). Design/Methods An epilepsy prevalence study was carried out in 2014, in two localities of the Bas-Uélé district, an onchocerciasis endemic region in the Orientale Province of the DRC. Risk factors for epilepsy were identified using a random effects logistic regression model and the distribution of epilepsy cases was investigated using the Moran’s I statistic of spatial auto-correlation. Results Among the 12,776 individuals of Dingila, 373 (2.9%) individuals with epilepsy were identified. In a house-to-house survey in Titule, 68 (2.3%) of the 2,908 people who participated in the survey were found to present episodes of epilepsy. Epilepsy showed a marked spatial pattern with clustering of cases occurring within and between adjacent households. Individual risk of epilepsy was found to be associated with living close to the nearest fast flowing river where blackflies (Diptera: Simuliidae)–the vector of Onchocerca volvulus–oviposit and breed. Conclusions The prevalence of epilepsy in villages in the Bas-Uélé district in the DRC was higher than in non-onchocerciasis endemic regions in Africa. Living close to a blackflies infested river was found to be a risk factor for epilepsy. PMID:27139245

Vietnam, a Hotspot for Chromosomal Diversity and Cryptic Species in Black Flies (Diptera: Simuliidae)

PubMed Central

Takaoka, Hiroyuki; Sofian-Azirun, Mohd; Low, Van Lun; Ya’cob, Zubaidah; Chen, Chee Dhang; Lau, Koon Weng; Pham, Xuan Da

2016-01-01

The increasing attention on Vietnam as a biodiversity hotspot prompted an investigation of the potential for cryptic diversity in black flies, a group well known elsewhere for its high frequency of isomorphic species. We analyzed the banding structure of the larval polytene chromosomes in the Simulium tuberosum species group to probe for diversity beyond the morphological level. Among 272 larvae, 88 different chromosomal rearrangements, primarily paracentric inversions, were discovered in addition to 25 already known in the basic sequences of the group in Asia. Chromosomal diversity in Vietnam far exceeds that known for the group in Thailand, with only about 5% of the rearrangements shared between the two countries. Fifteen cytoforms and nine morphoforms were revealed among six nominal species in Vietnam. Chromosomal evidence, combined with available molecular and morphological evidence, conservatively suggests that at least five of the cytoforms are valid species, two of which require formal names. The total chromosomal rearrangements and species (15) now known from the group in Vietnam far exceed those of any other area of comparable size in the world, supporting the country’s status as a biodiversity hotspot. Phylogenetic inference based on uniquely shared, derived chromosomal rearrangements supports the clustering of cytoforms into two primary lineages, the Simulium tani complex and the Southeast Asian Simulium tuberosum subgroup. Some of these taxa could be threatened by habitat destruction, given their restricted geographical distributions and the expanding human population of Vietnam. PMID:27695048

Vietnam, a Hotspot for Chromosomal Diversity and Cryptic Species in Black Flies (Diptera: Simuliidae).

PubMed

Adler, Peter H; Takaoka, Hiroyuki; Sofian-Azirun, Mohd; Low, Van Lun; Ya'cob, Zubaidah; Chen, Chee Dhang; Lau, Koon Weng; Pham, Xuan Da

2016-01-01

The increasing attention on Vietnam as a biodiversity hotspot prompted an investigation of the potential for cryptic diversity in black flies, a group well known elsewhere for its high frequency of isomorphic species. We analyzed the banding structure of the larval polytene chromosomes in the Simulium tuberosum species group to probe for diversity beyond the morphological level. Among 272 larvae, 88 different chromosomal rearrangements, primarily paracentric inversions, were discovered in addition to 25 already known in the basic sequences of the group in Asia. Chromosomal diversity in Vietnam far exceeds that known for the group in Thailand, with only about 5% of the rearrangements shared between the two countries. Fifteen cytoforms and nine morphoforms were revealed among six nominal species in Vietnam. Chromosomal evidence, combined with available molecular and morphological evidence, conservatively suggests that at least five of the cytoforms are valid species, two of which require formal names. The total chromosomal rearrangements and species (15) now known from the group in Vietnam far exceed those of any other area of comparable size in the world, supporting the country's status as a biodiversity hotspot. Phylogenetic inference based on uniquely shared, derived chromosomal rearrangements supports the clustering of cytoforms into two primary lineages, the Simulium tani complex and the Southeast Asian Simulium tuberosum subgroup. Some of these taxa could be threatened by habitat destruction, given their restricted geographical distributions and the expanding human population of Vietnam.

Evaluation of larvicides in developing management guidelines for long-term control of pest blackflies (Diptera: Simuliidae) along the Orange River, South Africa.

PubMed

Palmer, R W; Rivers-Moore, N A

2008-12-01

In 2000 and 2001 Orange River levels were higher than normal: associated serious outbreaks of blackfly had a substantial detrimental impact on the local economy. The poor control was attributed to the suspected development of larval resistance to temephos. A long-term solution to blackfly control, through the identification of a suitable replacement to temephos for use during high flow conditions, was proposed. This study, however, failed to identify or register a suitable larvicide for use during high flow conditions. Although permethrin was highly effective against blackfly larvae, it was rejected because of its detrimental impacts on non-target fauna. Various formulations of locally produced dry Bacillus thuringiensis var. israelensis (B.t.i.) were tested, but these were ineffective against blackflies. The study also confirmed that resistance to temephos has developed among Simulium chutteri in the middle and lower Orange River. The feasibility of "reversing" the resistance to temephos through the use of the synergist piperonyl butoxide (PBO) was investigated, but the results were not favourable. Furthermore, PBO was highly toxic to blackflies and non-target organisms, and was not recommended for further testing. This means that B.t.i. currently remains the only symptomatic measure of treatment currently applied. Although resistance to B.t.i. has not been reported for blackflies elsewhere in South Africa, there is a need to remain vigilant and to implement an operational strategy that minimizes the risks of resistance developing.

Protection of horse ears against Simulid parasitism: Efficacy of a mammal semiochemical solution over 10hours.

PubMed

Creton, Benjamin; Pageat, Patrick; Robejean, Myriam; Lafont-Lecuelle, Céline; Cozzi, Alessandro

2016-08-30

Hematophagous insects can be vectors of pathogens and cause significant economic loss in zootechnical production. Among biting insects, many dipteran species feed on horse blood. The black fly (Diptera: Simuliidae) group, is responsible for several disorders in horses and inflicts painful bites that lead to undesirable behaviours in horses, particularly when bites occur in sensitive areas such as the inner ear. A field study was conducted in a French equestrian center during which a semiochemical was applied on horses' ears to assess repellent efficacy against simulid infestation. During the first phase of the study, efficacy was evaluated over a one hour period. Then, during the second phase of the study, persistency of the effect was tested at 8, 9 and 10h after application. The results of the study's first phase showed 90% efficacy over one hour, with 121.5 insects found in control ears and 12 insects in treated ears (p=0.001). In the second phase of the study, a total amount of 411 insects were observed on control ears whereas only 2 insects were observed on treated ears (p<0.0001); the treatment remained over 98% effective up to 10hours after application. When using a slow release excipient, this semiochemical may offer at least 10h of protection against simulids. This safe, efficient, and long lasting protection could help horses and their owners to manage simulid parasitism. Copyright © 2016 Elsevier B.V. All rights reserved.

The black flies (Diptera: Simuliidae) of the Lesser Sunda Archipelago, Indonesia.

PubMed

Takaoka, Hiroyuki; Sofian-Azirun, Mohd; Ya'cob, Zubaidah; Chen, Chee Dhang; Lau, Koon Weng; Low, Van Lun; Suana, I Wayan

2017-05-01

Surveys of pupae and larvae of black flies were carried out in Bali, Lombok, Sumbawa and Flores in the Lesser Sunda Archipelago, Indonesia, where 10 species were known. A total of 14 simuliid species including four new species and five new records of the genus Simulium were collected, bringing the number of species from the Lesser Sunda Archipelago to 19. They are classified into four subgenera: two in Nevermannia, nine in Gomphostilbia, seven in Simulium and one in Wallacellum. One of four new species, Simulium (Simulium) baliense, is described based on females, males, pupae and larvae from Bali and Lombok. This new species, which is placed in the Simulium striatum species-group of the subgenus Simulium, is closely related to S. (S.) argyrocinctum De Meijere from Java and Sumatra, but it is distinguished from the latter species by the smaller number of the male enlarged upper-eye facets and larval abdomen lacking dorsal pairs of conical protuberances. The distribution record of S. (S.) upikae Takaoka & Davies from Flores is corrected as that of S. (S.) eximium De Meijere. Some aberrant characters of the pupal gill filaments of S. (G.) atratum De Meijere, S. (G.) floresense Takaoka, Hadi & Sigit and S. (G.) sunapii Takaoka, Sofian-Azirun & Suana are illustrated. Characteristics of the fauna of black flies in this archipelago are briefly noted. Keys to all 19 species are provided for females, males, pupae and larvae. Copyright © 2017 Elsevier B.V. All rights reserved.

Host–parasite behavioral interactions in a recently introduced, whooping crane population

USGS Publications Warehouse

King, Richard S.; McKann, Patrick C.; Gray, Brian R.; Putnam, Michael S.

2015-01-01

The whooping crane Grus americana has a long conservation history, but despite multiple attempts across North America, introduction success is lacking. Recently introduced, captively reared whooping cranes have had periods of poor reproductive performance in central Wisconsin that sometimes coincided with black fly (Diptera: Simuliidae) emergences. Sandhill crane Grus canadensis reproductive performance in central Wisconsin is approximately double that of whooping cranes. We used comfort behaviors as a measure of black fly harassment to infer whether behavioral differences existed between nesting sandhill cranes and nesting whooping cranes and between successful and unsuccessful whooping crane pairs. To further explore the interaction between black flies and incubating whooping cranes, we examined differences in behaviors between incubating birds and their off-nest mates. Compared to their off-nest mates, incubating whooping cranes exhibited elevated comfort behaviors, suggesting a bird at a nest may experience greater harassment from black flies. Sandhill cranes had elevated head-flicks over whooping cranes. Whooping cranes exhibited more head-rubs than sandhill cranes, and successful whooping crane pairs had elevated head-rubs over pairs that deserted their nests. Behavioral differences between sandhill cranes and whooping cranes as well as differences in reproductive performance, could be explained by exposure to local breeding conditions. Whereas sandhill cranes have nested in the area for hundreds, if not thousands, of years, whooping cranes were only recently introduced to the area. Behavioral differences between the species as well as those between successful and unsuccessful whooping crane pairs could also be explained by the effect of captive exposure, which could affect all whooping crane introductions.

Mechanistic approach to understanding the toxicity of the azole fungicide triadimefon to a nontarget aquatic insect and implications for exposure assessment.

PubMed

Kenneke, John F; Mazur, Christopher S; Kellock, Kristen A; Overmyer, Jay P

2009-07-15

Mechanistic and stereoselective based in vitro metabolism assays were utlilized to gain insight into the toxic mode of action of the 1,2,4-triazole fungicide, triadimefon, with black fly (Diptera: Simuliidae) larvae. Based on results from enzyme inhibitor studies, the metabolism of triadimefon in black fly larvae microsomes was found to occur predominantly via an oxidative P450-mediated pathway; triadimenol was formed via the stereoselective reduction of the prochiral carbonyl group of triadimefon. The relatively minor contribution of carbonyl reduction suggests that triadimefon may inhibit ecdysone 20-monooxygenase and disrupt insect molting hormone biosynthesis. 48-h LC50 tests for triadimefon and triadimenol with black fly larvae yielded median values (with 95% confidence intervals) of 6.1 (5.8-6.4) and 22.3 (20.3-24.1) mg/L respectively. The exposure of black fly larvae to sublethal concentrations of triadimefon resulted in increased microsomal P450 activity and affected the microsomal rates of both triadimefon depletion and triadimenol formation. In contrast to trout, black fly larvae produced a higher fraction of the more toxic triadimenol stereoisomers, which may explain in part why triadimefon exhibited a significantly greater toxicity with black fly larvae than trout. These results illustrate that while LC50 tests conducted with commercial triadimenol would presumably expose each organism to the same relative abundance of the four triadimenol stereoisomers, LC50 tests with triadimefon ultimately expose each organism to a unique set of triadimenol stereoisomers depending upon the organism's stereoselective metabolism.

Acute toxicity of cadmium, lead, zinc, and their mixtures to stream-resident fish and invertebrates

USGS Publications Warehouse

Mebane, Christopher A.; Dillon, Frank S.; Hennessy, Daniel P.

2012-01-01

The authors conducted 150 tests of the acute toxicity of resident fish and invertebrates to Cd, Pb, and Zn, separately and in mixtures, in waters from the South Fork Coeur d'Alene River watershed, Idaho, USA. Field-collected shorthead sculpin (Cottus confusus), westslope cutthroat trout (Oncorhynchus clarkii lewisi), two mayflies (Baetis tricaudatus and Rhithrogena sp.), a stonefly (Sweltsa sp.), a caddisfly (Arctopsyche sp.), a snail (Gyraulus sp.), and hatchery rainbow trout (Oncorhynchus mykiss), were tested with all three metals. With Pb, the mayflies (Drunella sp., Epeorus sp., and Leptophlebiidae), a Simuliidae black fly, a Chironomidae midge, a Tipula sp. crane fly, a Dytiscidae beetle, and another snail (Physa sp.), were also tested. Adult westslope cutthroat trout were captured to establish a broodstock to provide fry of known ages for testing. With Cd, the range of 96-h median effect concentrations (EC50s) was 0.4 to >5,329μg/L, and the relative resistances of taxa were westslope cutthroat trout ≈ rainbow trout ≈ sculpin << other taxa; with Pb, EC50s ranged from 47 to 3,323μg/L, with westslope cutthroat trout < rainbow trout < other taxa; and with Zn, EC50s ranged from 21 to 3,704μg/L, with rainbow trout < westslope cutthroat trout ≈ sculpin << other taxa. With swim-up trout fry, a pattern of decreasing resistance with increasing fish size was observed. In metal mixtures, the toxicities of the three metals were less than additive on a concentration-addition basis.

Life history of the fluted kidneyshell Ptychobranchus subtentum

USGS Publications Warehouse

Davis, V.M.; Layzer, J.B.

2012-01-01

The fluted kidneyshell Ptychobranchus subtentum (Say, 1825) is a candidate for listing under the Endangered Species Act by the US Fish and Wildlife Service. Fecundity, fish hosts, and selected population demographics were determined during 2005–2006 for the fluted kidneyshell in the upper Clinch River, Hancock County, Tennessee. Females were fertilized in Aug. within a 5 d period and contained viable glochidia about 4 wk later. As the embryos began to develop, the marsupium gradually changed color from white to dark brown. Glochidia were contained within conglutinates that resemble Simuliidae pupae likely to attract benthic insectivorous fish and were held over winter and released in May. Fecundity was positively related to mussel length (r2  =  0.81) and ranged from 43,000 to 500,000 glochidia. Eight species of darters (Etheostoma spp. and Percina spp.) were infested with glochidia in the laboratory to examine potential hosts and host suitability. Juveniles transformed on bluebreast darters E. camurum and dusky darters P. scieraand previously reported hosts: rainbow darters E. caeruleum and fantail darters E. flabellare. In addition, fantail darters and rainbow darters were infested with glochidia from two river systems. The median time of glochidial metamorphosis did not differ significantly between the two mussel populations. The observed ratio of adult females to males (1.9∶1) in the Clinch River differed significantly from 1∶1. Based upon thin-sections, individuals live to at least 26 y and females become sexually mature at age five.

The vectoral role of several blackfly species (Diptera: Simuliidae) in relation to human onchocerciasis in the Sierra Parima and Upper Orinoco regions of Venezuela.

PubMed

Basáñez, M G; Yarzábal, L; Takaoka, H; Suzuki, H; Noda, S; Tada, I

1988-12-01

Experimental and natural infections with Onchocerca volvulus were studied in several anthropophilic blackfly species present in the endemic area of the Upper Orinoco region of Venezuela. When fed on four different Yanomami volunteers in the Sierra Parima, the total infection rate was 31.4% for Simulium guianense in comparison with 7.5% for S. limbatum. The proportion of ingested microfilariae that entered the thorax during the first 24 hours and completed development to the infective stage was also much lower in the latter than in the former species. There was no larval development of O. volvulus in S. antillarum, but one female harboured in its head six infective larvae of a zoonotic filaria. When S. oyapokense s.l. was fed on an infected volunteer in the Upper Orinoco most flies ingested few microfilariae, and further development reached only the L1 stage. Natural infection and infectivity rates for S. guianense in two localities of the Sierra Parima were 0.2-4.0% and 1.3-10.2%, respectively, more than 50% of the L3 larvae being in the head. The corresponding data for S. oyapockense s.l. in the Upper Orinoco were 0.1-0.5%, although the only L3 larva found did not correspond to O. volvulus. It is suggested that S. guianense is the main vector of onchocerciasis in the Sierra Parima and that S. limbatum could play a secondary role. Simulium oyapockense s.l. replaces them in the Upper Orinoco and may maintain a degree of transmission, but its epidemiological importance remains to be assessed.

Seasonal biodiversity of black flies (Diptera: Simuliidae) and evaluation of ecological factors influencing species distribution at Doi Pha Hom Pok National Park, Thailand.

PubMed

Srisuka, Wichai; Takaoka, Hiroyuki; Otsuka, Yasushi; Fukuda, Masako; Thongsahuan, Sorawat; Taai, Kritsana; Choochote, Wej; Saeung, Atiporn

2015-09-01

This is the first study on the seasonal biodiversity of black flies and evaluation of ecological factors influencing their distribution at Doi Pha Hom Pok National Park, northern Thailand. Larvae were collected from six fixed-stream sites in relation to altitude gradients from May 2011 to April 2013. The water temperature, water pH, conductivity, total dissolved solids (TDS), salt, water velocity, stream width and depth, streambed particle sizes, riparian vegetation, and canopy cover were recorded from each site. Monthly collections from the six sites yielded 5475 last-instar larvae, belonging to 29 black fly species. The most frequently found species from all sites were Simulium asakoae (100%) followed by Simulium yuphae (83.3%), and Simulium chiangdaoense, Simulium gombakense, Simulium phahompokense, Simulium fruticosum, Simulium maeaiense and Simulium fenestratum (66.6%). Of the 5475 last-instar larvae, S. maeaiense (19.3%), S. chiangdaoense (15.8%) and S. asakoae (14.8%), were the three most abundant species. The Shannon diversity index (H) at the six sites with different altitudes of 2100m, 2000m, 1500m, 1400m, 700m, and 500m above mean sea level, were 2.042, 1.832, 2.158, 2.123, 1.821 and 1.822, respectively. The Shannon index and number of taxa in the cold season were higher than those in the rainy and hot seasons. Principal component analysis (PCA) indicated that at least three principal components have eigen values >1.0 and accounted for 93.5% of the total variability of ecological factors among sampling sites. The Canonical correspondence analyses (CCA) showed that most species had a trend towards altitude, canopy cover, riparian vegetation and water velocity. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

Gauging climate change effects at local scales: weather-based indices to monitor insect harassment in caribou.

PubMed

Witter, Leslie A; Johnson, Chris J; Croft, Bruno; Gunn, Anne; Poirier, Lisa M

2012-09-01

Climate change is occurring at an accelerated rate in the Arctic. Insect harassment may be an important link between increased summer temperature and reduced body condition in caribou and reindeer (both Rangifer tarandus). To examine the effects of climate change at a scale relevant to Rangifer herds, we developed monitoring indices using weather to predict activity of parasitic insects across the central Arctic. During 2007-2009, we recorded weather conditions and used carbon dioxide baited traps to monitor activity of mosquitoes (Culicidae), black flies (Simuliidae), and oestrid flies (Oestridae) on the post-calving and summer range of the Bathurst barren-ground caribou (Rangifer tarandus groenlandicus) herd in Northwest Territories and Nunavut, Canada. We developed statistical models representing hypotheses about effects of weather, habitat, location, and temporal variables on insect activity. We used multinomial logistic regression to model mosquito and black fly activity, and logistic regression to model oestrid fly presence. We used information theory to select models to predict activity levels of insects. Using historical weather data, we used hindcasting to develop a chronology of insect activity on the Bathurst range from 1957 to 2008. Oestrid presence and mosquito and black fly activity levels were explained by temperature. Wind speed, light intensity, barometric pressure, relative humidity, vegetation, topography, location, time of day, and growing degree-days also affected mosquito and black fly levels. High predictive ability of all models justified the use of weather to index insect activity. Retrospective analyses indicated conditions favoring mosquito activity declined since the late 1950s, while predicted black fly and oestrid activity increased. Our indices can be used as monitoring tools to gauge potential changes in insect harassment due to climate change at scales relevant to caribou herds.

Food Web Structure in a Harsh Glacier-Fed River

PubMed Central

Clitherow, Leonie R.; Carrivick, Jonathan L.; Brown, Lee E.

2013-01-01

Glacier retreat is occurring across the world, and associated river ecosystems are expected to respond more rapidly than those in flowing waters in other regions. The river environment directly downstream of a glacier snout is characterised by extreme low water temperature and unstable channel sediments but these habitats may become rarer with widespread glacier retreat. In these extreme environments food web dynamics have been little studied, yet they could offer opportunities to test food web theories using highly resolved food webs owing to their low taxonomic richness. This study examined the interactions of macroinvertebrate and diatom taxa in the Ödenwinkelkees river, Austrian central Alps between 2006 and 2011. The webs were characterised by low taxon richness (13–22), highly connected individuals (directed connectance up to 0.19) and short mean food chain length (2.00–2.36). The dominant macroinvertebrates were members of the Chironomidae genus Diamesa and had an omnivorous diet rich in detritus and diatoms as well as other Chironomidae. Simuliidae (typically detritivorous filterers) had a diet rich in diatoms but also showed evidence of predation on Chironomidae larvae. Food webs showed strong species-averaged and individual size structuring but mass-abundance scaling coefficients were larger than those predicted by metabolic theory, perhaps due to a combination of spatial averaging effects of patchily distributed consumers and resources, and/or consumers deriving unquantified resources from microorganisms attached to the large amounts of ingested rock fragments. Comparison of food web structural metrics with those from 62 published river webs suggest these glacier-fed river food web properties were extreme but in line with general food web scaling predictions, a finding which could prove useful to forecast the effects of anticipated future glacier retreat on the structure of aquatic food webs. PMID:23613751

Evidence of Niche Partitioning under Ontogenetic Influences among Three Morphologically Similar Siluriformes in Small Subtropical Streams

PubMed Central

Bonato, Karine Orlandi; Fialho, Clarice Bernhardt

2014-01-01

Ontogenetic influences in patterns of niche breadth and feeding overlap were investigated in three species of Siluriformes (Heptapterus sp., Rhamdia quelen and Trichomycterus poikilos) aiming at understanding the species coexistence. Samplings were conducted bimonthly by electrofishing technique from June/2012 to June/2013 in ten streams of the northwestern state of Rio Grande do Sul, Brazil. The stomach contents of 1,948 individuals were analyzed by volumetric method, with 59 food items identified. In general Heptapterus sp. consumed a high proportion of Aegla sp., terrestrial plant remains and Megaloptera; R. quelen consumed fish, and Oligochaeta, followed by Aegla sp.; while the diet of T. poikilos was based on Simuliidae, Ephemeroptera and Trichoptera. Specie segregation was observed in the NMDS. Through PERMANOVA analysis feeding differences among species, and between a combination of species plus size classes were observed. IndVal showed which items were indicators of these differences. Niche breadth values were high for all species. The niche breadth values were low only for the larger size of R. quelen and Heptapterus sp. while T. poikilos values were more similar. Overall the species were a low feeding overlap values. The higher frequency of high feeding overlap was observed for interaction between Heptapterus sp. and T. poikilos. The null model confirmed the niche partitioning between the species. The higher frequency of high and intermediate feeding overlap values were reported to smaller size classes. The null model showed resource sharing between the species/size class. Therefore, overall species showed a resource partitioning because of the use of occasional items. However, these species share resources mainly in the early ontogenetic stages until the emphasized change of morphological characteristics leading to trophic niche expansion and the apparent segregation observed. PMID:25340614

Breeding habitat preference of preimaginal black flies (Diptera: Simuliidae) in Peninsular Malaysia.

PubMed

Ya'cob, Zubaidah; Takaoka, Hiroyuki; Pramual, Pairot; Low, Van Lun; Sofian-Azirun, Mohd

2016-01-01

To investigate the breeding habitat preference of black flies, a comprehensive black fly survey was conducted for the first time in Peninsular Malaysia. Preimaginal black flies (pupae and larvae) were collected manually from 180 stream points encompassing northern, southern, central and east coast of the Peninsular Malaysia. A total of 47 black fly species were recorded in this study. The predominant species were Simulium trangense (36.7%) and Simulium angulistylum (33.3%). Relatively common species were Simulium cheongi (29.4%), Simulium tani (25.6%), Simulium nobile (16.2%), Simulium sheilae (14.5%) and Simulium bishopi (10.6%). Principal Component Analysis (PCA) of all stream variables revealed four PCs that accounted for 69.3% of the total intersite variance. Regression analysis revealed that high species richness is associated with larger, deeper, faster and higher discharge streams with larger streambed particles, more riparian vegetation and low pH (F=22.7, d.f.=1, 173; P<0.001). Relationship between species occurrence of seven common species (present in >10% of the sampling sites) was assessed. Forward logistic regression analysis indicated that four species were significantly related to the stream variables. S. nobile and S. tani prefer large, fast flowing streams with higher pH, large streambed particles and riparian trees. S. bishopi was commonly found at high elevation with cooler stream, low conductivity, higher conductivity and more riparian trees. In contrast, S. sheilae was negatively correlated with PC-2, thus, this species commonly found at low elevation, warmer stream with low conductivity and less riparian trees. The results of this study are consistent with previous studies from other geographic regions, which indicated that both physical and chemical stream conditions are the key factors for black fly ecology. Copyright © 2015 Elsevier B.V. All rights reserved.

Chemical control of Simulium ochraceum Walker (Diptera: Simuliidae) larvae in an onchocerciasis endemic area of Guatemala.

PubMed

Yamagata, Y; Ochoa, J O; Molina, P A; Sato, H; Uemoto, K; Suzuki, T

1987-09-01

Chemical control against larvae of Simulium ochraceum, the principal vector of onchocerciasis, was carried out from 1979 to 1984 in a 91.3 km2 area of Guatemala where onchocerciasis is endemic. The control operation was divided chronologically into three phases according to the different tactics employed. Phase 1 (1979-1981), using briquettes of fat and detergent containing 10% temephos, was effective only in perennial streams. Phase 2 (1981-1982), which limited the application target to small streams with discharges of 0.1-1 litre/sec, was not effective. Successful control was achieved by Phase 3 (1982-1984), which consisted of fort-nightly applications of 5% temephos water dispersable powder in fixed doses of 24 g (1.2 g active ingredient) to every 50-100 m stretch of all streams with discharge rates of 0.1-50 l/sec. Vector biting rates were reduced by 97.8% in 1982 to 1983 and 97.6% in 1983-1984. The biting density of S. ochraceum at all five stations was reduced to less than 1.9/man/hour, the proposed critical level for long term transmission of onchocerciasis. The biting density of the S. metallicum/horacioi complex was not apparently affected by this operation. Through analysis of the density of S. ochraceum at various distances from the untreated areas, infiltration of the flies was found to be rare, if the distance was beyond 2 km. Fly-round surveys proved to be practical as a surveillance method for detecting larval breeding in untreated or improperly treated streams. The cost for a nation-wide vector control operation was presented.

A biological tool to assess flow connectivity in reference temporary streams from the Mediterranean Basin.

PubMed

Cid, N; Verkaik, I; García-Roger, E M; Rieradevall, M; Bonada, N; Sánchez-Montoya, M M; Gómez, R; Suárez, M L; Vidal-Abarca, M R; Demartini, D; Buffagni, A; Erba, S; Karaouzas, I; Skoulikidis, N; Prat, N

2016-01-01

Many streams in the Mediterranean Basin have temporary flow regimes. While timing for seasonal drought is predictable, they undergo strong inter-annual variability in flow intensity. This high hydrological variability and associated ecological responses challenge the ecological status assessment of temporary streams, particularly when setting reference conditions. This study examined the effects of flow connectivity in aquatic macroinvertebrates from seven reference temporary streams across the Mediterranean Basin where hydrological variability and flow conditions are well studied. We tested for the effect of flow cessation on two streamflow indices and on community composition, and, by performing random forest and classification tree analyses we identified important biological predictors for classifying the aquatic state either as flowing or disconnected pools. Flow cessation was critical for one of the streamflow indices studied and for community composition. Macroinvertebrate families found to be important for classifying the aquatic state were Hydrophilidae, Simuliidae, Hydropsychidae, Planorbiidae, Heptageniidae and Gerridae. For biological traits, trait categories associated to feeding habits, food, locomotion and substrate relation were the most important and provided more accurate predictions compared to taxonomy. A combination of selected metrics and associated thresholds based on the most important biological predictors (i.e. Bio-AS Tool) were proposed in order to assess the aquatic state in reference temporary streams, especially in the absence of hydrological data. Although further development is needed, the tool can be of particular interest for monitoring, restoration, and conservation purposes, representing an important step towards an adequate management of temporary rivers not only in the Mediterranean Basin but also in other regions vulnerable to the effects of climate change. Copyright © 2015 Elsevier B.V. All rights reserved.

Human onchocerciasis in the Amazonian area of southern Venezuela: spatial and temporal variations in biting and parity rates of black fly (Diptera: Simuliidae) vectors.

PubMed

Grillet, M E; Basáñez, M G; Vivas-Martínez, S; Villamizar, N; Frontado, H; Cortez, J; Coronel, P; Botto, C

2001-07-01

We investigated some entomological factors underlying altitudinal prevalence variation in the Venezuelan Amazonia human onchocerciasis focus. Spatial and temporal variation in relative abundance, daily biting rate, proportion of parous flies, and monthly parous biting rate were studied for the three main simuliid vectors (based on their vectorial competence: Simulium oyapockense s.l. Floch & Abonnenc approximately = S. incrustatum Lutz < S. guianense s.l. Wise). Yanomami villages were selected among sentinel communities of the ivermectin control program, representing hypo- to hyperendemicity conditions of infection. Spatial variation was explored via increasing village altitude on two river systems (A: Ocamo-Putaco and B: Orinoco-Orinoquito). Temporal variation was studied between 1995 and 1999 by sampling the biting population during dry and rainy mouths. Environmental variables included monthly rainfall and maximum river height. Simuliid species composition itself varied along the altitudinal and prevalence gradient. S. oyapockense s.l. prevailed below 150 m. Above this altitude and up to 240 m, S. incrustatum and S. guianense s.l. became more frequently and evenly collected along A but not along B, where S. incrustatum remained absent. The daily biting rate of S. oyapockense s.l. was higher during the dry season along A, whereas the converse took place along B. Daily biting rate of S. incrustatum was lowest during early rains. By contrast, the daily biting rate of S. guianense s.l. was highest during this period. There was a significant negative cross-correlation between proportion of parous of S. oyapockense s.l. and river height (2 and 3 mo lagged), whereas this variable (1 and 2 mo lagged) was positively correlated with the proportion of parous flies for S. incrustatum. Monthly parous biting rate values suggest that the months contributing most to onchocerciasis transmission in the area are likely to be the dry season and the transition periods between seasons.

Bioenergetics of lotic filter-feeding insects Simulium spp. (Diptera) and Hydropsyche occidentalis (Trichoptera) and their function in controlling organic transport in streams

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCullough, D.A.; Minshall, G.W.; Cushing, C.E.

1979-06-01

This study derives a set of bioenergetic parameters for the blackfly Simulium spp. (Diptera: Simuliidae) and the caddisfly Hydropsyche occidentalis (Trichoptera: Hydropsychidae) and evaluates the impact of these filter feeders on the lotic environment. In addition, comparison is made between field- and laboratory-derived estimates of ingestion and between 2 methods of calculating assimilation rate. Digestion (gut-clearance) time for Simulium ranged between 0.33 and 1.25 h compared to 1.54 to 2.63 h for Hydropsyche. Mean ingestion rate for Simulium in a series of experiments ranged from 1.36 to 54.74 ..mu..g DW/mg DW/h. The mean assimilation efficiency for diatoms was about 55%more » as measured by the dual-label technique. Mean ingestion rates of diatoms for Hydropsyche in 3 experiments were 31.3, 31.0 and 29.2 ..mu..g DW/mg DW/h, respectively; low values (3 ..mu..g DW/mg DW/h) from a 4th experiment were associated with high concentrations of green algae. An assimilation rate for diatoms of 7.5 ..mu..g AFDW/mg DW/h was derived for Hydropsyche. Measurements of growth rates of Hydropsyche under natural conditions were 3.6 to 4.4 ..mu..g DW/mg DW/h. Respiration rate of Hydropsyche for water greater than or equal to 62% O/sub 2/ saturation was about 2.3 ..mu..l O/sub 2//mg DW/h at 20/sup 0/C. The results of this research in combination with literature derived values, yielded the following mean energy budgets for Simulium and Hydropsyche, respectively(J/mg/h): ingestion (C) 0.318, 0.393; respiration (R) 0.092, 0.042; growth (G) 0.092, 0.100; assimilation (A) (as C x AE) 0.182, 0.192; (as G + R) 0.184, 0.142 (values times 0.239 = cal/mg/h).« less

Ecosystem ecology meets adaptive management: food web response to a controlled flood on the Colorado River, Glen Canyon

USGS Publications Warehouse

Cross, Wyatt F.; Baxter, Colden V.; Donner, Kevin C.; Rosi-Marshall, Emma J.; Kennedy, Theodore A.; Hall, Robert O.; Wellard Kelly, Holly A.; Rogers, R. Scott

2011-01-01

Large dams have been constructed on rivers to meet human demands for water, electricity, navigation, and recreation. As a consequence, flow and temperature regimes have been altered, strongly affecting river food webs and ecosystem processes. Experimental high-flow dam releases, i.e., controlled floods, have been implemented on the Colorado River, USA, in an effort to reestablish pulsed flood events, redistribute sediments, improve conditions for native fishes, and increase understanding of how dam operations affect physical and biological processes. We quantified secondary production and organic matter flows in the food web below Glen Canyon dam for two years prior and one year after an experimental controlled flood in March 2008. Invertebrate biomass and secondary production declined significantly following the flood (total biomass, 55% decline; total production, 56% decline), with most of the decline driven by reductions in two nonnative invertebrate taxa, Potamopyrgus antipodarum and Gammarus lacustris. Diatoms dominated the trophic basis of invertebrate production before and after the controlled flood, and the largest organic matter flows were from diatoms to the three most productive invertebrate taxa (P. antipodarum, G. lacustris, and Tubificida). In contrast to invertebrates, production of rainbow trout (Oncorhynchus mykiss) increased substantially (194%) following the flood, despite the large decline in total secondary production of the invertebrate assemblage. This counterintuitive result is reconciled by a post-flood increase in production and drift concentrations of select invertebrate prey (i.e., Chironomidae and Simuliidae) that supported a large proportion of trout production but had relatively low secondary production. In addition, interaction strengths, measured as species impact values, were strongest between rainbow trout and these two taxa before and after the flood, demonstrating that the dominant consumer—resource interactions were not necessarily congruent with the dominant organic matter flows. Our study illustrates the value of detailed food web analysis for elucidating pathways by which dam management may alter production and strengths of species interactions in river food webs. We suggest that controlled floods may increase production of nonnative rainbow trout, and this information can be used to help guide future dam management decisions.

Drift induced by repeated hydropeaking waves in controlled conditions

NASA Astrophysics Data System (ADS)

Maiolini, Bruno; Bruno, M. Cristina; Biffi, Sofia; Cashman, Matthew J.

2014-05-01

Repeated hydropeaking events characterize most alpine rivers downstream of power plants fed by high elevation reservoirs. The effects of hydropeaking on the benthic communities are well known, and usually each hydropeaking wave causes an increase in tractive force and changes in temperature and water quality. Simulations of hydropeaking in artificial system can help to disentangle the direct effects of the modified flow regime from impacts associated with other associated physio-chemical changes, and with the effects of river regulation and land-use changes that often accompany water resource development. In September 2013 we conducted a set of controlled simulations in five steel flumes fed by an Alpine stream (Fersina stream, Adige River catchment, Trentino, Italy), where benthic invertebrates can freely colonize the flumes. One flume was used as control with no change in flow, in the other four flumes we simulated an hydropeaking wave lasting six hours, and repeated for five consecutive days. Flow was increased by twice baseflow in two flumes, and three times in the other two. We collected benthic samples before the beginning (morning of day 1) and after the end (afternoon of day 5) of the set of simulations to evaluate changes in the benthic communities due to induced drift migration. During each simulation, we collected drifting organisms at short time intervals to assess the responses to: 1) the initial discharge increase, 2) the persistence of high flows for several hours; 3) the decrease of discharge to the baseflow; 4) the change in drift with each successive day. Preliminary results indicate typical strong increases of catastrophic drift on the onset of each simulated hydropeaking, drift responses proportional to the absolute discharge increase, a decrease in the drift responses over successive days. Different taxa responded with different patterns: taxa which resist tractive force increased in drift only during the periods of baseflow that follow the habitat stress (behavioral drift) (e.g., Simuliidae, behavioral drift); other taxa which can not resist the increase in tractive force, drifted from the beginning of the simulation (e.g., Chironomidae, catastrophic drift).

Stability and change in the distribution of cytospecies of the Simulium damnosum complex (Diptera: Simuliidae) in southern Ghana from 1971 to 2011.

PubMed

Post, Rory J; Cheke, Robert A; Boakye, Daniel A; Wilson, Michael D; Osei-Atweneboana, Mike Y; Tetteh-Kumah, Anthony; Lamberton, Poppy Hl; Crainey, J Lee; Yaméogo, Laurent; Basáñez, María-Gloria

2013-07-13

Simulium damnosum s.l., the most important vector of onchocerciasis in Africa, is a complex of sibling species that have been described on the basis of differences in their larval polytene chromosomes. These (cyto) species differ in their geographical distributions, ecologies and epidemiological roles. In Ghana, distributional changes have been recorded as a consequence of vector control and environmental change (e.g. deforestation), with potential disease consequences. We review the distribution of cytospecies in southern Ghana and report changes observed with reference to historical data collated from 1971 to 2005 and new identifications made between 2006 and 2011. Larvae were collected from riverine breeding sites, fixed in Carnoy's solution and chromosome preparations made. Cytotaxonomic identifications from 1,232 samples (including 49 new samples) were analysed. We report long-term stability in cytospecies distribution in the rivers Afram, Akrum, Pawnpawn and Pru. For the rivers Oda, Ofin and Tano we describe (for the first time) patterns of distribution. We could not detect cytospecies composition changes in the upper Pra, and the lower Pra seems to have been stable. The elimination of the Djodji form of S. sanctipauli in the Volta Region seems to have had no long-term effects on the distribution of the other cytospecies, despite an initial surge by S. yahense. There has been a recent increase in the occurrence of savannah cytospecies in the river Asukawkaw, and this might be related to continuing deforestation. Cytospecies' distributions have not been stable from 1971 to 2011. Although there are no obvious causes for the temporary appearance and subsequent disappearance of cytospecies in a particular location, a major influence has been vector control and migration patterns, probably explaining observed changes on the Black Volta and lower Volta rivers. Deforestation was previously implicated in an increase of savannah cytospecies in southern Ghana (1975-1997). Our data had little power to support (or refute) suggestions of a continuing increase, except in the Asukawkaw river basin.

Stability and change in the distribution of cytospecies of the Simulium damnosum complex (Diptera: Simuliidae) in southern Ghana from 1971 to 2011

PubMed Central

2013-01-01

Background Simulium damnosum s.l., the most important vector of onchocerciasis in Africa, is a complex of sibling species that have been described on the basis of differences in their larval polytene chromosomes. These (cyto) species differ in their geographical distributions, ecologies and epidemiological roles. In Ghana, distributional changes have been recorded as a consequence of vector control and environmental change (e.g. deforestation), with potential disease consequences. We review the distribution of cytospecies in southern Ghana and report changes observed with reference to historical data collated from 1971 to 2005 and new identifications made between 2006 and 2011. Methods/Results Larvae were collected from riverine breeding sites, fixed in Carnoy’s solution and chromosome preparations made. Cytotaxonomic identifications from 1,232 samples (including 49 new samples) were analysed. We report long-term stability in cytospecies distribution in the rivers Afram, Akrum, Pawnpawn and Pru. For the rivers Oda, Ofin and Tano we describe (for the first time) patterns of distribution. We could not detect cytospecies composition changes in the upper Pra, and the lower Pra seems to have been stable. The elimination of the Djodji form of S. sanctipauli in the Volta Region seems to have had no long-term effects on the distribution of the other cytospecies, despite an initial surge by S. yahense. There has been a recent increase in the occurrence of savannah cytospecies in the river Asukawkaw, and this might be related to continuing deforestation. Conclusions Cytospecies’ distributions have not been stable from 1971 to 2011. Although there are no obvious causes for the temporary appearance and subsequent disappearance of cytospecies in a particular location, a major influence has been vector control and migration patterns, probably explaining observed changes on the Black Volta and lower Volta rivers. Deforestation was previously implicated in an increase of savannah cytospecies in southern Ghana (1975–1997). Our data had little power to support (or refute) suggestions of a continuing increase, except in the Asukawkaw river basin. PMID:23849451

Long-term macroinvertebrate response to flow abstraction at Alpine water intakes

NASA Astrophysics Data System (ADS)

Gabbud, Chrystelle; Savioz, Amélie; Lane, Stuart

2016-04-01

The natural flow hydrological characteristics of Alpine streams, dominated by snowmelt and glacier melt, have been established for many years. More recently, the ecosystems that they sustain have been described and explained, following the hydrological, biochemical, morphodynamic, and biotic elements specific to Alpine streams. However, natural Alpine flow regimes may be strongly modified by hydroelectric power production, which impacts upon both river discharge and sediment transfer, and hence on downstream flora and fauna. These kinds of impacts are well studied where river are regulated by dams, with sediments retained behind walls, but they are much less focus on water intakes, whose storage capacity is very smaller and thus have to flush flow and sediment regularly. Here we focus on the impacts of flow abstraction on macroinvertebrates, the most widely ecological group used in freshwater biomonitoring as they act typically as indicators of environmental health. Some key generalizations can be made. For instance, in European glacially fed river systems, Plecoptera, Chironomidae, Ephemeroptera, Simuliidae, and Diptera are the main taxa found in spring as they are better adapted to cold conditions. Petts and Bickerton (1994) published macroinvertebrate samples from the upper part of the glacial stream system the Borgne d'Arolla (Valais, Switzerland), highlighting that: (1) taxa variability and productivity decline in the river because of flow abstraction, (2) 60 % of the communities were provided by tributaries, (3) there is migration upstream of the species in response to the passage from a dominant ice-melt to a snow-melt regime, (4) the colonisation is difficult because of a significant modification of the habitat in the river by sediment transport, until it becomes warmer, clearer and more stable further downstream. In order to establish the long-term impacts of flow abstraction upon instream ecology where sediment delivery is maintained but transport capacity is reduced, and to determine if the above trends are accelerated, maintained or reversed, we revisited the study of Petts and Bickerton (1994) by repeating transects of interest for both the river and the tributaries during summer 2015. Based on macroinvertebrate sampling, determinations and statistics, preliminary results show that these trends have been maintained, with macroinvertebrate presence restricted to zones immediately downstream of unregulated tributaries. Despite the river having been protected as an alluvial zone of national importance since the 1990s, there is no evidence of life in the river except in isolated tributary-fed hotspots. The data suggest that restoring this kind of system will need new approaches to manage sediment, ones that environmental flows alone are unlikely to be able to address. Reference Petts GE, Bickerton MA (1994). Influence of water abstraction on the macroinvertebrate community gradient within a glacial stream system: La Borgne d'Arolla, Valais, Switzerland. Freshwater Biology, 32:375-386.

Risk factors for epilepsy in Bas-Uélé Province, Democratic Republic of the Congo: a case-control study.

PubMed

Colebunders, Robert; Mandro, Michel; Mokili, John L; Mucinya, Gisele; Mambandu, Germain; Pfarr, Kenneth; Reiter-Owona, Ingrid; Hoerauf, Achim; Tepage, Floribert; Levick, Bethanie; Begon, Michael; Laudisoit, Anne

2016-08-01

The reason for the high prevalence of epilepsy in onchocerciasis endemic areas remains unknown. The aim of this study was to detect risk factors associated with epilepsy in a region endemic for onchocerciasis. In June 2014, a case-control study was performed in Titule, Bas-Uélé Province in the Democratic Republic of the Congo. Individuals with unprovoked convulsive epilepsy of unknown aetiology were enrolled as cases (n=59). Healthy members of families without cases of epilepsy in the same village were recruited as controls (n=61). A multivariate binomial logistic regression analysis was performed to identify potential risk factors associated with epilepsy. To evaluate the potential protective effect of ivermectin treatment on the development of epilepsy, a nested age-matched case-control study was performed including only those who were eligible for ivermectin treatment in the year before they developed epilepsy. Suspected onchocerciasis skin lesions were more often present in cases than in controls: 12/41 (29%) vs. 1/56 (2%), respectively (odds ratio (OR) 20.26, 95% confidence interval (CI) 2.42-170; p<0.01). Ivermectin had been taken 7 months earlier in 29/59 (49%) cases and 29/61 (48%) controls. Onchocerca volvulus (OV) DNA was detected by PCR in skin snips in 26/34 cases (76%) and 10/14 controls (71%) (p=0.7), and there was presence of OV IgG4 antibodies in 35/48 (73%) cases and 15/18 (83%) controls (p=0.5). OV DNA was not detected in the cerebrospinal fluid of cases (controls not tested). Both cases and controls reported frequent bites by blackflies (Diptera, Simuliidae). Bathing daily as opposed to less often (OR 16.7, 95% CI 2.2-125.8; p<0.01), bathing between 11 a.m. and 4 p.m. (OR 12.7, 95% CI 1.6-103.7; p=0.02), and washing clothes between 11 a.m. and 4 p.m. (OR 10.9, 95% CI 1.5-77.3; p=0.02) were all independently associated with epilepsy. Blood screening by specific PCR tests for Toxoplasma and Wuchereria bancrofti was negative in all cases and controls. A Loa loa infestation was found in only one case and one control by PCR and Giemsa smear. Antibodies to Taenia solium, Toxocara, and Trypanosoma sp were not detected in any of the participants. In an age-matched case-control analysis, 16/18 (89%) cases had not taken ivermectin the year before they developed epilepsy, compared to 7/18 (39%) controls that same year (p=0.002). These data suggest that frequent activities at rivers known to be blackfly breeding sites and a historical lack of ivermectin treatment were risk factors for epilepsy in this onchocerciasis endemic area. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

River restoration and biocoenoses improvement in two streams renaturated using bioengeneering.

NASA Astrophysics Data System (ADS)

Leoni, B.; Forasacco, E.; Dobner, R.; Cotta Ramusino, M.

2003-04-01

The Bioengineering is a constructive discipline having its own technical, ecological and environmental friendly scopes, by using living materials. The aim of this study is to assess the river restoration efficiency of Bioengineering. The basic goals of many management-concepts are the integrity of the river habitat, self-regulation and self-regeneration, the preservation of intact resources, to recreate the uniqueness, diversity and beauty of natural river landscape. From an ecological point of view the richness, diversity and age composition of the populations developing after restoration as a result of habitat improvement reveal the degree to which comprehensive concepts were applied (Jungwirth et al., 1995). The following results summarised an investigation on streams Boesio and Rancina in Valcuvia, (Varese, Northern Italy). These streams are characterised by human impacts like water pollution, river engineering and river bioengineering (palificata doppia viva). The samples of macrobenthic fauna were collected between August 2000 and July 2001 in 4 stations for each stream, where the 3rd station of Boesio and Rancina streams is characterised by bioengeneering measure, using a Surber sampler (0.125 m2, mesh size 0.45 mm). The zoobenthic communities of these pre-alpine streams are characterised by low richness and diversity and few families and genera were predominant. In Rancina stream, Ephemeroptera (genus Baetis), Trichoptera (families Hydropsychidae, Limnephilidae and Rhyacophilidae) and Diptera (families Chironomidae and Simuliidae) are present throughout the year with significant densities. The faunal composition of Boesio stream is similar. It differs, only, from stream Rancina to costant presence of Plecoptera with genus Leuctra. To evaluate the restoration of environmental quality two indices were applied: Indice Biotico Esteso (I.B.E.- Ghetti, 1995); Indice di Funzionalità Fluviale (I.F.F.- Siligardi, 2000). The E.B.I. scores of Boesio stream indicate that stations 1 and 2 are in good condition (Ecological status classification: II): therefore the level of diversity and abundance of macrobenthic taxa is slightly outside the range associated with the normal conditions and the most of the sensitive taxa of the type specific communities are present. The stations 3 and 4 are in moderate condition (Ecological status classification: III): the level of diversity and abundance of invertebrate taxa is moderately outside the normal condition range, the taxa indicative of pollution are present and many of the sensitive taxa of the type specific communities are absent. In the Rancina stream in all of the 4 stations the ecological status is indicated like moderate (Ecological status classification: III): there is a predominance of taxa more resistant at pollution and at changes in other biological components of the stream. The I.F.F. show that in Boesio stream the right shore score is moderate-good and the left shore score is moderate-poor. Differently, the Rancina stream presents the right shore with a value poor and the left shore with a wide gradient between good and poor-bad. In conclusion, we can affirm the low efficiency of Bioengineering to restore the Boesio and Rancina streams, because we cannot observe the habitat and aquatic biocoenoses improvement. An explication could be that the conversions are restricted to morphological measures, which are carried out on a small way of banks. Whereas, the restoration using the Bioengineering requires taking the entire catchment area into consideration.