physiological studies on an isolate of saprolegnia ferax from the larval gut of the blackfly simulium vittatum. 19769585
larvicidal and ovicidal activity of dimilin against simulium vittatum. 1977326838
a simplified membrane technique for feeding blackflies (diptera: simuliidae) on blood in the order to overcome the difficulties of colonizing simuliidae in the laboratory, a membrane system has been developed which was successfully used to feed simulium vittatum and s. verecundum on out-dated human whole blood. thirty-seven (41.1%) of 90 s. vittatum and 4 (8.6%) of 46 s. verecundum took blood meals in 6 trials. the membrane system was also shown to be more effective and consistent in providing blood meals compared with the use of laboratory animals.19761085662
biological transmission of vesicular stomatitis virus (new jersey) by simulium vittatum (diptera: simuliidae).simulium vittatum females were shown to be competent vectors for the new jersey serotype (vsnj) of vesicular stomatitis virus (camp verde strain). seventy percent of females infected intrathoracically transmitted infectious virions in their saliva after a 10-d incubation period. when infected with virus per os, 63% of the flies tested were positive at day 10, and 45% of flies infected in this manner also secreted virus in their saliva by day 9 or 10 after infection. when ingested by s. vittatum ...19921322991
mitochondrial transfer rna genes in a black fly, simulium vittatum (diptera: simuliidae), indicate long divergence from mosquito (diptera: culicidae) and fruit fly (diptera: drosophilidae).sequences are given for nine complete genes and one partial mitochondrial trna gene of the black fly, simulium vittatum (zetterstedt). sequenced trna genes were for alanine, arginine, asparagine, aspartic acid, glutamic acid, glycine, leucine(cun), lysine, serine(agn), and valine. nucleotides were aligned with the same previously sequenced genes in aedes albopictus skuse and drosophila yakuba burla. a cluster of six trna genes, which differ in arrangement in ae. albopictus and d. yakuba, was amp ...19921379642
morphological and functional classification of the hemocytes of adult female simulium vittatum (diptera: simuliidae).morphology and function of the hemocytes of 1-d-old, female simulium vittatum zetterstedt were studied using light and scanning electron microscopy. four types of hemocytes, comparable with those of other medically important diptera, were identified: prohemocytes, plasmatocytes, granulocytes, and spherulocytes. plasmatocytes and granulocytes contained neutral red granules, but only granulocytes exhibited significant acid phosphatase activity. plasmatocytes and granulocytes were identified as the ...19921625294
toxicity of microencapsulated permethrin to selected nontarget aquatic invertebrates.microencapsulated permethrin (penncapthrin) was evaluated under laboratory conditions for its toxicity toward several nontarget aquatic invertebrates. average lc50 estimates for selected lotic invertebrates, based on a one hour dosing regime, were: 2.71 mg/l for simulium vittatum, 4.59 mg/l for hydropsyche spp., and 13.41 mg/l for isonychia bicolor. in acute static tests with daphnia magna, there was no significant difference (p less than or equal to 0.05) between the toxicity of penncapthrin at ...19912014998
comparison of mitochondrial dna sequences of seven morphospecies of black flies (diptera: simuliidae).universal primers constructed from the 16s ribosomal rna gene in the drosophila yakuba mitochondrial genome were successfully used to amplify, via the polymerase chain reaction, the homologous region of mitochondrial dna from seven black fly morphospecies. amplification was achieved from single larval salivary glands and from single adults preserved in carnoy's fixative (ethanol - acetic acid, 3:1), allowing dna sequences and polytene chromosome banding pattern data to be gathered from the same ...19912055453
isolation and characterization of a coagulation factor xa inhibitor from black fly salivary glands.we have discovered and characterized a novel coagulation factor xa inhibitor from the salivary gland of the black fly, simulium vittatum. salivary glands were surgically dissected from the flies and a crude salivary gland extract was tested for inhibition of a number of coagulation assays. the gland extract inhibited both thrombin and factor xa. to purify further the factor xa inhibitor, a factor xa affinity column was utilized. final purification of the black fly factor xa inhibitor was achieve ...19902270532
identification of species-specific dna sequences in north american blackflies.blackflies are vectors for onchocerca volvulus, a filarial parasite that infects tens of millions of people in africa and latin america. different species of the insect vectors, varying greatly in their ability to transmit the infection, may populate overlapping geographical regions and be morphologically similar. a rapid and reliable method for distinguishing among blackfly species is presently not available. we have isolated cloned dnas coding for repetitive sequences that can distinguish betw ...19883387825
avoidance of scouring by larvae of simulium vittatum (diptera: simuliidae) during a spring flood. 19863507519
techniques for inducing oviposition in simulium vittatum (diptera: simuliidae) and for rearing sibling cohorts of simuliids. 19873694633
efficacy of flowable concentrate formulations of bacillus thuringiensis var. israelensis against black flies (diptera:simuliidae).seven flowable concentrate formulations of bacillus thuringiensis (h-14), teknar wdc, auto-dispersible teknar, teknar 2x aqueous concentrate, teknar 2x oil base concentrate, vectobac as, bactimos fc and skeetal f, were evaluated in small streams against simulium vittatum. there was no significant difference in efficacy among the formulations with the exception of the teknar 2x aqueous concentrate, which required considerably less formulation (5 mg/liter/1 min) than the others to produce 95% mort ...19853880264
susceptibility of larval and adult simulium vittatum (diptera: simuliidae) to the solubilized parasporal crystal of bacillus thuringiensis israelensis. 19854045942
ultrastructural changes in the nuclear envelope of larval fat body cells of simulium vittatum (diptera) induced by microsporidian infection of thelohania bracteata. 19724348051
mercury residues in wood ducks and wood duck foods in eastern tennessee.liver, breast muscle and body fat from 50 juvenile and five adult wood ducks (aix sponsa) collected on the holston river, tennessee were analyzed for total mercury content. black fly larvae (simulium vittatum) sago pondweed (potamogeton pectinatus), tapegrass (vallisneria americanus), water stargrass (heteranthera dubia), elodea canadensis, and river bottom sediments were also analyzed to elucidate the distribution of mercury in the wood duck's environment. liver tissues of juveniles contained t ...19836887432
laboratory studies on blood-feeding of blackflies (diptera: simuliidae). 1. factors affecting the feeding blood/membrane apparatus was used to study the feeding responses of field-collected and lab-reared simulium vittatum and prosimulium mixtum. both species showed preferences for human, horse, cow and pig bloods while neither fed in high rates on dog or goose bloods. these results are discussed in the context of field data on host preferences. size was shown to be related to the feeding rates in s. vittatum, larger flies feeding more readily. lab-reared s. vittatum females fed in decreasing rat ...19807445070
laboratory studies on blood-feeding of blackflies (diptera: simuliidae). 2. factors affecting fecundity.the fecundity of autogenous simulium vittatum and prosimulium mixtum females was shown to be related to the size of the female which in turn was a result of the quantity of food provided to the larvae. among females of equal size, sucrose allowed a greater expression of autogeny compared to females given only water. in the case of lab-reared s. vittatum, a blood-meal enhanced autogenous egg production when females were fed within 24 h after emergence. preliminary data indicated that for p. mixtu ...19807445071
the black fly simulium vittatum trypsin gene: characterization of the 5'-upstream region and induction by the blood meal.the events leading to blood digestion in hematophagous insects are not well understood at the molecular level. here we report on the characterization of a trypsin gene from the black fly simulium vittatum. southern blot analysis indicated that the s. vittatum genome contains at least two trypsin genes. primer extension experiments identified two closely spaced transcription initiation sites, 3 bp apart. a genomic clone containing the trypsin gene was restriction mapped and the nucleotide sequenc ...19957498433
analysis of migration success of onchocera lienalis microfilariae in the haemocoel of simulium vittatum.migration success (i.e. the proportion of worms that reach the thorax) of onchocerca lienalis microfilariae (mf) in the haemocoel of simulium vittatum was studied by inoculating mf into the posterior abdomen, and recording their distribution in the blackfly body at predetermined time points. mf arrive into the thorax by active locomotion rather than by drifting in haemolymph currents. migration into the thorax was completed by 12 h post inoculation (pi) but was not continuous throughout this per ...19957622790
larvicidal activity of the entomopathogenic fungus tolypocladium cylindrosporum (deuteromycotina: hyphomycetes) on the mosquito aedes triseriatus and the black fly simulium vittatum (diptera: simuliidae).laboratory bioassays evaluated the pathogenicity of the entomopathogenic fungus tolypocladium cylindrosporum against aedes triseriatus. all larval instars were found to be susceptible at temperatures from 18 to 25 degrees c. blastoconidia were more virulent than conidia. mortality was proportional to exposure time in assays using blastoconidia. blastoconidia and exposure time appear to be a more adequate method for bioassay of t. cylindrosporum virulence than the standard procedure of using coni ...19947707051
nematocera (ceratopogonidae, psychodidae, simuliidae and culicidae) and control methods.the biology, veterinary importance and control of certain nematocera are described and discussed. culicoides spp. (family ceratopogonidae) transmit the arboviruses of bluetongue (bt), african horse sickness (ahs), bovine ephemeral fever (bef) and akabane. some other arboviruses have been isolated from these species, while fowl pox has been transmitted experimentally by culicoides. these insects are vectors of the parasitic protozoans leucocytozoon caulleryi and haemoproteus nettionis, and the pa ...19947711309
chemical guidance of onchocerca lienalis microfilariae to the thorax of simulium vittatum.the behavioural responses of onchocerca lienalis microfilariae (mf) to tissue factors of the surrogate black fly host, simulium vittatum, were studied using a novel in vitro bioassay. mf accumulated towards thoracic tissues to a density 4 times higher than towards abdominal tissues, despite the larger surface area and volume of abdominal tissues. mf migrated toward thoracic tissues regardless of whether or not contact with thoracic tissues was possible. therefore, mf directed themselves toward t ...19957724240
anticoagulant activity in salivary gland extracts of black flies (diptera: simuliidae).anticoagulant activity was determined in salivary gland extracts from four species of black flies, i.e., simulium vittatum zetterstedt, simulium argus williston, simulium metallicum bellardi, and simulium ochraceum walker. inhibition of coagulation factor xa occurred among all four, whereas thrombin inhibition was detected in s. argus and s. vittatum only. both bovine and human alpha-thrombins were inhibited with the highest activity occurring with s. argus salivary gland extracts. factor xa inh ...19947815406
entomopathogenic fungi of the order entomophthorales (zygomycotina) in adult black fly populations (diptera: simuliidae) in quebec.infections by insect-pathogenic fungi of the order entomophthorales in two adult black fly populations were studied in the réserve faunique du saint-maurice (quebec). entomophaga near limoniae infected simulium verecundum/rostratum in june whereas erynia curvispora predominantly parasitized simulium decorum from the 2nd week of july to september and erynia conica attacked the simulium venustum complex, simulium verecundum/rostratum, and the simulium vittatum complex from may to september. the fu ...19947922891
notes on sugar feeding and selected wild mammalian hosts of black flies (diptera: simuliidae) in newfoundland.this study, done on the avalon peninsula, newfoundland, identified selected wild mammalian hosts and quantified the incidence of sugar feeding for several species (species complexes) of black flies. female flies were taken from fox, snowshoe hare, lynx, caribou, and human baits. simulium truncatum/venustum complex females took blood from fox, lynx, rabbit, and caribou and were frequently taken in sweep net collections around humans. blood-fed females of the simulium rostratum/verecundum complex ...19947932603
modulation of murine cellular immune responses and cytokines by salivary gland extract of the black fly simulium vittatum.salivary gland extract (sge) of the blood-feeding black fly simulium vittatum is known to modulate immunological responses. in the present study, the ability of s. vittatum sge to modulate responses during heterologous antigenic challenge was investigated in a murine model, with particular emphasis on characterizing the patterns of cytokine response. mice were injected repeatedly with sge or saline (sham), then challenged with the t dependent antigen ovalbumin (ova) to generate antigen-specific ...19947939161
onchocerca lienalis: a comparison of microfilarial loss in simulium jenningsi and simulium vittatum. 19948056080
onchocerca lienalis: rapid clearance of microfilariae within the black fly, simulium vittatum.a rapid decrease of about a third of the number of onchocerca lienalis microfilariae (mf) parenterally inoculated into simulium vittatum black flies occurred within 5 hr postinoculation (pi). the change of mf counts over time was modeled by a segmented linear regression. during 2 hr pi the slope was -3.5 mf/hr (p < or = 0.001) and between 2 and 24 hr pi the slope was -0.1 mf/hr. although significantly different from the former slope (p < 0.001), the latter was not significantly different from ze ...19948119373
peritrophic matrix of the black fly simulium vittatum: formation, structure, and analysis of its protein components.the peritrophic matrix (pm) (same as peritrophic membrane) is secreted by the midgut epithelium of insects and completely surrounds the ingested food. the pm is likely to influence disease transmission by hematophagous insects. as a prelude to a more detailed examination of pm function, we report on morphological and molecular studies of the pm type 1 (pm1) from simulium vittatum. the blood meal induces major changes in epithelial cell morphology: cells become flattened, microvilli decrease dram ...19948195743
modulation of murine immunological responses by salivary gland extract of simulium vittatum (diptera: simuliidae).the influence of simulium vittatum zetterstedt salivary gland extract on several immunological mechanisms was investigated in murine model hosts (laboratory mice). these mechanisms included the expression of major histocompatibility complex class ii cell surface molecules, the in vitro mitogen responsiveness of lymphoid cells, and the antibody responses to heterologous foreign antigens (sheep erythrocytes). experiments were designed to determine the influence of salivary gland extract following ...19938254643
gut-specific genes from the black fly simulium vittatum encoding trypsin-like and carboxypeptidase-like haematophagous insects digestion of the blood meal provides nutrients for survival and essential components for egg production. we have isolated and partially characterized two gut-specific genes from the black fly simulium vittatum. sequence analysis revealed that both are highly similar to digestive proteases, one to trypsins and the other to carboxypeptidases. rna blot analysis indicates that the expression of these two genes is regulated in a sex-specific manner; when fed the same sucrose ...19938269093
antibody responses of balb/c mice to salivary antigens of hematophagous black flies (diptera: simuliidae).the humoral antibody responses to salivary antigens of simulium vittatum zetterstedt were investigated in a balb/c mouse laboratory model. production of antisera was stimulated by intraperitoneal immunization with salivary gland extract or by feeding flies directly on depilated mice. antibody responses in these two groups of mice were compared by western blotting, thus characterizing "true" salivary immunogens present in salivary gland extract. immunized mice developed igg, igm, and ige antibodi ...19938360895
factors affecting the acquisition of plagiorchis noblei (trematoda: plagiorchiidae) cercariae by black fly (diptera: simuliidae) larvae and the effect of metacercariae on host survival.larvae of 4 species of black flies, prosimulium mixtum, simulium vittatum, s. decorum and stegopterna mutata, were exposed in the laboratory to cercariae of the digenean plagiorchis noblei in flowing water. prevalence and intensity of infection of all species varied directly with exposure intensity and decreased with increasing water velocity; prevalence increased with larval size. infection levels for p. mixtum were higher than for the 3 other species. mortality among infected larvae of all spe ...19938468573
novel anticoagulant from salivary glands of simulium vittatum (diptera: simuliidae) inhibits activity of coagulation factor v.anticoagulant activity was detected in fractions of a reversed phase-high-performance liquid chromatography (rp-hplc) of salivary gland lysate from simulium vittatum zetterstedt. using a plasma recalcification time assay, these fractions did not inhibit factor xa or thrombin. hplc-purified fractions showing the anticoagulant property were pooled and examined using the activated partial thromboplastin time test conducted on normal plasma and plasmas deficient in factors v, viii, ix, xi, and xii. ...19968906925
black fly (diptera:simuliidae) salivary secretions: importance in vector competence and disease.when blood-feeding, black flies introduce secretions into the feeding lesion that act in a coordinated manner on the 3 arms of the vertebrate hemostatic system (platelet aggregation, coagulation, and vasoconstriction). apyrase activity inhibits platelet aggregation and is ubiquitous in the saliva of black flies, although activity per gland varies by species and has a positive association with anthropophagy. anticoagulants target components in the final common pathway of the coagulation cascade, ...19979103750
vector competence of select black fly species for vesicular stomatitis virus (new jersey serotype).black flies collected from southern arizona were evaluated for their vector competence to the oaxaca and camp verde isolates of vesicular stomatitis virus (new jersey serotype) (vsv-nj). the camp verde isolate is the index isolate of the 1982-1983 vsv-nj epizootic that infected humans and livestock in 14 western states. previous experiments have shown that colonized simulium vittatum females are competent laboratory vectors of both virus isolates. however, under controlled laboratory conditions, ...19979242316
analyses of cdna and recombinant protein for a potent vasoactive protein in saliva of a blood-feeding black fly, simulium vittatum.a cdna was cloned from the salivary glands of a blood-feeding black fly simulium vittatum. the encoded protein has been given the name simulium vittatum erythema protein or svep, because of its ability to increase blood perfusion in skin capillaries, resulting in the well-characterized erythema of black fly bites. the full-length cdna contains 548 base pairs which encode 152 amino acid residues of the nascent protein. post-translational processing produces a mature, secreted protein of 133 resid ...19989556538
rapid induction by a blood meal of a carboxypeptidase gene in the gut of the mosquito anopheles gambiae.a search for genes induced rapidly (< 3 h) after a blood meal in the gut of the human malaria vector anopheles gambiae led to the identification of a carboxypeptidase gene (agcp). we report the sequence of the 1302 nt agcp transcribed sequence, 710 nt of upstream and 585 nt of downstream dna. the agcp open reading frame is 60.4% identical at the nucleotide level to a blackfly, simulium vittatum, carboxypeptidase gene. the transcriptional start site of agcp was determined by primer extension. exp ...19979569647
blood-feeding strategy of haematobia irritans (diptera: muscidae).the economic impact on livestock production by haematobia irritans (l.) is estimated to approach $1 billion per year in north america. however, there is little information regarding the blood-feeding strategy used by these insects. information presented here shows that horn fly saliva interferes with the normal coagulation response as measured by the recalcification time assay. the relative anticoagulant activity on a per-gland basis was more than or equal to that reported for simulium vittatum ...19989701950
bite transmission of vesicular stomatitis virus (new jersey serotype) to laboratory mice by simulium vittatum (diptera: simuliidae).laboratory-reared female black flies (simulium vittatum zetterstedt) were infected experimentally with a 1997 vesicular stomatitis virus new jersey serotype isolate and allowed to feed on susceptible laboratory mice. all mice exposed to black fly bite seroconverted by day 21 after infection, an indication of virus transmission. in addition, viral rna was detected in the spleen of several mice. these findings are consistent with the hypothesis that black flies are involved in vsv-nj transmission ...199910467765
simulium vittatum (diptera: simuliidae) and lutzomyia longipalpis (diptera: psychodidae) salivary gland hyaluronidase activity.hyaluronidase activity in the salivary gland homogenates of simulium vittatum (zetterstedt) is described, and its optimal ph determined. salivary activity was reduced significantly after a blood meal, indicating that it was secreted after blood feeding. phlebotomus papatasi (scopoli) also exhibited salivary hyaluronidase activity. these results indicate that hematophagous pool-feeding insects may secrete this enzyme to help the spread of salivary antihemostatic agents in the vicinity of the feed ...200011004788
laboratory vector competence of black flies (diptera:simuliidae) for the indiana serotype of vesicular stomatitis previous experiments we have demonstrated that colonized and wild black flies are competent laboratory vectors of different mexican and western usa isolates of vesicular stomatitis virus, serotype new jersey (vsv-nj). we have recently demonstrated biological vsv-nj transmission by black flies using animal models. in the study described here, we tested the vector competence of colonized and wild black flies for the vesicular stomatitis virus, serotype indiana (vsv-in). a 1998 equine isolate wa ...200011193658
ecdysteroids and oocyte development in the black fly simulium vittatum.oocyte development was studied in the autogenous black fly, simulium vittatum (diptera, nematocera), a vector of onchocerca volvulus, the causative agent of onchocerciasis.200212015816
immunolocalization of vesicular stomatitis virus in black flies (simulium vittatum).vesicular stomatitis, a disease of cattle, horses, and swine, is caused by either vesicular stomatitis virus, new jersey serotype (vsv-nj), or vesicular stomatitis virus, indiana serotype, which are related viruses in the genus vesiculovirus, family rhabdoviridae. although recognized for at least 160 years, the epidemiology and pathogenesis of this disease remains undefined. black flies have been suggested as a vector for vsv-nj. in this study we infected three- to four-week-old female black fli ...200212381614
orientation of onchocerca lienalis stiles (filarioidea: onchocercidae) microfilariae to black fly flies (simulium spp.) are intermediate hosts and vectors of parasitic nematodes belonging to the genus onchocerca (filarioidea onchocercidae). infection and subsequent transmission of infective third-stage larvae occur at the vertebrate host-skin interface. experimental evidence presented here demonstrates that onchocerca lienalis stiles microfilariae orient to one or more components (microfilarial orientation factor [s]; mof) in black fly saliva. mofs may serve as a means for microfilaria ...200212495191
completion of the sequence of the nuclear ribosomal dna subunit of simulium sanctipauli, with descriptions of the 18s, 28s genes and the igs.we describe the igs-ets, 18s and 28s ribosomal gene sequences of simulium sanctipauli vajime & dunbar, a member of the s. damnosum theobald (diptera: simuliidae) complex of blackflies (diptera: simuliidae). these regions, together with the its-1, its-2 and 5.8s rdna presented elsewhere (accession number u36206), constitute the composite sequence of the entire rdna unit, making s. sanctipauli the second dipteran species of medical importance for which the entire rdna has been sequenced. despite t ...200212510891
susceptibility of black fly larvae (diptera: simuliidae) to lawn-care insecticides individually and as mixtures.urban and suburban watersheds have the potential to be highly impacted by chemicals, especially insecticides to control insect pests on lawns, ornamental plants, and home gardens. three of the most common lawn-care insecticides detected in urban watersheds, carbaryl, chlorpyrifos, and malathion, have been evaluated using an acute orbital shaker toxicity test to determine their respective concentrations that produce 50% mortality (lc50) in simulium vittatum zetterstedt cytospecies is-7 larvae. re ...200312836985
the histaminic and anticoagulant activity of extracts of the black fly; simulium vittatum and simulium venustum. 195313112803
molecular differentiation of two sibling species of the black fly simulium vittatum (diptera: simuliidae) based on random amplified polymorphic dna.larvae of the black fly morphospecies simulium vittatum from colorado, montana, nebraska, and new hampshire were cytologically identified as either the is-7 or the iiil-1 cytospecies. dna was pcr amplified from cytotyped larvae using eight 10-mer primers, labeled with 33p, and run on polyacrylamide gels. the entire data set of 96 amplicons produced incomplete separation of the two cytospecies when subjected to neighbor-joining and maximum parsimony analyses. however, when analyzed within geograp ...200415060590
local modification of benthic flow environments by suspension-feeding stream insects.larval black flies often exhibit spatially aggregated distributions, and individuals within patches can potentially reduce the supply of suspended food particles to downstream neighbors by modifying local flow characteristics. we used hot-film anemometry to quantify the magnitude and spatial extent of flow modifications downstream from feeding simulium vittatum larvae in a laboratory flume, and to determine whether temporal patterns of flow variation are related to movements of the larval feedin ...200415179587
effects of algae on the efficacy of bacillus thuringiensis var. israelensis against larval black flies.personnel from several black fly control programs have reported that the efficacy of bacillus thuringiensis var. israelesis (bti) is reduced during periods when algal concentrations are high in the waterways. although the reduction in bti-induced mortality in black fly larvae is presumed to be related to the presence of algae, no scientific data support this theory. in this study, 4 genera of algae (microcytis, scenedesmus, dictrosphaerium, and chlorella) commonly detected in pennsylvania rivers ...200415264627
triacylglycerol-rich lipophorins are found in the dipteran infraorder culicomorpha, not just in mosquitoes.lipophorin is the major hemolymph protein responsible for lipid transport between tissues of insects. lipophorins from several insect species in order diptera (the fruit fly drosophila melanogaster from the suborder brachycera, the mosquito aedes aegypti; the phantom midges chaoborus maximus and minimus; the black fly simulium vittatum; the crane fly nephrotoma abbreviata, all from the suborder nematocera) were isolated and characterized. all lipophorins consisted of two protein subunits of appr ...200215455049
influence of developmental stage on susceptibilities and sensitivities of simulium vittatum is-7 and simulium vittatum iiil-1 (diptera: simuliidae) to chlorpyrifos.determination of the most sensitive and susceptible organismal life stage is important for use of the organism in toxicity assessments of environmental pollutants. in the present study, the sensitivities and susceptibilities of larval developmental stages of two black fly sibling species, simulium vittatum zetterstedt cytospecies is-7 and s. vittatum zetterstedt cytospecies iiil-1, were determined using the organophosphate-insecticide chlorpyrifos. differences in sensitivity and susceptibility w ...200415648760
acute toxicity of imidacloprid and fipronil to a nontarget aquatic insect, simulium vittatum zetterstedt cytospecies is-7. 200516097320
chromosomal localization of two antihemostatic salivary factors in simulium vittatum (diptera: simuliidae).the chromosomal locations of two genes encoding the salivary protein products simulidin (svat) and simulium vittatum erythyma protein (svep) were identified using high-resolution cytogenetic mapping. chromosomal subsection levels were determined from larval and adult salivary gland polytene chromosomes and adult malphigian tubule chromosomes. syntenic relationships occurred for both loci from a wild population of simulium vittatum iiil-1 collected in central alabama and the colonized is-7 s. vit ...200516363163
toxicity of fipronil and its enantiomers to marine and freshwater non-targets.fipronil is a phenylpyrazole insecticide used in agricultural and domestic settings for controlling various insect pests in crops, lawns, and residential structures. fipronil is chiral; however, it is released into the environment as a racemic mixture of two enantiomers. in this study, the acute toxicity of the (s,+) and (r,-) enantiomers and the racemic mixture of fipronil were assessed using simulium vittatum is-7 (black fly), xenopus laevis (african clawed frog), procambarus clarkii (crayfish ...200717562454
the effect of temperature and host species on the development of the trichomycete smittium culisetae (zygomycota).we examined the growth and development of the trichomycete smittium culisetae (harpellales: legeriomycetaceae) in the larval hosts simulium vittatum zetterstedt (diptera: simuliidae) and aedes aegypti (l.) (diptera: culicidae) at three temperatures, 17, 22 and 30 c. trichospore maturation of sm. culicetae external to the host as well as the ability of these trichospores to colonize new hosts also was investigated. although the development of sm. culisetae varied with both temperature and host th ...200717883033
fractionation and metabolic turnover of carbon and nitrogen stable isotopes in black fly fractionation factors and metabolic turnover rates of delta15n and delta13c were assessed in laboratory-reared black fly (simulium vittatum is-7) larvae fed isotopically distinct diets. five treatments consisted of using food with different delta15n signatures throughout the experiments (19-26 days), a sixth shifted from a low to high delta15n signature diet (uptake) on day 14, and the last shifted from a high to low delta15n signature diet (elimination) on day 14. in the larvae, die ...200818257111
mermithids (nematoda: mermithidae) parasitizing different blackfly (diptera: simuliidae) populations in quebec: environmental parameters related to their presence or absence in the studied brooks.specimens of isomermis wisconsinensis, gastromermis viridis, mesomermis flumenalis, and mesomermis camdenensis have been found in 14 out of 28 studied sites. their hosts were the following blackfly species: cnephia dacotensis, cnephia mutata, prosimulium sp., simulium decorum, simulium tuberosum, simulium venustum/verecundum complex, and simulium vittatum. superparasitism was observed in several simuliid larvae and, occasionally, with 2 different mermithid species. the prevalence of different me ...200818939698
the aedes aegypti larval transcriptome: a comparative perspective with emphasis on trypsins and the domain structure of peritrophins.the genome sequence of aedes aegypti was recently reported. a significant amount of expressed sequence tags (ests) were sequenced to aid in the gene prediction process. in the present work we describe an integrated analysis of the genomic and est data, focusing on genes with preferential expression in larvae (lg), adults (ag) and in both stages (sg). a total of 913 genes (5.4% of the transcript complement) are lg, including ion transporters and cuticle proteins that are important for ion homeost ...200919054160
assessment of the toxicological interaction of sertraline with cholinesterase inhibiting insecticides in aquatic insects using the black fly, simulium vittatum is-7.sertraline is a selective serotonin reuptake inhibitor (ssri) prescribed as an antidepressant. although ssris are known to block serotonin reuptake sites on cell membranes, they also have been shown to inhibit acetylcholinesterase (ache) activity. thus, the interaction of these chemicals with other ache inhibitors, namely, organophosphate and carbamate insecticides, is of interest. in addition, these insecticides have been shown to interact with serotonergic neuronal pathways creating questions ...201019161234
insight into the sialome of the black fly, simulium vittatum.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 the frog-feeding corethrellidae. sialotranscriptome analyses from several species of mosquitoes and sand flies and from one biting midge indicate divergence in the e ...200919166301
experimental transmission of vesicular stomatitis new jersey virus from simulium vittatum to cattle: clinical outcome is influenced by site of insect feeding.vesicular stomatitis new jersey virus (vsnjv) is an insect-transmitted rhabdovirus causing vesicular disease in domestic livestock including cattle, horses, and pigs. natural transmission during epidemics remains poorly understood, particularly in cattle, one of the most affected species during outbreaks. this study reports the first successful transmission of vsnjv to cattle by insect bite resulting in clinical disease. when infected black flies (simulium vittatum zetterstedt) fed at sites wher ...200919645291
cloning of ige-binding proteins from simulium vittatum and their potential significance as allergens for equine insect bite hypersensitivity.insect bite hypersensitivity (ibh) is an allergic dermatitis of horses caused by bites of culicoides and sometimes simulium spp. the aim of this investigation was to identify simulium allergens associated with ibh. a phage surface display cdna library expressing recombinant simulium vittatum salivary gland proteins was screened using sera of ibh-affected horses sensitized to s. vittatum salivary gland proteins as shown in immunoblot, resulting in the identification of seven cdnas encoding ige-bi ...200919836085
insect bite hypersensitivity in the horse: comparison of ige-binding proteins in salivary gland extracts from simulium vittatum and culicoides nubeculosus.insect bite hypersensitivity (ibh) is an ige-mediated allergic dermatitis of horses caused by bites of insects such as culicoides or simulium spp. the aim of the present study was to compare the ige-binding pattern of sera of ibh-affected horses to culicoides nubeculosus and simulium vittatum salivary gland extracts (sge). individual ige responses to proteins of s. vittatum and c. nubeculosus sges were evaluated in 15 ibh-affected and three healthy horses on immunoblots. fourteen out of the 15 i ...200919836841
mechanical transmission of vesicular stomatitis new jersey virus by simulium vittatum (diptera: simuliidae) to domestic swine (sus scrofa).biting flies have been suggested as mechanical vectors of vesicular stomatitis new jersey virus (family rhabdoviridae, genus vesiculovirus, vsnjv) in livestock populations during epidemic outbreaks in the western united states. we conducted a proof-of-concept study to determine whether biting flies could mechanically transmit vsnjv to livestock by using a black fly, simulium vittatum zetterstedt (diptera: simuliidae), domestic swine, sus scrofa l., model. black flies mechanically transmitted vsn ...200919960709
cloning, production and characterization of antigen 5 like proteins from simulium vittatum and culicoides nubeculosus, the first cross-reactive allergen associated with equine insect bite hypersensitivity.insect bite hypersensitivity (ibh) is an ige-mediated seasonal dermatitis of the horses associated with bites of simulium (black fly) and culicoides (midge) species. although cross-reactivity between simulium and culicoides salivary gland extracts has been demonstrated, the molecular nature of the allergens responsible for the observed cross-reactivity remains to be elucidated. in this report we demonstrate for the first time in veterinary medicine that a homologous allergen, present in the sali ...201020537727
molecular comparison of quebec and newfoundland populations of the blackfly, simulium vittatum, species complex.specific haplotypes at five positions in the coi and coii mitochondrial genes allowed a partial differentiation of simulium vittatum zetterstedt (diptera: simuliidae) populations from quebec-ontario and newfoundland, respectively. this geographical signature was superimposed on about 40 other polymorphic sites such that sequence divergence alone did not enable a clear-cut distinction between the two populations. together with the sporadic occurrence of haplotypes intermediate to the newfoundland ...201020604865
influence of selected antibiotics on the response of black fly (simulium vittatum) larvae to insecticidal proteins produced by bacillus thuringiensis subsp. israelensis.a controlled current toxicity test (cctt) was developed to evaluate the response of black fly (simulium vittatum) larvae to insecticidal proteins following exposure to various antibiotics. the bacterium, bacillus thuringiensis subsp. israelensis (bti), produces proteins that are toxic to nemotoceran diptera, such as black flies and mosquitoes, when ingested. these insecticidal crystalline proteins (icps) are highly efficacious in controlling black flies; however, speculation has arisen regarding ...201020821641
lesion development and replication kinetics during early infection in cattle inoculated with vesicular stomatitis new jersey virus via scarification and black fly (simulium vittatum) bite.vesicular stomatitis viruses are the causative agents of vesicular stomatitis, an economically important contagious disease of livestock that occurs in north, central, and south america. little is known regarding the early stages of infection in natural hosts. twelve adult holstein steers were inoculated with vesicular stomatitis new jersey virus (vsnjv) on the coronary bands (cb) of the feet via scarification (sc) or by vsnjv-infected black fly (simulium vittatum) bite (fb). three additional an ...201120858740
domestic cattle as a non-conventional amplifying host of vesicular stomatitis new jersey virus.the role of vertebrates as amplifying and maintenance hosts for vesicular stomatitis new jersey virus (vsnjv) remains unclear. livestock have been considered dead-end hosts because detectable viraemia is absent in vsnjv-infected animals. this study demonstrated two situations in which cattle can represent a source of vsnjv to simulium vittatum zetterstedt (diptera: simuliidae) by serving: (a) as a substrate for horizontal transmission among co-feeding black flies, and (b) as a source of infectio ...201021133963
the microdistribution of the trichomycete smittium culisetae in the hindgut of the black fly host simulium vittatum.we examined the distribution of hyphae of the trichomycete fungus smittium culisetae (harpellales: legeriomycetaceae) in the hindgut of a larval black fly (simulium vittatum, cytospecies is-7) by analyzing its prevalence and relative abundance. hyphal prevalence was highest in the posterior colon (93.1%) and rectum (86.3%), with low prevalence (12.0%) in the anterior colon. relative abundance of hyphae was highest in the posterior colon, followed by the rectum; relative abundance of hyphae in th ...200321149008
An insight into the sialome of Simulium guianense (DIPTERA:SIMULIIDAE), the main vector of River Blindness Disease in Brazil.ABSTRACT: BACKGROUND: Little is known about the composition and function of the saliva in black flies such as Simulium guianense, the main vector of river blindness disease in Brazil. The complex salivary potion of hematophagous arthropods counteracts their host's hemostasis, inflammation, and immunity. RESULTS: Transcriptome analysis revealed ubiquitous salivary protein families - such as the Antigen-5, Yellow, Kunitz domain, and serine proteases--in the S. guianense sialotranscriptome. Insec ...201122182526
the effect of seston on mortality of simulium vittatum (diptera: simuliidae) from insecticidal proteins produced by bacillus thuringiensis subsp. israelensis.water was collected from a site on the susquehanna river in eastern pennsylvania, where less-than-optimal black fly larval mortality had been occasionally observed after treatment with bacillus thuringiensis subsp. israelensis de barjac insecticidal crystalline proteins (bti icps). a series of experiments was conducted with simulium vittatum zetterstedt larvae to determine the water related factors responsible for the impaired response to bti icps (vectobac 12s, strain am 65-52). seston in the w ...201122217757
major histocompatibility complex and other allergy-related candidate genes associated with insect bite hypersensitivity in icelandic horses.insect bite hypersensitivity (ibh) is an allergic dermatitis of horses caused by bites of insects. ibh is a multifactorial disease with contribution of genetic and environmental factors. candidate gene association analysis of ibh was performed in a group of 89 icelandic horses all born in iceland and imported to europe. horses were classified in ibh-affected and non-affected based on clinical signs and history of recurrent dermatitis, and on the results of an in vitro sulfidoleukotriene (slt)-re ...201223275235
simukunin from the salivary glands of the black fly simulium vittatum inhibits enzymes that regulate clotting and inflammatory flies (diptera: simuliidae) feed on blood, and are important vectors of onchocerca volvulus, the etiolytic agent of river blindness. blood feeding depends on pharmacological properties of saliva, including anticoagulation, but the molecules responsible for this activity have not been well characterized.201222383955
identification of communal oviposition pheromones from the black fly simulium vittatum.the suite of pheromones that promote communal oviposition by simulium vittatum, a north american black fly species, was identified and characterized using gas chromatography-mass spectrometry, electrophysiological, and behavioral bioassays. behavioral assays demonstrated that communal oviposition was induced by egg-derived compounds that were active at short range and whose effect was enhanced through direct contact. three compounds (cis-9-tetradecen-1-ol, 1-pentadecene, and 1-tridecene) were id ...201525786206
mortality patterns of simulium vittatum larvae (diptera: simuliidae) following exposure to insecticidal proteins produced by bacillus thuringiensis var. israelensis.products containing insecticidal crystalline proteins (icps) produced by bacillus thuringiensis var. israelensis (bti icps) are used to suppress vector and nuisance populations of black flies. the efficacy of an application of these products is often determined by a posttreatment evaluation of larval mortality. larvae are typically removed from the substrate at some point in time after application of the product and mortality is determined. the time necessary for the effects of bti icps to cause ...201525843175
pathogenesis of vesicular stomatitis new jersey virus infection in deer mice ( peromyscus maniculatus) transmitted by black flies ( simulium vittatum).the natural transmission of vesicular stomatitis new jersey virus (vsnjv), an arthropod-borne virus, is not completely understood. rodents may have a role as reservoir or amplifying hosts. in this study, juvenile and nestling deer mice ( peromyscus maniculatus) were exposed to vsnjv-infected black fly ( simulium vittatum) bites followed by a second exposure to naive black flies on the nestling mice. severe neurological signs were observed in some juvenile mice by 6 to 8 days postinoculation (dpi ...201727312365
identification of semiochemicals attractive to simulium vittatum (is-7).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 throug ...201727910106
novel aquatic silk genes from simulium (psilozia) vittatum (zett) diptera: simuliidae.the silks of arthropods have an elementary role in the natural history of the organisms that spin them, yet they are coded by rapidly evolving genes leading some authors to speculate that silk proteins are non-homologous proteins co-opted multiple times independently for similar functions. however, some general structural patterns are emerging. in this work we identified three major silk gland proteins using a combined biochemical, proteomic, next-generation sequencing and bioinformatic approach ...201324514879
stream insects as passive suspension feeders: effects of velocity and food concentration on feeding performance.benthic suspension feeders are important components of aquatic ecosystems, often dominating the use of space and influencing patterns of material cycling between the water column and benthos. biomechanical theory predicts that feeding by these consumers is governed by the flux (i.e., product of food concentration and velocity) of particulate material to their feeding appendages. we performed a laboratory flume experiment to test how feeding by larval black flies (simulium vittatum zett.) respond ...200228547504
fluid-mediated dispersal in streams: models of settlement from the drift.i propose proximal mechanisms that help explain, unify, and expand the predictions of widely accepted empirical models of settlement in streams. i separated the process that leads to settlement of a drifting particle into three stages: (1) initial contact with a substrate, (2) attachment, and (3) settlement sensu stricto. i used physical principles (height above the bed, sinking rate, current speed profile) to predict time until contact (stage 1). i compared these predictions with empirical meas ...199928308561
predator-prey interactions in a benthic stream community: a field test of flow-mediated refuges.ecological theory suggests that the impact of predation can be strongly modified by the existence of regions of the environment in which prey are less accessible to predators, which underscores the need for empirical studies examining the factors influencing the availability and importance of such prey refuges. our study tested whether benthic microhabitats with high flows provide suspension-feeding larval black flies (simulium␣vittatum) with a spatial refuge in which the negative impact of pred ...199828307941
cytogenetics of laboratory colonies of simulium vittatum cytospecies is-7 (diptera: simuliidae).laboratory colonies of the black fly simulium vittatum zetterstedt cytospecies is-7 were analyzed cytogenetically and compared with the original new york population from which source material was collected 18 yr earlier. all sex chromosomes and major autosomal polymorphisms that were present in the source population were still represented in the laboratory colonies. however, the extent of sex linkage and the frequencies of four of the five major autosomal inversions changed significantly in at l ...200211931029
cellular hemolymph response of simulium vittatum (diptera:simuliidae) to intrathoracic injection of onchocerca lienalis (filarioidea:onchocercidae) microfilariae.hemolymph cellular changes in simulium vittatum zetterstedt in response to intrathoracic injection with onchocerca lienalis stiles were characterized by increased numbers of tissue fragments that contained cells embedded within a noncellular matrix. cell numbers within the matrix fragments increased both for sham and microfilariae-injected files, indicating a blastogenic response to injection alone. morphological characteristics of fixed, giemsa-stained cells within these tissue fragments were m ...19979086712
instar susceptibility of simulium vittatum (diptera: simuliidae) to the entomogenous nematode neoaplectana carpocapsae.laboratory bioassays showed that the susceptibility of simulium vittatum to neoaplectana carpocapsae increased with successive larval instars. first, second, and third instar larvae were resistant to infection, while seventh instars were highly susceptible. significant differences in intra-instar susceptibility were also evident, as mortality ranged from 58% for the smallest seventh instar larvae to 97% for the largest. dissections revealed that the basis for the resistance of early instars was ...198119300712
biological transmission of vesicular stomatitis virus (new jersey serotype) by simulium vittatum (diptera: simuliidae) to domestic swine (sus scrofa).the role of hematophagous arthropods in vesicular stomatitis virus (new jersey serotype; vsv-nj) transmission during epizootics has remained unclear for decades in part because it has never been shown that clinical or subclinical disease in a livestock host results from the bite of an infected insect. in this study, we investigated the ability of vsv-nj-infected black flies (simulium vittatum zetterstedt) to transmit the virus to domestic swine, sus scrofa l. experimental evidence presented here ...200414989350
ultrastructural localization of glycogen in the flight muscle of the blackfly, simulium vittatum zett. 19715546101
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