| arbovirus surveillance in six states during 1972. | a virus surveillance project was established and maintained during 1972 along 10 major river drainages in six states. mosquitoes, biting flies, and blood specimens from sentinel equines were collected during 83 field trip visits to 141 arthropod collecting sites and 22 sentinel locations from april into december 1972. there were 173,074 mosquitoes tested and 303 arboviruses isolated from 11 of 41 species. from 13,388 biting flies tested, 8 arbovirus isolations were obtained in 1 of 5 species. th ... | 1976 | 7148 |
| failure to propagate equine infectious anemia virus in mosquitoes and culicoides variipennis. | laboratory-colonized mosquitoes, culex tarsalis, aedes aegypti, culiseta inornata, and anopheles free-borni, and the biting gnat, culicoides variipennis, were exposed to equine infectious anemia virus. exposure to the virus was by intrathoracic inoculation for mosquitoes and by oral ingestion of an infective blood meal through a membrane for c variipennis. after various intervals, groups of 15 to 20 insects were homogenized and inoculated into susceptible ponies. positive immunodiffusion test r ... | 1978 | 31831 |
| bluetongue: the disease in cattle. | most researchers in south africa found that although bt virus could be isolated from apparently healthy cattle and from inoculated cattle the virus did not produce overt clinical disease in cattle. however, when epizootics were reported outside africa, clinical signs were observed in cattle in israel, palestine, syria, portugal, and spain. most natural bt infections in cattle in the united states do not result in overt clinical signs. however, in certain infected herds, approximately 5% of the c ... | 1975 | 169786 |
| serial cyclic transmission of bluetongue virus in sheep and culicoides variipennis. | bluetongue virus (strain 62-45s) was transmitted from sheep to sheep throughout a year by vector bites. a colonized population (sonora strain, 000 line) of the biological vector culicoides variipennis (coquilllett) was used. fifteen serial cyclic transmissions covered a period of 13 months from october through november of the following year. the mean infection rate of the biting gnats was 37 percent. the clinical response to bluetongue virus was significantly more severe in sheep infected by vec ... | 1976 | 185003 |
| culicoides, the vector of epizootic hemorrhagic disease in white-tailed deer in kentucky in 1971. | the biting gnat, culicoides variipennis (coquillett), was shown to be a vector of epizootic hemorrhagic disease (ehd) in white-tailed deer, odocoileus virginianus, in kentucky because of virus isolations from parous females. epidemiological evidence showed a close relationship of this vector to the animal host during an outbreak of ehd in penned deer. larval breeding sites of c. variipennis were found and c. variipennis was the most abundant biting fly present during the outbreak. females of c. ... | 1977 | 190421 |
| transmission of two strains of epizootic hemorrhagic disease virus in deer by culicoides variipennis. | two strains of epizootic hemorrhagic disease virus (ehdv), new jersey (nj) and kentucky (ky), of deer were biologically transmitted between white-tailed deer, odocoileus virginianus, by culicoides variipennis. the ky strain, isolated from c. variipennis collected during an epizootic in deer, was identified as ehdv by serological tests. deer exposed to the ky or the nj strains of ehdv developed an acute hemorrhagic disease; most deer died 6 to 13 days after infection. sheep inoculated with ehdv d ... | 1977 | 190424 |
| overwintering mechanism for bluetongue virus: biological recovery of latent virus from a bovine by bites of culicoides variipennis. | bluetongue virus (btv) was biologically transmitted by the bites of colonized culicoides variipennis gnats to recipient sheep from a hereford bull with latent infection. four biological recoveries of btv were mediated over 2 years by multiple feedings of the vector during a 4- to 72-hour interval. initial stimulation by gnat bites at 0 hour permitted biological recovery of btv by gnats that fed at later intervals. the 4th biological recovery of the virus from the bull clearly indicated a vector- ... | 1977 | 192095 |
| bluetongue in cattle: effects of culicoides variipennis-transmitted bluetongue virus on pregnant heifers and their calves. | | 1977 | 201192 |
| bluetongue in cattle: effects of vector-transmitted bluetongue virus on calves previously infected in utero. | three of 7 principal calves, after a challenge of immunity exposure by bites of bluetongue (bt) virus-infected culicoides variipennis, became latently infected with bt virus. these calves were born to heifers infected with the homologous virus by bites of c variipennis at 60 or 120 days' gestation. latent bt virus infection was detected by isolation of bt virus from washed erythrocyte samples obtained from the calves at 57, 100 to 102, 200 to 202, 300 to 302, and 400 to 402 days after challenge ... | 1977 | 201193 |
| bluetongue in cattle: repeated exposure of two immunologically tolerant calves to bluetongue virus by vector bites. | a heifer and steer that were immunologically tolerant to bluetongue (bt) virus became immunologically competent after repeated exposures by bites of bt virus-infected culicoides variipennis. immunologic tolerance ended in the heifer at 25 months of age, after the 2nd exposure to the virus, and in the steer at 22 months, after the 4th exposure. high hemic concentrations of bt virus were detected in both animals after they became immunologically competent, but neither developed an overt bt clinica ... | 1977 | 201194 |
| relevance of laboratory colonies of the vector in arbovirus research--culicoides variipennis and bluetongue. | relevance for laboratory colonies of culicoides variipennis (coquillett) in arbovirus research was determined during colonization by comparing a vector-competence characteristic for the parent (p) field and subsequent colonized generations. three colonies established in 1972-1973 were used to determine whether each was representative of the field population from which it was derived for oral infection to 2 to 4 serotypes of bluetongue virus (btv). two colonies that were based on small numbers of ... | 1978 | 204208 |
| heterogeneity of culicoides variipennis field populations to oral infection with bluetongue virus. | a standard colonized population (000 line) of culicoides variipennis (coquillett) was used as the control for comparing the infection rate (ir) responses of different field populations of the vector to oral infection with several strains of bluetongue virus (btv) that belonged to four serotypes. three field populations from colorado and oregon tested concurrently in 1969 were differently susceptible to three btv strains representing three serotypes. the ir's of each of the three populations vari ... | 1978 | 204209 |
| multiplication rate of bluetongue virus in the vector culicoides variipennis (diptera: ceratopogonidae) infected orally. | | 1979 | 220423 |
| persistence of enterobacteriaceae in female adults of the biting gnat culicoides variipennis (diptera: ceratopogonidae). | | 1978 | 344884 |
| pigmentation associated with oogenesis in the biting fly culicoides variipennis (diptera: ceratopogonidae): determination of parity. | | 1979 | 522122 |
| morphometric variability in natural and laboratory populations of culicoides variipennis (diptera: ceratopogonidae). | | 1977 | 609067 |
| laboratory transmission of onchocerca cervicalis with culicoides variipennis. | | 1978 | 626281 |
| infection of culicoides variipennis, culicoides nubeculosus, culicoides riethi and aedes aegypti with mansonella ozzardi. | | 1976 | 1006770 |
| the growth of african horse-sickness virus in embryonated hen eggs and the transmission of virus by culicoides variipennis coquillett (diptera, ceratopogonidae). | seven-day-old embryonated hen eggs were infected with african horse sickness virus by the yolk sac and intravenous routes. virus reached a high titre in the blood of infected embryos. culicoides variipennis midges which took a blood meal from infected eggs became infected with virus, and after 7 days at 26 degrees - 27 degrees c transmitted african horse sickness virus to uninfected eggs. c. variipennis may therefore be considered a biological vector of african horse sickness virus in the labora ... | 1975 | 1169930 |
| proceedings: a trypanosomatid parasite of laboratory-bred culicoides variipennis. | | 1975 | 1216306 |
| microgeographic and temporal genetic variation in populations of the bluetongue virus vector culicoides variipennis (diptera: ceratopogonidae). | seven colorado populations of the bluetongue virus vector culicoides varipennis (coquillett) were analyzed for genetic variation at 19-21 isozyme loci. permanent populations, which overwinter as larvae, showed little temporal genetic change at 19 loci. pgd and mdh showed seasonal changes in gene frequencies, attributable to selection at two permanent populations. two temporary populations showed low heterozygosity compared with permanent populations. independent estimates of gene flow, calculate ... | 1992 | 1320698 |
| specificity of molecular hybridization techniques for the detection of bluetongue virus serotypes in culicoides variipennis. | direct blot hybridization (dbh) and sandwich hybridization (sh) were evaluated for their ability to detect bluetongue virus (btv) rna in the biting midge culicoides variipennis (coquillett). probes were derived from the l3 rna segment of btv, serotype 17. rna of the five btv serotypes occurring in the usa (btv-2, btv-10, btv-11, btv-13, and btv-17) was extracted from pools of varying numbers of infected and uninfected biting midges and assayed by direct blot and sandwich hybridization tests. dir ... | 1992 | 1335548 |
| survival and vertical distribution of larvae of culicoides variipennis (diptera: ceratopogonidae) in drying mud habitats. | the ability of third and fourth instars of culicoides variipennis (coquillett) to survive in drying sandy loam soil was tested under simulated field conditions. two hundred larvae were added to each of a number of soil-filled, plastic tubes, which were buried in the field and retrieved after 2, 5, and 7 d. of 306 pupae or pupal exuviae recovered, 98.1% were in the top 2 cm of mud. estimated larval mortality on day two ranged from 25.6 to 87.1% among three trials, and 92.3% of live larvae were in ... | 1992 | 1404251 |
| spatial and seasonal distribution of potential vectors of hemorrhagic disease viruses to peninsular bighorn sheep in the santa rosa mountains of southern california. | blood-feeding midges (culicoides sp. and leptoconops sp.) were sampled in the santa rosa mountains, riverside county, california (usa), to determine which species might be involved in the transmission of bluetongue and epizootic hemorrhagic disease viruses to peninsular bighorn sheep (ovis canadensis cremnobates). host-seeking midges were sampled with co2-baited suction traps over a period of 30 mo. nineteen species of culicoides and seven of leptoconops were collected. five of the culicoides sp ... | 1992 | 1602570 |
| sources of variation in an enzyme-linked immunoassay of bluetongue virus in culicoides variipennis (diptera: ceratopogonidae). | an enzyme-linked immunoassay for detecting bluetongue virus in infected culicoides variipennis was evaluated using a nested analysis of variance to determine sources of experimental error in the procedure. the major source of variation was differences among individual insects (84% of the total variance). storing insects at -70 degrees c for two months contributed to experimental variation in the elisa reading (14% of the total variance) and should be avoided. replicate assays of individual insec ... | 1991 | 1647459 |
| genetic control of oral susceptibility to infection of culicoides variipennis with bluetongue virus. | a family selection scheme, based on the progeny from individual females, was used to select several families of the insect vector culicoides variipennis that were resistant or susceptible to oral infection with bluetongue virus. genetic crosses between families showed results consistent with control by a single genetic locus (blu). reciprocal crosses suggested a maternal effect in which the genotype of the mother determined the phenotype of the offspring. the dominant and recessive natures of th ... | 1991 | 1662471 |
| isolation of northway serotype and other bunyamwera serogroup bunyaviruses from california and oregon mosquitoes, 1969-1985. | eight previously untyped bunyamwera serogroup bunyaviruses that had been isolated from mosquitoes collected in california and oregon between 1969 and 1985, were identified by cross-neutralization tests. four viruses from anopheles freeborni and a virus from aedes sierrensis collected in butte county in the central valley of california in 1970-71 were shown to belong to the northway serotype. the existence of a northway serotype virus in california had been inferred from previous serologic survey ... | 1991 | 1677543 |
| temperature effects on the gonotrophic cycle of culicoides variipennis (diptera: ceratopogonidae). | the duration of oogenesis and time to oviposition after blood feeding was studied in culicoides variipennis held at constant laboratory temperatures. as assessed by daily dissection of ovaries, the time required for greater than or equal to 80% of females to complete egg development at 13, 17, 21, 27, 30 and 34 degrees c was 10, 5, 4, 3, 2 and 2 days, respectively. mean times to oviposition at these temperatures were 13.8, 8.2, 4.9, 3.6, 3.0, and 2.6 days, while modal values were 13, 6, 4, 3, 3 ... | 1991 | 1787404 |
| effect of carbon dioxide on the collection of adult culicoides spp. (diptera: ceratopogonidae) by a new modification of black light new jersey light traps. | comparisons were made between black light-modified new jersey traps with and without dry ice as a carbon dioxide bait. the black light trap with co2 collected significantly more nulliparous and parous empty culicoides variipennis than the black light trap without co2. no significant difference was detected in the number of gravid, blood engorged or male c. variipennis collected by the 2 trap types. the baited trap collected a larger proportion of nulliparous females than the black light trap. no ... | 1991 | 1791457 |
| infection of the midgut of culicoides variipennis (diptera: ceratopogonidae) with bluetongue virus. | when culicoides variipennis (coquillett) ingested a bluetongue virus (btv)-defibrinated sheep blood suspension, btv adsorbed to sheep red blood cells (rbcs) within 2 h. the virus had entered rbcs by 6 h and was still seen in rbcs 2 d after ingestion of the blood meal, even though the rbcs had been dehydrated. the peritrophic membrane began to form on day 1, and it contained breaks by day 3. the peritrophic membrane did not prevent infection of the midgut epithelium. viral replication occurred in ... | 1991 | 1851848 |
| estimation of survival and gonotrophic cycle length of culicoides variipennis (diptera: ceratopogonidae) in california. | the use of a time series analysis to estimate the survival rate and gonotrophic cycle length of culicoides variipennis at 2 california sites is described. collections were made daily for 28 days in yolo county (northern california) and for 25 days in riverside county (southern california) in july and august of 1989, respectively, using co2-baited suction traps. the time series analysis of these collections yielded a gonotrophic cycle length estimate of 3 days. stage-specific and daily survivorsh ... | 1991 | 1895081 |
| detection of epizootic hemorrhagic disease virus in culicoides variipennis (diptera: ceratopogonidae). | nucleic acid hybridization was used to detect epizootic hemorrhagic disease (ehd) virus serotype 1 and serotype 2 in culicoides variipennis (coquillett). adult females were inoculated intrathoracically with virus, then were assayed daily for the presence of viral rna for 2 wk, at which time maximum virus replication is likely to occur. viral rna of ehd serotypes 1 and 2 was first detected by hybridization on days 9 and 7 after infection, respectively, and then for up to 14 days after infection. ... | 1991 | 1941947 |
| absence of transovarial transmission of bluetongue virus in culicoides variipennis: immunogold labelling of bluetongue virus antigen in developing oocytes from culicoides variipennis (coquillett). | 1. culicoides variipennis midges were fed on a blood meal containing bluetongue virus (btv) serotype 11 (btv-11) and on four subsequent non-infective blood meals at 4-day intervals. 2. eggs were collected before each blood-feeding and reared to adults. 3. progeny from each egg batch were incubated for 14 days (20 degrees c, 40-60% rh) before plaque assay. 4. oocytes from several parent flies were sectioned for immunoelectron microscopy. 5. thirty-two percent of the parent females tested by plaqu ... | 1990 | 1975536 |
| a rna virus in cells from culicoides variipennis. | a virus was detected in cells (designated cuva) cultured from one laboratory colony of the biting midge, culicoides variipennis. by electron microscopy (30 nm), nonenveloped, icosahedral virions arranged separately and in crystalline matrix arrays were seen in the cytoplasm but not in the nucleus of cuva cells. separation by 10% polyacrylamide gel electrophoresis revealed multiple bands of viral-induced double-stranded rna. inoculation of this virus onto different cell lines and intracranially i ... | 1991 | 2022869 |
| rubidium for marking adults of culicoides variipennis (diptera: ceratopogonidae). | culicoides variipennis adults were reared from media with nine concentrations of rubidium (rb) ranging from 0.0 to 1,000 ppm. rubidium levels were measured using an atomic absorption spectrophotometer. concentrations of 500 and 1,000 ppm of rb reduced pupal production, adult emergence, and adult longevity; lower levels of rb had no noticeable effects. adult females reared from media containing 15.6 ppm rb were marked for a period of at least 13 d, and rb levels were unaffected by a blood meal on ... | 1991 | 2056505 |
| genetic variation in laboratory and field populations of the vector of bluetongue virus, culicoides variipennis (diptera: ceratopogonidae). | laboratory colonies and several natural populations of the biting midge culicoides variipennis (coquillett) were analyzed for genetic variation at 21 electrophoretic loci. the laboratory colonies maintained high levels of genetic variation measured by average expected heterozygosities (he = 0.142 +/- 0.008), although levels were lower than those observed in field collections (he = 0.198 +/- 0.009). a field population from colorado, analyzed five times over a 1-yr period, showed a consistent tren ... | 1990 | 2153832 |
| effects of anesthetization and storage temperature on bluetongue virus recovery from culicoides variipennis (diptera: ceratopogonidae) and sheep blood. | monitoring infection rates of culicoides variipennis (coquillett) with bluetongue virus in rangeland deer and cattle often requires prolonged field excursions. methodology that fits field processing and storage was evaluated under controlled laboratory conditions. triethylamine was used to anesthetize culicoides for sorting. a portable liquid nitrogen vapor shipping container offered a convenient means of insect storage at temperatures that ensured preservation of the virus and eliminated fungal ... | 1990 | 2159074 |
| detection of bluetongue virus in culicoides variipennis (diptera: ceratopogonidae) by an antigen capture enzyme-linked immunosorbent assay. | an antigen capture enzyme-linked immunosorbent assay (elisa) was developed to detect bluetongue virus (btv) in the vector culicoides variipennis (coquillett). this elisa used polyclonal and monoclonal antibodies in a biotin-avidin immunoperoxidase system to detect btv in individual adult female flies that had taken an infectious blood meal. detection of btv with the elisa correlated with detection of btv from the same flies by plaque assay in cell culture. the elisa was group-specific for the fi ... | 1990 | 2167373 |
| detection of bluetongue virus serotype 17 in culicoides variipennis by nucleic acid blot and sandwich hybridization techniques. | molecular hybridization techniques were developed for the detection and surveillance of bluetongue virus (btv) serotype 17 in the insect vector culicoides variipennis, a biting midge. radiolabeled rna and cdna probes were generated from sequences of the l3 segment of btv serotype 17. these probes were used to detect btv rna in pools of infected c. variipennis by hybridizing the probes directly to analyte immobilized on nylon membranes or by using a nucleic acid sandwich hybridization test. hybri ... | 1990 | 2172294 |
| specific immunotherapy in the treatment of culicoides hypersensitive horses: a double-blind study. | fourteen privately owned horses completed a six month, controlled, double-blind trial to assess the efficacy of immunotherapy using an aqueous extract of whole, unfed culicoides variipennis in the treatment of culicoides hypersensitivity. selected horses had a history of a seasonal, pruritic dermatitis, clinical signs and distribution compatible with culicoides hypersensitivity, failed to improve in response to ivermectin therapy, and reacted to several dilutions of culicoides extracts without s ... | 1990 | 2209518 |
| comparison of new jersey light traps for collection of adult culicoides variipennis (diptera: ceratopogonidae). | comparisons between standard incandescent new jersey and modified ultraviolet new jersey light traps were made. both trap types collected the same proportions of males, nulliparous, parous empty, gravid and blood engorged female culicoides variipennis. although both traps were highly attractive to females that had taken at least one blood meal, the black light trap collected ca. 10-fold more parous empty and gravid flies than the incandescent and would therefore be recommended for use in trappin ... | 1990 | 2230788 |
| evaluation of membranes for feeding culicoides variipennis (diptera: ceratopogonidae) with an improved artificial blood-feeding apparatus. | an artificial blood-feeding apparatus for culicoides variipennis (coquillett) was improved by developing a simpler design to heat and mix the blood meal and by increasing the surface area for insect feeding. the skin from a 1- to 3-d-old chick and a reinforced silicone membrane were the most satisfactory of nine membranes evaluated for c. variipennis, with 81 and 83% mean blood-feeding rates, respectively. the operational advantages of the reinforced silicone membrane for feeding c. variipennis ... | 1990 | 2231631 |
| comparison of several different trapping methods for culicoides variipennis (diptera: ceratopogonidae). | when battery operated cdc miniature incandescent and black light traps (with and without light bulbs) were operated with and without co2, the rank of trap effectiveness for total numbers of female culicoides variipennis caught was: black light plus co2; co2-baited trap without light bulb; black light without co2; incandescent light plus co2 and incandescent light without co2. in 1983, the black light trap plus co2 caught significantly more males and females than any other traps, and the incandes ... | 1989 | 2511272 |
| detection of bluetongue virus antigens in culicoides variipennis by enzyme immunoassay. | a solid-phase enzyme immunoassay (eia) was developed to detect bluetongue (bt) virus antigens in infected cell cultures and in suspensions of infected culicoides variipennis midges. the technique was equally sensitive for detecting the five u.s. bt virus serotypes (2, 10, 11, 13, and 17) in cell cultures. eia reliably detected about 3.8 log10 median tissue culture infective doses per ml of bt virus in infected cell culture lysates. the eia readily detected virus antigens in pools of midges infec ... | 1989 | 2546975 |
| immunodetection of bluetongue virus and epizoötic hemorrhagic disease virus in culicoides variipennis (diptera: ceratopogonidae). | the avidin-biotin complex immunoperoxidase system has been used with nitrocellulose membranes to detect bluetongue virus serotypes 10 (btv-10) and 11 (btv-11) and epizootic hemorrhagic disease virus (ehdv) serotype 1 (ehdv-1) in individual specimens of culicoides variipennis (coquillett). the cross reactivity between btv-10 and btv-11 indicates that polyclonal antisera cannot be used to distinguish between flies infected with btv-10 and btv-11; however, the procedure can be used to discriminate ... | 1989 | 2549249 |
| cell lines from culicoides variipennis (diptera: ceratopogonidae) support replication of bluetongue virus. | cell lines have been developed from 2-day-old embryos of the biting midge, culicoides variipennis (diptera: ceratopogonidae). in north america c. variipennis is the primary insect vector of bluetongue virus (btv), an orbivirus that causes disease of ruminants. the c. variipennis (cuva) cells, grown in schneider's drosophila medium, consist primarily of a fibroblast-like cell type. cuva cells are very hardy. they can grow over a wide range of temperature and ph and adapt to growth in minimal esse ... | 1989 | 2553822 |
| asynchronous mixed infection of culicoides variipennis with bluetongue virus serotypes 10 and 17. | culicoides variipennis (diptera: ceratopogonidae) the primary vector of bluetongue virus (btv) in the u.s.a. were asynchronously mixedly infected with two btv serotypes (btv-10 and btv-17); flies first ingested a blood meal that contained btv-17 and 1, 3, 5, 7, and 9 days later selected flies ingested a second blood meal that contained btv-10. control flies ingested each parental virus separately, or both viruses simultaneously, in a single blood meal. electrophoretic analysis of progeny virus c ... | 1989 | 2558162 |
| environmental factors affecting mortality of adult culicoides variipennis (diptera: ceratopogonidae) in the laboratory. | the effects of several environmental factors on mortality of adult culicoides variipennis in the laboratory were evaluated. daily mortality rates significantly increased when adult midges were maintained at an elevated constant temperature (26 degrees c). adult c. variipennis handled the least during routine maintenance procedures had the lowest daily mortality rate. survival was not significantly affected by varying density levels of adult midges in the size of container routinely used in our l ... | 1989 | 2584972 |
| a quantitative survey of culicoides variipennis (diptera: ceratopogonidae) in dairy wastewater ponds in southern california. | culicoides variipennis (coquillett) larvae were sampled five times over a 10-wk period in late summer in each of 26 dairy wastewater ponds in western riverside county, calif. slope, degree of cattle access, prevalence of visible manure solids, salinity, chemical oxygen demand, plankton volume, and whether the ponds were pumped for irrigation were determined concurrently. larvae of c. variipennis were associated positively with plankton volume, degree of animal access, and salinity, and negativel ... | 1989 | 2585451 |
| response of culicoides variipennis (diptera: ceratopogonidae) to water level fluctuations in experimental dairy wastewater ponds. | water levels were fluctuated in experimental dairy wastewater ponds in southern california to study the response of culicoides variipennis (coquillet). immatures consistently were found in surface mud at the water's edge in ponds where the water level was stable. in ponds where the water level was fluctuated, immatures did not relocate to the new, lower waterline when the water quickly receded 3 m in horizontal distance. younger larvae apparently were stranded above the waterline and were killed ... | 1989 | 2585452 |
| culicoides: biological vectors of akabane virus. | akabane virus replicated in culicoides nubeculosus and culicoides variipennis after intrathoracic inoculation and was maintained in both species of midge for at least 9 days post-infection. the virus also replicated to high concentration in c. variipennis after oral infection and was transmitted through a membrane by this species of midge 7-10 days after infection. the experiments described in this paper provided the first definitive evidence that culicoides spp. are able to act as fully compete ... | 1989 | 2609498 |
| comparisons of light traps for monitoring adult culicoides variipennis (diptera: ceratopogonidae). | from 1984 to 1986 tests were conducted to evaluate 4 trap types (abadrl baffle trap, new jersey trap, cdc trap, and updraft trap) with or without an incandescent light source, a suction fan or dry ice (as a source of co2) for sampling adult culicoides variipennis. the fewest flies were caught in the cdc and updraft traps. the new jersey trap with suction, a strong light source and dry ice caught most flies, due to a significant increase in nulliparous females. the same new jersey trap without dr ... | 1989 | 2614406 |
| body size of culicoides variipennis (diptera: ceratopogonidae) in relation to bloodmeal size estimates and the ingestion of onchocerca cervicalis (nematoda: filarioidea) microfiliariae. | | 1989 | 2708982 |
| mixed infection of culicoides variipennis with bluetongue virus serotypes 10 and 17: evidence for high frequency reassortment in the vector. | the primary vector species for bluetongue virus (btv) in the united states, culicoides variipennis, was orally infected with btv serotype 10, btv serotype 17, or a mixture of the two viruses. the recovery of virus from the infected flies was low following a period of extrinsic incubation. electrophoretic analysis of progeny virus from singly infected flies revealed that only the parental electropherotype could be isolated from those flies. in contrast, electrophoretic analysis of virus from mixe ... | 1987 | 2821173 |
| nontransmission of bluetongue virus by embryos from bluetongue virus-infected sheep. | donor sheep were infected either by bites of bluetongue virus (btv)-infected (serotype 11, "texas station strain") culicoides variipennis or by inoculation with 100,000 median chicken embryo intravascular lethal doses of btv (serotype 11) from a suspension made from infected c variipennis. fourteen embryos from 4 btv-infected ewes bred by rams not infected with btv were transferred to 8 btv-seronegative recipient ewes, and 35 embryos and 4 unfertilized eggs from 14 btv-infected ewes bred by btv- ... | 1988 | 2837113 |
| distribution of bunyamwera serogroup viruses in north america, 1956-1984. | we attempted to tabulate all bunyamwera serogroup (family bunyaviridae, genus bunyavirus) isolates from north america. by summarizing information from the laboratories of the centers for disease control, data generously shared by other laboratories, and the published literature, we were able to accumulate data regarding 1,372 bunyamwera serogroup viruses. these were: tensaw (664, including 8 from vertebrates), cache valley (396, including 6 from vertebrates), main drain (160, including 14 from v ... | 1986 | 2869708 |
| salivary gland homogenates from the vector culicoides variipennis may aid in detection of bluetongue virus in chronically infected cattle. | studies were conducted on 2 cows chronically infected with bluetongue virus (btv) acquired in utero from their dam. in previous research, btv had been isolated 4 times from 1 cow and 8 times from the other. btv was undetectable between spontaneous febrile and leukopenic episodes and antibodies to btv were not detectable in the serum. previous work had shown that bites by uninfected females of the vector culicoides variipennis (coquillett) caused virus to recrudesce in the blood to detectable lev ... | 1985 | 2989848 |
| observations on larval habitats of suspected culicoides vectors of bluetongue virus in florida. | potential breeding sites for culicoides variipennis (coquillett) and c. insignis lutz, suspected vectors of bluetongue virus (btv) in florida, were examined at 7 livestock facilities located in different geographic regions of the state. the 2 most productive habitats were mud contaminated by effluent from milking parlors (92.3 larvae/sample) and margins of vegetated ponds (18.8 larvae/sample). four species of biting midges, c. crepuscularis malloch, c. haematopotus malloch, c. insignis, and c. v ... | 1985 | 2989856 |
| methodology in preserving field-collected flies for bluetongue virus assay. | preliminary tests were conducted to evaluate the use of phosphate buffered saline (pbs) as a collecting medium for the preservation of flies for virus assay from our bluetongue (bt) study areas in colorado, usa. these tests were made possible by the use of a colony of culicoides variipennis (coquillett) that is highly susceptible to infection with bt virus (btv). | 1985 | 2989857 |
| the virogenesis of bluetongue virus in culicoides variipennis. | a direct immunofluorescence (if) technique was developed to detect bluetongue virus (btv) antigen in culicoides variipennis. after approximately 10 days extrinsic incubation (ei), the if test was as sensitive as virus isolation for detection of infected flies. the if technique was used to determine the virogenesis of btv in the fly. after 6 days ei, virus antigen was detected in most midguts; by 10 days, most head squash preparations contained antigen. other secondary target organs, such as ovar ... | 1985 | 2989860 |
| epizootiological study of bluetongue virus infection in california livestock: an overview. | an epidemiologic program was undertaken in california to study bluetongue virus (btv) infection in domestic livestock. the study was designed to determine: a) prevalence of btv infection, b) serotypes of btv actively causing infection, c) seasonality of infection and d) species infected. a total of 8,751 cattle, 14,639 sheep and 4,785 goats were tested over the 3 1/2 year study. serologically, 41% of the cattle, 42% of the sheep and 21% of the goats were positive. virologically, 2.4% of the catt ... | 1985 | 2989906 |
| research on the control of bluetongue in livestock by vector suppression. | from 1979-83, research has been conducted along the south platte river drainage system northeast of denver, co, to develop and evaluate techniques of wide-area vector suppression for the control of bluetongue (bt) disease in ruminant livestock. water management and chemical treatment at larval development sites have resulted in a decrease in the activity of culicoides variipennis (coquillett) in the 100 km2 treatment area, and there is some correlation between levels of vector activity (as refle ... | 1985 | 2989910 |
| who/fao working team report: entomology. | a summary of the more important concerns of the working team with particular reference to bluetongue (bt) virus (btv), is as follows: with the exception of australia, the us, and possibly parts of africa, there are almost no concrete data that could be used to direct control efforts against the responsible vector(s) of btv in a specific geographic area. in australia, a broad plan of attack yielded data that showed that members of the subgenus avaritia are the primary vector species. it has been ... | 1985 | 2989917 |
| exposure of culicoides variipennis (diptera: ceratopogonidae) to hair clippings to evaluate insecticide-impregnated ear tags in cattle. | | 1986 | 3018058 |
| the comparative virogenesis of three serotypes of bluetongue virus in culicoides variipennis (diptera: ceratopogonidae). | | 1987 | 3029373 |
| variation in the responses of culicoides variipennis (diptera, ceratopogonidae) to oral infection with bluetongue virus. | the infection rate of an established colony of culicoides variipennis to oral infection with bluetongue virus (btv) type 4 was found to be highly variable and ranged from 0 to 51.6 per cent. this type of wide variation has previously only been reported to occur between individual populations of a species and not between samples from a single population. this must be taken into account when such colonies are used as reference standards for interpretation of field and laboratory data, particularly ... | 1987 | 3038052 |
| factors influencing the ingestion of onchocerca cervicalis microfilariae by culicoides variipennis (diptera: ceratopogonidae). | culicoides variipennis were fed under controlled conditions on two ponies that exhibited seasonal changes in onchocerca cervicalis microfilarial (mf) skin density and skin distribution. the seasonal changes did not radically affect mf ingestion. flies were fed on the umbilicus of infected ponies by two methods: individual feeding in consecutive order at the same site, or by mass feeding. linear regression analysis indicated that ingestion of microfilaria was independent of feeding time and engor ... | 1988 | 3199113 |
| colonization and response of culicoides variipennis (diptera: ceratopogonidae) to pollution levels in experimental dairy wastewater ponds. | | 1988 | 3204623 |
| heleidomermis sp. (nematoda: mermithidae) infecting culicoides variipennis (diptera: ceratopogonidae) in alabama. | | 1987 | 3504920 |
| seasonal size variability in culicoides variipennis (diptera: ceratopogonidae) in southern california. | | 1987 | 3504939 |
| the effect of salinity on oviposition and egg hatching in culicoides variipennis sonorensis (diptera: ceratopogonidae). | the preferences of culicoides variipennis sonorensis females for oviposition on different salinities were tested in experiments using small wells in a 4 x 4 latin square array. the mean numbers of eggs deposited on wet surfaces on salinites of 0.0, 9.9, 19.0 and 34.0o/oo, were 1212, 659, 287, and 0, respectively. within a higher range, salinites of 19.0, 23.0, 28.0 and 34.0o/oo yielded mean numbers laid of 110, 3, 6 and 0, respectively. the overall relationship could be reasonably well described ... | 1986 | 3507474 |
| seasonal changes in density and tissue distribution of onchocerca cervicalis microfilariae in ponies and related changes in culicoides variipennis populations in louisiana. | seasonal changes in density and spatial distribution of onchocerca cervicalis microfilariae were studied in ventral-midline skin of 15 infected pony mares in southern louisiana. triple running mean analysis of data over a 13-mo period indicated that a distinct pattern exists in total microfilariae population density and in microfilariae occurrence in different levels of the dermis. microfilariae density reaches peak levels in the spring followed by a 58% decrease in the summer, a 19% increase in ... | 1987 | 3585627 |
| seasonal microdistribution of immature culicoides variipennis (diptera: ceratopogonidae) at saltville, virginia. | | 1987 | 3585929 |
| development of immature culicoides variipennis (diptera: ceratopogonidae) from saltville, virginia, at constant laboratory temperatures. | | 1987 | 3585933 |
| larval population dynamics of culicoides variipennis (diptera: ceratopogonidae) in southern california. | | 1987 | 3669029 |
| swimming behavior of the larva of culicoides variipennis (diptera: ceratopogonidae) and its relationship to temperature and viscosity. | | 1986 | 3772953 |
| pigmentation associated with oogenesis in the biting fly culicoides variipennis (diptera: ceratopogonidae): light and electron microscopy. | | 1987 | 3820232 |
| use of a pyrethrin larvicide to control culicoides variipennis (diptera: ceratopogonidae) in an alkaline lake. | laboratory bioassays with culicoides variipennis larvae from borax lake, ca, indicated an lc90 of 16.8 ppb for pyrethrins at 23 degrees c. a field test in a pond adjoining the lake reduced adult c. variipennis emergence greater than 99% for over 30 days after treatment at a rate of 131 ppb pyrethrins. further small scale field tests indicated that c. variipennis could be controlled in the lake at a rate of 701 g/ha pyrethrins applied as a peripheral treatment. the first lake treatment resulted i ... | 1985 | 3880253 |
| a comparison of three traps for adult culicoides variipennis (ceratopogonidae). | | 1985 | 3880256 |
| mechanical transmission of rift valley fever virus by hematophagous diptera. | experimental studies were conducted to determine if hematophagous diptera were capable of mechanical transmission of rift valley fever (rvf) virus to laboratory animals. all species tested (glossina morsitans, aedes aegypti, aedes taeniorhynchus, culex pipiens, stomoxys calcitrans, lutzomyia longipalpis, and culicoides variipennis) mechanically transmitted the virus to hamsters. mechanical transmission rates for g. morsitans ranged from 0-100%, with the probability of mechanical transmission pos ... | 1985 | 3970308 |
| the taxonomic complex, culicoides variipennis. | the morphological and biological characteristics of the 5 subspecies of culicoides variipennis as proposed by wirth and jones are reviewed in the light of research performed since 1957. proposals have been made to recognize the eastern and western populations as distinct species; others prefer to consider the population as 1 species with extensive and complex variation resulting from the interplay of ecological and genetic factors. the authors recommend the use of the term "variipennis complex" ... | 1985 | 4011613 |
| spatial distribution of immature culicoides variipennis (coq.). | circadian fluctuation in the spatial distribution of immature culicoides variipennis (coq.) was studied in saltville, virginia, usa during the summer of 1983. pupae and early instar larvae (1st and 2nd) were localized above the shoreline in the top cm of mud and displayed little migration from this region during the 24 hr sampling period, however, later instar larvae (3rd and 4th) showed marked migration patterns. most larval movement was horizontal rather than vertical and was confined to the t ... | 1985 | 4011615 |
| the effect of repeated blood meals infective for bluetongue on the infection rate of culicoides variipennis. | | 1971 | 4334249 |
| storage of bluetongue virus-infected culicoides variipennis. | | 1972 | 4340818 |
| bluetongue virus transmission with culicoides variipennis via embryonating chicken eggs. | | 1973 | 4360591 |
| oral infection of culicoides variipennis with bluetongue virus: development of susceptible and resistant lines from a colony population. | | 1974 | 4368984 |
| transmission of bluetongue between sheep and cattle by culicoides variipennis. | | 1967 | 4962156 |
| isolations of arboviruses from parous midges of the culicoides variipennis complex, and parous rates in biting populations. | | 1972 | 5054488 |
| patterns of flight activity of culicoides variipennis (coquillett) (diptera: ceratopogonidae). | | 1971 | 5118869 |
| blood-feeding patterns of midges of the culicoides variipennis complex in kern county, california. | | 1971 | 5160258 |
| observations on bluetongue virus in the salivary glands of an insect vector, culicoides variipennis. | | 1966 | 5911888 |
| multiplication of bluetongue virus in culicoides variipennis following artificial infection. | | 1966 | 5950517 |
| laboratory infection of the mosquito, toxorhynchites brevipalpis (diptera, culicidae), with bluetongue virus. | the use of toxorhynchites brevipalpis as a system for the propagation and isolation of bluetongue virus (btv) was investigated. btv was found to multiply in t. brevipalpis after infection by intrathoracic inoculation. virus concentrations of up to 6.9 log 10 tcid50 per mosquito were found within 7 days of infection and were maintained for at least 6 days. virus could be detected by an indirect fluorescent antibody test applied to head and thorax tissue smears. these results are comparable to tho ... | 1984 | 6141782 |
| the effect of paraffin wax embedding procedures on the ability of the fluorescent antibody test to demonstrate bluetongue virus antigen in insect tissue. | the effect of the reagents used in paraffin wax embedding procedures on the fluorescent antibody technique was investigated with a view to using this test for virus location studies on paraffin wax sections of bluetongue virus infected culicoides variipennis. experiments were carried out using tissue smears rather than prepared sections, enabling the effect of individual reagents to be evaluated. infected smears treated with acetone alone showed bright specific fluorescence, while treatment of i ... | 1984 | 6152128 |
| antibodies to bluetongue viruses in animals imported into united states zoological gardens. | three hundred forty-five serum samples from 30 zoological animal species which had been imported into the united states were examined retrospectively for the presence of antibody to bluetongue viruses. ninety eight (28.4%) were positive for antibody to bluetongue group antigen by the bluetongue agar gel immunodiffusion test. bluetongue antibodies, most of which were against serotypes exotic to the united states, were detected in 13 animal species from africa not previously reported to be infecte ... | 1982 | 6178486 |
| evaluations of three insecticides against colonized and field-collected larvae of culicoides variipennis (diptera: ceratopogonidae). | | 1982 | 6185552 |
| bluetongue and epizootic hemorrhagic disease virus isolation from vertebrate and invertebrate hosts at a common geographic site. | one serotype of bluetongue virus (btv) and two serotypes of epizootic hemorrhagic disease virus (ehdv) were isolated from vertebrate and invertebrate hosts on a farm in colorado. the isolations were from blood samples collected a week apart from a dairy heifer with stomatitis and laminitis; ehdv serotypes 1 and 2 were isolated from the first blood sample, and btv serotype 13 and ehdv serotype 1 were isolated from the second. antibodies to ehdv and btv were detected in the serum from this heifer. ... | 1980 | 6243617 |
| the susceptibility of the sandfly lutzomyia longipalpis (lutz & neiva), diptera, phlebotomidae, to laboratory infection with bluetongue virus. | bluetongue virus multiplied in the sandfly lutzomyia longipalpis after intrathoracic inoculation but not after oral ingestion of virus. the level of virus multiplication was lower than that observed in similar experiments with the north american vector of bluetongue, culicoides variipennis. inoculated sandflies did not transmit virus after 6 to 9 days incubation at 25 degrees c. it is unlikely that l. longipalpis would be important in the maintenance of bluetongue virus in the wild. | 1980 | 6247994 |
| epizootiologic study of bluetongue: virologic and serologic results. | heparinized blood and serum samples were obtained from 1,295 ruminants in herds or flocks with bluetongue virus (btv) infection in 4 western states. submissions were from herds or flocks with clinical bluetongue (bt), as well as from animals on premises with no history of bt disease. insects, including culicoides variipennis, were collected in areas enzootic for bt disease. viral isolations were in 10-day-old embryonating chicken eggs that were then adapted to vero cells for serotyping. sera wer ... | 1981 | 6266296 |
| bluetongue virus in pregnant elk and their calves. | two pregnant north american elk (cervus canadensis), in the 3rd and 4th months of gestation, were inoculated with bluetongue (bt) virus (btv) serotype 11. the virus was not isolated from the blood of the cows beyond postinoculation day (pid) 8, but was isolated from bone marrow and spleen samples obtained at necropsy on pid 190. although neither cow had overt clinical signs of bt infection, fluctuations in specific neutralizing btv antibody titers indicated viral replication. however, in 2 attem ... | 1982 | 6280527 |