| host feeding patterns of connecticut mosquitoes (diptera: culicidae). | blood-engorged coquillettidia perturbans, psorophora ferox, culex, culiseta, and aedes mosquitoes were collected principally by sweep net from salt marsh and woodland habitats in connecticut. of the 570 mosquitoes tested, precipitin tests identified the origins of 517 blood meals and revealed distinct host feeding patterns. aedes mosquitoes fed chiefly on mammals; a. abserratus, a. cantator, and a. vexans showed selectivity for cattle and (or) horses. a. cantator also obtained blood from avian h ... | 1977 | 17310 |
| organophosphorus multiresistance in culex pipiens quinquefasciatus in california. | | 1975 | 1159164 |
| californian hybrid zone between culex pipiens pipiens and cx. p. quinquefasciatus revisited (diptera:culicidae). | phallosome morphology (dv/d ratio) and allozyme variation were used to reexamine the transition from culex pipiens pipiens l. to cx. p. quinquefasciatus say, detected in california from the northern central valley to the mexican border of the united states of america. significant deficiency of heterozygotes was observed at the diagnostic locus mdhp-2 in populations from the central part of the hybrid zone. long tails of introgression were detected: populations from both north and south ends of t ... | 1997 | 9103754 |
| comparative effectiveness of three adult mosquito sampling methods in habitats representative of four different biomes of california. | the effectiveness of new jersey (nj) light, dry ice baited, and gravid female traps for collecting adult mosquitoes was compared at representative habitats in the coachella, san joaquin, and sacramento valleys and the los angeles basin of california. the nj light traps effectively sampled anopheles freeborni, culex tarsalis, psorophora columbiae, and several aedes when abundance was high in rural areas with minimal competitive illumination. dry ice-baited encephalitis virus surveillance or cdc s ... | 1999 | 10342265 |
| baseline susceptibility to bacterial insecticides in populations of culex pipiens complex (diptera: culicidae) from california and from the mediterranean island of cyprus. | bacterial insecticides play an increasingly important role in mosquito control. to establish guidelines for detecting resistance at an early stage, information on natural variation in susceptibility of insect populations to these insecticides is needed. between 1990 and 1993, the susceptibility of culex pipiens l. complex to bacillus thuringiensis subsp. israelensis de barjac and/or bacillus sphaericus neide was determined in 31 collections from california. these collections were undertaken befo ... | 2001 | 11561853 |
| differences in extent of genetic introgression between sympatric culex pipiens and culex quinquefasciatus (diptera: culicidae) in california and south africa. | comparisons of five morphological characters, 12 enzyme electrophoresis profiles, and wolbachia pipientis infection rates were used to characterize populations of members of the culex pipiens l. complex in california and south africa. in south africa, male phallosome dv/d ratio, male maxillary palp index, branching of siphonal seta 1a, the enzyme locus mdhp-1, and w. pipientis infection rates proved highly diagnostic for separating culex quinquefasciatus from cx. pipiens phenotypes. in johannesb ... | 2003 | 12597651 |
| wolbachia and cytoplasmic incompatibility in the california culex pipiens mosquito species complex: parameter estimates and infection dynamics in natural populations. | before maternally inherited bacterial symbionts like wolbachia, which cause cytoplasmic incompatibility (ci; reduced hatch rate) when infected males mate with uninfected females, can be used in a program to control vector-borne diseases it is essential to understand their dynamics of infection in natural arthropod vector populations. our study had four goals: (1) quantify the number of wolbachia strains circulating in the california culex pipiens species complex, (2) investigate wolbachia infect ... | 2003 | 14704183 |
| vertical transmission of west nile virus by three california culex (diptera: culicidae) species. | three california culex species previously identified as efficient laboratory vectors of west nile (wn) virus were tested for their capability to vertically transmit wn virus. wild-caught culex pipiens pipiens l., culex pipiens quinquefasciatus say, and two populations of culex tarsalis coquillett females were inoculated intrathoracically with 10(2.7 +/- 0.1) plaque-forming units of wn virus. f1 progeny were reared at 18 degrees c and subsequently tested as adults for infectious virus on vero cel ... | 2003 | 14765647 |
| an initial survey for wolbachia (rickettsiales: rickettsiaceae) infections in selected california mosquitoes (diptera: culicidae). | knowledge of biogeographic variation in wolbachia infection rates and inferred susceptibility to infection among different mosquito taxa has fundamental implications for the design and successful application of wolbachia-based vector-borne disease control strategies. using a wolbachia-specific polymerase chain reaction assay, we tested 14 north american mosquito species in five genera (aedes, anopheles, culiseta, culex, and ochlerotatus) for wolbachia infection. wolbachia infections were only de ... | 2004 | 15061286 |
| pyrethroid tolerance in culex pipiens pipiens var molestus from marin county, california. | in may 2001 a sample of culex pipiens pipiens variety molestus forskål from marin county, california, collected as larvae and reared to adults, was found to show reduced resmethrin and permethrin knock-down responses in bottle bioassays relative to a standard susceptible cx. pipiens quinquefasciatus say colony (cq1). larval susceptibility tests, using cq1 as standard susceptible, indicated that the marin mosquitoes had lc50 resistance ratios of 18.3 for permethrin, 12 for deltamethrin and 3.3 fo ... | 2004 | 15119598 |
| overwintering of west nile virus in southern california. | west nile virus (family flaviviridae, genus flavivirus, wnv) invaded southern california during 2003, successfully overwintered, amplified to epidemic levels, and then dispersed to every county in the state. although surveillance programs successfully tracked and measured these events, mechanisms that allowed the efficient overwintering and subsequent amplification of wnv have not been elucidated. our current research provided evidence for three mechanisms whereby wnv may have persisted in south ... | 2006 | 16619621 |
| role of corvids in epidemiology of west nile virus in southern california. | the invasion of different southern california landscapes by west nile virus (wnv) and its subsequent amplification to epidemic levels during 2004 enabled us to study the impact of differing corvid populations in three biomes: the hot colorado desert with few corvids (coachella valley), the southern san joaquin valley (kern county) with large western scrub-jay but small american crow populations, and the cool maritime coast (los angeles) with a large clustered american crow population. similar su ... | 2006 | 16619622 |
| seasonal variation in susceptibility to west nile virus infection in culex pipiens pipiens (l.) (diptera: culicidae) from san joaquin county, california. | | 2006 | 17249364 |
| genetic differences between culex pipiens f. molestus and culex pipiens pipiens (diptera: culicidae) in new york. | the definition and phylogenetic placement of the autogenous molestus form of culex pipiens has puzzled entomologists for decades. we identified genetic differences between cx. p. pipiens (l.) and cx. pipiens f. molestus forskål in the sh60 fragment described previously. single-strand conformation polymorphism analysis, cloning, and sequencing of this fragment demonstrated high polymorphism within and among individual cx. p. pipiens, with common sh60 variants shared among individuals from distant ... | 2007 | 17294920 |
| geographic variation in vector competence for west nile virus in the culex pipiens (diptera: culicidae) complex in california. | we evaluated the susceptibility to infection and transmission of west nile virus (wnv) in seven populations of culex pipiens pipiens (l.), cx. p. quinquefasciatus say, and from populations containing cx. pipiens/quinquefasciatus hybrids in a north-south transect of california. samples were identified to species or as hybrid forms based on morphology of male terminalia. after 7 and 14 days of extrinsic incubation, few females were infected and none transmitted wnv from samples of cx. p. pipiens f ... | 2007 | 17627438 |
| high subclinical west nile virus incidence among nonvaccinated horses in northern california associated with low vector abundance and infection. | although horse cases frequently are reported during west nile virus (wnv) outbreaks, few investigations have focused on the epidemiology of this transmission. from april to october 2003 to 2005, mosquito abundance and infection were monitored 3 days per week at an equine research facility at the university of california, davis. thirty-two nonvaccinated horses enrolled as controls in a vaccine study were bled monthly, and their serum was tested for evidence of wnv infection by plaque reduction ne ... | 2008 | 18187784 |
| identification of culex pipiens complex mosquitoes in a hybrid zone of west nile virus transmission in fresno county, california. | culex pipiens sensu lato mosquitoes were collected from 24 gravid traps (mid-june to mid-october, 2005) in fresno county, ca. captured gravid females were allowed to oviposit before sibling species identification by ace.2 pcr and detection of west nile virus (wnv) rna by rt-pcr were performed on the mother and her offspring. of the 442 cx. pipiens s.l. female mosquitoes collected, 88 were positive for wnv viral rna (peaked in august) with no significant differences among complex members or habit ... | 2008 | 18256434 |
| hematophagous diptera collected from a horse and paired carbon dioxide-baited suction trap in southern california: relevance to west nile virus epizootiology. | hematophagous diptera landing on a horse were removed by vacuum, and their numbers were related to a paired carbon dioxide-baited suction trap at three locations in southern california where west nile virus activity was high during the preceding year. insects collected from the horse included mosquitoes (nine species), biting midges (culicoides sonorensis wirth & jones), and black flies (simulium bivittatum malloch). mosquitoes were predominantly collected from the head, crest, withers, neck, ch ... | 2008 | 18283951 |
| persistent west nile virus transmission and the apparent displacement st. louis encephalitis virus in southeastern california, 2003-2006. | west nile virus (family flaviviridae, genus flavivirus, wnv) invaded the colorado desert biome of southern california during summer 2003 and seemed to displace previously endemic st. louis encephalitis virus (family flaviviridae, genus flavivirus, slev, an antigenically similar flavivirus in the japanese encephalitis virus serocomplex). western equine encephalomyelitis virus (family togaviridae, genus alphavirus, weev), an antigenically distinct alphavirus, was detected during 2005 and 2006, ind ... | 2008 | 18533445 |
| impact of aerial spraying of pyrethrin insecticide on culex pipiens and culex tarsalis (diptera: culicidae) abundance and west nile virus infection rates in an urban/suburban area of sacramento county, california. | in response to an epidemic amplification of west nile virus (family flaviviridae, genus flavivirus, wnv), the sacramento and yolo mosquito and vector control district (symvcd) sprayed ultralow-volume (ulv) formulations of pyrethrin insecticide (evergreen ec 60-6: 6% pyrethrin insecticide, 60% piperonylbutoxide; mgk, minneapolis, mn, applied as 0.003 kg/ha [0.0025 lb/acre] ) over 218 km2 in north sacramento and 243.5 km2 in south sacramento on three consecutive evenings in august 2005. we evaluat ... | 2008 | 18714879 |
| does variation in culex (diptera: culicidae) vector competence enable outbreaks of west nile virus in california? | since the invasion of california by west nile virus (family flaviviridae, genus flavivirus, wnv) in 2003, we have annually monitored vector competence for the ny99 strain in culex tarsalis coquillett, culex pipiens quinquefasciatus say, culex p. pipiens l., and culex stigmatosoma dyar populations from four areas: deserts of coachella valley, densely urbanized maritime los angeles, southern san joaquin valley in kern county, and southern sacramento valley near davis in sacramento county. overall, ... | 2008 | 19058638 |
| evaluation of efficacy and human health risk of aerial ultra-low volume applications of pyrethrins and piperonyl butoxide for adult mosquito management in response to west nile virus activity in sacramento county, california. | the sacramento and yolo mosquito and vector control district (symvcd, also referred to as "the district") conducts surveillance and management of mosquitoes in sacramento and yolo counties in california. following an increase in numbers and west nile virus (wnv) infection rates of culex tarsalis and culex pipiens, the district decided on july 26, 2007, to conduct aerial applications of evergreen ec 60-6 (60% pyrethrins: 6% piperonyl butoxide) over approximately 215 km2 in the north area of sacra ... | 2010 | 20402352 |
| west nile virus emergence and persistence in los angeles, california, 2003-2008. | west nile virus (wnv) invaded los angeles in september 2003, and during the subsequent five-year period followed a pattern of amplification, subsidence, and resurgence. enzootic transmission was tracked by abundance and infection incidence in culex pipiens quinquefasciatus and cx. tarsalis and by seroprevalence in peridomestic passerine birds, infection in dead birds, and seroconversions in sentinel chickens. culex p. quinquefasciatus served as the primary vector of wnv, with gravid traps servin ... | 2010 | 20682890 |
| seasonal abundance of culex tarsalis and culex pipiens complex mosquitoes (diptera: culicidae) in california. | large-scale patterns in the seasonal abundance profiles of the arboviral mosquito vectors culex tarsalis coquillett and the species of the culex pipiens complex were described based on a decade of counts from 868 new jersey light traps located throughout the urban and agricultural areas of california. mean seasonal abundance profiles varied markedly among hydrologic regions. for all species, abundance increased earlier and declined later in drier, warmer southern regions, but variation could not ... | 2010 | 20939368 |
| blood-feeding patterns of the culex pipiens complex in sacramento and yolo counties, california. | mosquitoes in the culex pipiens complex are competent vectors of west nile virus (wnv; family flaviviridae, genus flavivirus) in the laboratory, and field-collected mosquitoes have tested positive for the virus in california and elsewhere. a better understanding of cx. pipiens complex blood-feeding patterns will help define the threat that these mosquitoes pose to human health and their role in wnv amplification in northern california. we collected blood-engorged cx. pipiens complex mosquitoes f ... | 2011 | 21485380 |