First records for Culex (Melanoconion) limacifer Komp and Culex (Melanoconion) dunni dyar from Guatemala

Larvae of Culex (Melanoconion) limacifer Komp and Culex (Melanoconion) dunni Dyar were collected during June 2004 in Guatemala. All specimens were individually reared to the adult stage. Specimens were identified based upon examination of the male genitalia and characters of the associated larval and pupal exuviae. These are the first records of these 2 species in Guatemala.     

Culex (Micraedes) biscaynensis n. sp. from Florida (Diptera: Culicidae).

The female, male, male genitalia, pupa, and larva of Culex biscaynensis, a new species in the Bisulcatus Group of subgenus Micraedes, are described and illustrated. The species, which is presently known only from south Florida, United States, is most similar to Culex (Micraedes) antillummagnorum Dyar.     

Vector competence of Culiseta incidens and Culex thriambus for West Nile virus

The vector competence of Culiseta incidens (Thomson) and Culex thriambus Dyar for West Nile virus (WNV) were compared to Cx. quinquefasciatus Say or Cx. tarsalis Coquillett and Cx. stigmatasoma Dyar collected concurrently in California. Culiseta incidens were less susceptible to oral infection than Cx. quinquefasciatus, but transmitted virus at a significantly higher rate, thereby yielding comparable population transmission rates. Culex thriambus was equally susceptible to oral infection and transmitted virus at rates comparable to Cx. tarsalis or Cx. stigmatosoma. A mammalian host selection pattern most likely precluded detection of natural infection in Cs. incidens, a fairly abundant peridomestic species. In contrast, an avian host selection pattern and efficient vector competence resulted in repeated detection of WNV in Cx. thriambus; however, limited abundance and restrictive riparian larval habitat requirements would seem to limit the involvement of Cx. thriambus in WNV epidemiology.     

Potential for Central American mosquitoes to transmit epizootic and enzootic strains of Venezuelan equine encephalitis virus.

Experimental studies were undertaken to compare the vector competence of Culex (Melanoconion) taeniopus Dyar and Knab, Culex (Melanoconion) ocossa Dyar and Knab, and Psorophora confinnis (Lynch Arribalzalga) from Central America for epizootic (IAB) and enzootic (IE) strains of Venezuelan equine encephalitis (VEE) virus. Virus infection and dissemination rates were significantly higher in Cx. taeniopus orally exposed to IE as compared to those orally exposed to IAB virus. In contrast, both infection and dissemination rates were similar in Cx. ocossa exposed to either IAB or IE strains of VEE virus. Thus, susceptibility to epizootic and enzootic strains of VEE virus seems to be species specific within the subgenus Culex (Melanoconion). Both species transmitted each strain of VEE virus after intrathoracic inoculation, indicating that a midgut barrier affected vector competence in these species. Psorophora confinnis was equally susceptible to both IAB and IE viruses, but apparently had a salivary gland barrier, as only 1 of 16 mosquitoes with a disseminated infection transmitted VEE virus by bite.     

Phylogenetic relationships among eighteen neotropical Culicini species

The subgeneric relationships among 8 generic and infrageneric taxa of the Culicini tribe were examined by cladistic analysis based on 30 larval mouthpart characters (maxillae and mandibles) of 7 subgenera of Culex L. and 1 of Deinocerites Theobald. We analyzed 18 ingroup species as well as Deinocerites melanophylum Dyar and Knab as a sister group, and Aedes taeniorhynchus Wiedemann as an outgroup. A parsimony analysis using the Nona program resulted in 2 trees each of 109 steps (consistency and retention indices = 0.88). The topologies obtained were similar to the current classification of the tribe, based on nonexplicit methods mainly including adult characters, with 2 exceptions. In the present work, the monophyly of the tribe Culicini (Culex + Deinocerites) was supported by 4 synapomorphies. The subgenus Lutzia Theobald formed the most basal clade in the tribe Culicini and the placement of Phenacomyia Harbach and Peyton as a subgenus was validated by its location as a sister group of the subgenus Culex and other subgenera. The subgenus Carrollia Lutz was the most robust taxon, supported by 5 synapomorphies, and was congruent with the infragroups of the current classification. The relationships among Deinocerites, Anoedioporpa Dyar, Microculex Theobald, and Melanoconion Theobald were unresolved, but were placed in the most internal clade of the tribe. The 1st exception to the accepted classification was the poorly resolved boundary between Anoedioporpa and Microculex The 2nd was the strong support (with 11 synapomorphies) for the inclusion of Deinocerites as a subgenus of Culex in the Culicini, which is proposed here.     

Redescription of the pupa of Culex salinarius Coquillett and comparison with Culex nigripalpus Theobald

The pupa of Culex salinarius is redescribed with updated chaetotaxal nomenclature and a full illustration. The pupal chaetotaxy of Cx. salinarius and the similar species Culex nigripalpus is compared.     

Seasonal abundance of Culex restuans and Culex pipiens in southwestern Virginia through ovitrapping

Ovitrap collections were done to determine the seasonal distribution and ovipositional activity of Culex restuans and Culex pipiens in southwestern Virginia during summers 2002 and 2003. In both years, Cx. restuans was the first species collected and was the dominant species throughout the collecting period. More than 90% of the collections were comprised of Cx. restuans. Two oviposition peaks occurred in both years for Cx. restuans, the first in June and second in the middle of July. Culex pipiens made up less than 7% of the total catch and started to occur in the traps in the middle of the trapping season with a peak occurring in August. Although ovipositional activity began to decline for Cx. restuans, at the end of the trapping period, there was a slight increase in ovipositional activity for Cx. pipiens, but not enough to result in a crossover. A third species, Culex salinarius, was collected in the traps, but the total number of egg rafts accounted for less than 1% of the total collection.     

Insemination rates of hybrids between Culex pipiens pipiens and Culex pipiens quinquefasciatus or Culex pipiens pallens at high temperature

Females of Culex pipiens pallens are rarely inseminated at temperatures above 30 degrees C. Insemination and egg-hatching rates (F2) were examined in females of hybrids (F1) between Culex pipiens pipiens and Culex pipiens quinquefasciatus at 25 degrees C and 30 degrees C to examine temperature-dependent reproductive activity. Insemination rates were very high in hybrid females (F1) at 25 degrees C and 30 degrees C, and egg-hatching rate (F2) also was high at both temperatures. Crosses between Cx. p. pipiens and Cx. p. quinquefasciatus did not show insemination rates and egg-hatching rates similar to the rates observed in Cx. p. pallens, suggesting that the hybrids expressed reproductive activity characteristic of Cx. p. quinquefasciatus.     

First record of Culex (Culex) coronator in Louisiana, USA

The 1st confirmed record of Culex coronator for Louisiana was made at Fort Polk, LA, from carbon dioxide-baited light trap and gravid trap collections performed from April to October 2004. In addition to the new record, 17 mosquito species in 5 genera (Aedes, Anopheles, Coquillettidia, Culex, and Psorophora) were collected. Collection-site and species distribution data are included.     

Polymerase chain reaction assay identifies Culex nigripalpus: part of an assay for molecular identification of the common Culex (Culex) mosquitoes of the eastern United States

Nucleotide sequence information on internal transcribed spacer (ITS) 1 and ITS 2 regions of the nuclear ribosomal DNA multigene family was used to develop a polymerase chain reaction assay that identifies Culex nigripalpus Theobald. The assay uses species-specific forward and reverse primers for Cx. nigripalpus and can be used along with previously described primers to distinguish among 4 common taxa of Culex (Culex) of the eastern USA with a single thermal cycler program. The assay distinguishes among the 4 taxa Cx. nigripalpus, Cx. restuans Theobald, Cx. salinarius Coquillett, and members of the Cx. pipiens Linnaeus complex. This assay may be used to verify the morphological identification of individual specimens of Culex or to confirm the species composition of mosquito pools.     

江苏地区尖音库蚊复合组种群组成调查分析

目的了解江苏地区尖音库蚊复合组种群构成,为进一步防控蚊虫蚊媒病奠定基础。方法于2012年采集江苏省连云港、常熟、张家港、盐城、泰州、徐州、南京、南通和无锡9个地区蚊虫,通过扩增mtDNA—COI基因、测序和基因比对,对上述地区尖音库蚊复合组进行分析。结果mtDNA—COI基因分析显示,江苏地区的尖音库蚊复合组差异明显,进化树显示分为2支,南京、泰州、无锡、盐城、徐州地区为一支,与淡色库蚊同源性较高;连云港、南通、常熟、张家港地区为1支,与致倦库蚊同源性较高。结论江苏地区尖音库蚊复合组存在淡色库蚊和致倦库蚊两类基因型,未发现尖音库蚊和骚扰库蚊基因型,亦未发现新的隐藏种。     

Separation of fourth-instar larvae of Culex nigripalpus from Culex salinarius in Florida using the spiracular apodeme.

The spiracular apodeme of the 4th-instar larvae of Culex nigripalpus and Culex salinarius is described and illustrated. The development of this structure provides an additional character for separating these 2 species.     

淡色库蚊对4种常用杀虫剂的抗药性现状分析

目的了解青岛市淡色库蚊幼虫对4种常用杀虫剂的抗药性现状,为合理选用杀虫剂,指导蚊虫防治提供科学依据。方法采用WHO生物测定方法,测定淡色库蚊幼虫对常用杀虫剂的抗性水平。结果与敏感品系比较,淡色库蚊幼虫对残杀威和敌敌畏抗性为低抗水平,对溴氰菊酯的抗药性为中等水平,对氯氰菊酯呈高抗性。结论青岛市淡色库蚊对4种常用杀虫剂均产生不同程度的抗药性,应采取适当措施克服或延缓蚊虫抗药性的产生和发展。     

Eryngium spp. (Umbelliferae) as phytotelmata and their Culex (Culex) inhabitants in temperate Argentina

The host-plant fidelity, seasonality, and population dynamics of 3 species of Culex (Culex) were examined from monthly samples of mosquito immatures extracted from the leaf axils of Eryngium pandanifolium and Eryngium cabrerae growing sympatrically in the Punta Lara region of Buenos Aires Province, Argentina. Culex hepperi was collected only from E. pandanifolium, and abundance peaks of its larvae and pupae were asynchronous in forest and field habitats. However, the proportion of plants positive for Cx. hepperi, as well as larval densities and developmental success, did not differ between forest and field. Culex renatoi was collected only from E. cabrerae in the field habitat. The monthly numbers of Cx. hepperi and Cx. renatoi were not significantly correlated with the proportion of their host plants that held water. The stage-specific distributions of Cx. hepperi and C. renatoi numbers were highly skewed towards 1st instars and did not differ between species or, for Cx. hepperi, between forest and field habitats. Culex castroi was collected regularly from the axils of both species of Eryngium, but usually in lesser numbers than either Cx. hepperi or Cx. renatoi. Association analyses indicated significant positive associations between Cx. castroi and the other 2 culicine species in host plants. Culex renatoi occurred preferentially in small E. cabrerae, but Cx. castroi did not discriminate plants based on their size. These 3 species of Culex are known only from Eryngium spp. phytotelmata. We suggest that their host-plant specificity is maintained by oviposition preferences, which are more highly selective for Cx. hepperi or Cx. renatoi than for Cx. castroi.     

淡色库蚊对溴氰菊酯抗性的分子生物学检测

目的建立一种可以早期检测蚊虫对拟除虫菊酯抗药性的方法。方法采用聚合酶链式反应（PCR）方法，用特异性引物对蚊虫的钠离子通道基因进行扩增。结果敏感品系中只检测出SS（敏感纯合子）型，抗性品系中检测出SS型、RS（杂合子）型和RR（抗性纯合子）型。结论PCR能够快速完成蚊虫对拟除虫菊酯抗药性的检测，为蚊虫对拟除虫菊酯抗药性的早期监测提供了快速可行的方法。     

Redescription of the pupa of Culex (Culex) declarator Dyar and Knab (Diptera, Culicidae), with amendments to key to the Culex pupae of the eastern United States

The pupa of Culex declarator was partially described and illustrated by Lane. This species was recently discovered in Florida for the first time and a series of individual rearings have resulted in a number of pupae and an opportunity to redescribe it fully, with a complete illustration. Amendment to the key to the Culex pupae of the eastern United States is provided.     

邯郸市城区三带喙库蚊监测结果分析

目的掌握邯郸市城区三带喙库蚊的基础数据,为预防流行性乙型脑炎提供科学依据。方法诱蚊灯法。结果 2009年三带喙库蚊在公园和医院为优势种,共捕获1 980只,占总数的38.11%。结论三带喙库蚊的防控应以城市公园为重点。     

印楝素对淡色库蚊的生物活性研究

目的研究印楝素对淡色库蚊的生物活性。方法以不同浓度的印楝素溶液处理淡色库蚊不同发育阶段后，观察其对幼虫的毒杀活性、生长发育的影响；对成虫吸血、生殖、寿命的影响；以及对卯的毒杀活性。结果印楝素对淡色库蚊低龄幼虫的敏感性远高于高龄幼虫，具明显的慢性毒性，处理后随时间延长，LC50值逐步下降；印楝素对幼虫表现为明显的生长抑制作用，随浓度增加，抑制作用也随之增加。结论在一定处理条件下，印楝素对淡色库蚊的吸血率、产卵量、卵的孵化率及成虫寿命均有一定影响；印楝素只对新产4h内的卯伐有毒杀活性。