Identification of Aedes campestris from New Mexico: with notes on the isolation of western equine encephalitis and other arboviruses

An arbovirus survey was conducted during August 1985 at White Sands Missile Range in southcentral New Mexico following a suspected arboviral disease epizootic among feral horses. A total of 20,566 mosquitoes (18,505 females and 2,061 males) and 8,900 biting gnats were collected and assayed for virus. Female mosquitoes were principally Aedes campestris (54.8%), Aedes dorsalis (30.4%) and Culex tarsalis (13.2%). Arboviruses were not isolated from biting gnats, but mosquitoes yielded a total of 37 viral isolates, including western equine encephalitis (WEE) (18), California serogroup (15), Cache Valey (1), and Hart Park (1) viruses in addition to 2, as yet unidentified, rhabdoviruses. Isolates of WEE virus were from 9 pools of Ae. campestris, 6 of Cx. tarsalis and 3 of Ae. dorsalis. California serogroup viruses, including 2 subtypes, were obtained from 7 pools of females and 1 pool of males of Ae. campestris and from 4 pools of Ae. dorsalis. Cache Valley and Hart Park viruses were isolated from single pools of Ae. dorsalis and Cx. tarsalis, respectively, and the rhabdoviruses were obtained from Ae. campestris and Psorophora signipennis.     

West Nile virus in Pakistan. III. Comparative vector capability of Culex tritaeniorhynchus and eight other species of mosquitoes

Eight species of mosquitoes from Pakistan were compared with Culex tritaeniorhynchus as experimental vectors of West Nile (WN) virus. When fed by the membrane or cotton-pledget methods on a dose of WN virus 100% infective for Cx tritaeniorhynchus, 95% and 73% of the females of Cx fuscocephala and Cx pseudovishnui became infected, respectively. Cx quinquefasciatus, Cx univittatus, Aedes albopictus, Ae. caspius, Ae. indicus and Ae. lineatopennis were all significantly less susceptible than Cx tritaeniorhynchus. In agreement with the single dose comparisons, the median per os infective dose of WN virus for Cx fuscocephala, Cx pseudovishnui and Ae. caspius was substantially greater than for Cx tritaeniorhynchus. The median parenteral infective dose for all six species tested was less than 1 SMICLD50. Both Cx tritaeniorhynchus and Cx quinquefasciatus were more susceptible to infection with WN virus when fed on viraemic chickens than when fed on defibrinated blood using cotton pledgets or membranes. After infection by intrathoracic inoculation, only Ae. indicus and Ae. lineatopennis showed a reduced ability to transmit WN virus when compared to Cx tritaeniorhynchus.     

Comparison of four membranes for artificially bloodfeeding mosquitoes.

Four species of mosquitoes, Aedes aegypti, Ae. triseriatus, Culex pipiens and Cx. tarsalis, were allowed access to defibrinated rabbit blood via 4 different membranes and a standard membrane feeder. Natural animal skins (mouse or quail) were the most effective. More than 50% of the Aedes mosquitoes fed within 5 min and approximately 90% fed within 20 min on either mouse or quail skin. Culex species fed best on quail skin, but the difference in feeding on quail skin and sheep intestine was not significant at 10 or 20 min. In general Culex mosquitoes fed less readily on natural animal skins than Aedes.     

West Nile virus infection in mosquitoes, birds, horses, and humans, Staten Island, New York, 2000

West Nile (WN) virus transmission in the United States during 2000 was most intense on Staten Island, New York, where 10 neurologic illnesses among humans and 2 among horses occurred. WN virus was isolated from Aedes vexans, Culex pipiens, Cx. salinarius, Ochlerotatus triseriatus, and Psorophora ferox, and WN viral RNA was detected in Anopheles punctipennis. An elevated weekly minimum infection rate (MIR) for Cx. pipiens and increased dead bird density were present for 2 weeks before the first human illness occurred. Increasing mosquito MIRs and dead bird densities in an area may be indicators of an increasing risk for human infections. A transmission model is proposed involving Cx. pipiens and Cx. restuans as the primary enzootic and epizootic vectors among birds, Cx. salinarius as the primary bridge vector for humans, and Aedes/Ochlerotatus spp. as bridge vectors for equine infection.     

Seasonal activity of mosquitoes in an Ockelbo disease endemic area in central Sweden

In the S?ssman area, province of H?lsingland, Sweden, mosquitoes were sampled in 1983 from aquatic habitats, overwintering sites, cattle sheds, human bait, with UV-light traps, rabbit-, guinea-pig-, hen-, dove- and unbaited suction traps and similarly baited net traps. Anopheles beklemishevi, An. messeae, Aedes cantans, Ae. cataphylla, Ae. cinereus, Ae. communis, Ae. diantaeus, Ae. excrucians, Ae. hexodontus, Ae. intrudens, Ae. leucomelas, Ae. pionips, Ae. punctor, Ae. vexans, Culex pipiens, Cx. torrentium, Cx. territans, Culiseta alaskaensis, Cs. bergrothi, Cs. morsitans, Cs. ochroptera and Mansonia richiardii were recorded as new to the province. Data are presented on the ecology including seasonal abundance and seasonal blood-feeding activity of each species. Ockelbo disease, caused by a virus indistinguishable from Sindbis virus, is prevalent amongst humans in the study area. The ecological and behavioral potential of species of Culex, Culiseta and Aedes to transmit the virus is discussed.     

Getah virus in several species of mosquitoes

Vector competence of Aedes (Ae.) vexans nipponii (nip.) and Culex (Cx) tritaeniorhynchus for Getah virus was compared after incubation at 28 degrees C and 20 degrees C. Marked differences existed between Ae. vexans nip. strains Sapporo and Cx tritaeniorhynchus strain Kyoto in infection and transmission rates following ingestion of blood meals containing several concentrations of Getah virus. Simultaneous comparison of infectivity also revealed that infection rates of Ae. vexans nip. strains Sapporo (74%) and Shizunai (68%) were higher than those of Cx tritaeniorhynchus strain Kyoto (44%). No significant differences were seen in infection rates between three strains of Cx tritaeniorhynchus or between two strains of Ae. vexans nip. Getah virus propagated and was transmitted in Ae. vexans nip. as rapidly at 20 degrees C as at 28 degrees C. Following seven days' incubation both at 20 degrees C and 28 degrees C, Ae. vexans nip. was capable of transmitting the virus. 14 days' incubation at 20 degrees C were needed for Cx tritaeniorhynchus to acquire the same capability. Ae. japonicus, Ae. aegypti, Ae. albopictus, Cx pipens pallens, Armigeres subalbatus and Tripteroides bambusa were also susceptible to Getah virus infection.     

Vector potential of culicine mosquitoes in Faiyum Governorate, Egypt

Culicine mosquito populations were studied for 1 year in 2 neighboring villages in Faiyum Governorate, Egypt. Dominant species in larval collections included Culex pipiens, Cx. univitattus, Cx. antennatus, Aedes caspius and Uranotaenia unguiculata; Culiseta longiareolata was less common. Culex pipiens accounted for 98% of 3,743 mosquitoes captured in human-biting collection (164 man-nights), 96% of 1,136 mosquitoes collected inside houses and animal sheds (396 inspections), and 98% of 15,000 mosquitoes from 22 donkey-baited traps. Adult Cx. univittatus, Cx. antennatus and Ae. caspius were infrequently captured by any of the collection techniques. Although larval collections identified 5 common species, only Cx. pipiens showed a significant association with the human population.     

Larvicidal activity of leguminous seeds and grains against Aedes aegypti and Culex pipiens pallens

Larvicidal activity of methanol extracts of 26 leguminous seeds and 20 grains against early 4th-stage larvae of Aedes aegypti and Culex pipiens pallens was examined. At 200 ppm of the extracts from Cassia obtusifolia, Cassia tora, and Vicia tetrasperma, more than 90% mortality was obtained in larvae of Ae. aegypti and Cx. pipiens pallens. Extract of C. tora gave 86.7 and 100% mortality in the larvae of Ae. aegypti and Cx. pipiens pallens at 40 ppm but 59.2 and 78.3% mortality against larvae of Ae. aegypti and Cx. pipiens pallens at 20 ppm, respectively. At 40 ppm, extract of C. obtusifolia caused 51.4 and 68.5% mortality of the 4th-stage larvae of Ae. aegypti and Cx. pipiens pallens, respectively. Larvicidal activity of extract of C obtusifolia was significantly reduced when used at 20 ppm. Further studies of these plants as possible agents for mosquito control are warranted.     

A survey of mosquitoes breeding in used tire stockpiles in Connecticut

A larval survey of nine used tire disposal sites in Connecticut, was conducted from June through October 1987. No larvae of Aedes albopictus were uncovered indicating that this mosquito is not yet established in the state. However, eight other mosquito species in four genera were found. The most abundant and widely distributed species found breeding in permanent tire dumps were Ae. atropalpus, Ae. triseriatus and Culex restuans. Culex pipiens was the second most common Culex species followed by Cx. territans and Cx. salinarius. Other species included Anopheles punctipennis and Culiseta melanura. Larvae of Ae. atropalpus and Cx. salinarius were most frequently recovered from tire casings exposed to direct sunlight, while Ae. triseriatus and Cs. melanura predominated in tires shaded by bordering trees and low-lying vegetation. The other mosquito species showed no discernable preference for either habitat type.     

Mosquito larvicidal activity of aromatic medicinal plant oils against Aedes aegypti and Culex pipiens pallens

Larvicidal activity of essential oils derived from 11 aromatic medicinal plants against early 4th-stage larvae of Aedes aegypti and Culex pipiens pallens was tested in the laboratory. At 100 ppm, the essential oils of all plants caused 100% mortality against Ae. aegypti and Cx. pipiens pallens. At 25 ppm, the essential oils of Citrus bergamia, Cuminum myrrha, and Pimenta racemosa caused 100% mortality against larvae of Ae. aegypti and Cx. pipiens pallens. The oil of C. begamia caused 32.5% and 24.5% mortality against Ae. aegypti and Cx. pipiens pallens at 12.5 ppm, but 24.2% and 0% mortality against Ae. aegypti and Cx. pipiens pallens at 6.25 ppm, respectively. The oil of P. racemosa caused 52.3% and 38.5% mortality against Ae. aegypti and Cx. pipiens pallens at 12.5 ppm, but 32.2% and 0% mortality against Ae. aegypti and Cx. pipiens pallens at 6.25 ppm, respectively. The larvicidal activity of oils of C. bergamia, C. myrrha, and P. racemosa was significantly reduced when used at 6.25 ppm. These plants warrant further studies as possible agents for mosquito control.     

广东省蚊虫感染沃尔巴克氏体初步调查研究

目的 了解广东省蚊虫种群中沃尔巴克氏体（Wolbachia）的分布及其基因型别.方法 利用Wolbachia的wsp基因序列建立PCR检测方法,对蚊科中库蚊属、伊蚊属、阿蚊属和按蚊属部分蚊虫种类进行检测,同时利用Mega 5.2软件对所获基因序列进行系统分析.结果 分别从致倦库蚊、骚扰阿蚊、白纹伊蚊及未分型蚊种中检测到12条目的基因序列,其中11条成功进行测序,这些序列分别属于A和B2个超级基因组,分布在5个不同的基因族中.结论 广东省白纹伊蚊、骚扰阿蚊和致倦库蚊中均存在A大组（含2个小组）和B大组（含3个小组）基因型的Wolbachia感染,埃及伊蚊和中华按蚊未检测出Wolbachia.     

糖和维生素对淡色库蚊及白纹伊蚊产卵选择的影响

目的评价不同营养物质对淡色库蚊和白纹伊蚊雌蚊产卵选择的影响,为新型诱卵器的研制提供理论支持。方法在室内测定淡色库蚊和白纹伊蚊对不同种类糖和维生素溶液的产卵趋性。结果淡色库蚊怀卵雌蚊偏好在1000mg/L和100mg/L浓度的葡萄糖溶液及1000mg/L浓度的蔗糖溶液中产卵,而白纹伊蚊则对供试的各种糖液没有明显的产卵选择偏好;浓度为100mg/L的盐酸硫胺（VB1）溶液和抗坏血酸（VC）溶液、10mg/L的VB1溶液能显著引诱淡色库蚊产卵,10mg/L的VB1溶液还能显著引诱白纹伊蚊产卵。结论葡萄糖对淡色库蚊、VB1对淡色库蚊和白纹伊蚊在室内有较好的产卵引诱效果。     

蛋白质和氨基酸对2种蚊虫产卵选择的影响

目的评价不同蛋白质和氨基酸对我国2种重要媒介蚊虫淡色库蚊和白纹伊蚊雌蚊产卵选择的影响,为新型蚊虫诱卵器的研制提供理论支持。方法在室内测定淡色库蚊和白纹伊蚊对不同种类蛋白质和氨基酸溶液的产卵趋性。结果淡色库蚊怀卵雌蚊偏好在较高浓度的鱼蛋白胨溶液(1000和100mg/L)和酵母浸膏溶液(1000mg/L)中产卵,而10mg/L浓度的鱼蛋白胨溶液能显著引诱白纹伊蚊产卵;苯丙氨酸溶液在1000、100和10mg/L3个实验浓度下均能显著引诱淡色库蚊和白纹伊蚊产卵。结论鱼蛋白胨和苯丙氨酸对淡色库蚊和白纹伊蚊在室内有较好的产卵引诱效果。     

Stormwater ponds, constructed wetlands, and other best management practices as potential breeding sites for West Nile virus vectors in Delaware during 2004

We performed longitudinal surveys of mosquito larval abundance (mean mosquito larvae per dip) in 87 stormwater ponds and constructed wetland in Delaware from June to September 2004. We analyzed selected water quality factors, water depth, types of vegetation, degree of shade, and level of insect predation in relation to mosquito abundance. The 2004 season was atypical, with most ponds remaining wet for the entire summer. In terms of West Nile virus (WNV) vectors, wetlands predominantly produce Aedes vexans, culex pipiens pipiens, and Culex restuans. Retention ponds generally produced the same species as wetlands, except that Cx. p. pipiens was more abundant than Cx. restuans in retention ponds. Aedes vexans and Culex salinarius were the most abundant species to Conservation Restoration Enhancement Program ponds. Sand filters uniquely produced high numbers of Cx. restuans, Cx. p. pipiens, and Aedes japonicus japonicus, a newly invasive vector species. Site that alternately dried and flooded, mostly detention ponds, forebays of retention ponds, and some wetlands often produced Ae. vexans, an occasional WNV bridge vector species. Overall, seasonal distribution of vectors was bimodal, with peaks occurring during early and late summer. Ponds with shallow sides and heavy shade generally produced an abundance of mosquitoes, unless insect predators were abundant. Bright, sunny ponds with steep sides and little vegetation generally produced the fewest mosquitoes. The associations among mosquito species and selected vegetation types are discussed.     

Laboratory vector studies on six mosquito and one tick species with chikungunya virus

The tick Ornithodoros savignyi and the mosquitoes Culex horridus, Culex quinquefasciatus, Aedes fulgens, Ae. furcifer and Mansonia africana were tested for infection rates and ability to transmit chikungunya virus. O. savignyi and Cx quinquefasciatus did not become infected and Cx quinquefasciatus failed to transmit the virus between vervet monkeys, Cercopithecus aethiops. Only one of 17 Cx horridus feeding on a blood-virus mixture became infected which included infection of the salivary glands. Ae. fulgens had a high infection rate and transmitted the virus between Mystromys albicaudatus rodents. Ae. furcifer and Ma. africana both transmitted virus between vervet monkeys: the 50% infection threshold and the transmission rate were less than 4.5 logs and 25% respectively for Ae. furcifer and c. 5.5 logs and 29% for Ma. africana. In a further test, Ae. furcifer transmitted virus from a monkey to hamsters at a transmission rate of 32%. Attempts to demonstrate transovarial transmission of the virus in Ae. aegypti and Ae. furcifer were unsuccessful. It is concluded that Ae. furcifer is fitted for its suspected role as epidemic vector and that Ma. africana could also act as an important epidemic vector in southern Africa.     

不同动物(血)对蚊虫的引诱作用

目的比较不同动物及动物血液对蚊虫的引诱作用,探讨蚊虫对动物宿主的嗜血习性。方法以不同动物血液引诱实验室饲养的蚊虫,以不同动物进行野外现场引诱蚊虫实验。结果实验室内淡色库蚊对猪血的吸血率最高,为51%,其他依次为人血、狗血、绵羊血和牛血;白纹伊蚊对牛血吸血率最高,为47%,其他依次为绵羊血、狗血、人血和猪血;埃及伊蚊对牛血吸血率也最高,为44%,其他依次为狗血、绵羊血、人血和猪血。现场实验表明家鸡对淡色库蚊引诱力较强,共诱集到1420只,其他依次为肉鸽、麻雀和大白鼠;家鸡对白纹伊蚊引诱力较强,共诱集到11只,其他依次为大白鼠、肉鸽和麻雀。结论淡色库蚊嗜吸猪血,白纹伊蚊、埃及伊蚊嗜吸牛血;家鸡对淡色库蚊的引诱效果较好。     

Evaluation of octenol and Lurex as baits in Mosquito Magnet Pro traps to collect vector mosquitoes in China

The effectiveness of the attractants 1-octen-3-ol (octenol) and L-lactic acid (Lurex) on the collection of Aedes albopictus, Culex tritaeniorhynchus, Cx. pipiens pallens, and Anopheles sinensis was first evaluated in Mosquito Magnet Pro traps in Yamenkou and Badachu residential areas, Beijing City, and Lishui area, Zhejiang Province, China. The Mosquito Magnet Pro traps baited with octenol collected significantly more Ae. albopictus, Cx. tritaeniorhynchus, and An. sinensis, but fewer Cx. pipiens pallens than collection by the traps alone. There were no significant differences in the numbers of Cx. pipiens pallens, Cx. tritaeniorhynchus, and An. sinensis collected by Mosquito Magnet Pro traps baited with Lurex compared to the traps alone, but the Mosquito Magnet Pro traps baited with Lurex collected significantly more Ae. albopictus than the number collected by the traps alone at 2 areas in Beijing.     

诱蚊诱卵器和光催化捕杀蚊蝇器在蚊虫调查中的应用

目的了解陕西省白纹伊蚊分布边界地区的蚊类种群及生态习性;评价诱蚊诱卵器和光催化捕杀蚊蝇器在蚊虫现场调查中的应用效果。方法2006年7-9月在3个调查点选择6种不同生境,布放诱蚊诱卵器以诱获白纹伊蚊成虫及卵;布放光催化捕杀蚊蝇器捕获各种成蚊。结果宝鸡、韩城市发现白纹伊蚊分布。诱蚊诱卵器调查平均诱蚊诱卵指数(MOI)为17.92;白纹伊蚊繁殖高峰期在8月,以山地林地MOI最高,为33.20。光催化捕杀蚊蝇器在黄陵、宝鸡、韩城市共捕获成蚊925只,分属5属8种,淡色库蚊为优势种,构成比为76.11%。淡色库蚊、骚扰阿蚊、三带喙库蚊在各种环境均有分布,三带喙库蚊在养殖耕种区分布较多。结论白纹伊蚊分布边界与历史资料一致。淡色库蚊、三带喙库蚊、骚扰阿蚊为上述地区主要蚊种。诱蚊诱卵器和光催化捕杀蚊蝇器现场应用效果良好。     

Predation efficacy of the fish muddy loach, Misgurnus mizolepis, against Aedes and Culex mosquitoes in laboratory and small rice plots

Assessments of the biological control potential of muddy loaches, Misgurnus mizolepis, were conducted against Aedes togoi, Culex pipiens pallens, and Culex inatomii larvae both in the laboratory and in small rice plots in Pusan, Korea, from June to September 1997. Medium-sized fish consumed almost all of 500 3rd-stage larvae of Cx. pipiens pallens offered daily in the laboratory. Predation by the fish at release rates of 1, 2, 4, 8, and 16 fish per plot resulted in 1,004, 1,197, 1,198, 1,200, and 1,200 larvae of Ae. togoi consumed in 12 h, respectively, when each 1,200 3rd-stage larvae were given in the 1-m2 small rice plots. The average numbers of larvae eaten after introduction of the fish were 1,121.8 larvae in 24 h and 1,195.8 larvae in 36 h. Muddy loaches showed slightly higher predation rates on Cx. pipiens pallens and Culex inatomii larvae than on larvae of Ae. togoi. Therefore, M. mizolepis might be an efficient biological control agent against mosquito species in rice fields.