大连口岸蚊媒调查及流行性乙型脑炎病毒自然感染情况研究

〔目的〕了解大连口岸蚊虫种类、生态习性及淡色库蚊、三带喙库蚊自然感染流行性乙型脑炎病毒情况。〔方法〕用帐诱法、灯诱法、采集幼虫等方法进行调查,并应用逆转录-聚合酶联反应技术（RT-PCR）进行乙脑病毒鉴定。〔结果〕大连口岸捕获蚊虫3属9种,其中按蚊属1种,伊蚊属4种,库蚊属4种。大连口岸蚊虫于5月出现,8月达到高峰,9月逐渐减少,10月消失。侵袭人类以淡色库蚊（占47.98%）、东乡伊蚊（占12.15%）和背点伊蚊（占10.41%）为多。不同场所蚊虫密度差异反映出蚊虫的不同嗜血习性,淡色库蚊、凶小库蚊和白纹伊蚊喜嗜人血;淡色库蚊同时喜嗜猪、牛血;三带喙库蚊偏嗜猪血;中华按蚊偏嗜牛血;背点伊蚊和刺扰伊蚊偏嗜猪、牛血。2007年8月中旬首先在三带喙库蚊中检出乙脑病毒,共检测70批次样本,阳性率为4.28%。〔结论〕淡色库蚊、东乡伊蚊、背点伊蚊是该地区危害人类的主要蚊种。大连口岸蚊虫自然感染乙脑病毒于8月中下旬开始,三带喙库蚊首先染毒。本调查为蚊虫防制提供了生态学依据,为预报流行性乙型脑炎的发生时间和流行强度提供了科学依据。     

云南省蚊虫分布特点及自然感染乙型脑炎病毒的研究

目的分析云南省蚊虫分布特点及其与流行性乙型脑炎（乙脑）等虫媒病毒的关系,为防制提供依据。方法在云南省农村居民区住房、畜圈和野外竹林等生境捕蚊。结果采获成年雌蚊10属88种158909只,以库蚊、按蚊和伊蚊属蚊虫数量最多,分别占56．66％、25．35％和13．88％。在捕蚊总数中,居民区夜间捕获成蚊7属63种132081只,其中三带喙库蚊的构成比最高（42．12％）;其次为中华按蚊（23．31％）;野外白天捕获成蚊5属48种26828只,白纹伊蚊构成比最高（31．89％）,其次为圆斑伊蚊（20．21％）。对8属29种3957批131538只雌性成蚊进行病毒分离,结果从5属17种蚊虫体内分离到乙脑病毒81株,以库蚊分离出的毒株最多（59株）,占72．84％;其次为按蚊8株（9．88％）和伊蚊9株（占11．11％）;曼蚊和阿蚊均为2株（各占2．47％）。分离到乙脑病毒最多的蚊种为三带喙库蚊（27株）,占分离毒株总数的33．33％。结论居民区夜间活动蚊虫群落的优势种为三带喙库蚊、中华按蚊、棕头库蚊、霜背库蚊、伪杂鳞库蚊和迷走按蚊;野外白天活动蚊虫群落的优势种为白纹伊蚊、伪白纹伊蚊、圆斑伊蚊、骚扰阿蚊和刺扰伊蚊。三带喙库蚊和白纹伊蚊分别是云南省乙脑和登革热的丰要传播媒介。     

宁波市流行性乙型脑炎媒介的调查与分析

目的掌握宁波市流行性乙型脑炎(乙脑)传播媒介和疫情发生情况,为防治提供科学依据。方法收集、整理和分析乙脑疫情资料。灯诱和勺捕法调查蚊虫密度。结果2006年宁波市确诊乙脑42例,死亡6例。患者家中及不同场所成蚊密度指数分别为6.05和13.22只/(灯.h);三带喙库蚊分别占71.44%和76.01%。调查蚊幼虫孳生地26处,蚊幼密度指数为12.04条/勺,其中淡色库蚊占49.44%;三带喙库蚊占37.87%。容器、雨水缸蚊幼阳性率分别为54.31%和30.22%,其中白纹伊蚊占66.67%和49.66%;三带喙库蚊占25.11%和33.42%;淡色库蚊占8.22%和13.62%。结论宁波市普遍存在三带喙库蚊等乙脑传播媒介。要加强疫苗预防接种和灭蚊、防蚊工作。     

山西省临猗县2009年流行性乙型脑炎媒介调查

目的 了解临猗县4个乡镇蚊虫种类、密度及其自然感染流行性乙型脑炎（乙脑）病毒状况。方法 采用诱蚊灯捕蚊,提取蚊虫核酸进行RT-PCR,扩增乙脑病毒NS1区核酸片段,对核酸阳性样本进行序列测定。结果 捕获蚊虫4属6种4424只,三带喙库蚊构成比为52.0%,淡色库蚊为41.2%,中华按蚊及其他蚊种数量较少。6-8月蚊虫密度逐月增加,三带喙库蚊构成比逐月增高。对2109只三带喙库蚊分77批进行乙脑病毒核酸检测,阳性10批。对5个阳性标本进行测序,经与GenBank中序列比对和分析,均为基因Ⅰ型乙脑病毒。结论 临猗县7、8月蚊虫密度高,三带喙库蚊构成比及其乙脑病毒携带率均较高。三带喙库蚊密度及乙脑病毒携带率可作为乙脑防控的重要预警指标。     

天津市首次从淡色库蚊检测出基因Ⅰ型流行性乙型脑炎病毒

目的调查天津市部分地区蚊虫携带流行性乙型脑炎(乙脑)病毒状况,为乙脑防治提供依据。方法 2010年7-9月,使用灯诱法,每月在天津市5个区(县)采集蚊虫2次,用RTPCR检测乙脑病毒核酸;扩增的目标片段进行序列测定;用Mega 4.0软件以邻位相连法构建进化树。结果共捕获成蚊10285只,2属3种(淡色库蚊、三带喙库蚊、中华按蚊),一组淡色库蚊样品,经分子生物学鉴定呈乙脑病毒感染阳性,命名为TJ01(HQ718463),基因分型为Ⅰ型乙脑病毒。结论天津市蚊虫中存在基因Ⅰ型乙脑病毒感染,与上海市乙脑病毒分离株进化关系较近。     

上海口岸蚊虫与分种检索研究

目的了解上海口岸蚊虫种群和分布。方法灯诱法和捞勺法。结果2005—2007年间上海口岸共捕获蚊虫6属18种,其中按蚊属1种,伊蚊属3种,阿蚊属1种,库蚊属10种,曼蚊属1种,骚扰蚊属2种,背点骚扰蚊在上海首次捕获。广泛分布的有致倦库蚊、淡色库蚊、三带喙库蚊、中华按蚊和白纹伊蚊。结论致倦库蚊、淡色库蚊、三带喙库蚊、中华按蚊和白纹伊蚊是上海口岸可能骚扰人的常见蚊虫。     

广东省清远市快速城市化过程中蚊虫群落动态变化规律

目的 研究城市化过程中病媒蚊虫群落特征和演替动态变化,了解主要传播媒介蚊虫种群动态及与城市化的关系.方法 采用人诱法,连续4年在清远市调查蚊虫种群密度.结果 此次调查清远市蚊虫有致倦库蚊、骚扰阿蚊、白纹伊蚊、中华按蚊和三带喙库蚊5种;致倦库蚊为优势蚊种,占群落种群数量的92.27％;其次为骚扰按蚊,占3.98％;白纹伊蚊和三带喙库蚊数量较少,各占1.62％;中华按蚊仅占0.51％.在研究期间,比较2006年与2008、2009年数据,结果表明群落构成发生显著变化,其中致倦库蚊在种群中所占比例逐渐减少,白纹伊蚊所占比例逐渐增加,中华按蚊在种群中逐渐消失,三带喙库蚊在群落中数量波动较大.不同蚊种在夜间呈现不同活动节律,致倦库蚊和三带喙库蚊19:00-22:00其密度逐渐增加,高峰主要在21:00之后;白纹伊蚊在夜晚各个时间段都有活动,活动高峰主要在20:00之前;骚扰阿蚊呈现与白纹伊蚊相似的活动规律.结论 清远市在城市化过程中,登革热媒介白纹伊蚊逐渐增加,而流行性乙型脑炎(乙脑)媒介三带喙库蚊则在不同年份中波动较大;传疟媒介中华按蚊逐渐减少,甚至消失.因此在城市化过程中,需要加强登革热和乙脑媒介的监测和防控.     

早春猪舍三带喙库蚊自然感染乙脑病毒调查

目的　了解温带地区早春猪舍三带喙库蚊自然感染流行性乙型脑炎病毒情况。方法　于 2 0 0 1和 2 0 0 2年 3月 1日～ 5月 31日 ,每日 18:0 0至次日 6 :0 0 ,对上海奉贤地区陈河洪猪舍采用诱蚊灯诱获蚊虫 ,应用逆转录一聚合酶联反应技术 (RT -PCR)进行乙脑病毒鉴定。结果　 2 0 0 1年共诱获成蚊 4 4 2 8只 ,2 0 0 2年 82 6 8只 ,2年蚊种鉴定结果一致 ,均分为 4属 8种。 2 0 0 1年和 2 0 0 2年的优势蚊种均为三带喙库蚊 ,构成比分别为 5 7 81%和 72 0 4 % ;吸血率比较有显著性差异 (χ2 =171 2 7,P <0 0 1)。 2 0 0 1年 5月 2 2日首先在三带喙库蚊检出乙脑病毒 ,检测 99批次标本 ,阳性率为 4 9 4 9% ;2 0 0 2年 5月 19日也是首先在三带喙库蚊检出乙脑病毒。结论　在温带地区蚊虫自然感染乙脑病毒于 5月中下旬开始 ,2年均以三带喙库蚊首先染毒 ,其带毒率明显高于其他蚊种 ,为预报流行性乙型脑炎的发生时间和流行强度提供科学依据     

2003-2008年广西桂平市蚊媒密度消长与流行性乙型脑炎发病率的相关性分析

目的分析蚊媒密度及消长与流行性乙型脑炎（乙脑）发病率的相关性,为乙脑的预测预防提供科学依据。方法在桂平市的东、西、南、北、中各随机选择1个乡（镇）的1个村作为蚊媒密度消长调查点,每年在相同时间、使用相同诱蚊灯,对人房、猪圈、牛棚3种环境诱捕蚊虫,统计分析蚊虫种类、密度、消长与同期乙脑发病率的相关性。结果 2003-2008年桂平市捕获蚊虫有4属7种,即三带喙库蚊、二带喙库蚊、致倦库蚊、中华按蚊、微小按蚊、白纹伊蚊和骚扰阿蚊,优势蚊种为三带喙库蚊。每年蚊虫密度4月开始升高,均达40只（/灯·h）以上;5-9月维持在较高密度〔60～500只/（灯·h）〕;10月后回落,与乙脑发病时间分布相一致。结论桂平市蚊媒密度较高,乙脑传播媒介三带喙库蚊是优势蚊种,蚊媒密度消长与乙脑发病率密切相关,应加强对三带喙库蚊的防制工作。     

云南省边境地区蚊虫自然感染乙型脑炎病毒的研究

目的：阐明蚊虫自然感染乙型脑炎病毒情况，评价各蚊种的媒介地位。方法：夜间在农村人房、畜圈，白天在野外竹林捕蚊，用细胞和小白鼠法分离病毒。结果：在云南省15个边界县市采获6属45种92748只雄蚊，从13种蚊虫体内分离出乙型脑炎病毒42株。其中从三带喙库蚊分离到15株，霜背库蚊5株，伪杂鳞库蚊、中华按蚊各4株，刺扰伊蚊3株，棕头库蚊、白纹伊蚊、窄翅伊蚊各2株，雪背库蚊、环带库蚊、迷走按蚊、阿萨姆伊蚊和常型曼蚊各1株。结论：三带喙库蚊是该地区本病的主要传播媒介，霜背库蚊、伪杂鳞库蚊、刺扰伊蚊和白纹伊蚊亦为重要媒介。具有夜间以库蚊为主，白天以伊蚊为主的传播特点。     

Conservation of the names Culex stigmatosoma and Culex thriambus.

As a result of action by the International Commission on Zoological Nomenclature, the name Culex peus Speiser is suppressed and never to be used as a valid name, and the names Culex stigmatosoma Dyar and Culex thriambus Dyar are conserved for the western banded foul-water mosquito and the related southwestern U.S. species, respectively.     

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.     

Redescription of the pupa of Culex restuans and a comparison with Culex nigripalpus

The pupa of Culex restuans is redescribed in detail with a chaetotaxal table and a full illustration. The chaetotaxy of the pupa of Cx. restuans is compared with that of Cx. nigripalpus, the primary vector of St. Louis encephalitis and West Nile virus in Florida.     

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.     

Effects of high temperature on the emergence and survival of adult Culex pipiens molestus and Culex quinquefasciatus in Japan.

The emergence rate and adult survival (longevity) of Japanese strains of Culex pipiens molestus and Culex quinquefasciatus were compared at temperatures of 21, 25, and 30 degrees C. The pupation and emergence rates in both strains were higher at 21 and 25 degrees C than at 30 degrees C. The adult emergence rate, especially in females, was lower in Cx. p. molestus than in Cx. quinquefasciatus. Longevity of females and males was lower in Cx. p. molestus at 25 degrees C and above. The survival of Cx. p. molestus was adversely affected by temperatures of 28 degrees C and higher. High temperature may restrict the distribution of this species. Therefore, if Cx. p. molestus infests the Okinawa region, the likelihood that it will become established is minimal.     

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.     

浦东国际机场致倦库蚊和淡色库蚊的调查研究

目的了解致倦库蚊和淡色库蚊在浦东机场的分布与活动规律。方法帐诱法、灯诱法、人诱法、捞勺法和人工小时法。结果致倦库蚊和淡色库蚊是浦东国际机场的优势蚊种,4-11月均有危害;灯诱法调查,季节消长呈坡型,蚊虫于4月出现,5-6月达到高峰,10-11月逐渐减少至消失;蚊虫活动（帐诱法）主要在晚上,黄昏时有群舞习性,活动高峰为日落后1～4h,白天基本不活动;刺叮（人诱法）高峰时间为21：00,叮人频率最高为42次/15min;入室蚊虫以19：00-22：00为多,入室率最高为9只/15min;幼虫主要孳生于池塘、水坑、洼地、下水道和容器等污染或干净的静止水体中。结论致倦库蚊和淡色库蚊是浦东国际机场危害人类的常见蚊种,其活动规律的研究对媒介控制和虫媒病的预警提供了技术支撑。     

Attractiveness of selected oviposition substrates for gravid Culex tarsalis and Culex quinquefasciatus in California

Eight potential oviposition attractants were evaluated for gravid Culex tarsalis and Cx. quinquefasciatus under insectary, outdoor cage and field conditions. With the possible exception of a steer manure infusion under insectary conditions, none of the media consistently attracted large numbers of gravid Cx. tarsalis females. Reiter medium, steer manure infusion, cattle feces and Bermuda sod were attractive to gravid Cx. quinquefasciatus. Catch size at CDC gravid traps and oviposition traps were sensitive to the number of competitive oviposition sites and trap placement.