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.     

Temperature-induced morphological change in Culex pipiens

The effect of temperature on Culex pipiens pipiens, Cx. p. quinquefasciatus, and reciprocal hybrids of the two was investigated by monitoring the DV/D ratios of these stocks maintained at 15.6 degrees C and 23.9 degrees C over 10 generations. Little variation occurred in mean values of the parental subspecies at either temperature. At 23.9 degrees C, the mean ratios for both hybrid lines rose from an intermediate value to a level well above the accepted minimum for Cx. p. quinquefasciatus (0.4), and the proportion of individuals identifiable as that subspecies increased 16-fold. At 15.6 degrees C, hybrid mean DV/D ratios decreased to or below the pipiens maximum value (0.2), and the proportion of pipiens individuals increased 4 to 5 times. The need to monitor closely the status of Cx. pipiens hybrid colonies is evident.     

Is the Horaana strain of the Culex pipiens group Culex pipiens pallens?

The validity of the Horaana strain of the Culex pipiens group as Cx. pipiens pallens was studied. Judging from the fourth instar characters and morphology of the adult male genitalia, this laboratory strain is now out of the range of ordinary Cx.p. pallens in Japan, and must be identified as Cx. p. quinquefasciatus.     

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。     

溴氰菊酯泡腾片浸泡蚊帐对淡色库蚊和致倦库蚊的灭效观察

目的在实验室内观察溴氰菊酯泡腾片及乳油浸泡蚊帐对淡色库蚊和致倦库蚊的灭效。方法强迫接触法。结果当药剂浓度为2mg·ai／m2时，溴氰菊酯2种剂型浸帐对淡色库蚊的杀灭效果均达到100％，当药剂浓度达到10mg·ai／m2时，其对致倦库蚊杀灭效果不足100％。溴氰菊酯泡腾片浸泡蚊帐杀灭淡色库蚊的LC50为0．23mg·ai／ml，而乳油浸帐的LC50为0．31mg·ai/ml，方差分析结果表明，二者差异有统计学意义（t=3．04，P=0．023）；溴氰菊酯2种剂型浸帐对致倦库蚊的LC50分别为1．16和1．33mg·ai／ml，差异无统计学意义（t=1．65，P=0．470）。溴氰菊酯的2种剂型均采用5、10和20mg·ai／nl2 3种浓度浸泡蚊帐，对淡色库蚊和致倦库蚊的毒杀效果随着药物浓度的增高，LT50值明显缩短；溴氰菊酯泡腾片浸泡蚊帐对2种蚊虫的灭效均稍强于乳油浸泡蚊帐，且泡腾片浸泡蚊帐对2种蚊虫的击倒死亡时问均短于乳油浸帐。结论溴氰菊酯泡腾片作为一种新剂型浸泡蚊帐具有良好的灭蚊效果。     

淡色库蚊和致倦库蚊对杀虫剂抗药性的调查研究

目的 了解我国不同地区淡色库蚊和致倦库蚊对常用拟除虫菊酯类杀虫剂的抗性水平,为合理有效地使用化学杀虫剂提供依据.方法 采用滤纸接触筒法测定成蚊对10 000 mg/L溴氰菊酯和10 000 mg/L氯菊酯的1h击倒率和24 h死亡率.结果 北京市、河北和海南省淡色库蚊及致倦库蚊在溴氰菊酯和氯菊酯区分剂量下的24 h死亡率均＜80％,均为抗性种群.7株淡色库蚊对10 000 mg/L氯菊酯的24 h死亡率均＜50％;13株蚊虫对10 000 mg/L溴氰菊酯的抗性高低不一,24 h死亡率1％～66％不等.结论 北京市、河北及海南省淡色库蚊和致倦库蚊对拟除虫菊酯类杀虫剂均产生了高抗性,蚊虫抗药性的产生与杀虫剂的使用密切相关,在创建文明卫生城市工作中要科学合理用药,开展抗药性监测,采取适当措施延缓蚊虫抗药性的产生和发展.     

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.     

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.     

我国淡色库蚊/致倦库蚊对常用化学杀虫剂的抗药性

淡色库蚊/致倦库蚊是我国分布最广、危害最大的蚊种之一,也是家用杀虫剂的主要控制靶标.为了解其对常用化学杀虫剂的抗药性,应用WHO方法,各地在不同时期开展了抗药性监测、调查或研究工作,积累了大量数据.经对发表文献及监测资料的收集、整理、统计和分析,综述了我国淡色库蚊/致倦库蚊对常用化学杀虫剂的抗药性分布和特征,并对影响抗药性产生的原因进行了分析,为我国对该蚊预防控制策略的制定,抗药性监测工作的开展和不同区域抗药性治理策略的制定提供依据.     

尖音库蚊复组不同地理株蛋白质的比较研究

采用PAGF和薄层IEF技术,对镇江、青岛、济南及烟台等不同纬度地区尖音库蚊复组成蚊的蛋白质进行比较研究。结果表明:不同地理株及其不同亚种或型的蚊蛋白虽有所区别,但基本特征相似。从PAGE结果来看,尖音库蚊复组内不同地理株的蚊蛋白电泳带相似;除青岛外,各地淡色库蚊蛋白电泳带的扫描图形亦基本相似;青岛地区该蚊较特异,与其特殊的生境密切相关。此外,镇江地区致倦库蚊及其中间型的蛋白电泳带扫描曲线亦有所不同,这主要是由不同基因所决定的。从TEF结果来看,济南和烟台地区的淡色库蚊之间蛋白电泳的差异仅为14.29%。经分析,尽管上述蚊虫蛋白电泳扫描图形的基本特征略有差异,但蛋白电泳区带无明显不同,故差异仍未超过亚种阶元。薄层IEF分辨率高,明显优于PAGE,是值得推广的简便电泳分析技术。     

三种淡色库蚊抗菊酯品系的生存力比较

目的 在实验条件下通过对3种拟除虫菊酯抗性品系的蚊虫选育,了解抗性发生、发展规律,为蚊、蝇的防制提供理论依据。方法 采用浸液法,分别用三氟氯氰菊酯、溴氰菊酯、胺菊酯对淡色库蚊进行抗性品系的选育,了解抗性发生、发展规律;分析抗性品系的种群生存力等主要生物学特征,比较3个品系的相对适合度。结果 胺菊酯不易产生抗性,在连续选育8代后抗性仅达4．66倍;三氟氯氰菊酯、溴氰菊酯易产生抗性。对三氟氮氰菊酯抗性经6代的选育后达到41．8倍,对溴氰菊酯抗性经5代的选育后达到50．68倍。结论 抗性品系存在相对适合度缺陷。三氟氮氰菊酪、溴氰菊酯、胺菊酯抗性品系相对适合度分别为0．41、0．47和0．29。     

淡色库蚊对常用杀虫剂的抗性现状及治理对策

目的调查江苏省淡色库蚊对常用杀虫剂的抗性现状,提出蚊虫抗药性治理对策。方法在江苏省徐州、连云港和无锡3市郊区采集淡色库蚊幼虫,采用WHO生物测试法进行测定。结果江苏省淡色库蚊对氯菊酯和生物丙烯菊酯敏感;对敌敌畏抗性系数是29.42~205.55,属于高度抗性;对溴氰菊酯、高效氯氰菊酯、残杀威和双硫磷产生不同程度的抗药性。结论应加强对淡色库蚊抗药性监测,科学合理使用杀虫剂,预防或延缓抗药性产生。     

Molecular and electron microscopic identification of Wolbachia in Culex pipiens complex populations from the Upper Rhine Valley, Germany, and Cebu City, Philippines

We detected Wolbachia infections in Culex pipiens complex mosquitoes from the Upper Rhine Valley, Germany, and Cebu City, Philippines, with the use of polymerase chain reaction (PCR) amplification of the 16S rDNA of the bacteria and further confirmation by electron microscopy. Species of 5 different autogenous and anautogenous populations of Culex pipiens from Germany and 1 population of Culex quinquefasciatus from the Philippines were used in this study. Larvae were sampled from different localities and reared to the adult stage for further processing. Whole adult males and the heads of adult females were processed by PCR, whereas the abdomens of females were used for electron microscopic study when an infection was detected by PCR. All Culex populations assayed by PCR showed infection of Wolbachia at rates between 10 and 100%. Females from different populations exhibited higher infection rates than did the males, and, likewise, Cx. pipiens populations that were autogenous showed higher infection rates of Wolbachia than did anautogenous individuals. In Cx. quinquefasciatus populations, males were infected at 33.33% and females, only 10%. We studied the ultrastructure of Wolbachia in the ovaries of species belonging to Cx. pipiens complex by means of transmission electron microscopy. The bacteria exhibited typical morphology for Wolbachia with 3 enveloping membranes.     

宝鸡市淡色库蚊对常用杀虫剂的抗药性研究

目的了解宝鸡市淡色库蚊对常用杀虫剂的抗药性状况。方法用区分剂量法和半数致死量法测定淡色库蚊对常用药物的敏感性。结果依据区分剂量抗性评价标准,宝鸡市淡色库蚊对DDT、敌敌畏、氯菊酯、溴氰菊酯均属于抗性群体。与实验室敏感试虫比较,宝鸡市淡色库蚊各药物的抗药性均高过敏感试虫,抗性倍数在2.67~23.85之间,其中以氯菊酯相差最大(23.85倍)。抗性等级氯菊酯为高抗,高效氯氰菊酯、氯氰菊酯、DDT、残杀威为中抗,其余药物为低抗。结论应根据抗药性调查结果合理使用杀虫剂,积极提倡综合防治。     

淡色库蚊生物学的实验研究

在实验室条件下，对淡色库蚊进行了生物学的观察研究，得出该蚊的生殖营养周期为６．７天，平均每块卵筏含卵９４．２粒，卵的孵化率、幼虫及蛹的存活率均高达９０％以上；成蚊平均寿命为２７天，羽化后第２天即可交配，５天后受精率达５０％以上；１只雄蚊可与多只雌蚊有效交配，但在小空间范围内则不易交配；平均每蚊产卵３４１．０７粒，净增殖率为１７０．５３０３．内禀增长率为０．１９９５；３０天内种群增殖高达４００倍，生命力、繁殖力极其旺盛。根据结果，对该蚊种群传播丝虫病和防治措施加以讨论     

5株虫生真菌对淡色库蚊幼虫的致病力研究

目的测定菌株对淡色库蚊幼虫的致病力,筛选出高致病力菌株,为淡色库蚊的防治提供理论依据。方法选择生物防治中常用的5株菌株,测定不同浓度的孢子悬浮液对淡色库蚊幼虫的累计死亡率,计算半数致死浓度（LC50）。结果菌株GIM3.428、GIM3.45、GIM3.431、GIM3.95以及GIM3.436对淡色库蚊幼虫均具有致病性,试验10d,淡色库蚊幼虫累计死亡率分别为100%、82%、79%、73%和57%,菌株对淡色库蚊幼虫的LC50分别为2.98×102、1.41×103、1.26×104、1.02×104、2.07×105孢子/ml。结论菌株GIM3.428对淡色库蚊幼虫的致病力最高,可将其应用于淡色库蚊的防治。     

山东省淡色库蚊对化学杀虫剂的抗性及防治对策

目的了解山东省淡色库蚊对常用化学杀虫剂的抗性状况,为合理有效地进行蚊虫化学防治提供依据。方法采用WHO生物测定方法,测定淡色库蚊敏感品系和现场种群对5种杀虫剂的抗性。结果 6个现场淡色库蚊种群对DDT、DDVP、马拉硫磷、残杀威、溴氰菊酯的抗性指数分别为1.59～28.48、2.22～15.72、2.36～5.50、3.40～6.33、8.50～36.00倍。结论山东省淡色库蚊对5种常用化学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。     

商丘市区卫生杀虫剂使用状况及蚊蝇抗药性研究

目的调查商丘市区卫生杀虫剂使用情况,探讨其与当地淡色库蚊、家蝇抗药性的相关性,为治理病媒生物抗药性提供科学依据。方法采用现场调查市售及病媒生物防治专业机构使用的卫生杀虫剂状况;浸渍法测定淡色库蚊,点滴法测定家蝇对杀虫剂的敏感性。结果共调查208种次的卫生杀虫剂,其中杀虫气雾剂124种次、蚊香和电热蚊香77种次、其他7种次;一元制剂占25.00%、二元或三元制剂占75.00%;杀虫有效成分均含有拟除虫菊酯,以胺菊酯为主,占60.26%。淡色库蚊对高效氯氰菊酯、双硫磷的抗药性测定结果,均表现为低抗水平;家蝇对高效氯氰菊酯、氯菊酯、溴氰菊酯表现为高抗,对敌敌畏表现为低抗。结论商丘市区淡色库蚊和家蝇抗药性的产生与农药使用有关,科学合理使用卫生杀虫剂才能延缓蚊蝇抗药性的产生。     

The acetylcholinesterase gene Ace: a diagnostic marker for the Pipiens and Quinquefasciatus forms of the Culex pipiens complex

The taxonomy of the Culex pipiens complex remains a controversial issue in mosquito systematics. Based on morphologic characters, 2 allopatric taxa are recognized, namely Cx. pipiens (including the form "molestus") in temperate areas and Cx. quinquefasciatus in tropical areas. Here we report on variability at the nucleotide level of an acetylcholinesterase gene in several strains and natural populations of this species complex. Few polymorphisms were found in coding regions within a subspecies but many polymorphisms were observed between subspecies in noncoding regions. We describe a method based on a restriction enzyme polymorphism in polymerase chain reaction-amplified DNA, in which the presence or absence of one restriction site discriminates Cx. pipiens, Cx. quinquefasciatus, and their hybrids. This technique reliably discriminates mosquitoes from more than 30 worldwide strains or populations. Polymerase chain reaction amplification of specific alleles may also be a useful tool for characterizing specific alleles of each sibling taxon.     

冰冻储存对淡色库蚊非特异性酯酶活性的影响

目的探讨冰冻储存对淡色库蚊非特异性酯酶（non-specific esterase,NSE）活性的影响,为蚊虫抗药性生物化学检测方法的推广应用提供依据。方法以β-乙酸萘酯为底物,坚固蓝B盐为显色剂,测定单个蚊虫NSE活性。结果DDVP抗性品系淡色库蚊NSE活性水平明显高于敏感品系;经完全随机设计的方差分析比较,-20℃冰冻0、7、14、21、28d的淡色库蚊NSE活性A值之间的差别,敏感品系4龄幼虫的F值为0．7642,该品系3日龄雌成虫的F值为0．7452,DDVP抗性品系4龄幼虫的F值为0．1092,该品系3日龄雌成虫的F值为0．1521,P值均〉0．05,差异无统计学意义。结论-20℃冰冻28d对淡色库蚊4龄幼虫和3日龄雌成虫体内NSE活性无影响,可在现场采集蚊虫带回实验室集中测定。