非特异性酯酶在淡色库蚊对不同杀虫剂抗性中的作用研究

目的：探讨非特异性酯酶（Non-specific esterase,NSE)在谈色库蚊对不同杀虫剂抗性中的作用。方法：以β－乙酸萘酯为底物,坚固蓝B盐为显色剂,测定室内5个品系淡色库蚊的NSE活力。结果：5个品系淡色库蚊中以抗DDVP品系NSE活力水平最高,其次为抗DDVP降解品系和抗残杀威品系,抗氯氰菊酯品系较低,与敏感品系相近。结论：NSE在淡色库蚊对有机磷类杀虫剂的抗性中起重要作用,也是对氨基甲酸酯类杀虫剂产生的机制之一,与对拟除虫菊类杀虫剂的抗性关系不大。     

微板法测定抗药性醋酶检测淡色库蚊抗药性的研究

目的 研究简捷灵敏的蚊虫抗药性早期测报技术。方法 以β-乙酸萘酯为底物,坚固蓝B盐为显色剂,用酯酶微板法测定实验室和现场单个淡色库蚊体内非特异性酯酶活力。结果 实验室5个品系淡色库蚊以抗DDVP品系非特异性酯酶活力水平最高,其次为抗残杀威品系和抗DDVP降解品系,抗氯氰菊酯品系较低,与敏感品系相近;3个现场淡色库蚊种群对DDVP抗性为4.15～9.36倍,对残杀威抗性为1.02～3.81倍,其非特异性酯酶活力水平均较高。结论 酯酶微板法测定非特异性酯酶能够检测蚊虫对有机磷和氨基甲酸酯类杀虫剂的抗性水平,能够早期预测抗性发展趋势,便于制订抗药性克服对策。     

微板法测定抗药性酯酶检测淡色库蚊抗药性的研究

目的 研究简捷灵敏的蚊虫抗药性早期测报技术。方法 以β-乙酸萘酯为底物，坚固蓝B盐为显色剂，用酯酶微板法测定实验室和现场单个淡色库蚊体内非特异性酯酶活力。结果 实验室5个品系淡色库蚊以抗DDVP品系非特异性酯酶活力水平最高，其次为抗残杀威品系和抗DDVP降解品系，抗氯氰菊酯品系较低，与敏感品系相近；3个现场淡色库蚊种群对DDVP抗性为4．15～9．36倍，对残杀威抗性为1．02～3．8l倍，其非特异性酯酶活力水平均较高。结论 酯酶微板法测定非特异性酯酶能够检测蚊虫对有机磷和氨基甲酸酯类杀虫剂的抗性水平，能够早期预测抗性发展趋势，便于制订抗药性克服对策。     

微板法测定抗药性酯酶检测淡色库蚊抗药性的研究

目的研究简捷灵敏的蚊虫抗药性早期测报技术. 方法以β-乙酸萘酯为底物,坚固蓝B盐为显色剂,用酯酶微板法测定实验室和现场单个淡色库蚊体内非特异性酯酶活力. 结果实验室5个品系淡色库蚊以抗DDVP品系非特异性酯酶活力水平最高,其次为抗残杀威品系和抗DDVP降解品系,抗氯氰菊酯品系较低,与敏感品系相近;3个现场淡色库蚊种群对DDVP抗性为4.15～9.36倍,对残杀威抗性为1.02～3.81倍,其非特异性酯酶活力水平均较高. 结论酯酶微板法测定非特异性酯酶能够检测蚊虫对有机磷和氨基甲酸酯类杀虫剂的抗性水平,能够早期预测抗性发展趋势,便于制订抗药性克服对策.     

微板法测定淡色库蚊体内非特异性酯酶检测其对杀虫剂抗性的研究

目的　探讨简捷灵敏的蚊虫抗药性早期测报技术。方法　以 β -乙酸萘酯为底物 ,坚固蓝B盐为显色剂 ,用微板法测定实验室和现场单个淡色库蚊体内非特异性酯酶活力。结果　实验室五个品系淡色库蚊以抗DDVP品系非特异性酯酶活力水平最高 ,其次为抗残杀威品系和抗DDVP降解品系 ,抗氯氰菊酯品系较低 ,与敏感品系相近 ;三个现场淡色库蚊种群对DDVP抗性为 4 15～ 9 36倍 ,对残杀威抗性为 1 0 2～ 3 81倍 ,其非特异性酯酶活力水平均较高。结论　微板法测定非特异性酯酶能够检测蚊虫对有机磷和氨基甲酸酯类杀虫剂的抗性水平。方法简便快速 ,结果客观准确 ,可重复性强 ;可测出抗性频率 ,早期发现抗性的存在 ;可测知抗性机制 ,便于制订抗药性克服对策     

酯酶滤纸法检测淡色库蚊抗药性的研究

为探讨简捷灵敏的蚊虫抗药性早期测报技术,以α-乙酸萘酯为底物,坚硬固蓝B盐为显色剂,用滤纸法测定实验室和现场淡色库蚊（Cx.pipien pallens)酯酶活力,结果显示三个抗性品系淡色库蚊以抗DDVP品系抗性个体频率最高,其次为抗残杀威品系,抗氯氰菊酯品系较低,与敏感品系相近;三个现场淡色库蚊均对DDVP和残杀威产生不同程度抗性,其抗性个体频率均较高,表明酯酶滤纸法可用于检测蚊虫对有机磷和氨基甲酸酯类杀虫剂的抗性水平,该方法操作简便快速,观察结果直观灵敏,具有实用价值。     

不同品系淡色库蚊各发育阶段的非特异性酯酶和乙酰胆碱酯酶活力变化

研究并探讨非特异性酯酶（NSE）和乙酰胆碱酯酶（AChE）活力在不同品系淡色库蚊（Cules pipiens pallens）各发育阶段的变化，为应用生物化学方法检测蚊虫抗药性及科学合理地进行蚊虫化学防治提供依据。用微量滴定板法测定单个蚊虫NSE和AChE活力，结果显示，敏感品系、DDVP抗性品系和残杀威抗性品系淡色库蚊NSE活力水平在不同发育阶段有变化，I－Ⅲ龄幼虫较低，Ⅳ龄幼虫、蛹和3日龄雌成蚊较高，在各发育阶段均是DDVP抗性品系NSE活力最高，残杀威抗性品系次之，敏感品系最低，其中Ⅳ龄幼虫、蛹和3日龄雌成蚊阶段三个品系间NSE活力差别更明显；三个品系淡色库蚊AChE活力在I－Ⅳ龄幼虫和蛹期较低，3日龄雌成蚊较高，三个品系间AChE活力稍有差异，从高到低依次为残杀威抗性品系、DDVP抗性品系和敏感品系。测定蚊虫NSE活力判断抗药性可选择Ⅳ龄幼虫、蛹和3日龄未吸血雌成蚊；测定蚊虫AChE不敏感性判断抗药性可选择3日龄未吸血雌成蚊；蚊虫化学防治中应选择低龄幼虫阶段施药。     

抗DDVP和敏感淡色库蚊不同发育期非特异性酯酶活力变化的研究

目的 研讨非特异性酯酶（Non-specific esterase,NSE）活力在抗DDVP和敏感品系淡色库蚊不同发育期的变化,为应用生物化学方法检测蚊虫抗药性及科学合理地进行蚊虫化学防治提供依据。方法 以β－乙酸萘酯为底物,坚固蓝B盐为显色剂,用微量滴定板法测定蚊虫NSE活力。结果 敏感品系和抗DDVP品系淡色库蚊NSE活力水平在不同发育 变化,Ⅰ-Ⅲ龄幼虫较低,Ⅳ龄幼虫最高,蛹期略下降,成虫期较高,各发育期抗DDVP品系NSE活力均高于敏感品系,Ⅳ龄幼虫期二者差别明显。结论 测定NSE检测蚊虫抗药性可选择Ⅳ龄幼虫或3日龄未吸血雌成蚊;蚊虫化学防治中应选择低龄幼虫期施药。     

淡色库蚊抗性品系生态习性的探讨

实验观察淡色库蚊敏感品系的化蛹率显著高于抗DDVP品系及抗氯氰菊酯系 (χ2值为25.98和20.64,P＜0.05),而抗性品系幼虫历期略短于敏感品系;亚致死剂量氯氰菊酯对抗氯氰菊酯品系及敏感品系的Ⅲ～Ⅳ龄淡色库蚊幼虫化蛹有显著影响,抗性品系蚊虫寿命略有延长.表明长期使用单一的杀虫剂蚊虫易产生抗性.     

温度对酯酶测定法检测淡色库蚊对DDVP的抗药性的影响

目的：用室内多年选育的抗DDVP淡色库蚊抗性株在室内和现场进行试验，以比较WHO标准法和微板测定法在检测蚊虫对DDVP抗药性的差别。方法：微板测定法、生理测定法。结果：用两种方法在温度为23－32℃范围内分别对淡色库蚊进行DDVP抗药性检测，WHO法结果与温度无关，而NSE法结果与温度有关。为消除温度对检测的影响，在缩短孵育时间后，在27－31℃对野外淡色库蚊对DDVP抗性测定，NSE法测定为WHO法结果相同。结论：NSE法检测蚊虫的DDVP抗药性可随外界温度升高而增加，实际应用时应缩短孵育时间加以纠正。     

不同品系及不同性别淡色库蚊非特异性酯酶活性比较

目的探讨不同品系及不同性别淡色库蚊非特异性酯酶（NSE）活性的差异,为应用生物化学方法检测蚊虫抗药性提供依据。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。结果抗敌敌畏（Rd）和抗残杀威（Rp）品系淡色库蚊NSE活性水平明显高于敏感（S）品系,抗氯氰菊酯（Rc）品系淡色库蚊NSE活性水平与S品系相近。S、Rd、Rp、Rc4种品系淡色库蚊3日龄雌雄成虫NSE活性均为雌性大于雄性。结论测定NSE活性可判断蚊虫抗药性状况,不同性别蚊虫应分别制定判断标准。     

CytA enables CryIV endotoxins of Bacillus thuringiensis to overcome high levels of CryIV resistance in the mosquito, Culex quinquefasciatus

Cry proteins produced by Bacillus thuringiensis are selective biodegradable insecticides used increasingly in bacterial insecticides and transgenic plants as alternatives to synthetic chemical insecticides. However, the potential for development of resistance and cross-resistance in target insect populations to Cry proteins used alone or in combination threatens the more widespread use of this novel pest control technology. Here we show that high levels of resistance to CryIV proteins in larvae of the mosquito, Culex quinquefasciatus, can be suppressed or reduced markedly by combining these proteins with sublethal quantities of CytA, a cytolytic endotoxin of B. thuringiensis. Resistance at the LC₉₅ level of 127-fold for a combination of three CryIV toxins (CryIVA, B, and D), resulting from 60 generations of continuous selection, was completely suppressed by combining sporulated powders of CytA in a 1:3 ratio with sporulated powders of a CryIVA, CryIVB, and CryIVD strain. Combining the CytA strain with a CryIVA and CryIVB strain also completely suppressed mosquito resistance of 217-fold to the latter toxins at the LC₉₅ level, whereas combination of CytA with CryIVD reduced resistance in a CryIVD-selected mosquito strain from greater than 1,000-fold to less than 8-fold. The CytA/CryIV model provides a potential molecular genetic strategy for engineering resistance management for Cry proteins directly into bacterial insecticides and transgenic plants.     

山东省淡色库蚊对杀虫剂的抗药性

目的 检测山东省各地淡色库蚊对常用化学杀虫剂的抗性状况,探讨抗性治理对策。方法 采用世界卫生组织生物测定方法,测定蚊幼虫的LC_(50)确定抗性水平,计算抗性系数。结果 对山东省10个地区近10年的淡色库蚊抗性测定表明,各地淡色库蚊对常用杀虫剂均产生了一定的抗性,对DDVP的抗性最高达21.18倍,对马拉硫磷的抗性高达5.39倍,对溴氰菊酯的抗性高达42倍。各地抗性水平有逐年增高的趋势。结论 山东各地淡色库蚊对常用杀虫剂均产生了一定的抗性,急需研究实施抗性治理对策。     

Assessment of anti mosquito measures in households and resistance status of Culex species in urban areas in southern Ghana: Implications for the sustainability of ITN use

ObjectiveTo determine resistance status of Culex species to different class of insecticides and assess the major anti–mosquito strategies employed by urban households and their possible effects on malaria acquisition.MethodsStructured questionnaires were randomly administered to obtain information on demographic characteristics, measures that people use to prevent mosquito bites and their perception of where mosquitoes breed in their communities. Adult susceptibility assays were also carried out using WHO discriminating dosages of four insecticides from different chemical classes against Culex species.ResultsMajority of respondents (54.75%) preferred the use of domestic insecticides in the form of aerosols and coils. Among households that used domestic insecticides, the use of coil was most frequent (62.9%) with a mean (95% CI) of 9.18 (8.99, 9.37) coils per week. Strong level of pyrethroid–resistance and multiple insecticide resistance in Culex species were also detected in some of the study sites.ConclusionsThe excessive use of domestic insecticides and high level of resistance in Culex species observed in the study area has implications for the ITN component of the nation's malaria control program in more subtle ways. People will lose interest in the use of ITN when it fails to protect users from bites of resistant Culex species. Excessive use of domestic insecticides may also select resistance in both malaria vectors and Culex species. On this account we recommend that nuisance mosquitoes must be controlled as part of malaria control programs to improve acceptance and utilization of ITN.     

对溴氰菊酯抗性和敏感淡色库蚊不同发育阶段的抗性水平

对室内选育的淡色库蚊（对溴氰菊酯抗性品系和敏感品系）用浸渍法测定了Ⅱ龄、Ⅲ龄和Ⅳ龄幼虫，用接触筒法测定了早期、中期和晚期成虫；并观察了增效醚（ＰＢ）、磷酸三苯酯（ＴＰＰ）和杀虫脒与溴氰菊酯混用后的增效效果。结果表明：（１）淡色库蚊各发育阶段对溴氰菊酯的抗性水平，在敏感品系由高至低依次为中期、晚期、早期成虫、Ⅳ龄、Ⅲ龄和Ⅱ龄幼虫；在抗性品系则为早期、中期、晚期成虫、Ⅳ龄、Ⅲ龄和Ⅱ龄幼虫。（２）ＰＢ和杀虫脒均有明显增效作用，提示抗性可能与氧化代谢增强和靶标部位不敏感有关。其中似乎幼虫阶段以氧化代谢增强为主要抗性机制；在成虫阶段，氧化代谢增强和靶标部位不敏感性均在抗性中起重要作用     

Wolbachia-a foe for mosquitoes

Mosquitoes act as vectors for a wide range of viral and parasitic infectious diseases such as malaria, dengue, Chickungunya, lymphatic filariasis, Japanese encephalitis and West Nile virus in humans as well as in animals. Although a wide range of insecticides are used to control mosquitoes, it has only resulted in development of resistance to such insecticides. The evolution of insecticide resistance and lack of vaccines for many mosquito-borne diseases have made these arthropods highly harmful vectors. Recently, a novel approach to control mosquitoes by transinfection of life shortening maternally transmitted endo-symbiont Wolbachia wMelPop strain from fruitfly Drosophila into mosquito population has been developed by researchers. The wMelPop strain up-regulated the immune gene expression in mosquitoes thereby reducing the dengue and Chickungunya viral replication in Aedes aegypti, and also it significantly reduced the Plasmodium level in Anopheles gambiae. Here, we discuss the strategy of using Wolbachia in control of vector-borne diseases of mosquitoes.     

Do insecticide‐treated bednets have an effect on malaria vectors?

The use of insecticide-treated bednets (ITNs) has been widely adopted as an important method for malaria control. Few data exist on effects of ITNs on mosquito biology and ecology, other than the development of insecticide resistance against the insecticides used. There is no hard evidence that the insecticide resistance recorded is the result of insecticidal use on bednets or from agricultural use. Resistance against pyrethroids, the preferred class of insecticides for ITN use, has been recorded from countries in Asia, Africa and South America. Resistance is expressed as reduced excito-repellency and mortality of mosquitoes exposed to insecticide-treated materials. In the absence of resistance, however, most studies on ITN effects report a reduced survival of adult mosquitoes as well as mass killing. Other effects are highly variable, and shifts in time of biting, feeding site and blood hosts have occasionally been reported, but not in proportion to the scale of ITN use. In general, a reduced sporozoite rate is recorded in ITN programmes. Because many of the anticipated behavioural effects caused by insecticidal use will be avoided by the use of untreated nets, studies on the efficacy of untreated nets are required. Examples are presented in which untreated nets provided a reasonable degree of protection against malaria.     

Eave Screening and Push-Pull Tactics to Reduce House Entry by Vectors of Malaria

Long-lasting insecticidal nets and indoor residual spraying have contributed to a decline in malaria over the last decade, but progress is threatened by the development of physiological and behavioral resistance of mosquitoes against insecticides. Acknowledging the need for alternative vector control tools, we quantified the effects of eave screening in combination with a push-pull system based on the simultaneous use of a repellent (push) and attractant-baited traps (pull). Field experiments in western Kenya showed that eave screening, whether used in combination with an attractant-baited trap or not, was highly effective in reducing house entry by malaria mosquitoes. The magnitude of the effect varied for different mosquito species and between two experiments, but the reduction in house entry was always considerable (between 61% and 99%). The use of outdoor, attractant-baited traps alone did not have a significant impact on mosquito house entry but the high number of mosquitoes trapped outdoors indicates that attractant-baited traps could be used for removal trapping, which would enhance outdoor as well as indoor protection against mosquito bites. As eave screening was effective by itself, addition of a repellent was of limited value. Nevertheless, repellents may play a role in reducing outdoor malaria transmission in the peridomestic area.     

陕西省三带喙库蚊对常用杀虫剂的敏感性

目的了解陕西省三带喙库蚊对常用杀虫剂的敏感性。方法用浸渍法测定8种杀虫剂对5个地区三带喙库蚊的LC50。结果DDT、敌敌畏、氯菊酯、溴氰菊酯和双硫磷等5种杀虫剂汉滨区三带喙库蚊敏感性最高;氯氰菊酯和高效氯氰菊酯南郑县三带喙库蚊敏感性最高;残杀威陇县三带喙库蚊敏感性最高。结论敏感性测定结果可作为基础数据用于资料积累;连续开展敏感性监测,了解蚊虫抗药性趋势,有利于指导蚊虫防制。