淡色库蚊 (Culex pipiens pallens Coquillett)的抗性酯酶表现型及其在杀虫剂压力下的变化趋势(英文)

对来自杭州、临海和金华三个城市的淡色库蚊种群进行了抗性酯酶表现型频率分布的测定和分析 ,同时对三个种群进行双硫磷、敌百虫、毒死蜱和马拉硫磷等四种有机磷杀虫剂的抗性品系筛选 ,逐代测定和分析各种群在不同杀虫剂压力下 ,其抗性酯酶表现型频率分布的变化。结果表明 ,三个自然种群中都存在酯酶B1 、B2 纯合表现型及酯酶B1 /B2 杂合表现型 ,其中酯酶B1 纯合表现型占优势。各自然种群中的抗性酯酶表现型频率分布有差异。经过杀虫剂的逐代筛选 ,各种群相对于某一杀虫剂的压力 ,表现出选择较为单一的抗性酯酶表现型的趋势 :双硫磷有利于酯酶B1 纯合表现型的选择 ,敌百虫和毒死蜱有利于酯酶B2 纯合表现型的选择 ,马拉硫磷则似乎有利于酯酶B1 纯合表现型和酯酶B1 /B2 杂合表现型的选择 ,但酯酶B1 纯合表现型相对于B1 /B2 杂合表现型来说 ,对马拉硫磷抗性更强一些。根据研究结果 ,就蚊虫的抗性酯酶基因对不同杀虫剂的选择优势及相应的蚊媒控制策略进行了讨论。     

库蚊羧酸酯酶研究进展

在昆虫对有机磷杀虫剂抗性的研究中 ,羧酸酯酶 (ｃａｒｂｏｘｙｌｅｓｔｅｒａｓｅｓ)的过量产生是库蚊对有机磷杀虫剂 (ＯＰ)产生抗性的主要机制。羧酸酯酶能够与进入昆虫体内的有机磷杀虫剂快速结合 ,将杀虫剂在到达靶标作用位点前阻隔或降解 ,使其无法发挥原有的杀伤效用。1 .羧酸酯酶的命名库蚊中羧酸酯酶的命名一般根据其水解α 和 β 乙酸萘酯的先后顺序和电泳迁移率不同而定 ;在淀粉电泳中 ,当等量α 乙酸萘酯(α ＮＡ)和 β 乙酸萘酯 (β ＮＡ)同时存在时 ,优先水解α ＮＡ呈蓝色的为酯酶Ａ ,优先水解 β ＮＡ呈红色的为酯酶Ｂ[1] …     

库蚊野生种群扩增等位基因重组现象分析

羧酸酯酶 (carboxylesterases)的过量产生是库蚊Culexpipiens对有机磷杀虫剂 (OP)产生抗性的主要机制。由est 3和est 2组成的酯酶超级基因座 (estersuper locus)的基因扩增是引起酯酶基因扩增的主要遗传学基础。通过淀粉电泳研究了采自广州、佛山、郑州的库蚊野生蚊虫种群 ,发现在这些种群中存在着扩增等位基因重组现象。该现象可能是蚊虫受到杀虫药剂的选择压力、等位基因多样性和等位基因型频率的影响。这将提供一个研究抗性进化的自然模型。     

论淡色库蚊敌百虫抗性品系的抗药性机理

分别测定了淡色库蚊(Culex pipiens pallens)敏感品系(SEN)及敌百虫抗性品系(RD)雌成蚊的乙酰胆碱酯酶(AchE)对硫代乙酰胆碱(Atch)的米氏常数(K_m)和最大反应速度(V_max).SEN雌成蚊头部AchE的K_m=1.2×10^-4mol/L,V_max=7.7×10^-3mol/L(产物);胸部的K_m=0.8×10^-4mol/L,V_max=6.5×10^-3mol/L(产物).RD雌成蚊头部AchE的K_m=5.7×10^-4mol/L,V_max=25×10^-3mol/L(产物);胸部的K_m=0.8×10^-4mol/L,V_max=9.5×10^-3mol/L(产物).结果表明:1.SEN和RD二者的雌成蚊,它们自身头、胸间AchE是不同质的,是以同工酶的形式存在,因此RD雌成蚊头部AchE的性质与SEN雌成蚊的头部有显著差异也是由AchE同工酶的变异所造成.2.RD雌成蚊头部AchE在量上与SEN间也存在明显的差异.因此可以认为RD雌成蚊对有机磷产生抗性的主要机理是头部AchE在质和量上产生了变异.由于羧酸酯酶不是对具有磷酸酯键的有机磷制剂作用的靶子酶,因而不是敌百虫抗性产生的主要原因.     

羧酸酯酶和酸性磷酸酯酶在抗有机磷和敏感淡色库蚊发育期的变化

本文研讨羧酸酯酶(CarE)和酸性磷酸酯酶(ApE)在抗马拉硫磷(RM)、抗敌百虫(RD)和敏感(s)品系淡色库蚊Culex pipiens pallens不同发育期中的变化,以及某些杀虫剂和抑制剂对α-醋酸萘酯羧酸酯酶(α-NA CarE)的抑制作用。RD和s品系不同发育期的ApE变化情况如下:(1)RD和S品系间无明显差异;(2)幼虫发育期的ApE水平较低,而在变态期的ApE活性突然上升为最高,表明ApE可能参与蚊虫的发育和分化。RM、RD和S品系的CarE水平在幼虫期随虫龄增长而增高。RM和S品系的CarE活性比维持在20—35倍,RD品系在10—25倍,但三个品系的CarE活性在变态期突然下降。新羽化成蚊的CarE活性出现一个很高的峰。羽化后十天内CarE活性有一定的波动,十天后CarE活性逐渐下降,但仍高于幼虫期和蛹期。此外还讨论了对氧磷、敌敌畏、速灭威、毒扁豆碱、TPP和异稻瘟净对RM、RD和S品系α-NA CarE的抑制作用。     

不同地区致倦库蚊种群相关酯酶 基因的特征分析

分别从广州、沙市、武汉近郊采集到致倦库蚊Culex pipiens quinquefasciatus,对单只蚊虫进行淀粉凝胶电泳和Southern杂交方法的分析结果表明：3个实验种群中均分布有与抗性有关的高活性酯酶β1¹,酯酶α2/β2分布于广州实验种群中;广泛分布于地中海地区尖音库蚊Culex pipiens种群中的酯酶α4/β4、α5/β5在以上3个种群中均不存在。但是,在3个实验种群中均发现存在有一对新的高活性酯酶α8/β8,其电泳迁移率和限制性酶切片段均与目前已报道的几种高活性酯酶不同。含这两对新酯酶的蚊虫将应进一步从种群中纯化,纯合蚊虫新品系做分子特征的研究。     

羧酸酯酶和酸性磷酸酯酶在抗有机磷和敏感淡色库蚊发育期的变化

本文研讨羧酸酯酶(CarE)和酸性磷酸酯酶(ApE)在抗马拉硫磷(RM)、抗敌百虫(RD)和敏感(s)品系淡色库蚊Culex pipiens pallens不同发育期中的变化,以及某些杀虫剂和抑制剂对α-醋酸萘酯羧酸酯酶(α-NA CarE)的抑制作用.RD和s品系不同发育期的ApE变化情况如下:(1)RD和S品系间无明显差异;(2)幼虫发育期的ApE水平较低,而在变态期的ApE活性突然上升为最高,表明ApE可能参与蚊虫的发育和分化.RM、RD和S品系的CarE水平在幼虫期随虫龄增长而增高.RM和S品系的CarE活性比维持在20—35倍,RD品系在10—25倍,但三个品系的CarE活性在变态期突然下降.新羽化成蚊的CarE活性出现一个很高的峰.羽化后十天内CarE活性有一定的波动,十天后CarE活性逐渐下降,但仍高于幼虫期和蛹期.此外还讨论了对氧磷、敌敌畏、速灭威、毒扁豆碱、TPP和异稻瘟净对RM、RD和S品系α-NA CarE的抑制作用.     

有机磷抗性致倦库蚊种群中酯酶基因扩增的定量分析

致倦库蚊Culex qinquefasciatus是丝虫病的主要传染媒介。通过生物测定、单个蚊虫酯酶α2和β2基因拷贝数分析和酯酶β基因序列比较, 分析了抗性水平、抗性相关基因在种群中的分布及其基因拷贝数等的抗性分子特征。应用快速PCR仪（realtime quantitatIve PCRs）直接检测库蚊中酯酶基因和mRNA拷贝数。结果显示：上海致倦库蚊对对硫磷的抗性LC₅₀为8.12, 酯酶活性升高是上海致倦库蚊种群对有机磷杀虫药剂产生抗性的主要机理。编码致倦库蚊酯酶β的氨基酸序列同编码尖音库蚊酯酶B1的氨基酸序列相比同源性为98%;同致倦库蚊酯酶B2氨基酸序列相比同源性为100%,同环蹶库蚊酯酶B3氨基酸序列相比同源性为90%, 上海致倦库蚊中酯酶α和β基因均扩增。有机磷抗性的上海和PellRR蚊虫种群中单个蚊虫酯酶α2 和β2定量基因拷贝数均不同,其同一蚊虫个体的酯酶α2 比酯酶β2基因的拷贝数高,但没有明显的规律性,酯酶结构基因的扩增是上海致倦库蚊种群对有机磷杀虫药剂抗性的主要机理,估计在野外种群的杂合个体中存在多种调控机制。     

淡色库蚊中抗性相关羧酸酯酶的纯化及其生化性质

在库蚊Culex pipiens品系中,非专一性酯酶活性的升高是对有机磷杀虫剂产生抗性的重要机理之一。应用SDS/PAGE,比较淡色库蚊Culex pipiens pallens抗敌百虫品系(RD)、敏感型品系(S)和抗苄呋菊酯品系(PY)中可溶性总蛋白质带型,显示RD中含有一条特异蛋白带,其它两个品系中未检出。在RD成虫匀浆液总蛋白中含量高达2.1%。分子量测定为66 kD。应用柱层析法分离得到了较纯的纯品。以α-NA为底物测得K_m=64.1 mmol/L,V_max=249.8 mmol/(L·mg·min)。与羧酸酯酶相比较：其K_m值小于已报道的抗性品系及非抗性品系A-酯酶和B-酯酶。V_max值比已报道抗性品系A-酯酶低,比B-酯酶高。较高浓度的敌百虫并不能抑制其酶活,属于A-酯酶。在昆虫体内可能主要通过结合隔离作用(sequestration)提高昆虫对有机磷的耐受性,对有机磷杀虫剂水解作用的可能性也不能排除。     

混配杀虫剂毒杀淡色库蚊的增效作用

溴氰菊酯是一种高效,广谱的拟除虫菊酯类杀虫剂。长期使用可使昆虫产生抗药性,为了解杀虫剂复配增效潜力,提高药效,延缓抗性,降低农药成本发展我国新的农药制剂。我们用溴氰菊酯兑马拉硫磷混配增效杀虫剂作试验。结果表明溴氰菊酯对马拉硫磷有明显的增效作用。     

ESTERASE PHENOTYPES IN NATURAL POPULATIONS OF CULEX PIPIENS PALLENS (DIPTERA: CULICIDAE) AND THEIR VARIATIONS UNDER INSECTICIDE SELECTION*

Abstract Three populations of Culex pipiens pallens Coquillett, from Hangzhou, Linhai and Jinhua, were determined for their probability of resistant esterase phenotypes. Further, each population was selected with dipterex, chlorpyrifos, temephos and malathion at a given dose of 60%‐70% mortality and was determined for the variation of resistant esterase phenotypes in its offspring. The results indicated that esterase B₁ phenotype was dominant in three populations although different natural populations have a different probability distribution of esterase B phenotypes. Insecticide selection showed that various esterase loci seemed to have different selective advantages under different insecticide pressures. The esterase B₁ phenotype was selected under temephos, and the esterase B₂ phenotype was selected under dipterex and chlorpyrifos. Except for the esterase B₁ phenotype, the heterozygote of B₁/B₂ phenotypes was detected under malathion pressure. These results are discussed in relation to the selective advantages of esterase genes to OP pressure and mosquito control strategies.     

ANALYSIS ON LIFE TABLE OF ORGANOPHOSPHATE-RESISTANT STRAINS OF CULEX PIPIENS PALLENS

Abstract  Effects of dipterex, temephos and chlorpyrifos resistance on the relative fitness in Culex pipiens pallens were evaluated in terms of developmental and reproductive characteristics. Life tables of Dip-R (dipterex), Tem-R (temephos), Chl-R (chlorpyrifos) resistant strains and susceptible strain (S) were also constructed to determine the relative fitness by the net reproductive rates (r). The results indicated that three OP-resistant strains possessed reproductive and developmental disadvantages involving in bloodsucking ratio, average oviposition rate and survival ratio relative to the S strain. The Dip-R, Tem-R and Chl-R strains had the relative fitness value of 0. 542, 0. 631 and 0.618, respectively.     

在无杀虫剂压力下淡色库蚊的抗性稳定性研究(英文)

本文对淡色库蚊（Ｃｕｌｅｘ ｐｉｐｉｅｎｓ ｐａｌｌｅｎｓ Ｃｏｑｕｉｌｌｅｔｔ）的毒死蜱抗性品系、抗一敏杂交品系及抗性酯酶Ｂ_２纯合品系在无杀虫剂压力选择下的抗性水平变化进行了研究。结果表明,在毒死蜱抗性品系中,抗性水平逐代下降,ＬＣ_（５０）从Ｆ_０代的０．２０９９ｍｇ／Ｌ快速降至Ｆ_８代的０．０２６２ｍｇ／Ｌ,然后继续缓慢地降至Ｆ_（１６）代的０．０２０７ｍｇ／Ｌ。从毒死蜱抗性品系中的这种抗性水平下降,可以推断该品系中并不是纯的高抗性酯酶基因扩增个体,在传代中抗性个体的比例由于其生物学方面的不适应性而逐步减少。本研究中的抗性品系与敏感品系的杂交群体的抗性变化趋势也证实了这种推理。在纯的抗性酯酶Ｂ_２基因扩增品系中,抗性水平则在后代中基本上保持稳定,并且所有的个体抗性水平和酯酶活力水平更趋集中。本文进一步对蚊虫抗性的演替进行了讨论。     

STABILITY OF ORGANOPHOSPHATE RESISTANCE IN CULEX PIPIENS PALLENS COQUILLETT UNDER RELAXATION OF INSECITICDE SELECTION*

Abstract The stability of resistance in the organophosphate resistant strain of Culex pipiens pallens with amplification of single gene coding for esterase B₂ was determined under relaxation of insecticide selection. Insecticide resistance and amplification of esterase were both lost when strains were not homozygous for the presence of amplified gene, probably due to biological disadvantage of the esterase gene. LC₅₀ and LC₉₅ of chlorpyrifos for this strain were 0. 2099 mg/L and 0.9036 mg/L in the F₀ generation respectively, but 0. 0207 mg/L and 2. 8027 mg/L respectively in the F₁₆ generation. In the homozygous strain, insecticide resistance was still stable and amplification of esterase remained after 16 generations under relaxation of insecticide selection, which indicated that copy of esterase gene was not lost in the offspring of this strain. The evolution of insecticide resistance in mosquitoes is discussed.     

LETHAL AND SUBLETHAL EFFECTS OF ACETAMIPRID ON THE LARVAE OF CULEX PIPIENS PALLENS

Abstract Acetamiprid is a novel neonicotinoid insecticide invented by Nippon Soda Co., Ltd. To explore the possibility of acetamiprid as larvicide of mosquitoes, lethal and sublethal effects of acetamiprid on the larvae of Culex pipiens pallens were studied by immersion method in the laboratory. The results indicated that the larvae of Culex pipiens pallens were sensitive to acetamiprid. The mortality of larvae peaked at 72 h after treatment. The 1 st instar larvae was the most susceptible to acetamiprid, and the 4th instar larvae was the most tolerant to acetamiprid, the LC, values were 0. 020 mg/L and 0. 296 mg/L at 72 h after treatment, respectively. Sublethal concentrations of acetamiprid could delay the development of larvae and decrease the weight of pupa. We suggested that acetarniprid is a safe and effective substitute for the using larvicides of mosquitoes.     

啶虫脒对淡色库蚊幼虫的致死和亚致死影响

啶虫脒是日本曹达公司新开发的一种氯代烟碱类杀虫剂,为了探讨其用于蚊虫幼虫控制的可能性,我们在室内用浸渍法测定了啶虫脒对淡色库蚊幼虫的致死和亚致死影响,结果表明,淡色库蚊幼虫对啶虫脒较敏感,幼虫的死亡高峰出现在处理后第3天,幼虫的四个龄期中,一龄最敏感,四龄耐药力最强,二在处理后72h时的LC50值分别为0.020mg/L/升和0.296mg/L。幼虫在亚致死浓度的啶虫脒溶液作用下,发育期延长,蛹重下降。说明啶虫脒可用于蚊虫幼虫的控制。     

不同敌百虫抗性淡色库蚊幼虫中谷胱甘肽和谷胱甘肽转移酶的比较

本文比较了三种不同敌百虫抗性淡色库蚊的谷胱甘肽和谷胱甘肽转移酶的活力。结果表明谷胱甘肽含量随着从幼虫、蛹、成虫的发育面逐渐增加,敌百虫抗性品系比敏感晶系有明显高的谷胱甘肽转移酶的活力,同时敌百虫处理幼虫导致谷胱甘肽含量下降。推测敌百虫抗性可能同谷胱甘肽和谷胱甘肽转移酶活力增高有关。     

淡色库蚊有机磷抗性品系实验种群的生命表分析(英文)

本文在敌百虫、双硫磷和毒死蜱三种抗性品系筛选的基础上,通过抗性品系和敏感品系的吸血、繁殖、存活和发育等生物学特性的测定和比较,组建实验种群生命表,分析抗性品系的适合度。结果表明：三种抗性品系的吸血率、产卵率和发育速率与敏感品系相比都有所降低;抗敌百虫品系、抗双硫磷品系和抗毒死蜱品系相对敏感品系分别具有0．542、0．631和0．618的适合度。     

EVALUATION OF EXTRACTS FROM BAMBOO FOR BIOLOGICAL ACTIVITY AGAINST CULEX PIPIENS PALLENS

Abstract The extracts from 7 species of bamboo were tested for larvicidal activity against Culex pipiens pallens . At the tested concentration, the extracts of selected bamboo had different degree of toxic effects on the fourth instar larvae of Culex pipiens pallens . Among them, the extracts of Pleioblastus juxianensis, Brachystachyum albostriatum, Phyllostachys platyglossa and Pleioblastus amarus were found to be effective with LC₅₀values at 24 h of 30.65 mg/L, 53.94 mg/L, 41.21 mg/L and 54.49 mg/L respectively, against Culex pipiens pallens larvae. The extract of Pleioblastus juxianensis by Soxhlet method showed stronger activity than the extract obtained by interval-shaking, the LC₅₀ of which were 30.65 mg/L and 48.34 mg/L, respectively. The diethyl ether extract of Pleioblastus juxianensis exhibited better larvicidal activity than the methanol extract and the petroleum ether extract. The results would help to provide the basis for the study of environment acceptable pesticide for mosquito control, and also help to comprehensively utilize the source of bamboo.