淡色库蚊敌敌畏抗性和氯氰菊酯抗性品系对常用化学杀虫剂的交互抗性

The cross-resistance of DDVP-resistant and cypermethrin-resistant strains of Culex pipiens pallens to the common chemical pesticides

目的 了解淡色库蚊对6种常用化学杀虫剂的交互抗性,为科学使用化学杀虫剂提供依据. 方法 采用WHO生物测定方法检测淡色库蚊敏感品系、敌敌畏抗性品系和氯氰菊酯抗性品系Ⅳ龄幼虫对三氯杀虫酯、敌敌畏、马拉硫磷、残杀威、氯氰菊酯和溴氰菊酯等6种常用化学杀虫剂的敏感性,每次测定设置7个浓度,每个浓度设2组,每组25个幼虫,24h后统计幼虫死亡数据,计算致死中浓度（median lethal concentration,LC50）、回归方程和抗性指数. 结果 淡色库蚊敌敌畏抗性品系对三氯杀虫酯、敌敌畏、马拉硫磷、残杀威、氯氰菊酯和溴氰菊酯的LC5分别为1.962 3 mg/L、1.160 7 mg/L、0.7359 mg/L、0.9002 mg/L、0.0220 mg/L和0.000lmg/L,回归方程分别为Y=3.528 7＋5.025 4X、Y=4.696 2＋4.693 7X、Y=5.505 1＋3.853 6X、Y=5.235 0＋5.147 6X、Y=10.499 5＋3.318 4X和Y=13.297 7＋2.168 3X,抗性指数分别为9.25、12.17、9.14、7.93、183.47和0.71;淡色库蚊氯氰菊酯抗性品系对三氯杀虫酯、敌敌畏、马拉硫磷、残杀威、氯氰菊酯和溴氰菊酯的LC50分别为5.572 8 mg/L、0.2464 mg/、0.089 2 mg/L、0.202 7 mg/L、0.064l mg/L和0.008 5 mg/L,回归方程分别为Y=2.772 8＋2.985 2X、Y=7.205 4＋3.6260X、Y=9.475 1＋4.263 5X、Y=6.810 6＋2.612 5X、Y=8.740 4＋3.135 2X和Y=14.695 1＋4.685 3X,抗性指数分别为26.27、2.58、1.10、1.79、534.31和40.60. 结论 长期使用一种化学杀虫剂会导致蚊虫产生抗药性,并对其他化学杀虫剂产生不同的交互抗性,应采取合理选择杀虫剂品种和确定使用剂量等有效措施以避免蚊虫抗药性的产生.

Objective To investigate the cross-resistance of Culex pipiens pallens to common pesticidesso as to provide a basis for the rational use of chemical pesticides.Methods The sensitivity of sensitive,dichlorvos （DDVP）-resistant and cypermethrin-resistant strains of Culex pipiens pallens Ⅳ instar larvae to six common chemical pesticides （acetofenate,DDVP,malathion,propoxur,cypermethrin and deltamethrin） was detected based on WHO bioassay method.Seven concentrations were set up for each experiment.Two groups were set up for each concentration and each group had 25 larvae.The dead larvae were detected after 24 h exposure.The median lethal concentration （LC50）,regression equations and resistance indices were then calculated.Results The LC50 of DDVP-resistant strain of Culex pipiens pallens to acetofenate,DDVP,malathion,propoxur,eypermethrin and deltamethrin were 1.962 3 mg/L,1.160 7 mg/L 0.735 9 mg/L,0.900 2 mg/L,0.022 0 mg/L and 0.000 1 mg/L respectively.And the regression equations for them were Y=3.528 7＋ 5.025 4X,Y=4.696 2＋4.693 7X,Y=5.505 1＋3.853 6X,Y=5.235 0＋5.147 6X,Y=10.499 5＋3.318 4X and Y=13.297 7＋2.168 3Xrespectively.The resistance indices for them were 9.25,12.17,9.14,7.93,183.47 and 0.71respectively.The LC50 of cypermethrin-resistant strain of Culex pipiens pallens to acetofenate,DDVP,malathion,propoxur,cypermethrin and deltamethrin were 5.572 8 mg/L,0.246 4 mg/L,0.089 2 mg/L,0.202 7 mg/L,0.064 1 mg/L and 0.008 5 mg/Lrespectively.The regression equations for them were Y=2.772 8＋2.985 2X,Y=7.205 4＋3.626 0X,Y=9.475 1＋4.263 5X,Y=6.810 6＋2.612 5X,Y=8.740 4＋3.135 2X and Y=14.695 1＋4.685 3X respectively.The resistance indices for them were 26.27,2.58,1.10,1.79,534.31 and 40.60 respectively.Conclusion Mosquito will generate resistance when using one kind of chemical pesticide in a long time.It will also generate different levels of cross-resistance to other pesticides.So when using chemical pesticides,we should take measures such as rationally selecting chemical pesticides and determining the appropriate dose of chemical pesticides to avoid generating the resistance of mosquito to the chemical pesticides.