药物筛选对高抗氯氟氰菊酯家蝇的抗性变化研究

The Variation of Cyhalothrin Resistance in High Cyhalothrin Resistant Housefly(Diptera:Muscidae) Strains by Deltamethrin and Pirimiphos-methyl Selection

目的 用溴氰菊酯、甲基嘧啶磷两种杀虫剂筛选及不接触药物自然衰退的方式，研究氯氟氰菊酯高抗性家蝇品系的变化，探讨蝇类抗药性治理的方法。方法 用喷雾法分别喷洒溴氰菊酯和甲基嘧啶磷于氯氟氰菊酯高抗药性家蝇品系（Cyh—R），进行进一步的抗性选育，分别命名为中溴（ZX）、中甲（ZJ），同时自然衰退法得到中衰（ZX）品系。用点滴法测定氯氟氰菊酯对这些家蝇品系的毒力，比较抗药性的变化。结果 与敏感品系比较，Cyh—R品系的抗药系数为561．9；氯氟氰菊酯对ZJ品系第2～6代的LD50呈递减趋势，抗药系数从F2的518．2降为F4的110．3与F6的122．6；氯氟氰菊酯对ZX品系第2～8代的LD50呈先递减再上升的趋势，抗药系数从F2的476．4降为F4的217．2，上升为F8的808．0；ZS品系的抗药系数由F0的561．9下降为F8的242．3。结论 对于氯氟氰菊酯高抗性品系家蝇，用有机磷杀虫剂后，可降低对氯氟氰菊酯的抗药性；用拟除虫菊酯筛选可造成对氯氟氰菊酯抗药性增长；不用杀虫剂筛选对氯氟氰菊酯的抗药性也有显著下降，但下降的速率低于甲基嘧啶磷筛选。

Objective The high cyhalothrin resistant Musca domestica strain （Cyh-R） was further selected by deltamethrin and pirimiphos-methyl to study the difference of toxicity and to explore the methods of flies resistance management. Methods Chy-R strain was regularly selected with deltamethrin and pirimiphos-methyl by spray method, the former named ZX strain, the later named ZJ strain. Cyh-R was selected with no insecticide and normal bred, named ZS strain. The toxicity of the cyhalothrin was tested in generations of different resistant strains every twice after selection with topical application bioassay, to compare the difference with Cyh-R strain no-selected. Results The Cyh-R strain was 561.9-fold resistant compared with insecticide resistant strains at LD50. The LD50 of ZJ strain from F2 to F6 showed declining trend, the resistance factors at LD50 declined from 518.2-fold of F2 to 110.3-fold of F4 and to 122.6-fold of F6. The LD50 of ZX strain from F2 to F8 showed declining firstly and increasing later, the resistance factors at LD50 increased from 217.2-fold of F4 to 808.0-fold of F8. The resistance factors at LDs0 of ZS strain declined to 242.3-fold of F8 . Conclusion The high insecticide resistant strain to cyhalothrin was selected with organophosphates, could decline resistant to cyhalothrin. The strain was selected with pyrethroids, could cause resistance elevated higher to cyhalothrin. The strain was selected with no insecticide, could also prohibit resistant development to cyhalothrin, but the ratio of decline was lower than pirimiphos-methyl selected.