增效剂对菜蚜茧蜂杀虫剂敏感性的影响

以田间菜蚜茧蜂为试虫,采用药膜法研究了增效剂胡椒基丁醚(PB)、磷酸三苯酯(TPP)和马来酸二乙酯(DEM)对6种杀虫剂的增效作用。结果表明,三种增效剂对6种杀虫剂均有显著增效作用,其大小依次为PB>DEM>TPP。PB对甲胺磷、阿维菌素、氟虫腈、氰戊菊酯、氯氰菊酯和吡虫啉的增效比达5.0～9.6倍。TPP和DEM对甲胺磷、DEM对氟虫腈的增效比达2.6～3.0倍,但TPP和DEM对阿维菌素、氰戊菊酯和氯氰菊酯、TPP对氟虫腈的增效比均在1.9倍以下。PB、TPP和DEM对吡虫啉的增效比分别高达9.6、6.8和8.2倍。体内抑制试验结果显示,PB、TPP和DEM对菜蚜茧蜂AChE活性无明显抑制作用,而PB和TPP对羧酸酯酶(CarE)、DEM对谷胱甘肽S转移酶(CST)活性有显著抑制作用。由此认为,菜蚜茧蜂对所用的6种杀虫剂的耐药性与多功能氧化酶(MFO)、CarE和GST的解毒作用有关。

Effects of synergisms on insecticide susceptibility and detoxification enzyme in a field population of parasitoid Diaeretiella rapae

The synergisms of enzyme inhibitors on the susceptibility to 6 insecticides in a field population of parasitoid Diaeretiella rapae ( M ' Intosh ) ( Hymenoptera; Aphididae ) , collected from vegetable district in Fuzhou, China, were detected with a dry residual film bioassay. Significant synergisms of piperonyl butoxide ( PB ) , triphenyl phosphate ( TPP) and diethyl mal-eate (DEM) , in the order of PB > DEM > TPP, on methamidophos, fipronil, avermectins, fenvalerate, cypermethrin, imidacloprid were found in D. rapae. PB showed the highest syner-gism ratio, ranged from 5.0- to 9. 6-folds, to methamidophos, fipronil, avermectins, fenvalerate , cypermethrin and imidacloprid. The synergism ratios of TPP and DEM for avermectins, fenvalerate and cypermethrin , and that of fipronil by TPP were less than 1. 9-folds, although synergism ratio of TPP and DEM for methamidophos and that of DEM for fipronil ranged from 2.6- to 3.0-folds. In addition, TPP and DEM also displayed high synergism on imidacloprid, and the synergism ratios of PB, TPP and DEM were 9.6, 6. 8 and 8. 2-fold, respectively. PB, TPP and DEM showed no inhibitions on the activity of acetylcholinesterase, but strong inhibitions on the activity of carboxylesterase (CarE) by PB and TPP, and on the activity of glutathi-one S-transferase ( GST) by DEM were found in D. rapae in vivo. The results suggested that the tolerance to the insecticides tested was associated with mixed-function oxidase ( MFO) , CarE and GST. In particular, MFO might play the most important role in the detoxification metabolism to the insecticides tested in D . rapae.