增效醚对棉铃虫的毒理学研究

本文以棉铃虫 3龄幼虫为试虫材料对增效醚 (PBO)的毒理学进行了研究。结果表明 ,PBO对棉铃虫(H elicoverp a armigera) 3龄幼虫的 L D50 为 5.7532 μg/ larva;在活体抑制实验中 ,用 4 μg/ larva的剂量点滴处理1h后 ,幼虫体内乙酰胆碱酯酶 ACh E的活性被抑制 4 8.31% ,羧酸酯酶 Carb E被抑制 4 4 .97% ,多功能氧化酶MFO被抑制 6 0 .82 % ;在离体抑制试验中 ,PBO对 ACh E、Carb E和 MFO的抑制中率 (I50 )分别为 3.35× 10 -7mol/ L、4 .4 6× 10 -7mol/ L和 1.4 2× 10 -7mol/ L ;PBO对酯酶的抑制为不可逆抑制。因此 ,PBO的增效机理在抑制代谢酶系的水平上并不是专一的 ;对于棉铃虫而言 ,PBO具有明显的杀虫活性 ,用其进行增效实验判断MFO是否参与抗性时应注意 PBO的这一特点 ;同时文章还证明了磷酸三苯酯 (TPP)和顺丁烯二酸二乙酯(DEM)抑制作用的专一性。

STUDY ON THE TOXICOLOGY OF PBO ON THIRD INSTAR COTTON BUDWORM (HELICOVERPA ARMIGERA) LARVA

Toxicology of PBO on third instar cotton budworm (Helicoverpa armigera) larva has been studied in this paper. The results show that, LD 50 of PBO on third instar cotton budworm is 5.7532μg/larva. With the treatment of PBO at 4μg/larva for 1 hour, AChE, CarbE,MFO are all inhibited, and the inhibition rates are 48.31%, 44.97% and 60.82%, and I 50 s are 3.35×10 -7 mol/L, 4.46×10 -7 mol/L and 1.42×10 -7 mol/L respectively. Moreover, the inhibited AChE and CarbE are unreversible. All these prove that PBO has the capacity to inhibit more than one enzyme and has certain toxicity to cotton bollworm just like an organophosphorous pesticide. So we can not justify whether MFO is involved in resistance development only according to the synergistic result of PBO. In addition, specific effects of TPP and DEM have also been confirmed.