5种杀虫剂亚致死剂量对龟纹瓢虫捕食作用的影响

Sublethal Doses of Five Insecticides on Predation of Propylaea japonica(Thunberg)

测定5种杀虫剂亚致死剂量对龟纹瓢虫捕食作用的影响效应,在龙眼角颊木虱同一猎物密度条件下,亚致死剂量处理的龟纹瓢虫对猎物的捕食量显著低于对照组,但是其捕食功能反应模型结构没有改变,均属于HollingⅡ型,只是功能反应模型参数发生了明显的变化,即捕食者对猎物的瞬间攻击率a下降,处理时间Th延长,最大理论捕食量下降。结果表明:杀虫剂亚致死剂量处理对龟纹瓢虫的捕食作用存在明显的不良影响,5种杀虫剂中以吡虫啉对龟纹瓢虫的捕食作用影响最小,氰戊菊酯的影响程度最大。

The effects of sublethal doses of five insecticides, imidacloprid, chlorpyrifos, alphacypermethrin, cyhalotbrin and fenvalerate on functional response of Propylaea japottica（Thunberg）preying on CornegenapsyUa sinica Yang et Li were determined. In the same prey density, the predatory capacities of P. japonica treated with five sublethal insecticides were all reduced conspicuously compared to the control group. Results showed that the functional response models were all conformed to Holling ]I type in spite of ladybird treated with insecticides or not. But the predatory function and parameters of models were negative influenced by the sublethal insecticides, it revealed that the searching rate（a）redueed, handling time（Ta）prolonged and the maximal predatory capacities were also reduced. These findings suggested that insecticides at sublethal level had some extent harmful influence on the predation of P. japonica. Among the five insecticides, imidacloprid performed the minimum harmful influence to the predation of P. japonica, but fenvalerate did the maximum.