甲胺磷预处理小菜蛾对菜蛾绒茧蜂的影响

分别在菜蛾绒茧蜂处于卵期、早期幼虫和中期幼虫时,饲喂小菜蛾2龄幼虫亚致死剂量甲胺磷,研究甲胺磷处理对寄主体内菜蛾绒茧蜂结茧率和羽化率的影响.试验表明,经亚致死剂量甲胺磷处理后,菜蛾绒茧蜂的结茧率和羽化率与对照相比均显著降低.在菜蛾绒茧蜂处于卵期时饲喂寄主幼虫,菜蛾绒茧蜂的结茧率和羽化率分别下降59.1%和32.5%;在菜蛾绒茧蜂处于早期幼虫时饲喂寄主幼虫,菜蛾绒茧蜂的结茧率和羽化率分别下降40.5%和32.8%;而在菜蛾绒茧蜂处于中期幼虫时饲喂寄主幼虫,菜蛾绒茧蜂的结茧率和羽化率分别下降18.2%和37.2%.结果表明,在绒茧蜂处于不同发育阶段时,饲喂小菜蛾幼虫甲胺磷对菜蛾绒茧蜂结茧率的影响较大,但对羽化率的影响不大.

Effects of sublethal methamidophos on cocoon formation and adult emergence of Cotesia plutellae

Significant declines of cocoon formation and adult emergence in C.plutellae were found when the hosts,2nd instar larvae of P.xylostella were fed with the leaves treated with sublethal dosage of methamidophos as compared with the control.The cocoon formation and adult emergence of C.plutellae reduced by 59.1% and 32.5%,40.5% and 32.8%,18.2% and 37.2%,respectively when the larvae of P.xylostella were fed with the insecticides at egg stage,early larval stage,and mid larval stage of the parasitopid.The results indicated that the scope in the declines of the cocoon formation varied depending on methamidophos treatment time in different development stages of the parasitoid.!However,no significant differences in the declines of parasitoid's adult emergence were found when the host larvae were treated with methamidophos in different development stages of parasitoid.