新型非甾醇蜕皮激素类杀虫剂对棉铃虫幼虫蜕皮的影响

用透射电镜技术研究了新型非甾醇蜕皮激素类杀虫剂W200013对棉铃虫4龄幼虫蜕皮的影响。结果表明W200013使棉铃虫产生早熟、致死的蜕皮。中毒试虫6 h表现出内表皮层沉积加快，皮细胞中粗面型内质网大量增加，糖原颗粒减少；12 h蜕皮间隙开始形成，细胞质凝集；24 h新、旧表皮同时存在，皮细胞空泡化严重；36 h新上表皮覆盖于仅沉积几层的新原表皮上，旧表皮仍然保持，皮细胞呈恶化、降解状态，宏观上虫体不表现出蜕皮行为而死亡。而且比较研究可见W200013在中毒症状、生物测定结果、超微结构水平与RH-5992具有相似的作用。

The effects of a new type of nonsteroidal ecdysteroid agonist on cuticle formation in larvae of the cotton bollworm (Helicoverpa armigera )

Effects of a new type of nosteroidal ecdysone agonist W200013 on the fourth instar larvae of the cotton bollworm (Helicoverpa armigera) were studied by transmission electron microscopy. These observations revealed that W200013 initiated a precocious and lethal larval moult. At 6 h post treatment (pt), the deposition of additional layers of endocuticle, a dramatic increase in rough endoplasmic reticulum and a decrease in glycogen particles were noted in the epidermis. At 12 h pt, the ecdysial space had formed and epidermal cytoplasts appeared “frozen”. At 24 h pt, a double cuticle separated by the ecdysial space had formed and the epidermis was highly vacuolated. At 36 h pt, new epicuticle coated an incomplete new procuticle containing only a small number of lamellae, and the epidermis showed increasing signs of degeneration. As a result, the treated larvae died without normal ecdysis. At the same time, comparison with RH-5992 revealed that the two insect growth regulators produced similar toxic symptoms, bioassay results and ultrastructural changes of the integument.