扑虱灵对褐稻虱若虫生物活性及作用机制

Biological and Toxicological Activities of Buprofezin in Brown Planthopper Nymphs

新型昆虫几丁质合成抑制剂扑虱灵对褐稻虱具有优异的生物活性和独特的组织学影响。对褐稻虱五龄若虫触杀中浓度比常用药剂叶蝉散和甲胺磷等低3倍左右,内吸活性更高,室内测定50％残效期长达20—30天,对低龄若虫效果更佳。扑虱灵破坏了虫体体壁内表皮层几丁质片层结构和一些富含几丁质组份的组织器官,导致虫体在蜕皮过程中死亡。因此,扑虱灵对体壁几丁质生物合成和沉积过程的破坏是该农药引起褐稻虱若虫死亡的重要原因。

Buprofezin is a new chitin synthesis inhibitor. Its biological and histological interference in the brown planthopper (Nilaparvata lugens Stal was investigated. The contact LC-50 value for fifth instar nymphs was some 3 times lower than that of some conventional insecticides such as MIPC and methamidophos,and the oral activity was higher than the contact. The residue effect remained for 20-30 days in a greenhouse pottest. The toxicity declined as the nymphal stages proceeded. Histological observation and ultrastructural inspection showed that the destruction of chitin lamellae in the endocuticle of treated nymphs and other organs rich in chitin is the main cause of moult-inhibiting. So buprofezin seems to inhibit chitin biosynthesis.