21种化学药剂对新疆棉田主要害虫毒力及对多异瓢虫的安全性

为明确现阶段棉田常用化学杀虫剂对新疆维吾尔自治区（简称新疆）棉花主要害虫的毒力以及对新疆本地优势天敌多异瓢虫Hippodamia variegata的安全性，于室内分别测定当前21种棉田常用化学药剂对新疆棉田3种主要害虫棉蚜Aphis gossypii、截形叶螨Etranychus truncatus和棉铃虫Helicoverpa armigera以及优势天敌多异瓢虫的毒力，比较不同药剂对各种害虫和天敌的相对毒力指数以及益害毒性比。结果表明，药剂处理24 h后，10种蚜虫防治药剂对棉蚜成蚜的半致死浓度LC₅₀由高到低依次为氟啶虫胺腈、啶虫脒、吡虫啉、环氧虫啶、噻虫嗪、丁硫克百威、烯啶虫胺、呋虫胺、螺虫乙酯和吡蚜酮，其中益害毒性比较高的药剂主要有氟啶虫胺腈和螺虫乙酯；5种叶螨防治药剂对截形叶螨成螨的LC₅₀从高到低依次为阿维菌素、哒螨灵、四螨嗪、噻螨酮和炔螨特，其中益害毒性比较高的药剂主要有四螨嗪、噻螨酮和阿维菌素；6种鳞翅目害虫幼虫防治药剂对棉铃虫3龄幼虫的LC₅₀由高到低顺次为甲氨基阿维菌素苯甲酸盐（简称甲维盐）、氯虫苯甲酰胺、茚虫威、灭多威、毒死蜱和高效氯氰菊酯，其中益害毒性比较高的药剂主要有甲维盐和氯虫苯甲酰胺。综合上述2个方面结果，氟啶虫胺腈、阿维菌素、甲维盐和氯虫苯甲酰胺不仅对棉花害虫毒力效果强，而且对有益天敌安全性高。

Toxicities of 21 pesticides against major cotton insect pests and their safety to variegated ladybird Hippodamia variegata in Xinjiang

In order to clarify the indoor toxicities of chemical insecticides commonly used in cotton fields against the main pests of cotton and the dominant natural enemy, Hippodamia variegata, in Xinjiang cotton fields, 21 pesticides were tested against three major cotton pests in Xinjiang (adults of Aphis gossypii, adults of Etranychus truncates, 3rd instar larvae of Helicoverpa armigera) and the 3rd instar larvae and adults of H. variegata. The relative toxicity indexes and ratios of pesticides were compared among different pests and pest-natural enemy combinations. The results showed that the toxicities (LC₅₀) of ten pesticides against the cotton aphid from high to low were sulfoxaflor, acetamiprid, imidacloprid, cycloxaprid, thiamethoxam, carbosulfan, nitenpyram, dinotefuran, spirotetramat, and pymetrozine after 24 h. Among them, sulfoxaflor and spirotetramat had higher toxicity ratios. The toxicities (LC₅₀) of five pesticides against E. truncatus from high to low were abamectin, pyridaben, clofentezine, hexythiazox, propargite. The pesticides with higher toxicity ratios were clofentezine, hexythiazox and abamectin. The LC₅₀ values of six pesticides against H. armigera from high to low were emamectin benzoate, chlorantraniliprole, indoxacarb, methomyl, chlorpyrifos, and beta-cypermethrin. Emamectin benzoate and chlorantraniliprole had higher toxicity ratios. In conclusion, this study revealed the higher toxicity of sulfoxaflor, abamectin, emamectin benzoate and chlorantraniliprole, and their higher safety to beneficial natural enemies.