19种防治棉叶螨药剂室内毒力测定及安全性评价

Toxicities of 19 Acaricides to Tetranychus cinnabarinus and Their Safety Evaluations

室内毒力测定结果表明:阿维菌素对棉叶螨活性最高,唑螨酯、哒螨灵、甲氨基阿维菌素、四螨嗪次之;其它药剂对棉叶螨杀螨活性依次为多杀菌素、甲氰菊酯、浏阳霉素、联苯菊酯、倍硫磷、三氯杀螨醇、双甲脒、噻螨酮、克螨特、毒死蜱、喹硫磷、氯氟氰菊酯、对硫磷和伏杀硫磷。哒螨灵、阿维菌素、四螨嗪和唑螨酯对棉叶螨有极高选择性;浏阳霉素、多杀菌素、甲氨基阿维菌素、噻螨酮、克螨特、三氯杀螨醇、双甲脒、倍硫磷和甲氰菊酯次之;喹硫磷、氯氟氰菊酯、对硫磷和伏杀硫磷则无选择性。阿维菌素和甲氨基阿维菌素对中红侧沟茧蜂影响最小。

Tetrans, chuscinnabarinu was one of the important pests of cotton in China. The damage of Tetranychus cinnabarinus to cotton plant was becoming serious as Bt cotton planted area increased in recent years. The management was commonly done based on repetitive application of acaricides. Some farmers used to apply high toxic acaricides, like organophosphate insecticides, or dicofol for Tetranychus cinnabarinus control. For environment safety and o perators health, high toxic insecticides would be banned in China sooner or later. Dicofol was also limited to be produced and applied because its intermediate DDT belonging to persistent organic pollutants （POPs）. Screening alternative acaricides to high toxic organophosphate insecticides and dicofol for Tetranychus cinnabarinus was important for cotton production. Nineteen acaricides were evaluated in laboratory by slide-dip method against Tetranychus cinnabarinus occurred naturally in the suburb of Wuhan. Hubei Province in the summer of 2005. The results showed that the LC50 of abamectin to Tetranychus cinnabarinus was 0. 0012 mg· L^-1. with the best activity and should be applied for Tetranychus cinnabarinus control in cotton field as the first choice. The LC50 of fenproximate, pyridaben, emamectin and clofentezine to Tetranychus cinnabarinus were all below 1 mg·L^-1 . showed excellent toxicities and all can be applied for red spider control. The LC50 of spinosad, fenpropathrin and liuyangmycin were all below 20mg ·L^-1 with better toxicities. The LC50. of bifenthrin, fenthion, dicolfol and amitraz were all b and with good toxicities. Chloropyrifos. quinalphos, cyhalothrin, parathion and phosalone showed normal toxicities to Telranychuscinnabarinus. and the LC50, were all above 100 mg·L^-1. The analysis of the vertebrate selectivity ratio （VSR） of different acaricides showed that pyridaben, abamectin. clofentezine and fenproximate had very high selectivity against Tetranychus cinnabarinus. Liuyangmycin spinosad and emamectinhad high selectivity. Hexythiazox, propargite, dicolfol, amitraz, fenthion and fenpropathrin had better selectivity, and quinalphos, cyhalothrin, parathion and phosalone showed no selectivity to Tetranychus cinnabarinus. The influence of different acaricides against the natural enemy, microplitis mediator in the cotton field, were also studied and the results showed that abamectin, emamectine had the least effect. Based on the toxicitybioassay, relative toxicity index and VSR and its safety evaluation to natural enemy of this study, abamectin, emamectine, fenproximate. pyridaben, clofentezine, spinosad, fenpropathrin, bifenthrin, liuyangmycin and amitraz could apply for Tetranychus cinnabarinus control as alternatives to dicofol and high toxic organophosphate insecti cides.