75种植物提取物对萝卜蚜杀虫活性的测定

用点滴法测定了75种植物甲醇提取物对萝卜蚜的触杀活性。24 h校正死亡率大于80%的植物有大头艾纳香等两种,校正死亡率在50%~80%的植物有朝天灌等15种,其余植物提取物的校正死亡率在50%以下。进一步测定了其中5种植物提取物对萝卜蚜的触杀毒力,其中,大头艾纳香茎叶的触杀毒力最高,LD50为3.959 7μg/头,5种植物相对毒力从高到低的顺序是:大头艾纳香>石油菜>相思豆>薏苡>朝天灌。

Contact Activity of 75 Plant Extracts against Lipaphis erysimi Kaltenbach

Contact activity of 75 methanol plant extracts against Lipaphis erysimi Kaltenbach was determined by topical application.2 plant(Blumea megacephala,etc) extracts had high contact activity,with a corrected moriality of >80% in 24 hours after the treatment at a dose of 10μg/larvae.15 plant(Osbeckia opipara C.Y.Wu et C.Chen,etc.) extracts had medium activity,their corrected mortality ranging from 50% to 80%.The other plants studied had low activity,the corrected mortality being below 50%.Contact toxicities of the extracts of 5 plants were further tested.The extract from branches and leaves of Blumea megacephala had the highest activity level against Lipaphis erysimi Kaltenbach,with a LC50 value of 3.9597μg/female.Relative toxicities of the 5 plant extracts were as follows: Blumea megacephala>Pilea cavaleriei>Abrus precatorius L.>Coix lacroyma jobi L.>Osbeckia opipara C.Y.Wuet C.Chen.