杀虫剂对苹果黄蚜与七星瓢虫的毒力及选择性研究

采用FAO推荐的点滴法,测定了15种常用杀虫剂对苹果黄蚜及其天敌七星瓢虫幼虫的毒力,比较了药剂在二者之间的毒力选择性。结果表明,供试杀虫剂中以吡虫啉对七星瓢虫幼虫和苹果黄蚜的选择性最高,其选择性比值(七里瓢虫LD50/苹果黄蚜LD50)为135．56,其次为氟氯氰菊酯、氯氰菊酯和马拉硫磷,其选择性比值分别为114．00、62．86和45．43。吡虫啉、氟氯氰菊酯、氯氰菊酯和马拉硫磷等选择性高的杀虫剂对苹果黄蚜相对毒力高,而对其天敌七星瓢虫相对安全,在协调苹果黄蚜的化学防治与生物防治策略中应选用对害虫毒力高,而对天敌相对安全的杀虫剂。

Selective toxicity of insecticides between Aphis citricola and Coccinella septempunctala

The selective toxicity of 15 insecticides between Aphis citricola von der Goot and Coccinella septempunctala L. was investigated with a topical application method recommended by FAO. The results show that the selective toxicity of imidacloprid is the highest among 15 insecticides tested, and its selective toxicity ratio(STR, ladybird LD50/aphid LD50)is 135.56.Other insecticides with higher selective toxicity are cyfluthrin, cypermethrin and malathion,of which STRs are 114.00,62.86 and 45.43,respectively.Therefore these insecticides,such as imidacloprid,cyfluthrin and malathion,show a higher toxicity to the aphid but safe for the natural enemy ladybird. They could be selected as a relatively ideal alternative for integrated chemical and biological control of aphids in the field.