杀虫剂对小菜蛾幼虫的毒力研究

采用浸叶法测定10种杀虫剂对海南省海口、三亚、儋州小菜蛾田间种群的毒力。结果表明：10种药剂对海口地区小菜蛾3龄幼虫的毒力LC50大小顺序为：Bt〉氟啶脲〉多杀菌素〉茚虫威〉虫螨腈〉阿维菌素〉丁醚脲〉虫酰肼〉杀螟丹〉高效氯氰菊酯：三亚地区小菜蛾3龄幼虫的毒力三％大小顺序为：Bt〉多杀菌素〉氟啶脲〉茚虫威〉虫螨腈〉阿维菌素〉虫酰肼〉丁醚脲〉杀螟丹〉高效氯氰菊酯：儋州地区小菜蛾3龄幼虫的毒力L氏大小顺序为：Bt〉多杀菌素〉茚虫威〉氟啶脲〉虫螨腈〉阿维菌素〉丁醚脲〉虫酰肼〉杀螟丹〉高效氯氰菊酯。3个地区对Bt和多杀菌素均表现敏感。海口地区小菜蛾种群除对高效氯氰菊酯、杀螟丹和Bt外，对其他药剂的敏感性均比三亚种群和儋州种群敏感。

Toxicity of Several Insecticides to Plutella xylostella L.

The toxicities of 10 insecticides to the 3 instar larvae of Plutella xylostella collected from Haikou, Sanya and Danzhou of Hainan Province were tested by leaf-dipping method. The result indicated that the orders of toxicity （LC50） to Plutella xylostella collected from Haikou were Bt 〉 chlorfluazuron〉 spinosad 〉indoxacarb 〉 chlorfenapyr 〉 abamectin 〉 diafenthiuron 〉tebufenozide 〉 Cartap 〉 Beta cypermethrin. The orders to Plutella xylostella collected from Sanya were Bt 〉spinosad 〉 chlorfluazuron 〉indoxacarb 〉 chlorfenapyr 〉 abamectin 〉 tebufenozide 〉 diafenthiuron 〉 Cartap 〉 Beta cypermethrin. The orders to Plutella xylostella collected from Danzhou were Bt 〉 spinosad 〉 indoxacarb 〉 chlorfluazuron 〉 chlorfenapyr 〉 abamectin 〉 diafenthiuron 〉 tebufenozide 〉 Cartap 〉 Beta cypermethrin. They were all sensitive to Bt and spinosad, Haikou population was more sensitive than Sanya and Danzhou, expect the insecticides of Beta cypermethrin, Cartap and Bt.