三种农药亚致死剂量对椰甲截脉姬小蜂功能反应的影响

测定了氯氰菊酯、啶虫脒和椰甲清3种杀虫剂亚致死剂量对椰甲截脉姬小蜂Asecodes hispinarumBoucˇek寄生椰心叶甲Brontispa logissima(Gestro)功能反应的影响。结果表明:亚致死剂量杀虫剂没有改变椰甲截脉姬小蜂功能反应模型的基本结构,但影响到了模型的各项参数。药剂处理后椰甲截脉姬小蜂的最大日捕食量降低,处理猎物时间延长,搜寻效应减弱。氯氰菊酯和啶虫脒的处理后瞬时攻击率减小,但椰甲清处理后瞬时攻击率高于对照。可见,在亚致死剂量下,氯氰菊酯和啶虫脒对椰甲截脉姬小蜂的寄生作用存在不良影响,椰甲清(30%杀虫单+15%啶虫脒)可提高其瞬时攻击率但减弱其搜索效应。

The effect of sublethal doses of insecticides on the functional response of Asecodes hispinarum

The effects of sublethal doses of the insecticides,cypermethrin,acetamiprid and Yejiaqing,on the functional response of Asecodes hispinarum Bouekwere determined.The density of B.longissima was set as 2,4,6,8,and 10 head/ tube. The test was divided into two groups.In one group,the beetles were pretreated with sublethal dose of insecticides,while the wasps were untreated.In another one,the wasps were pretreated with sublethal dose of insecticides,while the beetles were untreated.The results revealed that the functional response models were all still conformed to Holling's type Ⅱ curve while the parameters in the models had certain changes.The maximal predatory capacity of A.hispinarum pretreated with the insecticides reduced,the handing time prolonged,the searching efficiency declined.But the predatory rate of A.hispinarum reated with Yejiaqing was higher than that of control.It is concluded that the cypermethrin and acetamiprid at sublethal level showed negative influence to the functional response of A.hispinarum.While treated with Yejiaqing the predatory rate increased and the searching effiency of the wasp decreased.