3种杀虫剂对中稻田白背飞虱及捕食性天敌群落的影响

Effects of three insecticides on Sogatella furcifera and predatory natural enemy community in mid-season rice fields

采用室内毒力测定、田间试验和系统调查方法研究了3种杀虫剂对中稻田白背飞虱及捕食性天敌群落的影响,旨在提高水稻白背飞虱的化学防治效率,减少农药对环境的污染,保护天敌对害虫的自然控制作用,为水稻白背飞虱的综合治理提供依据。研究结果表明,阿维菌素、吡蚜酮和毒死蜱3种杀虫剂对白背飞虱3龄若虫均有较高的室内毒力,LC50分别为0.339 1、0.896 0和4.714 7mg/L,说明安徽省桐城市白背飞虱种群对这3种药剂尚未产生较高的抗药性。阿维菌素对白背飞虱的田间防治效果较差,毒死蜱药后3d即达到较好的防治效果,但持效期较短。吡蚜酮对白背飞虱有很好的防治效果,药后7d和14d的防效分别达到90.94%和89.94%,且对捕食性天敌群落影响较小,有助于保护和加强天敌的自然控制作用,是防治中稻田白背飞虱较理想的药剂。

In order to increase the chemical control efficiency against Sogatella furcifera,reduce insecticide pollution in the environment and protect the control effects of natural enemies,so as to provide basis for IPM of S.furciferain rice fields,the effects of three insecticides on S.furcifera and predatory natural enemy community in mid-season rice fields were investigated by toxicity test in laboratory,field experiment and systematic survey.The results showed that abamectin,pymetrozine and chlorpyrifos had relatively high toxicity to3 rd instar nymph of S.furciferain laboratory,with the LC50 value of 0.339 1 mg/L,0.896 0 mg/L and4.714 7 mg/L,respectively,indicating the population of S.furciferain Tongcheng City,Anhui Province had not developed evident resistance to the three insecticides.The field control effect of abamectin on S.furcifera was not satisfied and that of chlorpyrifos was relatively high in three days.Pymetrozine had satisfactory field control effect on S.furcifera with control efficacies of 90.94%（7 days after treatment）and 89.94%（14 days after treatment）,respectively.In the meantime,pymetrozine had minor negative impact on predatory natural enemy community,which was helpful to protect and increase the control effects of natural enemies.Therefore,pymetrozine is a candidate insecticide that can be recommended for S.furcifera control in mid-season rice fields.