中文摘要：

为了明确低温预处理对吡虫啉致死效应的影响,室内选择麦长管蚜作为研究对象,采用滤纸接触法首先试验了5℃低温预处理是否对吡虫啉毒力有影响,随后研究了5℃预处理时间（1、2、3、4h）和5、10℃下预处理后用药的间隔时间（1、3、5h）对吡虫啉致死效应的影响。结果表明,5℃预处理2h可显著降低吡虫啉的毒力,这种负效应随着低温处理时间的增加而增强,但随低温处理后用药间隔时间的增加而减弱,不同低温对吡虫啉致死效应影响不显著。本研究结论为科学用药提供了理论依据。

英文摘要：

In order to clarify whether low temperature pretreatment affects lethal effect of pesticides,we exposed a species of cereal aphids（Sitobion miscanthis）under 5℃for 2 hours and then tested the toxicity of imidacloprid to those pretreated aphids in laboratory with the method of contact filter paper.We further tested toxicity of imidacloprid after exposing aphids at 5 ℃for different time periods i.e.1,2,3,and4 hours,respectively.At last,we tested mortality of aphids which treated with imidacloprid after exposing those aphids at 5℃ and10℃respectively for 2 hours,then at room temperature for different interval times（0,1,3 and5 hours）,respectively.Our results indicated that cold treatment at 5℃ could reduce the toxicity of imidacloprid significantly.The toxicity of imidacloprid was inhibited as aphids＇ cold exposure increased.However,the inhibition effect on toxicity of imidacloprid declined with interval time became longer.The effect of different low temperatures on the toxicity was not significant.