Influence Of Temperature On The Sensitivity Of Sitobion Avenae To Imidacloprid

Temperature is the key environmental factor on the activity and effect of pesticides.In this text, grain aphid (macrosiphum avenae) as target pest, the effect of low temperature pretreatment,high temperature pretreatment and posttreatment to the sensibility of grain aphid to imidacloprid,and the effect of sublethal concentrations imidacloprid on the heat resistance and the first springs of grain aphid (macrosiphum avenae) were studied in laboratory with the method of filter paper contact. We also studied the influence of temperature on the effect of imidacloprid in the field.Results are as follows.1. Compared with pesticide control,the toxicity of imidacloprid to grain aphid pretreated by5℃was lower,5℃and10℃pretreatment reduced the sensitivity of macrosiphum avenae to imidacloprid, the effect increased with the pretreatment time increase, but weakened along with the extension of interval time between temperature treatments and pesticide treatments.2. The toxicity of imidacloprid to macrosiphum avenae pretreated by30℃was higher; Except for60min pretreatment of30℃and35℃reduced the susceptibility of macrosiphum avenae to imidacloprid.30>90,120min pretreatment had the opposite effect and the effects were enhanced with the treatment time increased.30and35℃pretreatment could increase the sensitivity of macrosiphum avenae to imidacloprid but it was declined with the extension of interval time between temperature treatments and pesticide treatments. Different post-exposure high temperatures and temperature exposure times after used imidacloprid2hours had significant influences on the sensitivity of grain aphids to imidacloprid,as the temperature and time went up the phenomenon was obvious. Sublethal concentrations of imidacloprid reduced the heat resistance of grain aphid (macrosiphum avenae) obviously. As the temperature rised the aberration rate of grain aphid (macrosiphum avenae) increased. But the Sublethal concentrations of imidacloprid has non-effect on the lifetime and reproduction of the first offsprings of grain aphid (macrosiphum avenae) 3. Choose two high temperature days (may20,2013and may2,2013), we used the imidacloprid at different times in the day. Our results manifest that the effects of time of imidacloprid sprayed on may20,2013had little difference on the imidacloprid effect, but it had some differences on may21,2013, the highest control effect of imidacloprid was sprayed at14:00, the lowest control effect of imidacloprid was sprayed at15:00, hey were65.793%,38.6%respectively。...