RH-2485对斜纹夜蛾幼虫生长发育的影响

目的]了解具有蜕皮激素活性的二酰基肼类化合物RH-2485对农业重要害虫斜纹夜蛾(Spodoptera litura)幼虫生长发育的影响。方法]分别用2μL的1、10、50、100、1 000 mg/L系列浓度的RH-2485点滴处理斜纹夜蛾3龄幼虫,测定幼虫的死亡率、半数致死浓度(LC50)、发育历期、化蛹率和羽化率等指标。结果]随着RH-2485浓度的升高,斜纹夜蛾幼虫死亡率也不断升高,而致死所需时间则不断下降,100 mg/L浓度的致死率在90%左右,1 000 mg/L浓度的致死率为96.7%。RH-2485对斜纹夜蛾3龄幼虫的LC50为5.220 91 mg/L。斜纹夜蛾1龄、2龄幼虫对RH-2485比较敏感,但它们之间则无显著差异。结论]试验结果为田间利用RH-2485防治斜纹夜蛾提供了理论依据。

Effects of RH-2485 on Growth and Development of Spodoptera litura Larvae

Objective]The aim was to explore the effect of RH-2485,a kind of non-steroids two acyl-hydrazine compounds with molting hormone activity,on the growth and development of Spodoptera litura,an important pest of agriculture.Method] The third instar larvae of S.litura were treated with 1,10,50,100 and 1 000 mg/L concentration series RH-2485 respectively,and their larval mortality,median lethal dose,developmental duration,pupation rate and eclosion rate were measured.Result] With the increase of larvae mortality,the lethal time declined accompanying by elevated RH-2485 concentrations.The mortality was about 90％ when the larvae was treated by RH-2485 on 100 mg/L concentration,and the mortality was 96.7％ when the larvae was treated by RH-2485 on 1 000 mg/L concentration.The median lethal concentration (LC50) of RH-2485 on the third instar larvae was about 5 mg/L.The first or second instar larvae were sensitive to RH-2485,and there was no significant difference in the susceptibility to RH-2485 of the larvae during the period of the first or second instar.Conclusion] These results will provide evidence and guidance role for using RH-2485 to prevent and control S.litura in the field.