亚致死剂量杀螨剂对刺足根螨休眠体形成与解除的影响

 【目的】剌足根螨休眠体对不良环境和杀螨剂具有良好的抵抗能力,为确定亚致死剂量杀螨剂制剂是否对其形成与解除具有影响。【方法】采用药膜法建立多种杀螨剂制剂对刺足根螨第一若螨和休眠体的毒力线,以阿维菌素和噻螨酮亚致死剂量（LC20）分别处理第一若螨和休眠体,观察休眠体的形成与解除情况。【结果】阿维菌素和噻螨酮对第一若螨的毒力线分别是：y=1.2986+0.7549x和y=1.2866+1.1189x,而对休眠体的毒力线则分别是：y=1.2986+0.7549x和y= -2.3442+1.3936x。亚致死剂量的阿维菌素和噻螨酮对形成休眠体以及直接发育为第三若螨的比率均无显著影响（P＞0.05）,但是对休眠体的解除有显著抑制作用,阿维菌素和噻螨酮处理49 d后休眠体的解除率分别为13.44%和3.11%,显著低于对照组。【结论】亚致死剂量阿维菌素和噻螨酮对休眠体的形成影响较小,但对休眠体解除影响较大。

Effects of Acaricides at Sublethal Dose on Formation and Completion of Hypopi of Rhizoglyphus echinopus

Objective] Hypopus of Rhizoglyphus echinopus has good resistance to the adverse environmental conditions and acaricide.In order to understand the effects of acaricides at sublethal dose on hypopus formation and completion,a series of experiments were conducted.Method] The dry residual film method was applied to test the toxicity of six acaricides to protonymphs and hypopi of Rhizoglyphus echinopus.The effects of sublethal doses (LC_(20)) of abamectin and hexythiazox on hypopus formation and completion were also studied.Result]The toxity line of abamectin EC and hexythiazox EC on protonymphs were y=1.2986+0.7549x and y=1.2866+1.1189x,the toxity line of abamectin EC and hexythiazox EC on hypopus were y=1.2986+0.7549xand y=-2.3442+1.3936x .The hypopus formation was not significantly affected by 1.8% abamectin EC and 5% hexythiazox EC (P＞0.05),however,only a few hypopi treated by two acaricides could reach the tritonymph stage in 49 days,13.44% and 3.11%,respectively.Conclusion]Sublethal doses (LC_(20)) of abamectin and hexythiazox have a little influce on formation of hypopi of Rhizoglyphus echinopus,but have a great influnce on its completion.