Abstract: Cascade (Flufenoxuron),the insect growth regulator (IGR) was assesed for its effects on the population dynamics of predatory groundbeetle as the Cascade bait applied to control rangeland grasshoppers in the Inner Mongolia in 1994.Laboratory studies were conducted to determine the acute lethal toxicity to Pterostichus gebleri when 2μl of 250ppm Cascade per head was poured into the mouth of groundbeetle for an observation of 1 to 15 days.The same result, 70-90% survival rate was achieved from either treated or untreated individually,and there were no significant differences between the, treatments(P>0.40).Activities of the groundbeetles by appling Cascade were determined from pitfall catches.Mean daily catches of P.gebleri from a pitfall were 28.3 in the plot treated with the baits,and 28.5 in the untreated plot.There was no siginficant difference from rnean daily catches of a pitfall between the treatments-Cascade has little adverse effect on natural enemy of insects,making Cascade idea1 partners in the integrated pest management programme.Moreover, P.geblerioccurs in huge population densities on rangeland, and associates with regulation of grasshopPer population.There fore, P.geblerimight be worth study as a dominant species among predators naturally controling rangeland grasshoppers.

Key words: Pterostichus gebleri, Cascade, Pitfalll catches, Lethal toxicity, Cumulative insect-days

摘要： 试验研究了卡死克对通缘步甲成虫的急性致死毒性及田间撒施卡死克毒饵后对其种群数量消长的影响。室内口腔灌喂250ppm浓度的卡死克药液2μl/头后的第1～15天,灌药组与灌清水组的存活率均在70～90%,统计结果无显著差异,说明药剂对该步甲元急性致死毒性。在毒饵撒施后的7～17天,采用陷阱诱捕法调查对通缘步甲田间种群数量的影响,结果表明：处理区与对照区的日均诱捕数量为28.3和28.5头,两区间的差异并不显著。卡死克既不杀伤草地上游猎捕食的通缘步甲又能有效控制蝗虫种群数量的增长,使其能够发挥控制害虫的作用。通缘步甲发生数量大,与蝗虫种群消长有跟随现象,是一种值得研究保护利用的优势天敌种类。

关键词: 通缘步甲, 卡死克, 陷阱诱捕, 致死毒性, 累积虫日