Abstract: The investigation mentioned in this paper was carried out on the grassland in Tianjun, Qinghai province in August 1979 and April 1980. In addition, we have made a series of experiments upon plateau pikas in laboratory to prove the effect on destroying the animals with RATAK-(DIFENACOUM).The results of these experiments may be summarized as follows:1. The lethal dose of RATAK LD₅₀ =1.971±0.637(mg/kg).2. A regression equation of lethal dose is Y= 2.591X+4.236.Coagulation time ED₅₀ = 0.324(mg/kg).3. In field test, the oats are used as baits mixed with three concentrations of 0.125%, 0.25% and 0.50% of RATAK’s stieky solution respectively and all these baits are of good acceptance. It has not been seen that plateau pikas become resistant to them. The efficiency of destroying lies in 90.9%96.5%(X²20.05,P>0.05), the average efficiency is up to 93.9%.

摘要： Difenacoum是近年来新出现的抗凝血杀鼠剂新品种。在国外,它的粒状毒饵Ratak已出现于商品市场(以下本文统一采用“鼠大克”作为Difenacoum及Ratak的中文名称)。 鼠大克是为了对付50年代以来,由于广泛应用华法令(warfarin)等一系列抗凝血杀鼠剂以后产生的褐家鼠和小家鼠等抗性鼠种群,而投入使用的新一代抗凝血杀鼠剂品种之一。鼠大克在英国做为商品杀鼠剂已出售几年了,使用它防治抗药性黑家鼠(Rattus rattus)、褐家鼠( Rattus norvegicus)和小家鼠( Mus muscudus)取得了良好的效果(Hadler 1975; Rennison1975)。