应用粉拟青霉防治南方马尾松毛虫初探

分离于油松毛虫上的粉拟青霉(Paecilomyces farinosus)经室内测定,在低温下对马尾松毛虫(Dendrolimus punctatus)的杀虫效果优于白僵菌(Beauveria bassiana)。在15℃时,其LD_(50)=1.3×10~6孢子/毫升,LT_(50)=17.5天,幼龄马尾松毛虫比老龄马尾松毛虫对粉拟青霉更敏感。本文还比较了粉拟青霉和白僵菌在不同温度、湿度下约分生孢子萌发率。实验结果表明:粉拟青霉对越冬代的马尾松毛虫的防治具有较大的应用价值。

A Study on Using Paecilomyces farinosus to Control Dendrolimus punctatus in Southern China

Paecilomyces farinosus, whrich was isolated from the naturally dead larvae of Dendrolimus tabulaeformis, has been used to control Dendrolimus pun ctatus in lab. The laboratory test shows that at low temperature, Paecilomyces farinosus is a better pesticide than Beauveria bassiana, that at 15°C, the LD50 of Paecilomyces farinosus treatment for the 3rd instar larvae of Dendrolimus punct-atus is 1.3×108 spores/ml, with the LT50 for the concentration of l.3×108spo-res/ml being 17.5 days, and that the young larvae are more sensitive to Paecilomyces farinosus than the old ones. In addition, the comparisons of the spore germination percentage have been made between Paecilomyces farinosus and Beauveria bassiana at different temperature and in different humidity, with the results indicating that Paecilomyces farinosus will be of great value in controlling the overwintering larvae of Dendrolimus punctatus.