安徽虫瘟霉强毒菌株对桃蚜的毒力测定

通过“孢子浴”方法,选择安徽虫瘟霉F97029菌株对桃蚜的2～3龄若蚜进行毒力测定。接种后第3～7天的LD_(50)为3.09～1.26个孢子/mm~2,在1.31～16.48个孢子/mm~2时的剂量范围内LT_(50)为2～5d。时间—剂量—死亡模型的剂量效应参数β值高达1.82,几乎与一些化学杀虫剂对害虫的同一参数估计值(1.2～4.5)接近。这表明该菌株对桃蚜具有极高的毒力,杀蚜活性强,是较为理想的杀蚜菌株。

Bioassay For The Virulence of The Intensity Zoophthora Anhuiensis Against The Green Peach Aphid Myzus Persicae

An isolate of Z. anhuiensis, F97029, was bioassayed against M. persicae nymphs in instar 2-3, The results were analyzed with a time-dose-mortality modeling technique. The values of LD50 were estimated as 3. 09-1. 26 conidia/mm2 3-7 d after exposure of the nymphs to spore shower from sporulating culture. The LT50 values ranged from 2 d to 5 d at the dosages of 1. 31 -16. 48 conidia/mm2. The estimated dose-effect parameter β was 1. 82. a high value for a microbial control agent and equivalent to that of some chemical insecticides. The results indicated that the i-solate was highly virulent to M. persicae nymphs. Thus, the isolate was used in the following studies.