为了筛选防治灰飞虱的高毒力生防真菌菌株及明确黄绿绿僵菌对灰飞虱的侵染致病温度条件,室内测定了黄绿绿僵菌 KM1104菌株在24~30℃下对灰飞虱成虫及3龄若虫的毒力。结果表明:黄绿绿僵菌菌株 KM1104对灰飞虱成虫和3龄若虫均具有较强的毒力,其中对成虫的毒力高于3龄若虫,在24~30℃下对成虫和3龄若虫的LC50分别为1.45×10^3~7.14×10^4和7.25×10^3~3.69×10^5孢子/mL,致死中时 LT50分别为3.02~11.53 d和6.85~11.58 d。不同温度下黄绿绿僵菌 KM1104菌株对灰飞虱的毒力不同,其中30℃下毒力最强,对成虫和3龄若虫的致死中浓度 LC50分别为1.45×10^3和7.25×10^3孢子/mL,接种1.01×10^5~1.01×108孢子/mL 后对成虫和3龄若虫的致死中时 LT50分别为3.02~6.86 d 和6.85~9.35 d。综合以上结果,黄绿绿僵菌菌株 KM1104具有良好的灰飞虱生防制剂开发潜力,且在30℃下使用致病力最强。
In order to screen the higher virulent entomopathogenic fungi and the optimal temperature for its infec-tion,the virulence of Metarhizium flavoviride strain KM1 104 against the adults and 3rd instar nymph of Laodel-phax striatellus was tested at different temperatures.The results showed that the strain KM1 104 was virulent against the adult and 3rd instar nymph of L .striatellus .The virulence against the adult was significantly higher than that against the 3rd instar nymph.The LC50 value for the adult and 3rd instar nymph was 1.45×10^3 -7.14× 10^4 and 7.25×10^3 -3.69×10 5 spores/mL,and the LT50 value was 3.02-1 1.53 d and 6.85-1 1.58 d,respective-ly.The virulence was significantly different at different temperature,the highest virulence was at temperature of 30 ℃,the LC50 value for the adult and 3rd instar nymph was 1.45×10^3 and 7.25 ×10^3 spores/mL,the LT50 value for the adult and 3rd instar nymph after inoculation of 1.01 × 10^5 - 1.01 × 10^8 spores/mL was 3.02 -6.86 d and 6.85- 9.35 d,respectively.Considering all the above,M.flavoviride strain KM1 104 had great potential for L .striatellus control,and the highest virulence was at 30 ℃.