绿僵菌MS01菌株的生物学特性及在不同温湿度下对光肩星天牛幼虫的致病力

The effect of culture media,temperature and humidity on the mycelium growth,spores germination of Metarhizium MS01 strain,a high virulent strain from the soil and the pathogenicity against Anoplophora glabripennis larvae was tested. The result showed that the optimum culture medium was PPDA,the optimum temperature for the mycelium growth and spore germination was 26 ℃,and A. glabripennis larvae had the highest mortality from the fungus at this temperature. The optimum RH for the mycelium growth ranged from 95%to 100%. The speed and rate of spore germination increased with increasing of RH. The larvae died from the fugus most quickly and the mortality reached the highest under 100% RH.

绿僵菌MS01对光肩星天牛成虫取食、产卵、孵化及子代幼虫存活的影响

采用喷菌法将3种不同密度的绿僵菌孢子悬浮液(106、107、108个.mL-1)接种到光肩星天牛(Ano-plophora glabripennis(Motschu lsky))成虫上,以0.1%吐温-80溶液为对照。研究其对光肩星天牛取食、产卵、孵化及其幼虫成活的影响。结果表明,光肩星天牛的选择取食效果随时间的推移均逐渐增大。与对照相比,其产卵量、孵化率和幼虫存活率均明显降低,且接种密度愈大,降低愈多。接种15 d后,3种染菌处理每对天牛产卵量分别为(21.25±1.71)、(18.00±1.41)、(11.50±2.88)粒,而对照可产(24.75±1.26)粒;孵化率分别比对照组降低了38.34%、30.43%和12.41%;幼虫死亡率分别比对照高67.53%、58.99%和46.68%,幼虫最终存活率分别为13.04%、20.83%和35.29%,而对照为79.80%。可见,光肩星天牛成虫感染绿僵菌MS01后可降低其取食量与产卵量,并通过水平传播传递给子代从而降低子代成活率。