金龟子绿僵菌对褐飞虱繁殖力的影响

Effects of Metarhizium anisopliae on the Fecundity of Nilaparvata lugens

褐飞虱Nilaparvata lugens (Stal)以单食性水稻为主,是亚洲地区重要的水稻害虫之一,繁殖力强的特点是其大面积为害水稻的重要原因。金龟子绿僵菌Metarhizium anisopliae是一种环境友好型的昆虫病原真菌,近年来被广泛用于害虫防治。本研究结果显示8×10^(10)孢子/mL金龟子绿僵菌悬浮剂在实验室条件和田间条件下对褐飞虱都具有明显的致死效果,最高校正死亡率与相对防效分别为55.67%和63.81%。与对照组相比,感染金龟子绿僵菌雌性褐飞虱16 d内产卵量下降了38.37%,卵孵化率下降37.5%,且羽化第1d的雌性褐飞虱Vg基因表达量最低,仅为对照组的32.26%,海藻糖含量为对照组44.64%。结果表明金龟子绿僵菌不仅对褐飞虱有较高的致死效果,也能通过影响Vg的表达和海藻糖的消耗从而减少褐飞虱的产卵量。

The brown planthopper Nilaparvata lugens(Stal) is monophagous on rice and one of the important rice pests in Asia. The high fecundity is an important reason for its severe damage to rice. Metarhizium anisopliae is an environment-friendly insect pathogenic fungus widely used to control pests in recent years. It was determined in this study that 8×10^(10) spores/mL M. anisopliae suspension resulted in high mortality of the brown planthopper under both laboratory and field conditions, with corrected mortality and relative control efficacy of 55.67% and 63.81%, respectively. Compared with the control, egg deposition of the females infected with M. anisopliae was decreased by 38.37% in 16 days after mating, and egg hatching was decreased by 37.5%. The expression of Vg gene in 1-d old female brown planthoppers was as low as 32.26% of that in the control. The trehalose content dropped to 44.64% of that in the control. The results indicate that M. anisopliae not only has a high lethal effect on the brown planthopper, it can also reduce planthopper fecundity through influencing on the Vg expression and trehalose content.