不同温度下绿僵菌对东亚飞蝗3龄蝗蝻的致病力影响

采用体表接菌法测定了商品生物农药金龟子绿僵菌油悬浮剂PD20080671在15、20、25、30、35和40℃等6个不同温度条件下对东亚飞蝗3龄蝗蝻的致病力的影响。结果表明：东亚飞蝗3龄蝗蝻的累积死亡率在接菌后19 d内均随天数的增加而升高。35℃的累积死亡率最高（82.50%），显著高于其他处理；40℃的累积死亡率最低，为55.00%。死亡个体的湿度培养结果显示绿僵菌在高温条件下萌发的时间较短，40℃为4.26 d，15℃为19.36 d。结果表明环境温度低于15℃或高于35℃都不利于绿僵菌杀死蝗虫。因此，在田间施用金龟子绿僵菌防治东亚飞蝗时应尽量避免高温天气，建议在上午低温时进行防治。

Virulence of Metarhizium anisopliae against 3rd Instar Nymphs of Locusta migratoria manilensis under Different Temperatures

The 3^rd instar nymphs of Locusta migratoria manilensis were treated by the commercial biopesticides Metarhizium anisopliae (PD20080671) through body surface inoculation under six different temperatures (15, 20, 25, 30, 35 and 40℃). The results showed that the cumulative mortality of locust nymphs increased within 19 d after inoculation. The highest (82.5%) was at 35℃ and the lowest (55.0%) was at 40℃. Most of the dead locusts were 3^rd instars and a few were adults as the nyphms molted during the test period. Spore germination from of the dead locusts appeared sooner (4.26 d) at 40℃ and took longer (19.36 days) at 15℃. The results indicate that temperature below 15℃ and greater than 35℃ are not optimal for fungal pathogenesis. These results demonstrate that the best time to apply biopesticides is early morning when the temperature is relatively low.