蝗虫微孢子虫与绿僵菌协调使用对东亚飞蝗的毒力测定

以东亚飞蝗三龄蝗蝻为试虫,室内生物测定蝗虫微孢子虫与绿僵菌对试虫的毒力,并研究了这两种病原物以5种比例联合使用的各方面效果。结果表明,蝗虫微孢子虫与绿僵菌对东亚飞蝗LD50分别是7.72×104个/g和5.04×105个/g。两者联合使用增效显著,其中绿僵菌与微孢子虫以1∶1比例处理试虫,饲养24d的LD50（2.5×104个/g）和LD90（1.99×106个/g）均较其他比例最小,效果最佳。比较7个不同剂量处理组的致死时间,LT50从小到大为2∶1,16∶1,1∶1,1∶2,0∶1,1∶0,1∶29;LT90从小到大为2∶1,1∶1,1∶2,16∶1,1∶0,0∶1,1∶29,若同时考虑接种剂量大小,则1∶1处理组致死时间相对最佳。比较6组处理的存活试虫的蝗虫微孢子虫感染情况,各组存活试虫仍可达到较高感染率,联合使用两种病原物在统计学生对微孢子虫感染情况无显著影响。综合各方面因素,当接种剂量绿僵菌∶蝗虫微孢子虫为1∶1时,达到防治东亚飞蝗的最佳实验室配比。

Virulence of Metarhizium anisopliae and Nosema locustae against the Nymphs of Locusta migratoria manilensis

The individual and synergigistic virulence of Metarhizium anisopliae var. acridum and Nosema locustae on the 3rd nymphs of Locusta migratoria were determined. The results showed that the LD50 of Nosema locustae and Metarhizium anisopliae var. acridum were 7.72×104spores/g and 5.04×105 spores/g,respectively. An increased effect was found when Nosema locustae and Metarhizium anisopliae were combined to be tested. When the ratio of Nosema locustae to Metarhizium anisopliae was 1∶1,the LD50 (2.5×104 spores/g) and LD90 (1.99×106 spores/g) were the minimum. Among seven different ratios∶ LT50,from small to big,are 2∶1,16∶1,1∶1,1∶2,0∶1,1∶0 and 1∶29; LT90,from small to big,are 2∶1,1∶1,1∶2,16∶1,1∶0,0∶1 and 1∶29,then if consider about the ratios of Metarhizium anisopliae var. acridum to Nosema locustae,the lethal time of 1∶1 groups was better than others. After microscopic examination of Nosema locustae,the results showed that there had no significant effect on the combined use of the two pathogens. All the analysis of this study showed that when Metarhizium anisopliae var. acridum (1∶0) and Nosema locustae (0∶1) control the nymphs of Locusta migratoria manilensis by artificial inoculation,the 1∶1 dose ratio was the optimum one in the experiment.