Abstract: In oriental migratory locust, Locusta migratoria manilensis (Meyen), the pathogenic microsporidia, Nosema locustae, passes two developmental stages, schizogony and sporogony, which can be observed under phase contrast microscope.Schizogonies occur mainly in earlier morbid corpses, and produce few spores only; while sporogonies are mainly in later morbid corpses and produce much more spores.The death time of the infected hosts relates directly to the inoculating dosage and the host age inoculated, which perform the key factors of mass propagation of the microsporidia.The wheat bran baits treated with N.locustae were proved to be successful to reduce the grasshopper population under ETL when the density of the natural population is low.The wheat-bran baits treated with N.locustae incorporated with low dosages of chemical insecticides were proved to be effective to control the high-density grasshoppers.

Key words: Nosema locustae, Microsporidia, Locust and Grasshopper, Biological control

摘要： 探索蝗虫微孢子虫在蝗虫体内增殖特性,用相差显微镜检查病死蝗虫体内病原物具有两种发育阶段。裂殖生殖期和孢子形成期。病虫在孢子形成期死亡则能获得较高产孢量,可见产孢量与病虫致死时间有关。接种病原浓度和寄主虫龄又影响致死时间,因而影响孢子产量。选择适宜接种病原浓度和寄主虫龄是获得较高孢子产量的重要因子。利用微孢子虫治蝗在蝗虫低密度下施用,可以控制煌害在经济阈值以下,高虫口密度下与少量化学农药混用也能收到治蝗效果。

关键词: 蝗虫微孢子虫, 微孢子虫大量增殖, 生物防治