甜菜夜蛾感染白僵菌、绿僵菌后的病症及组织病理学变化

Study on Histopathological Changes of Laphygma exigua (Hubner) Infected by Beauveria bassiana and Metarhizium anisopliae

甜菜夜蛾感染白僵菌和绿僵菌后,虫体颜色及外部形态均发生相应变化。其组织切片观察研究表明:两种供试菌株的致病过程基本一致,只在侵染速度上有所差异:绿僵菌侵染速度较快,而且其破坏裂解组织的程度远大于白僵菌。白僵菌菌株015处理24 h后肠道内未见萌发的孢子,组织没有发现变化;48 h,附着于甜菜夜蛾体壁外的孢子开始萌发;72 h体腔内明显的菌丝段,各组织器官均受到感染,之后进入体内的菌丝不断增殖,脂肪体、肌肉组织、消化道发生病变解体;120 h后,菌丝突破虫体,在体外形成菌丝层。较之于绿僵菌菌株060,72 h时菌丝充满血腔,肠壁细胞也受到严重侵染,肠腔内出现菌丝,部分菌丝突出体表,菌株086,96 h时各组织均解体。

Laphygma exigua Hubner was infected by two isolates of Metarhizium anisopliae and two isolates of Beauveria bassiana. There were some changes in color and morphology on the Laphygma exigua Hubner . The result of Paraffin sections showed that the invasion process by Beauveria bassiana were similar by Metarhizium anisopliae. But the invasion speed was different. The invasion speed of Metarhizium ansopliae was faster than Beauveria bassiana.. The spore in the intestine was not bourgeon and the organization of Laphygma exigua Hubner was not change at 24h. After 48h, the spore was bourgeon on the cuticular. By 72h,the hypha could be observed in the blood and began to reproduced in hemoooele. And then, the fattiness , muscle tissue and alimentary tract carryeg on a series of pathological changes. The hypha emerged through the cuticle and formed hyphal layer on the surface of the dead insect 120h postinooulation. The hypha emerged through the cuticle when Laphygma exigua Hubner was infected by Metarhizium anisopliae 060 at 72h By 96h,the organization of Laphygma exigua Hubner by Metarhizium anisopliae 086 was destroyed entirely.