铜绿丽金龟和黄褐丽金龟幼虫感染Bt HBF-1菌株后的病症及中肠组织病理变化

Symptoms of Anomala corpulenta and A. exoleta(Coleoptera:Rutelidae) larvae infected by Bt HBF-1 strain and histopathological changes in their midguts

研究了丽金龟科(Rutelidae)铜绿丽金龟Anomala corpulenta和黄褐丽金龟A.exoleta幼虫感染苏云金芽孢杆菌Bacillus thuringiensis HBF-1菌株后的病症,并采用组织切片的方法研究了感染HBF-1菌株后中肠的组织病理变化。结果表明:丽金龟科幼虫感染HBF-1菌株后,初期幼虫无明显感病症状,随着感染时间的延长,逐渐出现反应迟钝、麻痹、丧失条件反射能力等症状,最终虫体变黑、伸直或是收缩,直至死亡,时间稍长便会呈腐稠状。在相差显微镜下观察中肠组织切片发现,感染3d时,肠壁细胞出现变形及空洞;7d时,细胞破坏更加严重,甚至无法辨认细胞形状;10d时,肠壁细胞开始脱离底膜;新鲜死虫,肠壁细胞连同细胞内含物全部脱离,仅留底膜。

The symptoms and histopathological changes in the midguts of Anomala corpulenta and A. exoleta larvae infected by Bacillus thuringiensis HBF-1 strain were observed using histopathological slice. The results showed that no obvious symptom of the larvae was observed at the beginning of HBF-1 infection. With the time increasing, the infected insect appeared inactive, paralyzed and lost its sensitivity to the environment, and finally became blackish, straight or shrinked until to death. The results of histopathological obeservations under microscope showed that the midgut cells appeared with malformation and vacuolization 3 days after HBF- 1 infection, and were seriously damaged and even destroyed completely 7 days after infection, while the epithelium began to deviate from the membrane 10 days after infection. In the newly dead insects, the epithelium shed completely together with the endocyte.