Abstract: 【Aim】 The purpose of this study is to investigate the infection process by Beauveria bassiana in the integument and fat body of Antheraea pernyi pupae so as to further clarify the pathogenesis in A. pernyi pupae infected by B. bassiana. 【Methods】 The morphological changes in the integument and fat body of A. pernyi pupae infected by B. bassiana were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. 【Results】 SEM observation indicated that the infection of B. bassiana in A. pernyi pupae mainly occurred at valves, bristles root and the intersegmental membrane between head and thorax. Besides, conidia penetrated into the body directly from the thick and hard wall of the body. TEM observation indicated that in the fat body, organelles except mitochondria were first infected, and then the fat droplets were eroded. The infected fat droplets became shallow, their surface had many holes and became deformed, and the fat droplets were divided into small fat droplets, indicating that they were completely eroded. When pupae were rigid, fat cells were completely destroyed, leaving only the blastospores and hyphae. 【Conclusion】 The integument and fat body of A. pernyi pupae infected by B. bassiana have obvious histopathological changes.

Key words: Beauveria bassiana, Antheraea pernyi, pupae, scanning electron microscopy (SEM), transmission electron microscopy (TEM), infection process