Abstract:

The pathological changes in integument and midgut of Anoplophora glabripennis larvae infected by Metarhizium anisopliae were studied with a transmission electron microscopy.The results indicated that: in 16 h post-inoculation,the host cuticle was invaded by a few hyphal bodies.Up to 24 h hyphae widely penetrated into host cuticle.The germ tubes showed mechanical pressure and enzymatic activity during the penetration.The hyphae penetrated through the integument and entered the haemocoele from 36 h to 48 h.The hyphae and hyphal bodies invaded all organs and tissues via hemolymph circulation.With the quick and mass reproduction of the hyphae and hyphal bodies in the midgut epithelium,the midgut tissues were gradually destroyed,the midgut microvilli exfoliated,vacuole formed in the midgut epithelium,the peritrophic membrane was decomposed and disappeared,eventually the midgut tissues collapsed and disintegrated from 48 h to 72 h.

Key words: Metarhizium anisopliae, Anoplophora glabripennis, infection process, pathological changes, transmission electron microscopy