Abstract: The invasive processes of Pandora nouryi (Remaudière & Hennebert) Humber in the host aphid Myzus persicae (Sulzer) was observed with scanning electronic microscopy. It was found that the conidia attached to the surface of aphid germinated rapidly. About 60% conidia germinated to germ tube or globose appressorium for invasion within 3－5 h after attachment. By 12 h after attachment almost all conidia had germinated and invaded into the host successfully. By 60 h postinoculation the digital rhizoids were the first structures to emerge from the breast region of aphid body, attaching the host to the plant. Few pseudocystidia were found and just distributed at the two sides of aphid body, which may explain why existence of more moisture conditions is necessary for free discharge of conidial sporulation from cadavers killed by P. nouryi.

Key words: Pandora nouryi, Myzus persicae, invasive process, inoculation, scanning electronic microscopy