The pathogenic effects of Lecanicillium lecanii ITEM 3757 towards winged and wingless adult morphs of the species Schizaphis graminum were investigated under laboratory conditions. Fungus was applied to aphids in the form of ground dried cultures grown in solid state fermentation on rice kernels. This formulation affected aphid survival and reproduction, and it interacted differently with winged and wingless aphid morphs. Scanning Electron Microscope observations pointed out a higher amount of adhering formulation and faster rates of fungal germination and sporulation on the winged cuticle. Our results suggest that the strain might be a good candidate for a programme of biocontrol against S. graminum and other aphids species.