[Histology of insect infection by entomopathogenic fungi: interest in a new procedure for the study of precocious phases]. / Histologie de l'infection des insectes par les champignons entomopathogènes: intérêt d'une nouvelle procédure pour l'étude des phases précoces.

Infective and invasive processes of entomopathogenic fungi expected to be used in biological control shall be analysed in detail. Histological and ultrastructural studies are therefore essential. This paper is devoted to the field of light microscopy; its purpose is to show that coating, in a 4% agar solution, the insects infected by a fungus, prior to fixation and embedding, allows the preservation of the fungal structures present on the cuticle, especially the germinating conidia. This is useful when observing the initial stages of infection. The relevance of this coating technique is illustrated with the example of Pea aphid, Acyrthosiphon pisum, infected by Conidiobolus osmodes. This contribution is the first histological study of infective processes of this entomophthoralean fungus in an insect.