Abstract: A process is provided for the fermentation production of hyphal bodies which form conidia of species of the fungal order Entomophthorales, especially Entomophaga aulicae. The process uses an improved growth medium. The improved mediuem includes, in addition to a basal medium, filter-sterilized tryptic soy broth and calcium caseinate. Such medium allows the use of a protoplast and/or a walled stage inoculum in a batch fermentation process.