Entomogenous Fungi: Entomophthora Species with Pear-Shaped to Almost Spherical Conidia (Entomophthorales: Entomophthoraceae)

Abstract

Entomophthora Fres. (Phycoraycetes: Entomophthorales) presently comprises some 150 species, many of which cause, as a result of epizootics, significant reductions in numbers among various insect species. The taxonomy of the 48 species with pyriform to almost spherical conidia is considered in this paper. The various taxa are reviewed and it is concluded that 34 may be valid species, although 14 of them are thought to be insufficiently described; another 10 are regarded as synonyms, and four are excluded from the genus. A key for the separation and identification of the 20 adequately described species of Entomophthora is provided. As a further aid in the identification of these fungi, the host names as originally cited and the names by which they are presently known as well as the insect genera known to be infected by Entomophthora spp. are listed. In general, the morphology of these fungi varies and it is not always easy to assign specific status to the forms described. Indeed, it appears that certain species can only be separated on the basis of their pathogenicity to certain host species, or groups of insects. Additional studies to culture the more fastidious species on artificial media, to conduct cross inoculation tests with morphologically similar forms, and to clarify the life cycle of those taxa in which one spore form is known are required before a broader understanding of these species can be obtained.