Metarhizium robertsii

Metarhizium robertsii – formerly known as M. anisopliae, and even earlier as Entomophthora anisopliae (basionym) – is a fungus that grows naturally in soils throughout the world and causes disease in various insects by acting as a parasitoid. Ilya I. Mechnikov named it after the insect species from which it was originally isolated – the beetle Anisoplia austriaca. It is a mitosporic fungus with asexual reproduction, which was formerly classified in the form class Hyphomycetes of the phylum Deuteromycota (also often called fungi imperfecti).

Many isolates have long been recognised to be specific, and they were assigned variety status, but they have now been assigned as new Metarhizium species, such as M. robertsii, M. majus and M. acridum (which was M. anisopliae var. acridum and included the isolates used for locust control). Metarhizium taii was placed in M. anisopliae var. anisopliae, but has now been described as a synonym of M. guizhouense (see Metarhizium). The commercially important isolate M.a. 43 (or F52, Met52, etc.), which infects Coleoptera and other insect orders has now been assigned to Metarhizium brunneum. M. anisopliae has since been renamed M. robertsii, renamed in honor of Donald W. Roberts, who did his Ph.D. on this species, and has continued to work with it prolifically as a research professor ever since.