Beauveria bassiana is a fungus that grows naturally in soils throughout the world and acts as a parasite on various arthropod species, causing white muscardine disease; it thus belongs to the group of entomopathogenic fungi.

It is used as a biological insecticide to control a number of pests, including termites, thrips, whiteflies, aphids and various beetles.

[2] The species is named after the Italian entomologist Agostino Bassi, who discovered it in 1835 in silkworms (Bombyx mori).

[3] Bassi performed the first infection experiments, and determined the fungus to be the cause of the muscardine disease, which then led to carriers transmitting it by airborne means.

[4][3] The name B. bassiana has long been used to describe a species complex of morphologically similar and closely related isolates.

Beauveria bassiana parasitizing the Colorado potato beetle has been reported to be, in turn, the host of a mycoparasitic fungus Syspastospora parasitica.

[15] A microevolutionary experiment in 2013 showed that the Greater wax moth (Galleria mellonella) was able to adapt its defense mechanisms during 25 generations, while being under constant selective pressure from B. bassiana.

[28] In March 2013, genetically modified B. bassiana was found in a number of research laboratories and greenhouses outside of a designated containment area at Lincoln University in Christchurch, New Zealand.