The Beauveria species are imperfect filamentous fungi belonging to the class Deuteromycetes. The sexual form belongs to the class Ascomycetes (Cordyceps). The genus includes 4 saprophytes or parasites and entomopathogenic species.
Their slow-growing colonies are cottony to powdery are generally white or pale yellow to pale pink. The conidiophores have a typical form, with a swollen base and zigzag end. The unicellular and hyaline conidia are spherical (2-4 μm in diameter) or oval (1-5 x 1-3 μm). In an anaerobic medium, they form oval blastospores (2-3 x 7 μm).
Beauveria spp. are cosmopolitan and ubiquitous (plants, plant debris, soil), entomopathogenic and rarely pathogenic. In the wild, Beauveria bassiana causes the white hazel dormouse silkworms whose distribution is worldwide. Beauveria is a biopesticide used in biological control, to kill or control populations of crop pests (weevils, beetles, locusts, etc.).