1	Beauveria bassiana Aggressive Entomopathogenic & Parasitic Fungus
2	What is B. bassiana ? Globally occurring soil borne mycelial fungus. Produces conidiospores (exospores) Produces a low molecular weight toxin Beauvericin Produces the antibiotic oosporein Produces degrading enzymes
3	Historical Significance of B. bassiana Sever losses of silkworm larvae in 16^th & 17^th centuries due to “muscardine” Caterpillars appeared white & mummified Muscardine is derived from the French word for bonbon
4	Historical Significance of B. bassiana 1835: Italian scientist Agostino Bassi de Lodi showed the disease was caused by a fungus. The fungus is named in honor of its discoverer
5	Cycle of Infection: The spore Acropetal succession Non pigmented asexual spores
6	Cycle of Infection: The spore Conidium adhering to the host cuticle will germinate The fungal hypha secretes enzymes which attack and dissolve the cuticle, penetrate the skin and grow into the insect body Flies can pick up fungal spores just by walking on a fungus-treated surface, and they inadvertently spread the spores over their bodies by grooming
7	Cycle of Infection: Control Much like the crab parasite Sacculina Once inside, the fungus replicates and consumes the insects' internal organs and blood-like fluid, the hemolymph It produces a toxin called Beauvericin that weakens the host's immune system Forces fly to find high place & adhere proboscis to suface, thus gluing itself to the perch Eventually the entire body cavity is filled with fungal mass
8	Cycle of Infection: Exodus After the insect dies, an antibiotic (oosporein) is produced that enables the fungus to out compete intestinal bacteria When conditions are favorable the fungus will grow through the softer parts of the insect's body, producing the characteristic “white bloom" appearance Tendrils are spring-loaded packages of spores Relative humidity must be 92% or more for B. bassiana to grow outside the insect
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10	Exploitation of B. bassiana reduced risk microbial insecticide against foliar feeding pests fungal pathogens infect the insect with contact and do not need to be consumed by their host to cause infection has the capability of living in the vascular tissue of certain corn cultivars as an endophyte The rate at which Beauveria spores kill their host is dependent on temperature and humidity