Occurrence of the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana in soils from temperate and near-northern habitats

The occurrence of deuteromycetous entomopathogenic fungi was examined in 26 6 soil samples representing 86 locations across temperate and near northern habitats in Ontario, Canada. Entomopathogenic fungi were isolated by baiti ng the soil with waxworm larvae, Galleria mellonella L., and incubating at 8, 15, or 25 degrees C. Entomopathogenic fungi were isolated from 91% of th e locations sampled across Ontario. The most abundant species were Metarhiz ium anisopliae (Metschn.) Sorok. (357 isolates) and Beauveria bassiana (Bal s.) Vuill. (187 isolates). Thirteen isolates of Paecilomyces spp. were also found. Beauveria bassiana was isolated more frequently in soils from near northern locations, relative to M. anisopliae. Beauveria bassiana was isola ted more frequently from larvae baited in soils incubated at 8 and 15 degre es C, while M. anisopliae was isolated most frequently at 25 degrees C. Thu s, B. bassiana is more psychrophilic than M. anisopliae. From 47 of the loc ations in a temperate area (southern Ontario and the Kawartha Lakes region) , two sites, one from an agricultural habitat and one from a natural habita t, were sampled within 1 km of each other. In these locations, B. bassiana was predominantly recovered more often from soils of natural habitats, whil e M. anisopliae was recovered more often in agricultural habitats. The occu rrence of M. anisopliae and B. bassiana was not related to soil type or pH.