Molecular characterization of isolates of Metarhizium from locusts and grasshoppers

The relationships between 30 strains of Metarhizium were investigated by isoenzyme analysis, PCR-RAPDs, and protease production. The strains included representatives of M. anisopliae, M. flavoviride var. flavoviride and M. flavoviride var. minus. Thirteen isolates conforming to M. flavoviride from acridoid hosts and pathogenic to locusts and grasshoppers were shown to be a single, distinctive genotype with a pan-tropical distribution. In addition, the separation of M. flavoviride var. minus as a host specific taxon distinct from European isolates of M. flavoviride was also supported. The possibility of coevolution within some insect pathogenic populations is discussed.