Characterization of Metarhizium anisopliae isolates from Tasmanian pasture soils and their pathogenicity to redheaded cockchafer (Coleoptera: Scarabaeidae: Adoryphorus couloni)

Two hundred and four cultures of Metarhizium anisopliae var. anisopliae isolated from Tasmanian pasture soils were studied. Sixteen strains are distinguished by temperature requirements for germination and growth, conidial dimensions and sporulation colour. Hierarchical cluster analysis supports this classification. A key to the strains is provided. Pathogenicity testing of 184 of the cultures revealed that 50% (15/31) of isolates from one dendrogramic branch were pathogenic for L3 larvae of the scarab, Adoryphorus couloni. Only 4% (6/153) were found to be pathogenic amongst the other strains.