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Four hundred and nineteen pasture soil samples yielded 132 M. anisopliae var. anisopliae isolates, which were classified into 14 strains. The distribution of the strains varied with soil-type and average annual rainfall. Soil pH, conductivity, temperature and altitude had minor or no effect on distribution. Canonical Variate Analysis as used to plot the relative positioning of strains in relation to the environmental variables. The densities of strains (c.f.u. g−1 soil) were not significantly different (P > 0·05). Modal density was 1 × 103 c.f.u. g−1 soil. The density was not correlated with any of the environmental variables examined.

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.