Biological control of the black field cricket, Teleogryllus commodus (Walker) (Orthoptera: Gryllidae), using the fungal pathogen Metarhizium anisopliae (Metsch.) Sorokin (Deuteromycotina: Hyphomycetes)
Richard J. MilnerA, Lisa MillerB, George G. LuttonA and Felice DriverA
A CSIRO, Division of Entomology, GPO Box 1700, Canberra, ACT 2601, Australia.
B Agriculture Victoria, Colac, Victoria 3250, Australia.
The hyphomycete fungus, Metarhizium anisopliae, is a natural pathogen of black field cricket, Teleogryllus commodus, in Victoria. Comparison of 12 isolates, using Random Amplified Polymorphic DNA (RAPDs), from this insect collected in Victoria showed that they were all very similar genetically but quite distinct from the group 3 M. flavoviride isolates from grasshoppers and locusts. Screening bioassays showed that isolates from crickets were more virulent for this pest than isolates from other sources. One of these cricket isolates FI1099 was selected for use in field trials. An oil formulation of conidia of FI1099 was tested either as a ultra-low volume (ULV) spray or in a high volume oil/water emulsion at two sites in Victoria. At Warrambeen, a dose of 2 x 1013 conidia per hectare gave a 30-40% reduction in the cricket population after 21 days compared with 80% control in the malathion plots. At Turkeith, the higher dose of 4 x 1013 conidia per hectare gave 60-70% control while the malathion again gave about 80% control. These results are promising and show that M. anisopliae has the potential to control black field cricket when applied as an oil-based mycoinsecticide.
Plant Protection Quarterly (1996) 11 (1) 9-13.