The FungusBeauveria bassiana(Balsamo) Vuillemin in a Corn Ecosystem: Its Effect on the Insect PredatorColeomegilla maculataDe Geer

Isolate ARSEF 3113, of the fungusBeauveria bassiana(Balsamo) Vuillemin, has potential as a control agent in an integrated pest management program in corn for the European corn borer,Ostrinia nubilalis(Hübner), but its impact on beneficial insects must also be considered. This isolate ARSEF 3113 was tested in the field and laboratory for its compatibility with the coccinellid,Coleomegilla maculataDe Geer. Fourth instars ofC. maculatawere exposed by direct contact with a granular formulation ofB. bassianacontaining 1.1 × 108conidia per gram. No mortality ofC. maculatawas observed, nor was the fungus isolated from any of the exposed coccinellids.Coleomegilla maculatapopulations and indigenousB. bassianaon corn plants and in the soil also were monitored in field plots under three tillage systems. Results suggested a spatial and temporal specificity forB. bassiana.WhenC. maculatadensity was highest,B. bassianawas not isolated from corn plant tissues (leaf collar). We concluded that isolate ARSEF 3113 is compatible withC. maculatain managingO. nubilalisin an Iowa corn ecosystem.