Compatibility of entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae with some pesticides

Entomopathogenic fungi may be affected by pesticides used to protect crop plants. The in vitro compatibility of Beauveria bassiana and Metarhizium anisopliae with three fungicides and 16 insecticides was evaluated. The formulations of pesticides were tested in three concentrations (mean concentration (MC), half MC and twice the MC). All tested fungicides, at three concentrations, were incompatible with these two fungi and significantly inhibited fungal development, germination of spores and spore production. Insecticides, except for spinosad, deltametrin, imidachloprid and abamectin, were incompatible with these two fungi at high concentration and caused complete or strong inhibition of fungal development. The compatible insecticide with B. bassiana and M. anisopliae, at three concentrations, found to be spinosad. Abamectin, imidachloprid and deltametrin, however at half MC and MC were compatible with B. bassiana. Deltametrin, abamectin and hexafloron at half MC were compatible with M. anisopliae. We conclude that these pesticides with the defined formulations could be used with the entomopathogenic fungi in integrated pest management programs.