RESUMO
In biological control, different benefit organisms have to combine for an effective management. If entomopathogenic fungi will be integrated, than it has to be considered also the effect on non-target organisms Like beneficial arthropods. Because of the high importance of predatory mite Phytoseiulus persimilis in biological control it was to determine side effects of Leconicillium muscarium on this species. In two standardised biotests in petri dish and on plants (P. vulgaris) individuals were dipped in suspension or set down on leafs after spraying with L. muscarium at different spore density. Results indicate pathogenicity for the predatory mite in principle. But the dimension of infection risk decrease, all the more conditions approach to practical sequence. Under practical conditions on plants and in practical relevant concentration of 10(6) and 10(7) sp./ml no risk is to expect on the plant.