Testing of the fungus Akanthomyces muscarius (Ascomycota: Hypocreales) against the spider mite on lotus under high temperature conditions

The entomopathogenic fungus Akanthomyces muscarius (Ascomycota: Hypocreales) strain G-033 VIZR was tested against the spider mite Tetranychus urticae on the lotus Nelumbo nucifera in a water greenhouse. At elevated air temperature (33–36 °C) and an outbreak of the pest (up to 800 specimens per leaf), biological efficiency of fungal conidia (5×107 spores/mL) was high, up to 90 % on 7th day post treatment, which is comparable to the standard treatment with Fitoverm, CE 2 g/L. One month after, no spider mites were found on the treated leaves. In the second year, when the pest density was low (up to 250 specimens per leaf), a reduced concentration of spore suspension (5×106 spores/ml) was used. Its biological effectiveness was also high (up to 95 %). The trials showed the potential of strain G-033 VIZR against the motile stages of spider mites under conditions of elevated air temperature.