SOIL APPLICATION EFFECTS OF METARHIZIUM-ANISOPLIAE ON JAPANESE-BEETLE (COLEOPTERA, SCARABAEIDAE) BEHAVIOR AND SURVIVAL IN TURFGRASS MICROCOSMS

The effect of mycelial and conidial formulations of the insect pathogenic fungi, M. anisopliae, on the survival and behavior Japanese beetle, Popillia japonica Newman, larvae and ovipositing adults in turfgrass-soil microcosms was explored. Changes in Japanese beetle grub feeding site selection on sod roots, movement patterns, and survival in Metarhizium anisopliae inoculated soil were examined in greenhouse studies and through the use of radiographic analysis in the laboratory. Our studies indicate that the application of mycelial particles in soil affected the behavior of both larval and adult Japanese beetles. Japanese beetle grubs avoided soil that contained high concentrations of pathogen for up to 20 d after application. Conversely, the incorporation of mycelial particles increased oviposition in both choice and no choice studies. Our findings on scarab response to inundative applications of M. anisopliae mycelium may help explain some of the inconsistency in results that often occur when fungal pathogens are used to control insects in the field.