Effect of density of the termite, Reticulitermes speratus Kolbe (Isoptera: Rhinotermitidae), on the susceptibilities to Metarhizium anisopliae.

Abstract

Termites, Reticulitermes speratus Kolbe, reared individually were highly susceptible to the entomopathogenic fungus Metarhizium anisopliae. In contrast, termites reared in groups were highly resistant to M. anisopliae. When reared in groups, the termites treated with M. anisopliae conidia on the body surface were groomed by their nestmates and more than 90% of the conidia were removed from the cuticle within 3 h. However, the conidia affiliated with the termites reared individually did not show a marked reduction. Within 3 h, almost all of the termites held in groups contained the conidia in their foreguts, but no conidia were detected in the foreguts of the termites reared individually. These data suggest that one of the functions of grooming by nestmates is the removal of foreign bodies, such as fungal conidia, from the cuticle and the mutual grooming behavior is very effective in protecting them from M. anisopliae infection.