Present Status of Milky Disease of Japanese and Oriental Beetles in Connecticut1

Abstract

A survey of Japanese beetle, Papillia japonica Newman, and Oriental beetle, Anomala orientalis Waterhouse, grubs from 53 sites in the spring and 62 sites in the fall of 1974, showed that incidence of infection with Bacillus popilliae Dutky, causal agent of milky disease, was remarkably low in Connecticut. Laboratory tests conducted with B. popilliae from field collected Connecticut and New York grubs determined that spores were especially low in infectivity both by ingestion and by intrahemocoelic injection when compared to infection data from earlier published reports. A. orientalis and P. japonica seemed comparable in their sensitivity to B. papilliae by injection. Spores from diseased grubs collected at different locations in the state varied in their rates of infectivity.