MORTALITY INDUCED BY BACILLUS-POPILLIAE IN CYCLOCEPHALA-PARALLELA (COLEOPTERA, SCARABAEIDAE) HELD UNDER SIMULATED FIELD TEMPERATURES

The bacterium, Bacillus popilliae Dutky, causes milky disease in numer ous species of scarabs around the world. Bacillus popilliae induced mo rtality in naturally infected grubs (third instars) of Cyclocephala pa rallela Casey was measured when held under simulated field temperature s. Our data show that visual examination in the field underestimates t he percentage of grubs actually infected by B. popilliae. 5.6 to 8.2 t imes as many milky disease infected grubs died during the first 60 day s of incubation under simulated field temperatures than did uninfected grubs. These data show that the widely used prevalence value underest imates the total mortality which this bacterium ultimately causes to C . parallela.