Several isolates of the recently described bacterial species Chromobacterium sphagni Blackburn et al. were obtained from water collected from Sphagnum bogs in West Virginia and Maine. Bacterial isolates were cultured in a liquid medium and applied to artificial insect diets in the laboratory. The new isolates were toxic to larvae of the gypsy moth, Lymantria dispar (L.), and the diamondback moth, Plutella xylostella (L.), but were not toxic to larvae of the seedcorn maggot, Delia platura (Meigen), or adults of the red flour beetle, Tribolium castaneum (Herbst).