Research Product

Elimination of Bacillus sphaericus spores ingested by midge larvae, snails and oysters was most rapid among midge larvae. Spores remained in oysters up to 21 days and in snails up to 49 days. Viable spores were recovered in snail and oyster feces for these same periods. There was no indication of actively growing B. sphaericus in these invertebrates. Passage through the oyster gut detoxified the B. sphaericus mosquito larval toxin, but there was a 67% loss of toxicity following snail gut passage. Midge larvae reared to adult flies in spore-containing water carried spores in/on the adult fly body. This suggests the possibility that this animal could carry the bacteria to sites beyond the application area.