Acute and chronic effects of diflubenzuron (Dimilin) on freshwater fish and invertebrates

Two fish and seven invertebrate freshwater species were exposed to diflubenzuron (Dimilin®) in acute and chronic laboratory tests. No effects on newly hatched and juvenile fathead minnows or juvenile guppies were seen at or below 36 μg/L, the highest concentration tested. An early‐life‐stage test (30‐d) with fathead minnows showed no effect at or below 36 μg/L. No effects on survival, growth or reproduction were observed with two snail species, Juga plicifera and Physa spp., at or below 36 μg/L. Adult emergence of the caddis fly Clistoronia magnifica was inhibited at 0.1 μg/L. Daphnia magna were killed at 2.0 μg/L. Hyalella azteca mortality was significant at 2.0 μg/L. Molting and survival of the midge Tanytarsus dissimilis were affected at 4.9 μg/L. Molting and survival of the midge Cricotopus spp. were affected at 4.9 μg/L, and adult emergence did not occur at 1.6 μg/L.