Toxicity of the organophosphorous insecticide chlormephos to the earthworm Eisenia andrei and the terrestrial isopod Porcellio scaber

In the present study we determined the toxicity of chlormephos to two common soil organisms – earthworms (Eisenia andrei) and isopods(Porcellio scaber) using Lufa 2.2 soil. The LC50 values for the effects on earthworm and isopod survival were 58 and 76 mg/kg dry soil, respectively. Mass change of earthworms and behaviour of isopods were more sensitive end points as survival. Based on earthworm body mass changes, NOEC and LOEC values were 1 and 3 mg/kg dry soil, respectively. The earthworms did not reproduce even at the lowest chlormephos concentration (LOEC < 1 mg/kg dry soil). Isopods significantly avoided burrowing in soil treated with ≥40 mg/kg dry soil. Compared with some other organophosphate insecticides, chlormephos was highly toxic to beneficial terrestrial invertebrates.