Toxic effects of two organophosphate insecticides,monocrotophos and dichlorvos to common earthworm Lampito Mauritii (Kinberg)

The lethal concentrations (LC₅₀ 96 h^?1) were measured experimentally by exposing the earthworms (Lampito mauritii) in moist vermiculite and in water. The morphological changes observed during the exposure of animals to the monocrotophos and dichlorvos were outlined. The mortality rate was higher in the water medium than in moist vermiculite. The hyperactivity at low pesticide concentrations is found to influence the size of the population.