Comparative toxicities of five insecticides to the earthworm, Lumbricus terrestris

Earth worms (Lumbricus terrestris) were exposed under laboratory conditions to aldrin, endrin, DDE, parathion and carbaryl in seven different concentrations ranging from 1.5 to 150 μg/g of bedding. Results showed that earthworms were able to tolerate doses of up to 14 μg/g of bedding.without significant mortalities. However, some behavioral and physical symptoms such as “withdrawal responses” and discoloration of the skin were noted in animals where non-lethal dosages were employed. Aldrin and endrin gave an LD₅₀ of approximately 45 μg/g, DDE gave an LD₅₀ of 46 μg/g, parathion showed an LD₅₀ of 34 μg/g and carbaryl which gave an LD₅₀ of 28 μg/g showed the most lethal effect of all insecticides tested.