Abstract
Because of their high biomass in the soil, earthworms are used as bio-indicator species for assessing soil toxicity against pesticides. The regular observed sensitivity to relatively low pesticide concentrations exits in soils is a significant ecological observation. Insecticide residues harm the flora of beneficial invertebrates and harm the physiological functions of earthworms, resulting in death. They affect morphological parameters as well as internal organs, and eight different imidacloprid concentrations (0.050 µl/cm2, 0.100 µl/cm2, 0.150 µl/cm2, 0.200 µl/cm2, 0.250 µl/cm2, 0.300 µl/cm2, 0.350 µl/cm2, 0.400 µl/cm2) were prepared with water during the procedure. To establish the LC50 value, earthworms of Eisenia fetida were exposed to various concentrations of imidacloprid using the usual paper contact toxicity method, and their toxicity levels are established. The mortality percentage was estimated after 24 hours of imidacloprid exposure, and a dosage of 0.195 µl/cm2 resulted in 50% mortality of earthworms. When higher concentrations of imidacloprid were used, negative effects were observed. For ecotoxicological evaluations, the following morphological and behavioural changes were observed during the experiment: Preclittelar bulging, body constriction, blackening of the body, segment swelling, oozing of coelomic fluid, body constriction, cuticle rupture, and oozing of fluid from the body are all common side effects.