Assessment of Reproductive Toxicity of Malathion on the Earthworm, Eisenia foetida under Chronic Exposure Conditions.

The present study demonstrated that Malathion exposure produced a pronounced, concentration-dependent adverse effect on the reproductive performance of Eisenia foetida. Juvenile emergence progressively decreased with increasing Malathion concentration, declining from 58.00 juveniles in the control group to 11.66 ± 0.58 juveniles at 30 mg/kg. Correspondingly, reproductive inhibition increased from 8.04% at 5 mg/kg to 79.88% at 30 mg/kg, indicating substantial impairment of reproductive output at higher exposure concentrations. Statistical analysis confirmed the significance of these effects, with one-way ANOVA showing a highly significant difference among treatment groups (p < 0.001). Pearson correlation analysis further established a very strong negative relationship between Malathion concentration and juvenile emergence (r = −0.996, R² = 0.992, p < 0.001), while reproductive inhibition showed a very strong positive correlation with Malathion concentration (r = 0.996, R² = 0.992, p < 0.001). Thus, the findings clearly indicate that increasing Malathion exposure significantly reduces juvenile production and reproductive success in E. foetida. The results emphasize that reproductive parameters, particularly juvenile emergence, are sensitive indicators of sublethal pesticide stress and should be considered in the ecological risk assessment of Malathion. Prolonged exposure to elevated concentrations of Malathion may adversely affect earthworm population renewal and, consequently, important soil ecosystem processes. Overall, the study highlights the potential ecological consequences of Malathion contamination and supports the need for its judicious use and appropriate management to minimize adverse effects on beneficial soil organisms.

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