Effects of Dichlorovos Organophosphate on Growth, Reproduction, and Avoidance Behavior of Earthworm Eisenia foetida

The indispensable use of agrochemicals has created serious threats for earthworms abundance and their population; therefore, several earthworm protocols have gained acceptance for use in tests to assess the effects of soil chemicals on soil organisms. Dichlorovos, an organophosphorus pesticide, is one of the widely used pesticides in agricultural fields of M.P., Central India. The aim of the present investigation was to assess the effects of the dichlorovos on growth, reproduction, and avoidance behavior of an earthworm, Eisenia foetida. After evaluating LC50, artificial soil substrate was prepared using an evenly blended mixture of 68% mesh silica sand, 20% kaolin clay, and 10% sphagnum peat. Different concentrations after LC50 probit analysis of the pesticides were prepared in 1000ml of distilled water and mixed with 1 kg of the soil to expose the earthworms in a dose-dependent manner. A decrease was observed in the weight of earthworms at all concentrations of the pesticide used, whereas reproduction and avoidance behavior which are sensitive parameters were found to be significantly affected by all three doses of dichlorovos. Based on the findings of this study, it can be concluded that growth, reproduction, and avoidance behavior can be taken as useful indicators for assessing the sub-lethal effects of pesticides on non-target soil organisms such as earthworms.