Toxicological effects of cadmium and lead on growth, biochemical responses, and cocoon quality in tasar silkworm (Antheraea mylitta)

Abstract Background Cadmium (Cd) and Lead (Pb) are pervasive environmental pollutants known to accumulate in terrestrial ecosystems and enter the food chain, posing significant risks to economically important insects. In sericulture, silkworms are particularly vulnerable to heavy metal exposure through contaminated host plants, which can impair growth, metabolism, and silk production. Antheraea mylitta , an important wild sericigenous insect, is highly sensitive to environmental stressors, yet limited information is available on its response to heavy metal toxicity. Therefore, the present study aimed to evaluate the effects of Cd and Pb on the morphological, biochemical, and cocoon quality parameters of the silkworm A. mylitta . Results Larvae (5th instar) of A. mylitta were fed on Terminalia arjuna leaves were supplemented with trace elements Cd and Pb for 7 days. Experimental animals, comprising control (group I: without exposure of Cd and Pb) and all treated groups (groups II, III and IV), were exposed to Cd and Pb in different concentrations of 0.1 ppm, 1 ppm, and 10 ppm, respectively. Compared to the control, a dose-dependent variation was observed in morphological indices, including larval body length and weight, along with noticeable colour changes. Biochemical analysis revealed a significant reduction (p ≤ 0.05) in protein and carbohydrate contents, while catalase activity showed a stress-associated variation in treated groups. Cocoon quality parameters, such as cocoon weight, shell weight, and shell ratio, were also significantly reduced at higher concentrations (1 and 10 ppm). Conclusion The results suggest that Cd and Pb have a profound effect on its growth, biochemical indices, and cocoon quality in A. mylitta in a concentration-dependent manner. These results indicate potential risks of heavy metal contamination to tasar sericulture under polluted environmental conditions.