Residual Effect of Chemical Insecticides used Against Thrips on Larval Parameters of Silkworm Bombyx mori L

Author: Sithara H. and Fatima Sadatulla

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Abstract

A study was conducted to evaluate the safety period and residual effect of chemical insecticides used against thrips through rearing performance of silkworm Bombyx mori L. Insecticides were sprayed on mulberry at an interval of 25 (20 DAS), 30 (15 DAS) and 35 (10 DAS) days after pruning. Among the treatments acetamiprid recorded highest larval mortality per cent even upto 20 DAS, Mortality was zero in buprofezin, fipronil, dimethoate at 15 and 20 DAS. Where as in acephate and imidacloprid there was zero mortality at 20 DAS. Acetamiprid adversely affected the rearing performance of silkworm with residual toxicity symptoms like vomiting gut juice, rectal protrusion, stiffening of larval body and twisting of larval body in agony, hook shaped larvae with shrunken body, death of larvae without moulting, incomplete moulting and death of ripened larvae without spinning

Keywords

Mulberry, silkworm, DAS, insecticides, acetamiprid

Conclusion

Acetamiprid belongs to neonicotinoid group of chemicals which shows systemic and translaminar action and it is also belongs to broad-spectrum insecticide, which is mainly used to control sucking pests but it also shows its effect on biting and chewing type of insects hence its residue on mulberry leaves showed adverse effect on silkworm performance with toxicity symptoms like rectal protrusion, vomiting gut juice with shrinkage of larval body, twisting the body in agony and stiffening of the larval body etc. From this study it is suggested that fipronil and dimethoate had a reasonably good safety period of 15 days and resulted in better rearing parameters

References

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How to cite this article

Sithara H. and Fatima Sadatulla (2024). Residual Effect of Chemical Insecticides used Against Thrips on Larval Parameters of Silkworm Bombyx mori L.. Biological Forum – An International Journal, 16(5): 98-103.