Impact of newer insecticidal residue on mulberry silkworm, Bombyx mori L.

The present study evaluated the impact of three insecticides, Chlorantraniliprole 18.5% SC at a dosage of 0.02%, Imidacloprid 17.80% SL at 0.05%, and Fipronil 5% SC at0.2%, on silkworm development, cocoon production, and silk quality. Cross-breed silkworms (PM × CSR2) were reared on insecticide-treated mulberry leaves, and parameters such as larval mortality, instar duration, cocoon yield, and silk denier were assessed. The results indicated that all insecticides reduced disease incidence and boosted cocoon yield but adversely affected silk quality. Chlorantraniliprole exhibited a slow yet steady impact, reducing the third instar duration from 88.7 hr at 10 days after spraying (DAS) to 83.54 hr at 25 DAS. On the other hand, Imidacloprid showed a faster effect, decreasing the third instar duration from 84.57 hr at 5 DAS to 72.45 hr at 25 DAS. Fipronil accelerated development, with the shortest instar duration among all treatments. Despite the increase in cocoon yield, the control groups (water spray and untreated) outperformed the insecticide-treated groups in silk quality, with the highest cocoon yield (150.98 g/100 cocoons) and silk denier (2.5) observed in the untreated group. The findings emphasized that although insecticides improve productivity and pest control, natural or minimally treated conditions favour high-quality silk production, advocating for a balanced approach to pest management in sericulture.