Influence of metal ions on the economic parameters of mulberry silkworm Bombyx mori (Lepidoptera: Bombycidae).

Micronutrients contribute significantly to homeostasis at the cellular, physiological, and biological interface of silkworm growth and development. The silkworm cocoon traits are highly physiologically dependent, controlled by the optimum availability of micronutrient concentrations. Keeping this in view, two micronutrients, i.e., copper and iron, were investigated to understand their role in economic traits in popular bivoltine silkworm double-hybrid FC × FC. The mulberry leaves were bio-fortified with copper and iron in the form of copper chloride and ferric chloride with concentrations of 0.1%, 0.2%, 0.3%, and 0.5%, respectively. Irrespective of the micronutrients, all the studied pre- and post-cocoon parameters tend to increase at lower concentrations and decline at higher concentrations. ANOVA revealed a significant gain in larval weight (~ 9.28% and ~ 8.42%), single cocoon weight (~ 5.38% and ~ 6.45%), and filament length (~ 8.37%) when the silkworms were fed with the mulberry leaves fortified with a low concentration (0.2%) of copper and iron. The improvement in reelability (~ 4.92%), renditta (~ 1.91% and ~ 1.04%), and denier (~ 11.99% and ~ 7.19%) was maximum at 0.2% of copper- and iron-augmented leaves compared to the control. It is envisaged that copper and iron chlorides compounds have incremental impact in silk production. Therefore, feed bio-fortification with appropriate concentrations of copper and iron is recommended to improve cocoon production in both quality and quantity, thereby enhancing the economic returns for sericulture farmers.