Vol. 12, Issue 9 (2023)

Juvenile hormone analogues (JHA) are recognized for their ability to extend the larval stage in insects. These compounds have been observed to enhance both the qualitative and quantitative characteristics of the silkworm Bombyx mori L. In our current investigation, we applied the juvenile hormone analogue known as methoprene topically to a popular bivoltine hybrid of silkworms (CSR₂ x CSR₄) at different concentrations (0.01 µl, 0.1 µl, 1 µl per larva) at various time points (24, 48, 72, and 96 hours after the start of the fifth instar stage). This treatment combination resulted in a significant increase in the weight of individual cocoons, the weight of the cocoon shells and shell percentage. The most substantial improvement was observed in the silkworm groups treated with 0.1 µl of methoprene per larva 48 hours into the fifth instar. The incorporation of juvenile hormone analogue (Methoprene) into Sericultural practices holds promise for achieving higher quality and quantity of silk cocoons.