Effect of juvenile hormone mimic r394 on silkworm ( Bombyx mori L.) growth and development of silk gland

摘要

The effect of a juvenile hormone (JH) mimic R394 (ethyl 9-cyclohexyl-3, 7-dimethy l-2, 4-nonadienoate) applied topically on the abdominal tergum of silkworm ( Bombyx mori L.) after the fourth ecdysis has been studied. JH R394 ranging from 1.0, 0.1, 0.01 μl / larva was applied at 48, 72 and 96 hours of V instar larva that was improved the cocoon weight, shell weight and shell ratio etc. The most effective dose observed 0.01 μl / larva, when applied at 48 and 72 hours after resumption of the last moult. It was observed that the development of the silk gland takes place up to a particular period, after that the larval development increases due to the increase of the feeding period without any significant increase in silk and silk ratio.