Investigations on dynamics of juvenile hormone mimics on the economic parameters of silkworm, Bombyx mori L.

Abstract

Juvenile hormone mimics are known to prolong larval life in insects and thus in sericulture, it has been shown to boost good cocoon and silk yield. In the present experiment, the double hybrid (FC1XFC2) silkworm was utilized and analysed the performance of economic traits. The influence of juvenile hormone mimics ie., phytojuvenoids from Pinus (Pinus roxburghii), Custard apple (Annona squamosa) and Tapioca (Manihot esculenta), a commercially available juvenile hormone mimic Serimore and Pyriproxyfen has been recorded as quantitative characters of silkworm when administered topically with two different doses at two distinct larval instars. The quantum of expression of economic trait like cocoon weight, shell weight, shell ratio, filament length and denier were found to be increasing with the increase in the number of larval treatments which is double administration at the rate of 20% and 30% concentration for Pinus and Tapioca treated larvae. In case of custard apple treated larvae, double treatment at 20% concentration showed best results. Single treatment at 5µl and 10µl concentration of pyriproxyfen gave similar outcome with respect to all economic parameters. Among all, Pinus was found to be on par with Serimore for all the economic characters.