Biochemical Alterations in the Haemolymph of Silkworm [Bombyx mori (L).(Lepidoptera: Bombycidae)] Fed with Mulberry Leaves Enriched with Indian Bean (Dolichos lablab)

Abstract

A study was carried out to evaluate the effect of Indian bean (Dolichos lablab) supplementation on silkworm. Finely powdered Dolichos lablab was dissolved in distilled water and diluted to 2.5 %, 5 %, 7.5 % and 10 % concentrations. Fresh mulberry leaves (Morus alba L.) were sprayed by each concentration and were fed to silkworms, from 3rd to 5th instar, five feedings/day. Group 1 larvae received mulberry leaves sprayed with distilled water and served as control, group 2  larvae received 2.5% Dolichos lablab sprayed mulberry leaves, group 3 larvae received 5 % Dolichos lablab sprayed mulberry leaves, group 4 larvae received 7.5 % Dolichos lablab sprayed mulberry leaves and group 5 larvae received 10 % Dolichos lablab sprayed mulberry leaves. Silkworm larvae fed on Morus alba. L. (mulberry) leaves enriched with 7.5 % concentrations of Dolichos lablab, significantly gained more Cocoon weight, Shell weight and Shell/cocoon ratio as compared to those fed on normal MR₂ mulberry leaves. Hence, 7.5% dose was fixed as an effective dose. Further, same study was conducted to find out the biochemical changes in the haemolymph occurred in the first day of Vth instar larvae. There was a significant increase in the haemolymph glucose, cholesterol, urea, total protein, aspartate transaminase, alanine transaminase and alkaline phosphatase. But haemolymph uric acid was significantly decreased. The results suggest that coadministration of   Dolichos lablab with mulberry leaves at a concentration of 7.5% has enhanced the biochemical reaction involved in the silk production in the silkworm.