Four larval mutants namely Knobbed, Zebra, pere and Ursa of the silkworm, Bombyx mori L. were selected for the present investigation. The digestive juice and haemolymph were collected from fifth instar larvae (day 1 to day 6) and the samples were subjected to spectrophotometric analysis for estimation of amylase activity. The recorded O.D. values (at 525 nm) were converted into maltose released (µmoles ml-1). The results of the present study clearly indicate that the amylase activity gets enhanced with the increase in number of feedings along with the advancement of age during 5th instar larval stage (day 1 to 6). Based on the results obtained, Zebra performed better followed by Knobbed than the other two larval mutants under study. The larvae fed with V1 variety performed better than those batches fed with S36 variety of mulberry in both the samples. Of the two samples, amylase activity recorded higher in digestive juice than haemolymph in all the four larval mutants under study.
Digestive juice, Haemolymph, Mulberry, Mutant silkworm, S36, V1