Sericulture is a tradition in the lives of Indian people. Bivoltine silk is known for its good quality. J & K state is known for producing bivoltine silk of international quality, it is the only state in India which produces only bivoltine silk from Bombyx mori L. The present study involved morphological studies on 3 Jam and 3 Pam races of B.mori at egg, larval and cocoon level. Clustering was done on the basis of quantitative character i.e. larval weight gain of V instar from day 1 to day 5 before cocooning. The weight of worms is directly related to the yield of silk, higher larval weights leads to higher silk production. The results indicate that the clusters can be realized based on larval development parameters; further sub-grouping under the groups highlights the genetic differences associated with different races as well as their significance for silkworm breeding
