The effect of feeding leaves of mulberry varieties viz., S30, S36, S41, S&4, Kanva-2 and Mysore Local to bivoltine silkworm strains namely NB4D2 , NB7 and NB18 was studied in three rearing seasons in respect of pupal weight, pupal duration, fecundity and hatching. NB7 reared on S41, S54 and Mysore Local resulted in maximum pupal weight. Pupal dura­tion was less in NB7 reared on Mysore Local. In general fecundity was enhanced by S54 S41 and S36 leaf in all the breeds.