Five different varieties of mulberry leaves viz., AR-2, BR-2, K-2,S-1 and S-146 in laboratory showed that different developmental stages (incubation, Ist, IInd, IIIrd, IVth, Vth, pre-pupa and cocoon) attained significantly (F4, 24= 0.14, 0.13, 0.13, 0.14, 0.10, 0.15, 0.17 and 0.17; p<0.01) shortest period of 7.90�0.123, 3.10�0.078, 2.30�0.127, 3.20� 0.114, 3.60�0.123, 6.20�0.130, 4.80�0.071 and 8.00�0.114 days on mulberry variety S-146 during development. In contrast, the maximum period (F4, 24=0.14, 0.13, 0.13, 0.14, 0.10, 0.15, 0.17 and 0.17; p<0.01 for F4, 24=0.16, 0.13, 0.15, 0.12, 0.15, 0.14, 0.15 and 0.07 of development was observed as 8.80�0.071 days for incubation, 4.00�0.071 days for Ist instar, 3.00�0.055 and 3.10�0.089 days for IInd instar, 4.00�0.114 and days for IIIrd instar, 4.10�0.071 days for IVth instar, 7.80�0.130 days for Vth instar, 5.70�0 days during pre-pupal and 11.00�0.150 days for cocoon period on K-2 variety of mulberry during development.