The effect of photoperiod on the relative developmental speed of fifth instar
larvae of mulberry silkworm Bombyx moti were studied. Tested photoperiodic
conditions were: 24 hours lightO hours darkness(24L:OD), (12L:12D) and OL:24D).
The mean weight of each of mature larvae, pupae, shell cocoon and silk glands
significantly increased under complete darkness. Also, the other biometric
measurements,i.e, the total mean laid eggs/female and utilization of food increased
significantly under complete darkness compared with those reared under other tested
photoperiods.