PHOTORECEPTIONS IN THE ECLOSION OF THE SILKWORM, Bombyx mort

Abstract
When silkworms, Bombyx mori, were kept in a photoperiodic regime of LD 8:16 during pupal development, the moths showed overt bimodal eclosion rhythms with one peak in the dark period, and with the other peak at light‐on. When the developing pupae were transferred from the photoperiodic cycle to continuous darkness, the eclosion of the dark period persisted with a free‐running circadian rhythm, while the eclosion corresponding to the light‐on peak was not shown. Vitamin A‐deficiency. which brought about a loss of photoreceptive function in compound eyes, significantly reduced the light‐on peak, but did not influence the timing of eclosion in the dark period. Covering compound eyes with black wax also reduced the light‐on peak. These results show that the eclosion clock of the silkworm is most likely entrained by an extraretinal photoreceptor, but the eclosion at light‐on is evoked by an exogenous light effect that is mediated via compound eyes

This publication has 15 references indexed in Scilit: