Chiba College of Health Science
- 千葉県立衛生短期大学紀要 = Bulletin of Chiba College of Health Science (ISSN:02885034)
- vol.13, no.2, pp.3-9, 1994
In the velvet swallowtail butterfly, Papilio bianor dehaanii, there is a seasonal morph such as the spring-and summer-forms. When larvae were reared under a short photoperiod (less than LD 8 : 16hr.), all of them entered into pupal diapause and subsequently developed into small adults of the spring-form. On the other hand, under a long one (under room conditions), they all averted diapause and developed into large summer-form adults. The front wing length and size of the pupae were significantly different between diapause and non-diapause groups. It thus appears that a seasonal morph reflected in the size was deter-mined simultaneously by photoperiod during the larval period. When diapausing pupae were kept under various periods of chilling at 4℃, the longer the chilling brought the earlier onset of adult emergence and a narrower range of emergence. A well synchronized emergence from diapausing pupae was brought about by chilling for 140 days. In the Japanese swallowtail butterfly, Papilio xuthus, when larvae were reared under natural conditions in autumn, all of them entered into the pupal diapause. Three groups of diapausing pupae, that had overwintered from late autumn under natural conditions, were transfered to 20℃ conditions on Jan. 14, Mar. 2 and Apr. 4 respectively. In most of the diapausing pupae which had been transfered on Mar. 2 or Apr. 4, adult emergence occured within 20 days after the onset of incubation at 20℃. It thus seems that pupal diapause of them had terminated during their overwintering period.