Temperature Determines Diapause Termination in <i>Papilio troilus</i> (Lepidoptera: Papilionidae).


  • M. D. Deering
  • T. Haslitt
  • J. M. Scriber


biology, diapause termination, hostplants, Lauraceae, Michigan, Nearctic, North America, Ohio, photoperiod, pupal diapause, scotophase, spicebush swallowtail, temperature, USA


Diapausing pupae of the spicebush swallowtail butterfly, Papilio troilus Linnaeus, were individually set up in screened cages under one of 4 temperature and 2 photoperiod treatments (14°,18°,22°, or 26°; in 18:6 or 12:12 photo/scotophase). The breaking of diapause and eclosion of adult butterflies was significantly faster at 26°C (13-24 days) than 22°C (18-36 days) and 18°C (36-69 days) regardless of the photoperiod conditions. As of 88 days, none of the pupae eclosed as adults in either 14°C chamber (18:6 or 12:12). While diapause induction for these Ohio populations was known to be determined in the larval stages by a critical photoperiod of less than 15 hours, it did not matter whether the photophase was 12h or 18h for termination of diapause and eclosion of adults. In every treatment (n = 6), the majority of the first 10 individuals eclosed were males, suggesting that protandry is likely In the field.