K. Sawada et al., FLUCTUATION OF PROTANDRY IN ECLOSION OF ANTHOCHARIS-SCOLYMUS (LEPIDOPTERA, PIERIDAE) - CAN MALES ECLOSE OPTIMALLY UNDER EVOLUTIONARY EQUILIBRIUM, Environmental entomology, 26(3), 1997, pp. 572-579
To elucidate the adaptive significance of protandry (males eclosing ea
rlier than females), the eclosion patterns of males and females in a p
opulation of the univoltine pierid butterfly Anthocharis scolymus (But
ler) were studied by a mark-release-recapture method over 6 yr. We tes
ted whether the findings could be explained by the evolutionarily stab
le strategy model for optimal male eclosion. Protandry occurred every
year and the average protandry for the 6-yr period was not significant
ly different from the protandry predicted by the model. However, male
eclosion patterns fluctuated from year to year; although the male eclo
sion patterns for 3 yr indicated a fairly close fit to the optimal ecl
osion predicted by the model, those for the remaining 3 yr were signif
icantly earlier than the model predicted. We discuss the factors that
may have caused male eclosion earlier than the prediction of the model
.