Studies on Ecology and Behavior of Japanese Black Swallowtail Butterflies : VIII. Survivorship Curves of Adult Male Populations in Papilio helenus nicconicolens BUTLER and P. protenor demetrius CRAMER(Lepidoptera : Papilionidae)

Abstract

The survivorship curves of adult male populations in the Japanese black swallowtail butterflies Papilio helenus nicconicolens BUTLER and P. protenor demetrius CRAMER were estimated by the mark-and-recapture method. Censuses were conducted twice a week in the summers of 1977, 1978, and 1979 at a small woody hill in Kochi City, southwestern Japan. Survivorship curves for five age groups were constructed using wing condition as an indicator of adult age. Survivorship curves for the adult life were obtained by synthesizing survivorship curves for each age category. Average passage of time before 50% adult mortality was 16-17 days for the two species. The survivorship curves show that the mortality in young adults is lower than that in old ones irrespective of the species and the year. The mortality of the adult butterflies increases in proportion to the age of adults.