SUZUKI, Nobuhiko (Dept. Biol., Fac. Sci., Kyushu Univ., Fukuoka), NIIZUMA, Akio (Dept. Zool., Fac. Sci., Kyoto Univ., Kyoto), YAMASHITA, Keiko (Lab. Ent., Fac. Agric., Kyoto Prefec. Univ., Kyoto), WATANABE, Mamoru (Dept. Biol., Fac. Educ., Mie Univ., Mie), NOZATO, Kazuo (Lab. Ent., Fac. Agric., Kochi Univ., Kochi), ISHIDA, Akiyoshi (Tosa High School, Kochi), KIRITANI, Keizi (Div. Ent., Nat. Inst. Agro-Environ. Sci., Ibaraki) and MIYAI, Shun'ichi (Div. Inform. Anal., Nat. Inst. Agro-Environ. Sci., Ibaraki). 1985. Studies on ecology and behavior of Japanese black swallowtail butterflies. 2. Daily activity patterns and thermoregulation in summer generations of Papilio helenus nicconicolens BUTLER and P. protenor demetrius CRAMER (Lepidoptera : Papilionidae). Jap. J. Ecol., 35 : 21-30. Daily rhythms of flying activity and habitat selection in relation to thermoregulation were investigated in Kochi City, Shikoku, Japan, for the summer generations of Papilio helenus nicconicolens and P. protenor demetrius. Since the body temperature rose with the increase of ambient air temperature, cooling was considered to be more important than heating for thermoregulation in the summer. Both species normally flew inside the forest and seldom flew out from it in the daytime. Males seldom encountered females in the daytime, because most females roosted inside the closed forest. In the evening, the butterflies left the forest for a prolonged flight in the open area. Resources for feeding and oviposition were mainly restricted to the gaps and the forest margin, so that P. helenus, which was more sensitive to ambient air temperature than P. protenor, concentrated on feeding and oviposition activities in the evening. Females of P. protenor mainly flew for feeding and/or oviposition in the gaps in the afternoon. This resulted in high flight and chasing activities of males in the afternoon in P. protenor and in the evening in P. helenus. Activity patterns in relation to thermoregulation strongly affected the resource utilization patterns and mating systems of the butterflies.
