著者

加藤 義臣 大日向 健人 中 秀司

出版者

日本鱗翅学会

雑誌

蝶と蛾 (ISSN:00240974)

巻号頁・発行日

vol.60, no.1, pp.1-8, 2009-01-10

参考文献数

19

被引用文献数

1

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A nymphalid butterfly Hestina assimilis assimilis, which was recently discovered in Kanagawa prefecture in Japan, undergoes larval diapause and show a seasonal change in wing color pattern: summer and spring (white) morphs. In the present study, temperature and photoperiodic conditions responsible for the control of seasonal morph determination was investigated. First, when post-diapause larvae were reared under various temperatures (15℃, 20℃, 25℃ or 28℃) at a long photoperiod (16L-8D), most of the eclosed adults were of white morph (spring morph). Second, larvae were initially exposed to a short photoperiod (10L-14D), and then transferred to 16L-8D to avoid diapause occurrence. Resulting adults were white morph. Third, individuals were reared at various temperatures (15, 20 or 25℃) under a long photoperiod (16L-8D) through larval and pupal stages. Low temperatures of 15℃ were quite effective for white morph production, but moderate (20℃) or high (25℃) temperatures were not effective, and all butterflies produced developed black veins on the wing (summer morph). Fourth, in experiments where different rearing temperatures were combined during the larval life, a temperature of 15℃ combined with 20℃, but not with 25℃, was effective for producing some intermediate or white morphs. Fifth, the temperature-sensitive stage for white morph production was mostly located in the 3rd and 4th instars (in partiular, 4th instar). In these experiments, white morph production was closely linked with extremely delayed larval development. The results strongly suggest that not only a short photoperiod, but also a relatively cool temperature including 15℃ is quite effective for white morph production even without an intervening larval diapause. Probably, an unknown neuro-endocrine mechanism may be responsible for the seasonal morph regulation as in the case of other butterfly species.