Effect of larval brain extracts derived from three swallowtail butterflies, P apilio helenus   L ., P . machaon   L . and P . memnon   L ., on seasonal morph development of P . xuthus   L . ( L epidoptera: P apilionidae)

• Published in: Entomological science 2015-04, Vol.18 (2), p.266-270
• Main Authors: Yamanaka, Akira, Morioka, Ritsu, Kinugasa, Masahiro, Hasegawa, Hiroshi, Fuchigami, Soichiro, Kawasaki, Shuhei, Kitazawa, Chisato
• Format: Article
• Language: English
• ISSN: 1343-8786; 1479-8298
• DOI: 10.1111/ens.12101

Adults of the three papilionid butterflies, P apilio helenus   L ., P apilio machaon   L. and P apilio memnon   L ., exhibit seasonal diphenism comprising spring and summer morphs. To elucidate the physiological mechanism underlying seasonal morph development in papilionid butterflies, we investigated whether a cerebral factor showing summer‐morph‐producing hormone ( SMPH ) activity is present in the brain of three P apilio species using an assay system with chilled male short‐day pupae of P .  xuthus   L . When 2% N a C l extracts derived from 20 larval brains of the three species were injected into abdomens of chilled male short‐day pupae of P . xuthus , all recipients destined to develop into spring‐morph adults developed into summer‐ and intermediate‐morph adults. On the other hand, all recipients injected with distilled water as a control developed into spring‐morph adults. These results indicate that a cerebral factor showing SMPH activity is present in the larval brain of the three P apilio species. Additionally, all recipients injected with 2% N a C l extracts derived from 20 adult brains of B ombyx mori   L . also developed into summer‐ and intermediate‐morph adults. The results revealed that SMPH or a cerebral factor showing SMPH activity is widely distributed among lepidopteran insects.