title: Two lactones in the androconial scent of the lycaenid butterfly Celastrina argiolus ladonides.
abstract: Male adult butterflies of many species have characteristic odors originating from the disseminating organs known as androconia. Despite the fact that androconia exist in several species, there have been few investigations on adult scents from the lycaenid species. Celastrina argiolus ladonides (Lycaenidae) is a common species in Eurasia. We have reported that male adults of this species emit a faint odor, and the major components causing this odor have been newly found in the Insecta. By using field-caught individuals, we determined the chemical nature and location of this odor in the butterfly. Gas chromatography-mass spectrometry (GC-MS) analyses revealed that two lactone compounds, lavender lactone and δ-decalactone, are present in the extracts of males but absent in those of the females. On an average, approximately 50 ng of each compound was found per male. Chiral GC analyses performed using enantiomerically pure standards revealed that the natural lavender lactone was a mixture of two enantiomers with an R/S ratio of 32:68, whereas the natural δ-decalactone contained only the R-enantiomer. When the analyses were conducted using different parts-forewings, hindwings, and body-of three males, the lactones were more abundantly found on the forewings and hindwings than on the body. Microscopic observation of the wings demonstrated that battledore scales known as androconia are scattered on the upper surface of both the wings of C. argiolus ladonides males. These results indicate that the specialized scales on the wings of males serve as scent-disseminating organs.
authors.affiliation: Department of Biofunctional Science and Technology, Graduate School of Biosphere Science, Hiroshima University, Higashihiroshima 739-8528, Japan. homura@hiroshima-u.ac.jp
authors.forename: Hisashi
authors.initials: H
authors.lastname: Ômura
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Yakumaru
authors.forename: Keiichi
authors.initials: K
authors.lastname: Honda
authors.forename: Takao
authors.initials: T
authors.lastname: Itoh
mesh_terms: D000818:Animals; D002080:Butterflies / Q000737:chemistry*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D007783:Lactones / Q000737:chemistry*; D008297:Male; D010675:Pheromones / Q000737:chemistry*; D014921:Wings, Animal / Q000737:chemistry
chemical_list: D007783:Lactones; D010675:Pheromones