1Mecanismes de Communication, NAMC,UPS-Orsay, 91405 Orsay, France.
2ERATO Yamamoto Behavior Gene Project, Mitsubishi Kasei Life Science, Machida-shi, Tokyo, Japan.
Hawaiian islands are a well known model site for allopatric speciation. Several hundreds of Drosophila species have been found there, a number of them endemic to the archipelago or even restricted to one island. They have evolved original morphological features such as pictured wings and new behavioral patterns such as male leks. Flies belonging to 28 species were collected and their cuticular hydrocarbons were analysed by GC-MS. All species of the planitibia subgroup are alike with chain lengths longer than those of other species-often 33 or 35 carbons. Moreover they lack unsaturations but display two methyl in internal positions-typically 11,15. Species of both adiastola and grimshawi subgroups are more structurally diverse, with chain lengths close to 25 carbons and an abundance of unsaturated or methylated compounds. Species of the former subgroup are remarkable for a high degree of chemical sexual dimorphism. Non picture-winged species like the fungi breeders also show strong structural relations. Possible relations with known behavioural data will be commented.