Courtship songs of the picture-winged Drosophila planitibia subgroup species

Abstract. The Drosophila planitibia subgroup belongs to the endemic Hawaiian picture-winged Drosophila species group. The males of this subgroup may produce sounds by fanning or vibrating their wings or by bobbing the abdomen. These wing songs fall into three categories: pulse song, phrase song and sound bursts. Among the most primitive species only D. obscuripes males produce sounds: a low-frequency phrase song. In one intermediate species D. neoperkinsi , the males produce all three songs, while in the other species the males use different combinations of the songs: only the phrase song, the pulse song plus the phrase song or the pulse song plus the sound burst. The males of the advanced species produce only sound bursts. The fact that the males of different lineages use similar kinds of songs in their courtship suggests that all three songs have evolved before the evolution of the intermediate and advanced species. During the speciation processes some of the wing songs have been omitted from the courtship rituals of the evolving species, while the remaining songs have become less variable and more species-specific.