Scent of a female: The role of pheromones in the reproductive isolation of six species of Utetheisa (Lepidoptera: Arctiidae) on the Galápagos Islands, Ecuador

The sexual behavior of the Arctiid moth Utetheisa ornatrix is one of the most well studied of any lepidopteran. However, previous research has focused on populations in the absence of congenerics and has been unable to access the role of courtship pheromones in reproductive isolation. In the Galápagos Islands six species of Utetheisa have been studied and their pheromonal differences analyzed. Pheromone analysis of female U. ornatrix, galapagensis, and perryi found each species to posses a unique chemical blend determined by the relative concentration of three components: (Z,Z,Z)-3,6,9-heneicosatriene, (Z,Z,Z)-1,3,6,9-heneicosatetraene, and (Z,Z,)-6,9-heneicosadiene. The pheromone blends of the Galápagos endemics are much more similar than either is to U. ornatrix, perhaps reflecting the more recent divergence of the endemic communication systems.ems.