Floral Volatiles for Pollinator Attraction and Speciation in Sexually Deceptive Orchids

Pollination by sexual deception is a worldwide phenomenon, which has evolved independently multiple times. Sexually deceptive plants secure insect pollination by chemical and physical mimicry of the female of their pollinator. In the sexually deceptive orchids investigated so far, semiochemicals are of paramount importance for pollinator attraction. The taxonomic diversity of the male pollinators exploited by sexually deceptive plants is perhaps even wider than the plant diversity. Sexually deceptive orchids have long been considered prime candidates for pollinator-driven speciation. The often highly specialized pollination of orchids sets them apart from many plant groups with more generalized pollination, where a given plant species has many different species of pollinator. To test for signatures of pollinator-mediated selection among three sympatric Ophrys species, J. Mant et al. compared patterns of species divergence across active and nonactive volatiles, and neutral microsatellite genetic markers.