Pollinator attraction and mechanisms of chemical communication in sexually deceptive orchids

Nearly all orchids of the genus Ophrys are pollinated by means of sexual deception, mostly by bees (Superfamily Apoidea) and wasps (SF. Scolioidea, SF. Sphecoidea). Lured by the odour and insect-like shape of the flower, the pollinating male alights on the labellum and attempts to copulate with it. During these so-called "pseudocopulations", the male contacts the pollinia, which become attached to its head or abdomen. Flower’s odour is the most important cue for eliciting male mating behaviour.

In a comparative approach, we identify and compare the male-attracting odour compounds in female bees (wasps) and in Ophrys flowers. We conduct behavioural tests, quantitative chemical analyses, electroantennogram assays as well as combined gas chromatography and electroantennogram recordings of insect olfactory responses. 

Collaborations: Hannes Paulus (University of Vienna), Salvatore Cozzolino (University of Naples) , Pier Luigi Cortis (University of Cagliari)

Ophrys bilunulata and pseudocopulating Andrena flavipes male (Photo J. Stökl)