Sexual deception in Australian orchids

Since I’m covering this conference on behalf of Botany One/Annals of Botany, I’d be remiss if I didn’t briefly delve into the Annals of Botany lecture given on Tuesday afternoon by Rod Peakall of the Australian National University. Dr. Peakall, a specialist on orchid pollination systems, spoke about the morphology and biochemistry behind sexual mimicry in Australian orchids. Peakall’s work focusses on orchids using sexual deception to induce pseudocopulation by a male wasp, which is then tagged with pollinia. Though the orchids in question do indeed look similar to the female of the species in most cases, Peakall’s work has revealed that the novel chemical mimicry carried out by the plants to mimic wasp pheromones is at least as important as their morphology. The chemical compounds produced by the plant, several of which are new to science, are under strong selection to remain precisely matched to their pollinator’s pheromones.