E&E PhD Exit Seminar: How important is sexual chemistry? Pollination of Pterostylis orchids by male fungus gnats

The cross-kingdom mimicry of female insect sex pheromones by sexually deceptive orchids has fascinated evolutionary biologists ever since the importance of chemistry in pollination by sexual deception was first recognised. Remarkably, sexual deception has evolved multiple times in orchids to exploit a wide variety of male insect pollinators across different orders, from solitary bees and wasps (Hymenoptera) to beetles (Coleoptera) and tachinid flies and fungus gnats (Diptera). Fungus gnats are predicted to be pollinators of hundreds of sexually deceptive orchids,yet unlike orchids that sexually attract bees and wasps, there has been little research on the pollination or sexual chemistry of fungus gnat-pollinated orchids.

My doctoral research focused on the pollination of Pterostylis orchids, a diverse Australasian genus thought to be pollinated primarily by fungus gnats. In this seminar, I will talk about two sexually deceptive Pterostylis species which offer insight into the evolution of sexual deception in orchids, and the importance of chemical, visual and tactile stimuli in duping male insects. I also highlight the importance of integrating multi-disciplinary research from the fields of pollination biology, chemical ecology, biochemistry and mycorrhizal ecology, in understanding how sexual deception in orchids evolves as well as how we can ensure the survival of sexually deceptive orchids into the future.