SEXY SUNDAYS: Deceptive Liaisons
Posted by Richard Conniff on December 21, 2008
Pseudocopulation. Does that sound like your sex life lately? Or maybe you feel now and then as if you’ve been led on with false hopes–teased even–by a member of the opposite sex?
Well, stop feeling sorry for yourself. Here’s a story about creatures that gets duped by, of all things, a flower.
First a little background:
Plants attempting to swap genetic material usually employ two basic pollination strategies. They broadcast copious amounts of tiny pollen grains into the air, making life miserable for people with allergies. Or they lure insects with pretty flowers full of nutritious nectar and the insects inadvertently carry away pollen for delivery to the next plant.
But certain species employ–or maybe “turn” is the right word– some surprising tricks. For instance, some orchids attract the services of insect pollinators by providing sexual favors.
These orchids, like the Sicilian specimen of Ophrys ciliata in the photo, mimic the shape and coloration of female bees, wasps, flies, and winged ants. They also release osmophores—chemicals that duplicate the sexual perfume, or pheromones, of these insects.
It drives males wild. In Australia’s aptly named orchid dupe wasps,males may prefer the make-believe females to real ones. (Does this sound depressingly familiar?) They’ll actually break away from having sex with a real female to pseudocopulate with a flower.
Is it good for the flower? Yes, because, as a result of these intimate attentions, the wasp goes away carrying a pollen sac, or pollinia. And for the wasp? The experience must also be good, at least in theory, because the pollination only works if the wasp decides to have another go next time he sees a flower of the same type.
And now it’s not just theory: A recent study of Australian tongue orchids of the genus Cryptostylis found that flowers with the most extreme sexual behavior have the highest rates of pollination. And long, vigorous bouts of pseudocopulation with a flower actually cause male wasps to ejaculate. Since male insects often invest large amounts of costly nutrients and other materials in their sperm packets, this can be a big stupid mistake, reproductively speaking. But orchids and wasps both manage to survive in what may be a sexual arms race.
No word from the study on just how hurt and angry the female wasps are feeling. But don’t send flowers.
A. C. Gaskett, C. G. Winnick, and M. E. Herberstein1, “Orchid Sexual Deceit Provokes Ejaculation” Am Nat 2008. Vol. 171, pp. E206–E212