Floral And Faunal Fragrances

Richard Conniff ponders the role of scent in the natural world:

We are by no means the only species trying to smell like something (anything) other than ourselves. The caterpillar of South Africa’s Zulu Blue butterfly, for instance, mimics the chemical scent that the ants use to recognize their own brood. So the gullible ants carry the caterpillar into their nest, and don’t seem to notice when it proceeds to devour the very ant brood it has been mimicking.

Orchids are also wicked olfactory deceivers. They need to attract wasps, bees and other insects to spread their pollen. So some orchid species have evolved the shape and coloration of specific female insects – and also release chemicals that duplicate the come-hither perfume of the females they mimic. (It’s interspecies cross-dressing – and, wait, do I hear a Broadway musical?) The duped males respond at first with clumsy groping and then quickly proceed to copulation, sometimes to the point of ejaculation. It gets more interesting: Some male wasps actually seem to prefer the scent of make-believe females. They will break away from a real female to have sex with a flower.