This is a really cool topic that I may write a larger post on sometime in the future. Most orchids are deceptive – i.e. they attract their pollinators by fooling them – but only the most specialised ones are sexual deceivers.
One of the most widespread of these is the genus Ophrys in the Mediterranean. The flower mimics the female of the pollinator species, most often a bee or a wasp. Males of the species then fly to the flower and try to copulate with it, specifically the labellum. This is called pseudocopulation, even though the pollinator takes it very seriously. During the act, the pollen sticks on the pollinator, who then goes off to another flower for another round.
In Ophrys, the mimicry is so specific that each species only gets pollinated by one species (or a species group). The most important factor in the mimiry is smell: the flower produces many compounds that are almost identical to the sex pheromones of the female of the pollinator. This occurs besides visual and even tactile mimicry.
And because of how specific this interaction is, this has led to the co-evolutionary radiation of both the orchids and their pollinators in the Mediterranean – it’s another example of an insect-flower co-evolution.