Orchids and Wasps

Pollination Methods

• Many insect- or other animal-pollinated plants lure pollinators by providing pollen or nectar as food. The plant or flower uses scents or bright colors attracting insects, which in turn carry the pollen to other flowers. With orchids, up to 1/3 of its roughly 30,000 species draw pollination by deception. Those using sexual deception draw male insects by producing a floral scent mimicking the sex pheromone or olfactory cue the pollinator species uses to attract a mate.

How the Orchid Lures Wasps

• Some orchids release a sex pheromone so powerful that the wasp male wasp tries copulating with the blossom and actually ejaculates. This sexual deception method is seen with the terrestrial orchid genus Ophrys in Europe and nine genera of ground orchids in Australia. The Australian tongue orchid is especially good at luring male wasps. It has the greatest success at being pollinated among sexually deceptive orchids. These wasps are a species called orchid-dupe-wasps (Lissopimpla excelsa).

Other Orchid-Insect Relationships

• Orchids evolved in different ways ensuring the species' continuation. While some mimic female wasps to draw males, others generate a scent resembling flowers or possible mates for other insects. The orchid Dendrobium sinense releases the same chemical compound that honeybees use to draw other bees. The release of that pheromone is a powerful lure for the larvae of vespa hornets that feed on bees. The hornets seek food, but instead become orchid pollinators.

How Wasps Reproduce

• Females of wasp species are able to reproduce asexually without sperm from males. Research has shown, in fact, that there are about 200 insect species drawn to the orchid's sexual deception, and more than 90 percent of them have females able to produce offspring without male sperm.