Orchid Pollinators

Over 28,000 species of orchids grow worldwide. They are the largest family of flowering plants and have lived on the earth for over 75 million years. Pollinators are the key to survival for all flowering plants, and orchids have learned how to attract specific pollinators. Over the centuries, orchids have diversified the ways they attract pollinators to fit each variety’s blooms.

There are almost as many different pollinators as there are orchid species, and most orchids rely upon only one species of pollinator. Bees pollinate about 68% of orchids, followed by flies, wasps, birds, moths, butterflies, and beetles. About 1% of orchids are self-pollinating. In North America, large butterflies, day-flying moths, and small skipper butterflies are the main pollinators.

Orchids use a variety of methods to attract pollinators. Some orchids imitate a pollinating insect’s mate or its food. The spider orchid resembles a spider to attract a spider-hunter wasp. The wasp swoops down to sting the “spider” and carry it off to eat; but instead, it stings the bloom and pollinates it before flying away with no spider.

Flies are attracted to orchids with foul smells. Bees are attracted to brightly colored blooms, except red which they cannot see. Some orchids use traps for pollination. The hammer orchid resembles a female thynnine wasp and emits an odor similar to a female wasp. A male wasp lands on the bloom, thinking it is a female, and the lower lip of the bloom flips the wasp onto its stigma loaded with pollen, and pollination occurs.

Hummingbirds and sunbirds can’t smell an orchid’s scent, but they are attracted to tube-shaped blooms with bright colors, preferring yellow, orange, violet, and red blooms.

White and light-green blooms that glow at night attract moth pollinators seen flitting about in the evening hours. Some orchids have uniquely shaped flowers to attract pollinators. The bee orchid has a large petal that resembles a female Eucera solitary bee. A male bee attempts to mate with the flower and pollinates the flower in the process.

Orchids are masters at attracting pollinators and use a variety of deceptive strategies that have helped them survive for millions of years.

By Karen Bowen
Karen is a member of the Yuma Orchid & African Violet Society, a master gardener, and a Pacific Region Butterfly Chairman.

#1 Photo: Karen Bowen
Dendrobium orchid