JUNE
1993

 

 

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

 

 

 

 

06-10-93

Flowers are for the birds and bees

Aileen Fisher begins her poem “Buzzy Old Bees” with the lines:

“There wouldn’t be apples
on apple trees,
or daisies or clover
or such as these,
if it weren’t for fuzzy old
buzzy old bees,”

It’s true. There would be very few fruits or flowers if insects didn’t exist. Plants have flowers for only one purpose — reproduction. Some plants, such as wheat and corn, are wind pollinated. But plants with bright, showy flowers depend on living things to carry pollen from flower to flower.

To be sure, animals other than insects can carry pollen. Snails, slugs, spiders and mites visit flowers and have been shown to transport pollen. Some birds, including the familiar hummingbirds, are effective pollinators of flowers. A few bats are pollinating agents. However, all these animals are insignificant compared to the insects in the pollination of plants.

Many insects pollinate plants, including ants, beetles flies, butterflies, moths and wasps. However, the bees are the most important of the insect pollinators. Since the bees provision their nests with pollen and use nectar to make honey, these insects visit flowers on their food procurement forays. The flowers that depend on insect pollination have sticky pollen grains that adhere to the insect for the trip to the next flower.

Insect-pollinated flowers are bright colored, however the color we see is probably not what the insect sees. The insect sees the infrared pattern of light reflected from the flower. Insect-pollinated flowers also have a sweet odor that is used by insects to guide them to the plant.

The process of pollination is mutually beneficial for both the plant and the insect. The insect gains food, and the plant gets free transport of pollen. Some insects try to get out of their side of the bargain, however. Such insects are known as nectar thieves. They chew a hole in the corolla of the flower and steal the nectar without coming into contact with the pollen-laden anthers.


Some flowers are designed in such a way that only a specific species of insect can pollinate them. One such insect is the fig wasp, without which there would be no figs. Another small wasp is the only insect that can pollinate a species of orchid. Nectar of the common red clover plant is a favorite of bumble bees. The familiar honey bees have tongues too short to reach all the way down the long tubes that make up the red clover flower.

The next time you spy a beautiful flower and are tempted to take a whiff of its aroma, be careful. An insect might have beaten you to the posy. Don’t get mad, after all if it weren’t for the insects the flower would not be there anyway.

 

Writer: Tom Turpin
Editor: Andrea McCann