Dragonflies: Rainbows on the Wing

By George and Becky Lohmiller
8/1/2012 9:32:33 AM

Who hasn't marveled at the aerial abilities of dragonflies as they glide effortlessly over sparkling streams, pristine ponds and lakes, plucking insects from the air with deadly precision?

Dragonflies and their smaller cousins, the damselflies, belong to an ancient order of insects known as Odonata. Fossil records show that they were around for 100 million years before the dinosaurs. These prehistoric predators had wingspans of over three feet and are the largest insects known.

Surprisingly, these brilliantly colored masters of the air are classified as aquatic insects because they spend most of their lives as larvae underwater among plants or in silt. They may spend five years or more in the larval stage, molting several times before emerging as adults—and then living only a few weeks to a few months.

Photo Credit: Cindy Joyce

With keen eyesight and expert airmanship, odonates easily outmaneuver and catch insect prey. Their four gossamer wings move independently of one another, giving them the ability to fly forward, backward, and sideways, or to just hover in place. Bead-like eyes provide 360–degree stereovision, allowing them the ability to spot insects in any direction without turning or moving their heads. (In fact, dragonflies have the biggest eyes in the insect world.)

The dragonflies' and damsels' fondness for mosquitoes puts them in the category of beneficial insects, but even more important is their role as barometers of wetland health. Some insects are even good at predicting the weather. In order to survive, odonate larvae need clean, well-oxygenated water. Drainage of wetlands, pollution from farming and industry, and the development of new roads and houses have increasingly reduced odonate habitat. Conservation of existing wetlands is key to odonate survival, as is providing new habitats for them to colonize.

Photo Credit: Susan Williams

Constructing a pond or other backyard water feature will attract a surprising number of odonates. Size is not crucial, but dig the basin deep enough so that the water won't freeze solid in the winter. Plant a few native plants at its edge for wind protection. By providing needed habitat, you can help save dragonflies as well as damsels in distress.

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