Fascinating, fabulous Odonata

Some facts and tidbits about dragonflies and damselflies.

The difference:Damselflies are generally smaller and more delicate than dragonflies. They can be distinguished by their resting wings. The wings of damselflies are held together or partially open over their abdomens. Dragonflies' wings, at rest, are always straight out at their sides like an airplane.

Fear factor:The insects do not seek humans to bite. "They will never approach you to bite you like a mosquito," said New York Natural Heritage Program volunteer Steven J. Diehl. "They'll avoid you at all costs."

But M. Vici Diehl, Mr. Diehl's wife and fellow volunteer, said there is one species of dragonfly whose female may sting you by using its ovipositor, the egg-laying organ.

Fancy fliers:Damselflies and dragonflies have four wings, and they use them to be highly maneuverable when hunting.

Bug eyes:Dragonflies and damselflies have five eyes.

"We know what the big compound eyes do, but not the smaller, simple eyes," said Mr. Diehl.

Good appetites:As nymphs, dragonflies and damselflies eat mosquito and black fly larvae.

"As adults, they eat a lot of things considered pests by humans, like those mosquitoes and black flies," said Mr. Diehl.

Long-distance calling:Mr. Diehl said radio transmitters have been put on common green darner dragonflies. Researchers discovered they can fly from New Jersey to the Carolinas and Georgia, where they lay eggs. The nymphs emerge inspring and fly back to where their parents originated from.

Water indicator:Like frogs, dragonflies and damselflies can be useful indicators of water quality, Mr. Diehl said. He cited his hometown of Antwerp as an example.

Before the village's water treatment plant was installed in 1993, he said, wastewater flowed directly into the Indian River. When that stopped, there was an immediate increase in dragonflies and damselflies, he said.

Dragonflies and damselflies lay their eggs on the water or on water plants.

Legends:In Japan, a dragonfly is symbolic of courage and strength. But some cultures see them as evil.

Mr. Diehl said that in European myths, dragonflies (darners) would fly into the homes of children who used foul language to sew their mouths shut.

The name:According to the entomology department at the University of North Carolina, the name of the order of insects Odonata is based on the Greek word "odonto," meaning tooth, and refers to the strong teeth found on the mandibles of most adults.