Wikijunior:Bugs/Damselfly

What does it look like?

The damselfly is a close relative to the dragonfly. Both belong to the ancient order Odonata. Damselflies are smaller than dragonflies. The head has biting mouthparts and short antennae. The large compound eyes bulge to the side and are widely separated. They have four powerful wings that move independently. Unlike dragonflies, damselflies are able to fold their wings up over their bodies when resting. Both pairs of wings are similar in damselflies, whereas dragonfly hindwings are broader than their forewings.

Damselfly nymphs resemble adults but do not have wings. They are slender with long legs. There are three leafy gills on the tip of the abdomen. They have a moveable head with sharp biting mouthparts. The lower lip has bristles on the tip to grasp prey. When not in use the lip, called a “mask,” is folded under the head.

The Calopterygidae family includes Broad-winged, Black-winged and Ruby Spot damselflies. Colors are usually metallic green or black. These dragonflies are between 1 and 2 inches long. When resting, they hold their wings together vertically above the body. Calopteryx virgois is called the “Beautiful Demoiselle.” Males are metallic blue-green with dark wings. Females have pale yellow-brown wings.

Black-winged damselflies are between 1-5/8 and 1-3/4 inches long. Males have a metallic green body and black wings. Females are nonmetallic dark brown with brownish wings. Females have a glistening, irregular white spot (stigma) on the forewing. Nymphs are pale brown with dark-brown markings.

Ruby Spot damselflies have clear wings with a red or brown spot at the base. Males have a greenish-bronze to dark-brown abdomen. Females have a greenish colored abdomen. Head and thorax are dark. The base of the wings is ruby-red in color.

Most North American damselflies belong to the family Coenagrionidae. Narrow-winged damselflies are in this family. Males are pale blue with dark markings. Females are greenish in color. They are 1 to 2 inches long with slender bodies. Males are usually more brightly colored than females. Nymphs are about 1 inch long and have leafy gills at the tip of the abdomen.

Doubleday’s Bluet damselflies also belong to this family. Males have a blue head with yellow and black markings. The thorax is black, blue, or yellowish green. The abdomen is blue with black markings. Females have broad dark stripes along each side of a blue back. Red Bluets are less common members of this family. Instead of bright blue and black, they are bright red or reddish-yellow on the head, thorax, and abdomen.

The Common Fork-tail is the most common damselfly in North America. It is about 1-1/4 inches long with a wingspan of about 1-3/4 inches. It is blue-green in color. On the end of the abdomen there is a structure that looks like a “forked” tail. Colors are yellowish-green with bright blue on the abdomen. Some females have colors similar to those of males. Others have a color pattern of orange, yellow, and black.

Dark Lestes, Stocky Lestes and Spread-winged (Stalk-winged) damselflies belong to the Lestidae family. They are 1-1/4 to 2 inches long with slender bodies and clear wings. Each wing has a narrow, stalklike base and a dark mark on the fronr edge They look like dragonflies when resting because they are able to spread their wings. Lestes sponsa is called the Emerald Damselfly. Its body has a dark green metallic appearance. Nymphs have long gills with rounded ends.

Giant Damselflies belong to the Pseudostigmatidae family. They are called “helicopter” damselflies. They have a very long abdomen and large dark markings on the end of each wing.

Where does it live?

Black winged damselflies live in forests along edges of slow streams throughout North America.

Western Dark-winged damselflies range from northeast Canada and New York to Nevada and the West Coast. Their nymphs cling to roots and other materials in streams.

Ruby Spot damselflies are found throughout the United States and southern Canada. They live near woodland streams and sometimes along borders of marshes.

Common Bluets live near ponds, rivers, and other bodies of water. They are found from Central America to Nova Scotia to Oregon and Hawaii.

Common Fork-tail damselflies range from Nova Scotia to Georgia and west to the Great Plains. They live in weeds around quiet lakes, small streams, and ponds.

What does it eat?

Damselflies eat small, soft-bodied insects, including aphids, mosquitoes, and gnats. Giant damselflies pluck web-building spiders right from the web to eat them. Nymphs feed on small aquatic insects, tadpoles and small fish.

Damselflies usually sit and wait for prey instead of catching it in midair like dragonflies do. The bug has wings behind its eyes to help it hear.

How does it defend itself?

Although damselflies do not fly as fast or as well as dragonflies, they can fly backward, hover, and stop very quickly. These abilities along with keen vision help them avoid predators.

What stages of metamorphosis does it go through?

Damselflies undergo incomplete metamorphosis. Eggs are laid in water and on aquatic plants. Some species, like Broad-winged damselflies, lay eggs inside tissues of various aquatic plants. Males often remain close but do not make contact with the female while she lays eggs.

Aquatic nymphs are predacious. They have a hinged lip that can shoot forward to seize prey. The skin splits along the midline of the thorax to release the adult.

What special behavior does it exhibit?

Black winged damselflies can stay under water for almost an hour. They trap an air bubble in their wings so they can breathe under water.

Because they are so small, Common Bluet females often have trouble leaving the water surface after laying eggs. The male comes to her rescue by pulling her out of the water.

Southwestern Short damselflies are small enough to ride gentle breezes to new places.

Damselflies have weak wing muscles and beat their wings at different times, so they are slow and look a little clumsy in flight. On summer mornings they can be seen "warming up" on plants before taking to the air.

Short-stalked damselflies are called “dancers” because they flit from one place to another.

How does this bug affect people?

Both nymphs and adults are highly beneficial predators, destroying huge numbers of mosquitoes.

Fishermen use lures that look and move like damselfly nymphs. Fly fishermen have special lures designed to move through the air like adult damselflies.

In folklore of Central and South America, Giant damselflies are thought to be spirits of the dead.

Red Bluets sometimes land on people and nibble on clothing.

References

Borror, D.J. & White, A.E. (Eds.). (1970). The Fiftieth Anniversary Edition,Roger Tory Peterson Field Guides,Insects of America North of Mexico. Norwalk, CT: The Easton Press.

McGavin, G. C. (2000). Insects spiders and other terrestrial arthropods. New York, NY: Dorling Kindersley, Inc.

Milne, L. & Milne, M. (2009). National Audubon Society Field Guide to North American Insects and Spiders. New York, NY: Alfred A Knopf.

http://anr.ext.wvu.edu/r/download/48166

http://insects.tamu.edu/fieldguide/aimg7.html

http://www.loudounwildlife.org/HHDamselfly.htm

http://sandiegozoo.org/animalbytes/t-dragonfly.html

http://www.uky.edu/Ag/CritterFiles/casefile/insects/damselflies/damselflies.htm