Brazos Bend State Park
Pond Life
Dragonflies and Damselflies: Order Odenata
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Dragonflies and damselflies spend most of their lives, not as flying insects, but as aquatic larvae, crawling about on the bottom of ponds and lakes. Although most dragonflies live only a few weeks as adults, the larval stage usually lasts about 1 year, and in some species can take up to 5 years. Dragonfly larvae are one of the most common specimens that are found in the ponds at Brazos Bend State Park. Because of the long larval stage, they can be found year-round, and in almost all still bodies of water. Because of the great number of species of dragonflies, the larvae vary considerably in size and shape. Some are long and slender, others round and spider-like. All however have a wide head, short antennae, and 3 short gills at the end of their abdomens. The larva at the right is the larva of a darner, family (Aeshnidae), and is over 2 inches long. But dragonfly larva less than ¼ of an inch long are frequently found as well. |
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Skimmers, family (Libellulidae) are the most commonly found dragonflies at Brazos Bend State Park, so most of the larva found have the short spider-like body shown in the picture to the left. When dragonlflies have completely matured, they climb out of the water onto a twig or emergent plant. They swallow air to swell their bodies and make their shell split down the back. The adult dragonfly emerges. It pushes itself into the shape of an adult dragonfly by squeezing blood into its wings and swallowing more air to push its tail into the proper shape. Then it dries for about 2 hours. If it is lucky enough not to have been eaten by a passing bird, it flies away to begin its life as a dragonfly.
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In the water, as in the air, dragonflies are predators. They eat smaller insects and lavae, as well as crustaceans and anything else that they can catch. They use their lower lip to catch their prey. This is long and hinged, and at rest, is folded back against the thorax like a bib. When the prey is close enough, they can shoot this lip out. There are hooks on the end of it that seize the prey and draw it back to the mouth. There it is either swallowed whole or torn apart and eaten. |
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Damselfly larvae are longer and slenderer than dragonfly larvae. Their gills are also longer, and feather-like. Other than that, they are very similar in habits and lifestyle. They can be up to 35 mm long, but specimens have been collected that were less than 1 mm long. |
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Dobsonflies and Fishflies - Megaloptera |
Mayflies - Ephemerata |