Order Odonata - Characteristics of Dragonflies and Damselflies

Habits and Traits of Dragonflies and Damselflies

Black-winged damselfly. Photo: © Susan Ellis, Bugwood.org

Odonata means "toothed jaws," and indeed the larger species of dragonflies and damseflies may give you a startling but harmless bite. Despite what your mother told you about dragonflies sewing up your lips, they cannot stitch or sting you in any way. The order Odonata is subdivided into three suborders: Anisoptera, the dragonflies; Zygoptera, the damselflies; and Anisozygoptera, mostly fossilized species with only two known living members.

Description:

Two physical features identify most members of the order Odonata - extremely large eyes (in proportion to its head) and a long, slender abdomen. An insect with these characteristics is more than likely a dragonfly or damselfly.

Odonates are predacious as naiads and adults. Dragonflies and damselflies have tiny antennae, so vision is their primary means of navigating and capturing prey. Odonates can rotate their heads nearly 360 degrees, giving them an almost limitless field of view.

Large mandibles chew prey quickly and easily, an important feature since these insects tend to eat on the move. The thorax is tilted, positioning the legs just below the mandibles where they function as a prey-catching basket. Gnats and mosquitoes are easily scooped up, and the labium quickly snaps forward to grab the prey, moving it into the mouth in a split second.

Several differences in wing structure separate the Odonates from other insect groups.

Members of the order Odonata are considered "primitive winged," with wings that cannot be folded. Unlike more evolved insect groups, such as the Hymenoptera, dragonflies and damselflies operate each wing independently. This gives Odonates the interesting abilities to hover, fly backward, and take off vertically, similar to a helicopter.

Odonate eggs are laid in water, where they hatch into wingless naiads. The naiads have gills and will molt up to 15 times, depending on the species. Some naiads remain in their aquatic environment for as long as two years before reaching adulthood. The final molt produces functioning wings, and the adult dragonfly or damselfly can hunt over water or land.

Habitat and Distribution:

Odonates inhabit every continent except Antarctica, in habitats where fresh water is present. Most species in the order are tropical.

Major Families and Superfamilies in the Order:

  • Aeshnidae - darners
  • Libellulidae - common skimmers and chasers
  • Coenagrionidae - narrow-winged damselflies
  • Gomphidae - clubtails
  • Corduliidae - emeralds

Odonates of Interest:

  • The Dragonhunter, Hagenius brevistylus, specializes in preying on its dragonfly cousins and other large insects.
  • Shadowdragons (genus Neurocordulia) hunt for food just before dusk, when the shadows are falling.
  • Snaketails (genus Ophiogomphus) sport interesting "snakeskin" patterns on their abdomens.
  • The World Conservation Union lists the Hine's Emerald dragonfly, Somatochlora hineana, as an endangered species. In North America, where it is also a U.S.-listed endangered species, less than 50 occurrences are known.

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