What is a dragonfly?

Adult Dragonfly

Scientific Name: Class: Insecta Order: Odonata Suborder: Anisoptera

Dating back 300 million years, dragonflies are one of the first winged insects ever found. Fossils of these ancient aquatic insects show wingspans of up to 24 inches compared with the 2- to 5-inch spans of contemporary dragonflies. Scientists have discovered more than 5,000 species of dragonflies worldwide, including 450 in North America alone. Dragonflies belong to the insect order called Odonata, which also includes damselflies. Odonata is a Greek word meaning toothed one. It refers to the serrated teeth located on the insect's chewing mouth parts (mandibles). Myths about dragonflies warned children to keep quiet or else the dragonfly's "darning needles" would sew the child's mouth shut.

What does a dragonfly look like?

Dragonflies belonging to the family Libellulidae (common skimmer) or Aeschnidae (darners) have four independent, alternately moving wings that enable them to fly at speeds up to 60 miles per hour, hover, fly backward, stop on a dime, zip 20 feet straight up, and slip sideways in the blink of an eye! This ability, plus a long slender body and large compound eyes, make them true aerial masters of the insect

world. Their flight advantage enables dragonflies to generate large amounts of body heat. Thus, they burn 50 times as much energy in flight as the amount they use at rest. A dragonfly's freely movable head has large, hemispherical eyes (nearly 30,000 facets each), which the insects use to locate prey with their excellent vision.

The two pairs of wings are flat or horizontal at rest; some species can attain lengths of over 4 inches. The coloration of adult dragonflies ranges from brown to black and green.

Dragonfly Nymph

Nymphs - vary in shape, but most have robust, elongated, or "spider-like" bodies, often with algae growing on their backs; six legs at side of body or near front on elongated species. Dragonfly nymphs live in the water for several years. They are voracious predators which feed upon other aquatic macroinvertebrates such as mosquito larvae, small fish, and tadpoles. After shedding its skin about 12 times, depending on the species, the nymph (naiad), fully grown, crawls out of the water, usually in the early morning to rest on plant stems or rock. Its skin splits along a midline of the thorax, and the adult dragonfly emerges.

How do dragonflies live?

During their 2-week to 2-month lifespan, adult dragonflies terrorize the skies, snatching and eating midges, mosquitoes, moths, bees, butterflies, or even other dragonflies on the fly. You may see adult dragonflies flying or resting on a plant in tandem as they mate. They aggressively defend their territories from a perch or by patrolling in patterns at various heights.

Dragonflies are highly beneficial predators that destroy large numbers of mosquitoes. Their success as insects results, in part, from the large number of eggs they lay. Depending on the species, dragonflies lay hundreds of eggs by dropping them into the water and leaving them to hatch or by inserting eggs singly into a slit in the stem of a submerged plant. The incomplete metamorphosis (egg, youth nymph, mature nymph, adult) can take 2-3 years.

Where do dragonflies live?

Dragonflies are usually found in slower moving streams and in ponds.