Dragonfly larvae (nymphs) are aquatic, usually drab, with 6 legs, large eyes, and small wing buds on the back of the thorax. Gills are located inside the rectum (unlike those of damselflies, which extend from the hind end like 3 leaflike tails). They breathe by drawing water in and out of their hind end. By forcefully expelling this water, the animal can move quickly in a form of jet propulsion. The lower jaw is scooplike and covers most of the bottom part of the head.
Adult dragonflies have slender, elongated abdomens, robust bodies, and 2 pairs of wings that are usually outstretched horizontally. The wings are membranous and elaborately veined. The hindwing is wider at the base than the forewing. The eyes are compound, large, adjoin each other and nearly cover the head. The antennae are short. The six legs are poor for walking but good for perching.
Key identifiers for dragonfly larvae:
- Elongated or chunky aquatic insect, body usually constricted in front of the widened abdomen; usually drab.
- Six legs that are long and jointed.
- Each leg with 2 claws.
- Large eyes.
- Small wing buds on the back of the thorax.
- Abdomen often rounded or oval, segmented, often with 5 wedge-shaped or pointed structures at the hind end.
- Lower jaw scooplike, covering most of the bottom part of the head.
- There are no external feathery gills.
Larva length: from ¼ to 2½ inches (varies with age and species).
Habitat and Conservation
Nymphs are common in many aquatic habitats. They are especially common near clumps of aquatic vegetation or submerged tree roots. Because they lay eggs in water, adults are usually found near water, though their fast, strong flight takes them many places.
Dragonfly nymphs are lie-in-wait predators resting quietly on the substrate or on submerged plants. When a potential meal swims or walks near, the nymph’s extendable jaws flash outward to snatch and draw in the food, which can be any small aquatic animal or even the claw of an equal-sized crayfish. Adult dragonflies hold their legs in a basket shape during flight; they snatch up and eat small flying insects.
There are many species of dragonflies in our state, ranging from very common to unusual to rare to in danger of disappearing. Nine dragonflies are Missouri species of conservation concern: bayou clubtail, midland clubtail, skillet clubtail, golden-winged skimmer, brimstone clubtail, elusive clubtail, Hine's emerald, Ozark emerald, and treetop emerald. Hine's emerald is endangered in Missouri and is the only dragonfly that is federally endangered.
Adult male dragonflies commonly perch on branches or other objects, patrolling their territories, driving away rival males and attempting to mate with females. Mating pairs usually fly in tandem. The female usually flies low over the water, depositing eggs directly on the surface. Larvae (nymphs) undergo several molts as they grow and can take a few years to mature. When ready, they crawl out of the water to a safe place, shed their skin, and emerge as a young adult. In the next days or week, they complete their maturation.
Anyone who dislikes mosquitoes can appreciate dragonflies! Dragonflies are also admired for their beautiful forms. It should be noted that dragonflies cannot sting. The larger species can deliver a pinching bite when handled, but they cannot harm people.
Most of a dragonfly’s life is spent as a nymph. Some species live for 5 years underwater before becoming adults. They and the adult forms are important predators of mosquitoes, midges and other small insects. The nymphs are important food for fish, frogs, and other aquatic insectivores.