What Are Dragonfly Nymphs?

Dragonfly nymphs are dragonflies that have not yet matured into adults. Dragonflies generally have what is known as an "incomplete metamorphosis" life cycle, because these insects do not generally have a larval stage. Instead, dragonfly nymphs hatch directly from the eggs. These nymphs typically live in water, and will periodically shed their skins as they mature. The average dragonfly nymph sheds its skin eight to 17 times during its maturation into an adult, which can take up to four years, depending on species.

Female dragonflies usually lay their eggs in the water, near the water, or in the stalks of aquatic plants. Often, the fertilizing male guards the female until the laying of eggs is complete. While most adult dragonflies live for only a couple of months, the average female will lay several batches totaling many thousands of eggs. The eggs will generally hatch in about two weeks, allowing the nymphs, also known as naiads, to emerge.

Depending on species, dragonfly nymphs can spend up to four years in the water before they undergo their final transformation into adults. Most dragonfly nymphs have abdominal gills found in the interior of the rectum. They can usually propel themselves about by sucking water into their abdominal gills and squirting it back out again. In this manner, dragonfly nymphs can get up the speed to capture prey or escape from predators.

Water fleas, newt larvae, bloodworms, and pond snail eggs are among the organisms typically preyed upon by dragonfly nymphs. The nymphs are typically preyed upon in turn by larger insects, fish, and leeches.

It can take anywhere from one to four years for the typical dragonfly nymph to reach adulthood. The nymphs typically remain in the water until they mature. During their nymph stage, dragonflies will usually shed their skins and grow larger eight to 17 times. The developmental period between each molting is typically known as an instar.

Once the dragonfly nymphs have become sizable enough, they will generally leave the water to undergo their final molting. This final molting typically reveals the dragonfly's adult wings. Dragonfly nymphs often undergo their final molting at night, and will often do so in large groups. Biologists believe that dragonflies may molt on a large scale to ensure the availability of a mate, and as protection against predators. Once the dragonflies have matured, they will typically live for another six to eight weeks.

Dragonfly nymphs, also known as naiads, are the aquatic larval stage of dragonflies. They inhabit a variety of freshwater environments, including ponds, lakes, streams, and wetlands. These nymphs are voracious predators, feeding on other aquatic insects, tadpoles, and even small fish. They breathe through gills located in their rectum and can propel themselves by expelling water from their anal opening.

The duration of the larval stage in dragonflies can vary widely depending on the species and environmental conditions. Generally, dragonfly nymphs can spend anywhere from several months to several years underwater before emerging to undergo metamorphosis. According to the British Dragonfly Society, some species may remain in the nymph stage for up to four years before transforming into adults.

Dragonfly nymphs have a unique adaptation for breathing underwater. They possess internal gills within their rectum. By drawing water into their rectal chamber and then expelling it, they can extract oxygen from the water. This process not only aids in respiration but also provides a jet-propulsion mechanism that helps them move or escape from predators.

Dragonfly nymphs are formidable predators, feeding on a wide range of aquatic organisms such as mosquito larvae, other insect larvae, tadpoles, and sometimes small fish. They catch their prey using a specialized, extendable lower lip called a labium, which can shoot out quickly to snatch unsuspecting prey, bringing it back to the mandibles to be consumed.

Identifying a dragonfly nymph involves looking for specific characteristics such as a robust, elongated body, six legs, and the absence of wings. They also have large eyes and an extendable labium for catching prey. The nymphs of different dragonfly species can vary in size and coloration, but these general features are consistent across the group.

When a dragonfly nymph is ready to metamorphose, it leaves the water and climbs onto a plant or other surface. The nymph's skin then splits along the back, and the adult dragonfly begins to emerge. This process can take several hours as the dragonfly pumps hemolymph into its wings and body to expand them. Once fully emerged, the adult dragonfly will rest until its exoskeleton hardens and its wings dry, after which it will take its first flight.