What Is the Life Cycle of Damselflies? Egg to Adult in 4 Stages
What Is the Life Cycle of Damselflies? It runs through four stages: egg, nymph, teneral (subadult), and adult. Damselflies belong to the suborder Zygoptera within the order Odonata, and like dragonflies they develop through incomplete metamorphosis, so there is no pupal stage. A nymph molts repeatedly underwater, then climbs out and splits its skin one last time to become a winged adult.
Stage 1: Egg
Females lay eggs in or near freshwater, inserting them into plant stems, submerged wood, or the surface film with a blade-like ovipositor. Some species stay attached to their mate while laying, and a few submerge completely to place eggs deeper in aquatic vegetation. Most eggs hatch within a few weeks under warm conditions, though species that overwinter as eggs won’t hatch until the following spring. Fish, other aquatic insects, and fungi take a steady toll on eggs before they hatch.
Stage 2: Nymph
Once hatched, the nymph (also called a naiad) spends the rest of its immature life underwater, anywhere from a few months to several years depending on species, water temperature, and food supply. This is by far the longest stage of the life cycle.
Gills and Hunting
A damselfly nymph breathes through three leaf- or paddle-shaped gills called caudal lamellae, arranged in a tripod at the tip of the abdomen. That tail-gill arrangement is the easiest way to tell a damselfly nymph from a dragonfly nymph, which breathes through internal rectal gills and has no external tail gills at all. The lamellae also help propel the nymph, flexing side to side to push it away from danger. Nymphs hunt as ambush predators, shooting out a hinged, extendable lower lip called a labium to snatch mosquito larvae, small crustaceans, worms, and other insect larvae.
Molting
A nymph molts roughly a dozen times as it grows, since its rigid exoskeleton can’t stretch and has to be shed and regrown at each stage, called an instar. The exact number of molts and how long each instar lasts depends on the species, water temperature, and how much food is available.
Stage 3: Teneral (Subadult)
When a nymph is ready for its final molt, it climbs out of the water onto a reed, rock, or other surface above the waterline. Its skin splits down the back and a soft, pale teneral damselfly pulls itself free. Over the next few hours to a couple of days it pumps hemolymph into its wing veins to expand and stiffen them, while its exoskeleton hardens and darkens into adult coloration.
Tenerals are weak, uncoordinated fliers and lack the bright colors of mature adults, which makes this the most dangerous window in the entire life cycle. Birds, spiders, and even other odonates account for a large share of tenerals that never make it to their first mating flight.
Stage 4: Adult
A fully hardened adult spends its remaining time feeding, defending a perch or territory, and mating. Most adults live just a few weeks, though the exact span depends heavily on species and weather conditions.
Adults hold their legs forward in a basket shape while flying, built for snatching prey out of the air. Mosquitoes, midges, and other small flying insects are a primary food source for adult damselflies, which hunt on the wing using large compound eyes to track movement. Damselfly eyes sit on either side of the head with a visible gap between them, unlike a dragonfly’s eyes, which meet or nearly meet at the top of the head.
Mating and Egg-Laying
A male grips a female behind the head with claspers at the tip of his abdomen, and the pair forms a circular “wheel” as the female curls her abdomen forward to collect sperm. Many species stay linked, in tandem, through the entire egg-laying process, with the male guarding the female from rival males as she deposits eggs into plant stems or open water.
Habitat and Conservation
Damselfly nymphs live in marshes, ponds, lakes, streams, and other freshwater habitats, and because both eggs and nymphs need water, adults rarely stray far from it. Biologists survey nymph communities alongside other aquatic insects when checking pond and stream health, though damselflies as a group tolerate somewhat more pollution than sensitive groups like mayflies and stoneflies, so their presence alone isn’t a guarantee of pristine water.
Wetland loss, shoreline development, and pesticide runoff are the biggest threats to local populations. Leaving a buffer of native vegetation around ponds and streams, and keeping pesticide spray away from water, does more for damselfly numbers on a property than almost anything else a landowner can control.
