What Do Dragonflies Eat? Mosquito Larvae to Airborne Prey
What do dragonflies eat? The short answer is other insects, and lots of them, at every stage of life. As nymphs, they hunt underwater for up to four years before they ever grow wings; as adults, they capture prey at roughly a 97% success rate once they commit to a chase. Both stages are strictly carnivorous.
Two Very Different Feeding Stages
Dragonflies undergo incomplete metamorphosis: egg, nymph, adult. There's no pupal stage and no diet change from plant to animal matter, only a change of hunting ground.
Egg: Females lay eggs in or on submerged vegetation, or directly into water, depending on the species.
Nymph: Nymphs can live in the water up to four years before emerging as adults, molting repeatedly as they grow. This underwater phase, not the winged adult phase, is where a dragonfly spends most of its life.
Adult: Once it climbs out of the water and its exoskeleton hardens, a dragonfly spends the rest of its life, often just a few weeks to a few months, flying, hunting, and mating.
What Adult Dragonflies Eat
Adult dragonflies are generalist aerial predators: they take whatever day-flying insects are locally abundant rather than specializing in one prey type. Common targets include:
- Mosquitoes: mosquitoes are part of the diet of both dragonfly adults and nymphs, and a single adult can work through anywhere from several dozen to hundreds of mosquitoes in a day, which is why they're valued near ponds and wetlands.
- Flies and midges: often the bulk of the catch simply because they're the most numerous flying insects around.
- Moths: taken at dusk, when larger dragonfly species are still active.
- Bees, wasps, and other dragonflies: larger species such as darners will take prey close to their own size, including smaller odonates.
Dragonflies catch nearly all of this prey in flight. They scoop insects out of the air using bristled legs held forward like a basket, then transfer the catch to their mandibles while still flying, or after landing on a perch.
What Dragonfly Nymphs Eat Underwater
Nymphs (also called naiads) are just as predatory as adults, but they hunt by ambush instead of pursuit. Their diet includes:
- Mosquito larvae: a major food source in still or slow-moving water, and the basis for using dragonflies as a natural mosquito check in ponds.
- Other aquatic insect larvae: mayfly and caddisfly larvae, plus smaller dragonfly and damselfly nymphs, including their own species.
- Tadpoles and small fish: larger nymphs, especially in their final year before emerging, will take vertebrate prey when it's available.
A nymph's lower lip, the labium, is hinged and extendable. It normally folds against the underside of the head, then shoots forward in a fraction of a second to grab prey with a pair of hooked palps at the tip, functioning like a retractable claw rather than a simple mouth.
How Dragonflies Hunt
Aerial Interception
Adult dragonflies rely on two compound eyes made up of about 30,000 facets each, giving them nearly a full 360-degree field of vision processed at roughly 200 images per second. Rather than chasing prey directly, they track its flight path and fly to an interception point, closing the gap in well under a second.
Perch-and-Ambush
Some species, particularly larger ones like darners and clubtails, perch on stems or bare branches and wait. When prey passes within range, they launch, grab it, and often return to the same perch to feed.
Underwater Ambush
Nymphs stay still on submerged plants or in the substrate, relying on camouflage until prey comes within striking distance of the labium. Because the strike itself takes milliseconds, the nymph doesn't need to be fast anywhere except in that final lunge.
Digestion and Diet Requirements
Dragonflies bite prey with their mandibles and typically eat it in place, tearing off pieces rather than swallowing it whole for anything larger than a small fly. Digestion is fast; a well-fed adult can process a meal within hours, which supports the energy demands of near-constant flight. Because dragonflies burn through protein and fat quickly during hunting and mating, they need a steady intake of insect prey rather than occasional large meals.
Why Their Diet Matters Ecologically
Because both nymphs and adults feed heavily on mosquitoes, dragonflies function as a two-stage check on mosquito populations, one below the water and one above it. They're also prey themselves: birds, frogs, fish, and spiders all take dragonflies or their nymphs, which makes a healthy dragonfly population a rough proxy for water quality in a pond or wetland.
Pressures on Their Food Supply
Habitat Loss
Draining wetlands and developing shorelines removes the still and slow-moving water nymphs need, cutting off their food supply along with their habitat.
Water Pollution
Runoff and chemical contamination reduce the aquatic insect populations nymphs depend on, and can poison nymphs directly.
Shifting Water Levels
Drought and altered rainfall patterns change how long ponds and wetlands hold water, which affects both breeding sites and the prey base nymphs rely on during their multi-year development.
