What Do Dragonflies Eat?

What Dragonflies Eat, and How They Capture Their Prey

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Hadley, Debbie. "What Do Dragonflies Eat?" ThoughtCo, Jan. 29, 2017, thoughtco.com/what-do-dragonflies-eat-1968250. Hadley, Debbie. (2017, January 29). What Do Dragonflies Eat? Retrieved from https://www.thoughtco.com/what-do-dragonflies-eat-1968250 Hadley, Debbie. "What Do Dragonflies Eat?" ThoughtCo. https://www.thoughtco.com/what-do-dragonflies-eat-1968250 (accessed October 22, 2017).
Dragonfly nymph eating a fish.
Some dragonfly nymphs hunt small fish. Getty Images/Oxford Scientific/London Scientific Films

All dragonflies and damselflies are predators, in both their immature and adult life cycle stages. They feed mainly on other insects. Dragonflies are efficient and effective hunters, whether in the aquatic larval stage or the terrestrial adult stage.

What Do Adult Dragonflies Eat?

As adults, dragonflies feed on other live insects. They aren't picky eaters. They'll eat any insect they can catch, including other dragonflies.

Midges and mosquitoes make up the bulk of their diet, but dragonflies will also prey on flies, bees, beetles, moths, butterflies, and other flying insects.

The larger the dragonfly, the larger the prey insect it can consume (including other dragonflies and damselflies). A dragonfly will eat roughly 15% of its own body weight in prey each day, and larger species can easily consume much more than that. Keep in mind that dragonflies capable of eating larger prey are also capable of inflicting painful bites to human fingers.

How Do Adult Dragonflies Hunt?

Dragonflies use one of three techniques to find and capture prey: hawking, sallying, or gleaning. These are the same terms used to describe foraging behavior in birds.

Hawking - Most dragonflies capture their prey in flight, plucking live insects right out of the air. They're well equipped for pursuing and capturing flying prey. Dragonflies can accelerate in an instant, turn on a dime, hover in place, and even fly backwards.

By forming a basket of sorts with its legs, a dragonfly can overtake a fly or bee and simply scoop it up and pop it into its mouth, without stopping. Some, like darners and spreadwings, will just open their mouths and swallow whatever they catch as they fly. Dragonflies that use hawking to catch their prey include darners, emeralds, gliders, and saddlebags.

Sallying - Perching dragonflies will sit and watch for prey, and then rapidly sally forth to capture it as it passes by. Salliers include skimmers, clubtails, dancers, spreadwings, and the broad-winged damsels.

Gleaning - Other dragonflies use a strategy called gleaning, preferring to hover over vegetation and snatch insects perched on plant leaves or stems. Young dragonfly adults, which often hunt in forested environments, will grab and eat caterpillars suspended from the trees by silken threads. Most pond damselflies are gleaners.

What Do Immature Dragonflies Eat?

Dragonfly nymphs, which live in water, also feed on live prey. A nymph will lie in wait, most often on aquatic vegetation. When prey moves within reach, it unfurls its labium and thrusts it forward in an instant, grabbing the unsuspecting critter with a pair of palpi. Larger nymphs can capture and eat tadpoles or even small fish.

Some dragonfly nymphs skewer their prey with pointed palps. These include immature darners, clubtails, petaltails, and damselflies. Other dragonfly nymphs enclose their prey using mouthparts that grab and scoop. These include immature skimmers, emeralds, spiketails, and cruisers. 

 

Sources:

  • Dragonflies, by Cynthia Berger, 2004.
  • Borror and DeLong's Introduction to the Study of Insects, 7th Edition, by Charles A. Triplehorn and Norman F. Johnson, 2005.
  • Encyclopedia of Insects, 2nd Edition, by Vincent H. Resh and Ring T. Carde, 2009
  • Dragonflies and Damselflies of the East, by Dennis Paulson, 2011.