A large, fast-flying dragonfly that migrates thousands of kilometers across North America in a multi-generational journey, an ancient predator with extraordinary aerial agility.
Aerial predators of remarkable skill
Dragonflies are among the most lethal hunters in the natural world. They catch their prey mid-flight with a success rate of over 95% — far higher than lions, sharks, or any large predator. Three things enable this:
- Independent wing control. Dragonflies have four wings that can move independently in amplitude, frequency, and phase, allowing extreme maneuverability.
- Compound eyes with up to 30,000 ommatidia covering nearly 360°, providing superior motion detection.
- Predictive interception. Rather than chasing prey, a dragonfly tracks its target’s trajectory and aims for where the prey will be. This requires real-time motion modeling — a cognitive task once thought to be uniquely vertebrate.
A two-stage life
Dragonflies (and damselflies) undergo incomplete metamorphosis — no pupal stage. The aquatic stage (the nymph or naiad) is itself a fearsome predator, ambushing tadpoles, small fish, and other invertebrates with an extendable lower jaw that can shoot out faster than the naked eye can follow. The naiad lives underwater for most of the dragonfly’s life — sometimes years.
When ready to mature, the naiad climbs out of the water and the adult dragonfly emerges from the molt, expanding its wings, drying off, and taking flight within a few hours. Its remaining adult life is comparatively brief — measured in weeks.
Multi-generational migration
The common green darner is one of the only North American dragonflies that performs long-distance migration. The journey takes three generations:
- Generation 1 — emerges in the southern US in spring, flies north, breeds and dies.
- Generation 2 — emerges in the north in summer, flies south, breeds and dies.
- Generation 3 — emerges in the south, overwinters as adults, completes the cycle in spring.
A single individual never makes the round trip; the migration is a relay. The route was confirmed only in 2018 using stable isotope analysis of dragonfly wings.
An ancient lineage
Dragonflies are among the oldest insects on Earth. The fossil record shows essentially modern-looking dragonflies from over 300 million years ago — they predate dinosaurs by 100 million years. Some Carboniferous-era fossil species (Meganeuropsis permiana) had wingspans of nearly 70 cm, the largest insects ever known to have existed.
Mosquito control
A single adult dragonfly can eat hundreds of mosquitoes in a day. Their naiads also feed heavily on mosquito larvae underwater. They’re among the most effective natural mosquito controls in their habitats — though their populations are declining in many places due to wetland loss and water pollution.