Dragonflies are ancient and captivating insects, known for their striking appearance and aerial agility. They are formidable and efficient predators throughout their lives, hunting various flying insects.
Adult Dragonflies: Aerial Mosquito Hunters
Adult dragonflies effectively hunt mosquitoes in the air, using their speed, agility, and exceptional vision. Their large compound eyes, composed of up to 30,000 facets, provide nearly 360-degree vision. A brain that devotes approximately 80% of its capacity to visual processing enables dragonflies to track and intercept moving targets with high precision. They can process around 200 images per second, making the world appear in slow motion to them.
These aerial hunters predict their prey’s flight path, flying towards an interception point rather than directly chasing. Their powerful wings allow them to hover, fly backward, and change direction instantly, making them agile. As they fly, dragonflies form a basket with their legs to scoop up insects, often consuming them mid-flight. A single adult dragonfly can consume dozens to hundreds of mosquitoes daily and a fifth of their body weight in prey each day. Their hunting success rate reaches up to 95%.
Dragonfly Larvae as Aquatic Predators
Dragonflies spend the majority of their lives, often one to two years, as aquatic larvae or nymphs. These larvae inhabit various freshwater environments such as ponds, lakes, and slow-moving streams, typically found near aquatic vegetation or submerged roots. During this aquatic stage, they are predators of smaller aquatic organisms, including mosquito larvae, which form a significant part of their diet.
Dragonfly nymphs employ a specialized hunting mechanism: an extendable lower jaw, known as a labium or “mask.” This prehensile structure folds beneath their head when at rest and can shoot forward in as little as 15 milliseconds to snatch unsuspecting prey. The labium has pincers or hooks at its tip to grip the prey, which is then drawn back to the mouth. Research indicates that a single dragonfly or damselfly naiad can consume an average of 40 mosquito larvae per day in experimental settings, leading to a significant reduction in mosquito larval populations. The presence of dragonfly larvae in water bodies helps control mosquito populations before they emerge as adults.
Beyond Mosquitoes: The Dragonfly’s Diverse Diet
While mosquitoes are a notable part of their diet, dragonflies are generalist predators that feed on a wide variety of other insects. As adults, they commonly consume flies, gnats, midges, and other small flying insects. Their diet also includes larger insects such as butterflies, moths, beetles, wasps, and bees. Some larger dragonfly species even prey on smaller dragonflies or damselflies.
The larvae also have a diverse diet, extending beyond mosquito larvae to include other aquatic insects, insect larvae, small crustaceans, tadpoles, and even small fish. Their opportunistic feeding habits mean they will eat virtually any animal small enough to capture. Dragonflies help maintain the balance of insect populations within their ecosystems. Their predatory actions contribute to natural pest control and support the overall health of wetland environments.