Dragonflies are captivating insects often seen darting near water bodies, and their predatory nature frequently leads to questions about their diet, especially concerning mosquitoes. Understanding what dragonflies eat and how they hunt sheds light on their role in various ecosystems. This article explores the dietary habits and hunting strategies of dragonflies, as well as ways to encourage their presence in local environments.
Dragonfly Predation
Dragonflies are voracious predators throughout their lives, consuming a wide array of insects, including mosquitoes. Both the aquatic larval stage, known as nymphs, and the adult flying insects are effective hunters. Dragonfly nymphs live underwater, where they prey on mosquito larvae, other aquatic insects, small crustaceans, tadpoles, and even small fish. This underwater predation significantly impacts mosquito populations before they mature into flying adults.
Adult dragonflies continue this predatory behavior in the air, with mosquitoes and midges often forming a substantial part of their diet. They are opportunistic hunters, readily consuming flies, butterflies, moths, bees, beetles, and even other dragonflies. A single adult dragonfly can consume hundreds of mosquitoes in a day. Larger dragonfly species can eat their own body weight in insect prey each day.
Hunting Techniques
Adult dragonflies are skilled aerial hunters, utilizing their speed, agility, and keen eyesight to capture prey in flight. They can fly at speeds up to 30 miles per hour, accelerate instantly, turn sharply, hover, and even fly backward. Their large, multifaceted compound eyes provide them with nearly 360-degree panoramic vision, allowing them to spot prey up to 12 meters away. Many dragonflies employ a “hawking” technique, snatching insects directly out of the air. They use their spiny legs to form a basket-like trap to scoop up insects, which they can then transfer to their mouths without needing to land.
Dragonfly nymphs, living underwater, employ a different yet effective hunting strategy: ambush predation. They lie in wait on aquatic vegetation or the substrate, blending in with their surroundings. When suitable prey, such as mosquito larvae, comes within range, the nymph rapidly extends a specialized, hinged lower jaw called a labium. This extendable mouthpart, often referred to as a “mask,” shoots forward with pincers or hooks at its tip to grasp the prey. Once the prey is secured, the labium retracts, bringing the meal to the nymph’s mandibles for consumption.
Attracting Dragonflies
For those interested in encouraging dragonflies as natural mosquito control, creating suitable habitat is an effective approach. Dragonflies are aquatic insects that require freshwater for reproduction, as their eggs are laid in or near water and their larvae develop there. Establishing a pond or other clean water feature, even a small one, can attract them.
Providing a variety of aquatic vegetation is beneficial. Submerged plants offer protection for eggs and nymphs, while emergent plants allow nymphs to climb out during metamorphosis. Floating plants serve as perching spots and egg-laying sites for adults. Surrounding the water feature with native plants, tall grasses, and shrubs provides perching, roosting, and shelter for adult dragonflies, while also attracting other small insects that serve as prey. Avoiding the use of pesticides is important, as these chemicals can be harmful to both adult and larval dragonflies, impacting their populations.