Dragonflies are captivating insects, and many people wonder about their relationship with mosquitoes. While they do not “scare” mosquitoes away or possess a repellent quality, dragonflies are natural predators of mosquitoes, actively hunting and consuming them. Understanding their role helps appreciate their contribution to the ecosystem.
Dragonflies: Masters of the Air
Dragonflies are highly adapted predators, showcasing remarkable aerial prowess. Their large, multifaceted compound eyes provide nearly 360-degree vision, enabling them to detect prey with exceptional accuracy. Equipped with two pairs of strong, transparent wings that move independently, they achieve incredible maneuverability, including hovering and flying backward. This unique wing structure and muscular control contribute to their speed, with some species reaching up to 35-60 miles per hour. Their six legs are not used for walking, but instead form a basket-like trap to scoop prey mid-flight.
Their predatory efficiency is notable, with some species boasting a hunting success rate of up to 95% on attempted captures. These physical attributes and hunting strategies underscore their role as significant hunters in their aquatic and aerial environments.
Their Diet: More Than Just Mosquitoes
Dragonflies are carnivores throughout their life cycle, consuming a variety of insects. Both aquatic nymphs and adult dragonflies are voracious predators. Nymphs residing in water bodies feed on mosquito larvae, other aquatic insects, small crustaceans, tadpoles, and small fish. They are equipped with a unique, extendable lower jaw that shoots out to snatch prey.
Adult dragonflies primarily prey on other flying insects, including midges, flies, butterflies, bees, and even smaller dragonflies or damselflies. Mosquitoes form a significant part of their diet, with an adult dragonfly consuming hundreds daily. They are not selective eaters and will capture whatever suitable prey is available, often consuming a fifth of their body weight each day.
Do They Reduce Mosquitoes?
Dragonflies contribute to natural mosquito control by preying on both adult mosquitoes and their aquatic larvae. A single dragonfly nymph can consume an average of 40 mosquito larvae per day in experimental settings. Adult dragonflies are efficient hunters, capable of catching numerous adult mosquitoes in flight, which helps reduce populations.
However, dragonflies alone are unlikely to eliminate widespread mosquito problems in large areas. Mosquitoes reproduce much faster than dragonflies develop, allowing populations to quickly rebound. While dragonflies are a beneficial component of natural pest management, they are not a standalone solution for significant infestations. Their effectiveness is influenced by factors like local species density and habitat availability.
Encouraging Dragonflies in Your Environment
Creating an environment conducive to dragonflies supports their presence and natural pest control efforts. Establishing a water feature like a pond is effective, as dragonflies require water for breeding and their larval stage. The pond should have varying depths, including shallow edges for nymphs and a deeper center of at least two feet. Clean, unpolluted water is important for nymph survival.
Incorporating a variety of aquatic plants, such as submerged, emergent, and floating species, provides shelter for nymphs and sites for adults to lay eggs and perch. Examples include cattails, water lilies, and various grasses and reeds. Surrounding the water feature with native plants and tall grasses offers perching spots, shelter, and attracts other small insects that serve as additional prey. Avoiding chemical pesticides is crucial, as these can harm dragonflies and disrupt the ecosystem. Providing flat rocks for sunbathing can also attract adult dragonflies.