Dragonflies, butterflies and ladybugs are often considered “nice” insects with their pretty colors and seemingly harmlessness. However, dragonflies are far from harmless–they may be one of the most successful predators in the animal kingdom.
Dragonflies hold their wings straight out when at rest
African lions are ferocious but their hunts are only successful 25 percent of the time. The great white shark only captures prey 50 percent of the time.
For the small size of the dragonfly, it can be brutal. Dragonflies capture 90 to 95 percent of the prey they hunt and it can be devoured within seconds with the dragonfly’s serrated teeth. Some dragonflies capture and eat their prey so quickly the act can only be seen on high-speed cameras.
Tiny flies, leafhoppers, beetles, mosquitos, moths, bees and butterflies don’t stand a chance against dragonflies. Even smaller dragonflies and damselflies have to be wary of the aptly named dragonfly.
However, most insects don’t even know what is coming when a dragonfly snatches them. Unlike some predators that hunt their prey by actively chasing them, dragonflies prefer to ambush the prey from behind. Dragonflies can track their flying prey and intercept it precisely.
Dragonflies are thought to have the best vision in the insect world with almost a 360 degree view.
Dragonflies crush their prey with serrated teeth
Excellent vision coupled with incredible flight capabilities helps them hunt successfully. Their four wings move independently of each other and can be rotated independently like airplane propellers are feathered.
Not only can they fly forwards, dragonflies can fly backwards, up, down, turn on a dime and hover.
Adult dragonflies utilize these flight capabilities to forage for prey and the methods of hunting can be divided into three types: hawkers, salliers and gleaners.
Hawkers fly around, either in a small space or large, and capture flying insects much like swallows foraging.
Salliers perch to watch for flying prey and then fly up to capture the prey. Some hummingbirds also use this method to forage for insects.
Gleaners alternate slow flight through vegetation with perching to search for insects. Once spotted, the dragonfly darts at the stationary prey and plucks it from the vegetation. Some gleaners flush insects from the vegetation and capture them in flight.
Dragonflies position their legs during flight so the spines form a basket to catch prey
Not only are adult dragonflies fierce predators but so are the aquatic dragonfly larvae, called nymphs or naiads. Nymphs look completely different from adult dragonflies and hunt in different ways.
Nymphs capture prey by using hydrostatic pressure to project their labium (lower lip) to grab the prey with a pair of palps (grasping organs) located on the forward end of the labium. The palps open and shut and can be pointed to skewer the prey or spoon-shaped to enclose the prey. Then the nymph retracts its labium to bring the prey into its mandibles (jaws).
Nymphs eat almost anything including tadpoles, mosquitoes, fish, other insect larvae and each other.
Just as adult dragonflies forage in different ways, so do the nymphs. Some nymphs burrow below the sandy or muddy bottom and grab midge larvae as they encounter them.
Other nymphs hide in the bottom detritus with only their eyes and face exposed and then strike at any bottom dweller that passes by. Then other nymphs climb on aquatic vegetation and stalk their prey like a cat stalks a mouse.
Even though dragonflies may be one of the most successful predators in the animal kingdom, they are not at the top of the food chain like lions and great white sharks. Flycatchers, small falcons, spiders, frogs, fish, robber flies and even ants turn the tables on one of the animal kingdom’s most successful hunters.
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