Most bodies of fresh water on the planet, from humble ephemeral puddles to the mightiest rivers, likely host dashing, colorful predators of ancient lineage – dragonflies. Like their legendary namesakes, dragonflies are mysterious, ferocious, flying predators that have gotten markedly disparate receptions in eastern and western culture.
Like the dragons of European folklore, dragonflies were once feared and seen as evil omens of ill fortune in the West. But then, such beliefs largely came about during the Dark Ages, a period of time not known forenlightened, logical thinking, or good personal hygiene for that matter. Traditional east Asian cultures, on the other hand, revere both dragons anddragonflies and welcome them as harbingers of prosperity and extremely good luck. In reality, unless one happens to be an unwitting fly, dragonflies do indeed make for very good neighbors. Dragonflies are harmless to humans, serve as indicators of reasonably good water quality, perform interesting aerial antics for us to watch, and make for free, natural flying pest control.
Planet Earth currently hosts about 3,012 species of dragonflies, with approximately 100 species, give or take, regularly occurring and breeding somewhere within Florida’s borders. Our Florida dragonflies range in size from the petite, waspish Elfin Skimmer and Eastern Amberwing, with 0.8-inch and 0.9-inch body lengths respectively, to the impressive, accurately-named Regal Darner with a body length of 3.6 inches. Even the imposing darners are dwarfed by some Carboniferous Period fossils of ancient dragonfly ancestors, sometimes known as “griffinflies”, especially Meganeuropsis permiana which hailed from what is now modern day Kansas. M. permiana flew the prehistoric skies with an impressive body length of 17 inches and the wingspan of the average city pigeon, a whopping 28-inches.
In line with their fantastic and somewhat alien appearance, dragonflies have inspired some very colorful, captivating monikers. Taxonomists waxed very poetic when conjuring names for dragonflies and handed out some very creative epithets including Halloween Pennant, Mocha Emerald, Twilight Darner, and, a personal favorite, Cinnamon Shadowdragon. Many dragonfly names indicate the way the animal looks, flies, and hunts.
Speaking of hunting, dragonflies are obligate, efficient, and successful predators, capturing up to 95% of the diurnal insect prey they pursue. As adults, dragonflies are skillful masters of the air. One species, the golden Wandering Glider, is such an accomplished aerialist that it is cosmopolitan in distribution, flying by day and night for thousands of miles across vast expanses of ocean, drifting with the wind, feeding on aerial plankton on the wing, living and breeding on every continent except Antarctica. Dragonflies consume up to 1/5 of their body weight every day, making any flying insect a dragonfly can capture and overpower fair game, including other dragonflies and damselflies. More often, dragonflies will target flying insects that gather in numbers around water and open fields, and fortunately for us, their diet includes many biting, noxious and pesky fly species such as mosquitoes, midges, House Flies, deer flies, Stable Flies, horse flies, botflies, flesh flies, and Bluebottle Flies. This voracious predation begins in a dragonfly’s young, aquatic nymph stage, though the hunting strategy and lifestyle are wildly different from the insect’s adult life.
The dragonfly life cycle begins with the egg, and some dragonflies unceremoniously drop their eggs at the surface of a pond while others lay their eggs on or insert them into emergent aquatic plants. When the wingless nymphs hatch, they are aquatic, living on the pond bottom, breathing with the feathery or petal-like gills that tip their abdomens. The predatory nymphs slowly creep about or sit and wait to ambush prey using the labium, ajointed, arm-like appendage, tipped with fearsome seizing claws, that folds beneath the nymph’s head, to strike out and capture aquatic insects, worms, shrimp, small fish, and tadpoles with lightning speed. This unique feeding apparatus is the stuff of nightmares and very likely inspired the Xenomorphs’s mouthparts of the “Alien” movie franchise. Adding to their bizarre anatomy, some nymphs spurt water from their anuses (that’s right, you read correctly) like a water rocket to quickly squirt forward to capture prey or elude predation.
If the nymphs can avoid being eaten by fish, birds, amphibians, and other dragonfly nymphs, they eventually leave the water, climb up emergent vegetation, shed their exoskeletons like old husks, and spread their newly-formed adult wings. The adults live an average of about seven months, during which time they energetically hunt, breed, spawn the next generation of dragonflies, and try to avoid being eaten by fish, frogs, herons, nighthawks, kites, flycatchers, swallows, falcons, spiders, predatory wasps, and, because it’s a dragonfly-eat-dragonfly world out there, even their own kin. Dragonflies have existed on planet Earth for some 325 million years and we humans can do our part to continue this dynasty by maintaining healthy water quality in our wetlands and planting our waterways with native vegetation. In turn we’ll be rewarded with a colorful, protective army of fierce, little, good luck dragons.