Dragons on the wing
/The insect orders rule the earth, but most of the creepy-crawlies give us the creeps. Still, there are a handful of insects that inspire genuine respect and affection from those of us at the top of nature’s food chain.
There are ladybugs, those cute little spotted beetles; praying mantises, peering up at you with the face of a curious alien; butterflies, all aflutter like jewels on the wing, and lightning bugs, the fairy lights of summer.
There’s another bug of pure delight, an insect with fan clubs in the Americas, Britain and Japan — worldwide, as a matter of fact. The dragonfly has excited admiration, aesthetic appreciation and even practical gratitude, given its ferocious predation on some of our worst insect enemies, including mosquitoes.
The dragonfly and its close relation, the damselfly, belong to the order Odonata from the Greek odon, meaning toothed, referring to the toothed jaws of these fierce little beasts. Not to worry, though. You are in no danger if you are bigger than a mosquito, since these creatures don’t sting and do humans no harm.
It’s easy to tell the two groups apart. Dragonflies hold their wing horizontally, like a little airplane, while damselflies at rest clasp their wings together and upright, like a butterfly, or hold them at an oblique angle, as in the case of the “spreadwings.”
Late summer and fall is the time for the season’s final hatches of the beautiful adult form of these “Odes,” a slim needle of a creature with gossamer wings. It may surprise you to know that the winged adult is merely the end game for an insect that spends as much as 90 percent of its life as an aquatic nymph.
The nymphs live underwater for as little as three months and as much as six years, depending on the species. The “mud bugs” occupy seepages, streams, rivers, lakes, vernal ponds and even marshes of moderate salinity.
Great hunters of other insect larvae, tadpoles and even baby fish, the nymph locates its prey with its prominent eyes. Then, its specially adapted lower lip, hinged like an arm, shoots out and grabs the prey with a pair of hand-like palps. This is the stuff of science fiction! Killer nymphs!
In this phase of their life cycle, dragonflies are chiefly of interest to inland fishermen, who use them for bait. The fly-fishing crowd ties up artificial lures resembling these nymphs, giving them colorful names like “Bob’s Deadly Dragon,” “Bottom Walker” and “52 Buick.”
There is no pupal stage in the Odonate’s life. The winged adult emerges directly from the mature nymph in the shallows at water’s edge. They disperse rapidly to seek other habitat, a tactic that has evolved over 250 million years to assure the dragonflies’ survival.
As old as the dinosaurs, dragonflies were bigger back in the old days, with wing spans of 28 inches. Today there are some 5,000 species, with about 175 species known to occur in New Jersey. There are dashers and dancers and gliders and skimmers; jewelwings and emeralds and amberwings; meadowhawks, pondhawks, spiketails and clubtails.
Some of the individual names are startling and poetic: the lyre-tipped spreadwing, for instance, or the powdered dancer, or — my favorite — the stygian shadowdragon. Dragonflies are strong fliers, reaching speeds of up to 35 miles per hour, and capable of flying backwards and hovering, able to change direction in mid-air.
Damselflies are more leisurely in flight, but both groups catch their prey on the wing, scooping them from the air with a “basket” they form with their front legs. Many of these insects even mate in the air, forming a circle or “wheel” as they clasp one another in a mating embrace.
I must have ideal conditions along my stream for the ebony jewelwing, a type of damselfly, since I am never without them in season. Picture a slim neon needle of brilliant turquoise, outfitted with a pair of pitch black wings.
Occasionally I have had much bigger dragonflies swarming in the yard, so thickly I am sure we’ll collide as I romp around the lawn on my riding mower. These swarms could either represent a feeding frenzy (Eat up, guys!), or a gathering of skimmers or darners, which migrate like monarch butterflies, often in large numbers.
The biggest danger to dragonflies today is water pollution and the disappearance of suitable habitat as ponds and marshes are drained for development.
How can you help? If you build a backyard pond, no matter how small, they will come — providing you don’t keep fish or maintain waterfowl like duck and geese, which will eat the dragons and damsels. Should mosquitoes be a problem, use Bt “dunks,” impregnated with a bacteria that kills mosquito larvae, but won’t harm the dragonfly nymphs.
Meanwhile, take note of these beautiful flyers whenever you see them. You won’t find it easy to creep up on them, owing to the acuteness of their compound eyes. But you may catch a glimpse of a real-life survivor from the Jurassic Era – one that won’t consider you as a morsel suitable for lunch.