By Michele Byers
Hang out by a pond or marsh on a warm summer day, and you’re almost guaranteed to see dragonflies.
With colorful needle-shaped bodies and a double set of wings, they’re fun to watch as they hover, swoop and dart, sometimes at blink-of-the-eye speeds.
They’re actually hunting — and very effectively!
Dragonflies don’t bite or sting, but their fierce name is well-deserved. They’re voracious predators with bodies uniquely equipped to outrun and capture insect prey.
Dragonflies were among the first winged insects on Earth, some 300 million years ago. Fossil records show some ancient dragonflies had wingspans of up to 2 feet! Scientists think they may have grown that large because of higher oxygen levels in the air. Today’s dragonflies are smaller, although they’re still among the giants of the insect world.
Dragonflies and damselflies belong to the order Odonata, which means “toothed one” in Greek and refers to their serrated teeth.
New Jersey has 127 species of dragonfly and 52 species of damselfly. Dragonflies are generally larger and can be easily identified because they hold their wings straight out and flat when at rest. Damselflies tend to be smaller and more slender and hold their wings back while resting.
Some dragonfly species are widespread across the state, like the blue dasher and Eastern pondhawk. Others are more specialized, like the dragonhunter, which is found only near the most pristine streams. Some are migratory like the wandering glider, which ventures far off the Atlantic coast.
The life cycle of dragonflies is fascinating. Adult dragonflies mate in the air, and females lay their eggs on plants growing in lakes, ponds and marshes. The eggs hatch into nymphs, alien-looking aquatic creatures that feed on mosquito larvae, tadpoles, fish, worms and even each other. Most of a dragonfly’s life is spent as a nymph.
To complete its metamorphosis, the nymph crawls out of the water and onto a rock or stem where its exoskeleton cracks open and the young adult dragonfly emerges. Its lace-like wings take anywhere from hours to days to dry and harden.
These wings may look fragile, but they’re actually very strong. Each of the four wings operates independently, giving the dragonfly incredible maneuverability. They can hover and fly straight up and down.
Dragonflies catch insects by grabbing them with their legs, which have appendages that form a basket-like trap from which there’s little chance of escape. Most of the dragonfly’s head is taken up by its compound eye, giving it a nearly 360-degree view of prey and predators.
“They’re a key component of the ecosystem,” said Blaine Rothauser, a New Jersey biologist, naturalist and outdoor photographer.
Dragonflies help humans by keeping mosquito populations down. In turn, they become food for songbirds and herons.
“They make up a good part of the food chain at this time of year,” Rothauser said.
Just as birds and butterflies have their fans, so do dragonflies and damselflies. There’s Jersey Odonate Enthusiasts, or JOE for short, a club for those who enjoy watching dragonflies and damselflies.
Learn more about JOE and its research at www.njodes.com. There’s also a great Facebook page, Northeast Odonata, where enthusiasts post photos and seek identification help.
Enjoy dragonflies this summer, and remember: They need clean water so protect the watersheds near you!
Michele Byers is executive director of the New Jersey Conservation Foundation. For more information, contact her at info@njconservation.org or visit NJCF’s website at www.njconservation.org.
