One summer day many years ago, I was on a birdwatching trip. We had spent the morning hours observing Least Bitterns, Yellow-billed Cuckoos, and Golden-winged Warblers. As the sun was getting hotter, the birds were getting harder to find.
Sitting by a river, I noticed a shiny insect flying through the grass. It was bright blue and green and hardly bigger than a needle. I snapped a picture before it disappeared in the grass. The next thing I knew, I was finding these sparkling jewels everywhere we went. I was hooked on dragonflies.
The common Eastern Forktail that I saw that day remains one of my favorite dragonflies.
Did you know there are thousands of dragonfly species around the world? Over 160 species have been recorded in New Hampshire alone. They come in a rainbow of different colors, from Scarlet Bluets and Eastern Amberwings to Violet Dancers and Blue Dashers. Dragonflies are carnivorous, feeding on insects such as flies, mosquitoes, moths, leafhoppers, and sometimes even other dragonflies.
These beneficial insects are remarkably skilled hunters, with a success rate of 90 to 97%, which exceeds that of any other animal, including lions, sharks and cheetahs.
Each of their compound eyes contains up to 30,000 tiny lenses called ommatidia, contributing to their excellent eyesight. Another fascinating thing about dragonflies is their life cycle. As adults on the wing, they don’t live much longer than a couple of months. Dragonfly eggs usually hatch within days of being laid. They spend much more time as aquatic, wingless larvae, called nymphs, than as adults; the larval stage for some species lasts up to five years. In their underwater life, the larvae are also top-notch predators, catching other aquatic insects or sometimes small fish and tadpoles.
When they’re ready to emerge, the larvae climb out of the water, shed their skin, and expand their wings and abdomens by pumping blood through them. You will sometimes see the empty larval skins, called exuviae, left behind on plants next to the water’s edge after the terrestrial adults fly away. When they find a mate, the pair of them form a unique heart-shaped wheel and return to the water to lay their eggs, starting the cycle over again.
The term “dragonfly” is often used to refer to all members of the order Odonata, which consists of both dragonflies and damselflies. I am often asked how to tell the two groups apart. Taxonomically speaking, dragonflies belong to the suborder Anisoptera and damselflies belong to the suborder Zygoptera. They can generally be differentiated by how they hold their wings, their overall shape, and their behavior. When resting, dragonflies are typically seen holding their wings outward from their body, while damselfies tend to hold their wings folded over their abdomen. The hindwings and forewings are differently shaped on a dragonfly, while all four wings of a damselfly are a similar shape.
Overall, dragonflies tend to be thicker, while damselflies are more slender. Finally, the two large eyes of a dragonfly often touch, while the small eyes of a damselfly are further apart from one another.
Here is a sample of species that you might find in September and October.
Autumn Meadowhawk: In September and other fall months, be on the lookout for these colorful dragonflies. Males have a bright red abdomen, making them easy to spot, while females are more golden-orange to light-brown.
A widespread member of the genus Sympetrum, which includes about 50 other species of meadowhawks worldwide, the Autumn Meadowhawk can easily be distinguished from look-alikes by its golden-brown rather than black legs. Usually the last species on the wing, meadowhawks stay warm by perching on sunny rocks, tree trunks or boardwalks. Unlike some other dragonflies, they do not defend territories and are often seen together in small groups.
Common Green Darner: A migratory species, this three-inch-long flier is the only dragonfly seen in all 50 states. Males have a lime-green thorax and sky-blue abdomen, while females are all green. During this time of year, they can often be seen congregating in goldenrod fields or migrating along the coast in large numbers. American Kestrels and Merlins enjoy eating Green Darners while on their own fall migrations. These darners are often the first dragonflies of the spring, as they arrive before resident species have emerged.
Eastern Forktail: This is one of the most abundant damselflies in the Northeast. Males are green with a blue-tipped abdomen, and females are orange at first and turn a moonlight blue as they mature. In his book “A Handbook of the Dragonflies of North America,” James Needham writes of forktails: “They seem well contented to spend their lives flitting about among the grasses.” Forktails get their name from the fact that the males have a forked projection at the end of the abdomen.
All in all, dragonflies are amazing creatures with fascinating life histories. They are excellent bioindicators of the health of the wetland ecosystems they inhabit, and they provide food for a variety of other organisms including birds, spiders, frogs and fish. If you explore a local pond on a sunny day and take a closer look along the edge, you might just spot some of these beautiful winged wonders. Enjoy!
Kate McKay is a raptor biologist with the Harris Center for Conservation Education,
where she scans the skies for birds of prey but also migrating dragonflies. harriscenter.org/