The bass gave an audible gulp as it broke the water in front of the boat.  I assumed Lew had hooked another smallmouth, since he had out-fished me handily most of the morning. When I turned to see if Lew was into another good fish, I noticed that his line was nowhere near the circles in the water. Then another bass broke the surface and splashed back into the water. What the heck was going on?

The day was sunny, late July on the Androscoggin River south of Errol, NH. Lew Hinman and I were enjoying a day of floating down the river with guide Paul Starring in search of action for our fly rods. There was a variety of wildlife in evidence, from Common Mergansers to Yellow-rumped Warblers, muskrats and frogs, with insects galore.

Paul had told us to be alert for a particular insect hatch around 11 AM as the sun warmed the water, and it looked like he was spot on.  After lunch, there were hundreds of insects in the air and touching the river, keeping the bass active and making for an exciting afternoon of fishing.

The insect in question was not a midge or mayfly but a long-winged predator with a yellow-striped thorax and bulging eyes: a dragonfly called the blue dasher. This colorful insect (Pachydiplax longipennis) is one of the most familiar and widespread dragonflies in the country, part of the family Libellulidae, commonly known as the skimmers.  It is among the most vividly colored and behaviorally engaging dragonfly species, easily recognized by its bright blue body, striking metallic-green eyes, and confident, darting flight.

Adult blue dashers are between one to two inches in length, with a wingspan up to three inches. The male has a slender blue abdomen that appears powdery due to a waxy coating known as pruinescence, contrasting with a black-tipped tail. His thorax is brown with yellow side stripes, and his large compound eyes are a brilliant shade of green or blue-green. The female is slightly bulkier, typically brown or golden with a pattern of yellow and dark stripes along the abdomen.

Both sexes possess four transparent yet sturdy wings made of chitin that glisten in sunlight and move independently, giving them remarkable agility in flight. These wings also display a small dark mark—called a pterostigma—near the tips, which helps stabilize flight.

The blue dasher can be found across the US, extending north into southern Canada and south into Mexico and parts of the Caribbean. Adaptable and tolerant of human presence, the blue dasher often inhabits urban parks, small ponds or vernal pools. It prefers sunny, open areas with still or calm freshwater, and will often be spotted perching on reeds, sticks, or floating vegetation close to the water’s surface.

Blue dasher males establish and aggressively defend small territories, often returning to the same perch after chasing intruders. They are diurnal predators, feeding heavily early and late in the day, mainly on mosquitoes, flies, small moths, and other flying insects, snagging their prey in midair using their legs like a basket. Their keen eyesight—thanks to large compound eyes with nearly 360° vision—allows them to detect even tiny movements around them.

But these dashers may also display fascinating social behavior. Unlike primarily solitary dragonflies, they can be seen in loose colonies, with several individuals hunting and perching near one another without intense conflict, particularly later in the season when breeding is done.

Like all dragonflies, the blue dasher has three life stages: from egg, to nymph (larva), and finally the adult. After mating—often while flying in a “wheel” position—the female dips her abdomen into the water to deposit eggs, either directly into the water or onto submerged vegetation.

The nymphs live underwater for several months to a year, breathing via gills and preying on larvae, tadpoles, and small aquatic organisms. They are voracious hunters, using extendable jaws to seize prey with lightning speed. When fully grown, the nymph will climb onto a plant stem or rock, shed its skin, and emerge as an adult dragonfly – a process known as metamorphosis. Adults usually live for a few weeks to two months, depending on conditions.

Dragonflies are among the oldest and most remarkable insects on Earth. Fossil evidence shows that their ancestors—giant dragonflies with wingspans of over two feet—darted through ancient skies up to 300 million years ago. Today, about 3,000 to 3,200 dragonfly species are known worldwide, with approximately 325 species found in North America. If you consider the closely related insects known as damselflies, there are over 6,000 species to delight nature observers.

Today we can find dragonflies on every continent except Antarctica, thriving wherever freshwater habitats exist. One morning while relaxing next to an alpine lake high in northern Italy’s Dolomites mountain region, I enjoyed watching dragonflies flitting here and there among the aquatic vegetation in search of food.

The insects display great diversity in tropical regions such as the Amazon Basin, Central Africa, and Southeast Asia, where the warm climates and lush wetlands support hundreds of species. North America, though less diverse than the tropics, has a rich and well-studied dragonfly fauna where wetlands, lakes, and forested rivers provide ideal breeding grounds.

There are several common dragonfly species to be seen in our region and they vary widely in size, coloration, and behavior, but all share the dragonfly’s hallmark traits: large compound eyes, long slender abdomens, and two pairs of powerful, transparent wings that allow for superb flight control. They are capable of highly acrobatic flight maneuvers and speeds up to 30 miles per hour when on a mission for food.

Dragonflies play a vital role in aquatic and terrestrial ecosystems. First, they help to control insect populations, including mosquitoes and agricultural pests. As prey, they provide food for fish, birds, amphibians, and spiders. Highly sensitive to pollution and habitat change, dragonflies are also useful as bioindicators—they only exist around clean, healthy water systems.

While most of our favorite dragonfly species are common, some are threatened by loss of wetlands, pollution, and our changing climate. In the US and Canada, conservation efforts focus on protecting wetlands, restoring native vegetation, and monitoring species distributions through citizen science programs like the Dragonfly Society of the Americas. In places such as Southeast Asia and Central Africa dragonflies and most other insects face greater risk, as rapid development and deforestation eliminate vital breeding habitats.

Historically dragonflies have symbolized transformation, agility, and renewal. Native Americans revered the insects as examples of swiftness and purity; in Japan, they are depicted in art as emblematic of strength and courage. Scientists have studied dragonflies for insights into flight dynamics, vision, and climate change impacts with the insects’ unique flight characteristics inspiring drone research.

Beyond their ecological role, blue dashers are appreciated for their beauty and liveliness. They are among the most photographed and studied dragonflies in the United States, often used in education and citizen science projects to teach about insect life cycles and biodiversity.

The blue dasher may be small, but it embodies the grace, agility, and vitality that make dragonflies so fascinating. With its shimmering blue body, brilliant eyes, and inspiring flight, the blue dasher is a lovely symbol of the resilience of America’s freshwater habitats.

If you like Ed Robinson’s writing, check out his two Nature Notes books! Click here for more information.