view counter

Rooting for Dragonflies

These aerial acrobats have the appetites of wolves

Photo by Wayne Bierbaum

The hot summer months bring out hordes of mosquitoes and other flying, biting insects. One of the nemesis of the winged bugs is the dragonfly. Dragonflies are the wolves of the air. They are able to eat their own body weight in mosquitoes in an hour. Thus, a dragonfly can consume several hundred biting insects a day. 

            In Maryland, more than 180 species of dragonfly or damselfly have been identified. In warm weather, we see them flying around. During the winter, they live as nymphs in water, where they also eat like wolves, consuming anything smaller than

themselves.

            The nymph form looks nothing like the adult form. In the water they are stout, brown creatures living under rocks or in weedy areas. They grow by breaking through their old skin in a process called molting. Each nymph molts about 12 times in one to three years underwater. After the final molt, the nymph crawls out of the water and transforms into a winged insect-eater.

            In their eight more weeks of life, winged dragonfly mate, lay eggs in water, eat thousands of smaller insects and, if lucky, die of old age. But many are eaten by birds, frogs, robberflies, bats, other dragonflies — and the grills of cars.

            Damselflies are similar to dragonflies but with differences, especially in their eyes. Dragonflies have round heads with multifaceted eyes conforming to that shape. Damselflies’ eyes are rounded bulges on each side of a head that looks like a lightweight dumbbell.

            Dragonflies are larger, too. The largest has wings seven and a half inches across. Maryland’s largest has a wingspan close to four inches, while our smallest has a wingspan of about one and a quarter inches. 

            Dragonflies and damselflies all are amazing acrobats of the air. Many are very colorful. My favorite is the Halloween pennant, above, which lays eggs along streams and is commonly seen in the fields of Cromwell Valley Park. I also like the tiny colorful seaside dragonlet that live along tidal marshes and are commonly around the salt marshes of Chesapeake Beach. The green-sidedarner, top, can be seen hovering above freshwater ponds throughout Maryland.