September is a lovely time to sail on the Chesapeake, as the humidity of summer fades and the winds begin to become brisker. This is the time of year that the dragonflies and damselflies of the Chesapeake’s rivers, wetlands, ponds, and marshes will lay their last set of eggs and conclude their life cycle.
Dragonfly families of Maryland
Maryland has seven main families of dragonflies with names that seem like either fun types of fairy or a variety of dinosaur: spiketails, darners, petaltails, emeralds, river cruisers, and pond skimmers. North America’s only marine dragonfly is the tiny seaside dragonlet, and its larva can survive in the saline waters of the tidal marshes. If it hasn’t already been written, “The Damselfly and the Dragonlet” seems like a children’s fairy tale. Throw in some missing emeralds and a river cruise, and it is destined to be a classic.
The odonates are carnivorous insects with powerful jaws who spend the majority of their life in an aquatic larval stage. Molting from six to 15 times, dragonflies and damselflies can remain in their aquatic larval form called naiads from one to six years. When they emerge as adults with wings, they bypass the pupal phase and are considered “incomplete metamorphoses.”
Dragonflies have fixed horizontal wings and large bulging eyes, while damselflies’ wings are held vertically and their eyes bulge on the side. Aerial acrobats, the dragonflies are an ancient predator with fossil records dating 325 million years. The largest of the flying insects, their lacy wings do not work in direct coordination which allows for great maneuverability. Clocking in at up to 30 miles per hour, these fierce predators eat small fish, tadpoles, and other aquatic insects. They capture prey using their legs which they shape into a basket snare.
Their large eyes can have as many as 28,000 facets compared to a housefly which has 4000. The six-sided facets register light and dark, and the larger the number of facets the more precise the image. With incredible distance vision for an insect, dragonflies can detect motion up to 40 feet away. It is easy to imagine them in the time of the dinosaurs when the fossil record indicates they had a 30-inch wingspan.
Mating happens on the wing. The pair lands on a plant stalk or over the water, and the female deposits the fertilized eggs. Egg laying can occur several times over the summer and wraps up in September. Add a dragonfly field guide to your boat’s bookshelf, and learn to identify these fascinating insects which come in a wide variety of dazzling colors. Fairy tale submissions to SpinSheet will be appreciated.
by Pamela Tenner Kellett
