River jewelwings are beautiful, sparkly insects, even if the common name isn’t completely accurate. It’s not so much the wings, but mainly the thorax and abdomen of these broad-winged damselflies that is strikingly colorful.
These flashy fliers vary from green to blue, and even purple, depending on one’s viewing angle. (For more on iridescence vs pigment, see the source list below.) In both sexes, the outer third of the wings is shaded. Females have a white spot on the far end of the wings, and their wings may be lighter.
The BugLady (see below) says the species does something called “obelisking.” They tilt their abdomen up toward the sky when it’s hot, like they’re doing a handstand, so they don’t expose their bodies to direct sun. The resulting shape looks a little like the Washington Monument, if you squint and ignore the wings.
Calopteryx aequabilis are predators as larvae and as adults. They’ll take food from all corners of the buffet table, ranging from flies to mayflies and small moths. Their range paints a swath across the northern tier of the U.S. and into Canada.
Female Jewelwings have a fascinating egg-laying behavior: They submerge themselves up to a foot below the water for 30 minutes or more, to insert eggs into a plant stem.
These insects are incredibly flighty and don’t like to have their picture taken. At our June insect walk, Mount Pisgah Interpretation Coordinator August Jackson swept one up in a net and gently held it, to give us a rare, closeup look.
Stay curious!
See more of Karen’s work here.
Sources:
The Bug Lady’s article: https://uwm.edu/field-station/river-jewelwing-damselfly/. Accessed 6/21/23.
A nicely-written profile, including an explanation of the Jewelwing’s changeable colors: http://thedragonflywhisperer.blogspot.com/2012/09/river-jewelwings.html. Accessed 6/21/23.
