Last week, I introduced you to the world of dragonflies in a very general and superficial manner. This week, I shall endeavor to get up close and personal with a single species and, in the process, attempt to share with you some of the remarkable detail that can be associated with these beautiful insects. So, without further ado, I introduce you to the widow skimmer (Libellula luctuosa).
This species is an especially flashy and “sexy” dragonfly that can be found in all sorts of habitats. I often think of water when I think of dragonflies, and the widow skimmer definitely likes lakes and ponds. However, this species can often be found zipping and zigzagging around the tall grasses in meadows. Males in particular are drawn to water because it is in the calm waters of lakes, ponds and even quiet pools in streams that females will eventually arrive to mate and lay their eggs.
Males will become quite aggressive with one another and will energetically patrol and defend little territories along the shoreline. I have spent many happy hours just sitting and watching the little dramas unfold, and they are always flamboyant and entertaining. One male will somehow determine which patch of shoreline is his and then he will chase and attack any interloper he detects. A new arrival will swoop in and temporarily displace the first owner, only to be driven off when the original owner returns and vanquishes his opponent.
The male widow skimmer is a particularly showy animal that has beautifully decorated wings. If divided in two by length, then it can be said that the outer third of each wing is perfectly transparent, as is commonly seen in the majority of other dragonfly species. As you approach the body, however, the wing appears to have been coated with a narrow band of bright white spray paint. The inner half of each wing is an opaque shiny black.
Another interesting feature of the male is something called “pruinosity.” This is a coloration quality that produces a dusty white bloom (perhaps even a patina) that lies atop the blue abdomen of the male. The effect is generated by tiny particles of wax that are exuded from the abdomen and lie just on top of the shell. It turns out that the pale white color of the pruinescence indicates that the region will be highly reflective of ultraviolet light. To me, this suggests that insects, which may see the ultraviolet spectrum, will have bright, glowing tails that are extremely flashy. This is an effect that humans are completely blind to.
When it comes to the female widow skimmer, there is such a remarkable difference in coloration (a characteristic known as “sexual dimorphism” which generally means the sexes take two forms) that you might think the insects belong to different species. In fact, it wasn’t until I finally got a photo of a male widow skimmer that I saw the color pattern of a female and then realized that there was an “unknown” dragonfly in my photo collection that could finally be identified. That little trick only took me four years to pull off.
Adult widow skimmers only live about six weeks after they emerge into the world, so there is a limited time when you can actually go out and see them. This is the peak of the widow skimmer viewing season, so pack up a picnic lunch and head out to a local pond or meadow for an afternoon of dragonfly watching. Even if you don’t see a widow skimmer, you are guaranteed to see something interesting.
Bill Danielson has been a professional writer and nature photographer for 21 years. He has worked for the National Park Service, the U.S. Forest Service and Massachusetts State Parks, and currently teaches high school biology and physics. Visit www.speakingofnature.com for more information, or go to Speaking of Nature on Facebook.