Banded Net-wing (Colopteron reticulatum) -

Banded Net-wing (Calopteron reticulatum)
Photo by Brad Sylvester, copyright 2011. Do not copy.

These bugs have been flying around the open areas of my yard all summer. There are many, many of them. I see them sitting on leaves, outdoor table tops, and all over my gardens. I also see them flying around all day long. As they fly past, I see a set of non-functioning wing covers that are just being held out of the way while the hind wings do all the work. If you’ve been following this blog you know that fore-wings specialized into protective wing-covers for the membranous hind-wings means that this insect is almost certainly a beetle of the order Coleoptera.

Already, in just a few weeks, I’m recognizing things that make the identification of new insects much easier, and that is one of the main goals of this whole project. I not only want to know what lives in my yard, but I want to see an insect or any other animal and be able to narrow it down to taxonomic order and family even if it is a creature that I have never seen before. I want to know the key areas to look at in order to help get a positive ID. While wing-covers are pretty elementary, knowing to count the number of segments in the antennae and to look closely at the shape of the pronotum, on the other hand, are not things I would have known to do before I started this project.

Once we have this particular specimen down to the order of Beetles, it’s very distinctive coloration and patterning make it easy to pick it out of the Audubon Field Guide as a net-wing. Although the Audubon book shows a Banded Net-wing (Calopteron reticulatum) as the only close match, I use a secondary source to confirm, partly because the book represents only a subset of each genus. Sure enough, bugguide.net lists Calopteron discrepans (the Net-wing Beetle) as a close visual match. A slight detail of the patterning near the scutellum is the only readily visible difference -- a plate on the top (dorsal surface) of the thorax, often a small triangle right where the wings or wing cover— which, by the way, are called elytra— in beetles.

Banded Net-wing searching for nectar
Photo by Brad Sylvester, copyright 2011. Do not copy.

This one is indeed a Banded Net-wing. Which brings me to another point. I generally think of beetles as eating either the leaves of my plants, eating other bugs that eat the leaves of my plants, or eating dead things like leaf litter or carrion. In fact, the Audubon Field Guide says that the Banded Net-wing does just that, eating the juices of decaying plant matter while the larva lives under tree bark and eats mites and other small insects that it finds there.  I watched this one work this flower delicately for nearly a minute before it flew off. There are certainly no decaying plant juices, and no visible mites or other insects here. So what was it doing? Bugguide.net, an entomology site hosted by the Iowa State University Entomology Department, says that the Banded Net-wing, in fact, is a drinker of nectar and other plant juices.

Which brings up an interesting question. Perhaps they are both right and the diet of this insect is more varied than either one believes, but how much to we really know about the secret lives of very little things. A hungry bug in captivity may eat different things than it would in it's natural habitat, so unless they were followed and observed in the wild (or an artificial habitat that very closely simulates the natural environment), accurate data may be difficult to obtain.  I'll check some other sources about the diet of the Banded Net-wing to see if there is some more general agreement about it's diet when I have the chance.

Quick facts about the Banded Net-wing:
Range: Eastern and central United States
When is it here: Year round
Lifespan: no information found, likely one year
Diet: plant juices? as adults. small insects as larva
Life cycle: Adults lay eggs under the bark of dead tree. larva live under the bark and overwinter there. In the spring they pupate still under the tree bark and metamorphose into adults who live in moist woodlands and adjacent meadows.