While I took this picture in mid-August, I have delayed posting it. This is due partly to being busy, but to be honest, I was procrastinating research. I didn’t know if what I was looking at was a yellowjacket or a wasp or a hornet, or even what the difference was. Clearly, something was enjoying a moth as an afternoon snack.
What better way to celebrate a new year than by settling the question?
I have identified the apparently hungry insect as a Paper Wasp, more specifically, the Vespidae Polistes dominula. I don’t have the expertise, or perhaps the proper photographs, to further distinguish the wasp’s sex. (Comments from entomologists are, as always, welcome.)
It turns out, the family Vespidae includes three groups of social wasps. They all establish colonies annually, abandoning them in the fall, with only a few fertilizes queens overwintering; they all make nests of “paper” produced from chewed wood pulp; and they do not leave a stinger. With all this in common, how can we tell them apart?
The genus Vespula is the yellowjacket. The genus Dolichovespula is the hornet. And the genera Polistes and Mischosyttarus are the paper wasps, aka umbrella wasps, found in Colorado.
I was able to eliminate the Dolichovespula, but the coloration of the Vespula and the Polistes is very similar. This publication helped me enormously to make the final distinction.
- Careful analysis of my photographs (comparing it to the brick upon which it was standing) revealed that the wasp in question is at least 5/8 in. long. That’s longer than the average yellowjacket. It is also quite slender compared to a yellowjacket.
- The nests built nearby are clearly of a single comb and not enclosed.
Visitors to my house over the summer months would occasionally inform me that they had “discovered” a hornet’s nest — in fact, one of the paper wasp nests. They looked at me like I was crazy when I said, “Oh, yeah, I know it’s there.” Even without knowing what kind of insect I was dealing with, I knew that it was beneficial to my garden, killing other pest insects. Additionally, since they are most likely to sting to defend their nests, I thought it best to leave them alone.
However, I have read that one should remove nests found on eaves during the winter months, because other undesireable insects may use it. The paper wasps will make new ones come spring.
A final note on the prey: my best guess is that it was a Miller Moth. I imagine it was already deceased when the paper wasp came along.