After I’ve spent a few days in front of a computer working on presentations or papers, I need to see a real insect. That can be difficult during the winter when few insects are active outdoors in Pennsylvania, so the next best thing is looking through samples that I or others in the lab have collected in years past. There’s also something relaxing about sorting through samples, a zen-like quality that can come over you as your poke around and look at all of the different insects that can help reset your psyche after monotonous or stressful work.
With this in mind, a few weeks ago I was looking through yellow pan traps that Carolyn had collected in Wasatch County, Utah in July 2016. I pulled out some ants and other groups that are of interest to me that aren’t well represnted in the Frost Museum collection, at least in terms of species from the Western US. Then I saw it, a strange-looking wasp that I couldn’t immediately identify to family. Considering that’s that Penn State pays me for (insect ID), the times I can’t identify an insect to a gross level like family are not especially common and always a time for excitement. I had some ideas, perhaps a cockroach wasp (Ampulicidae) or something similar, but would have to curate the specimen and examine it using a better microscope.
Under higher magnification, I could tell immediately this wasn’t a cockroach wasp. The mandibles and overall look weren’t right. But I still didn’t know what it was. However, turning the specimen around and examining the wings gave a clue. The wing veination indicated the was was some kind of chrysidoid.
Five of the seven extant families that comprise Chrysidoidea are present in North America: Bethylidae, Chrysididae, Dryinidae, Embolemidae, and Sclerogibbidae. Embolemidae and Sclerogibbidae are species-poor families that are rarely collected and don’t look like the mystery wasp. Dryinidae look more similar, but most females have chelate (i.e., pincer-like) foretarsi, which this specimen lacks; they also have 10-segmented antennae, while this specimen has antennae with 13 segments. Bethylidae can have 13-segmented antennae and are diverse in North America (~200 species), but have elongate heads and are often ant-like in appearance. They also have 6 or 7 visible abdominal segments, while this specimen only has 5.
The only family left is Chrysididae, the cuckoo wasps. The chrysidids that most people are familiar with are metallic green with coarse sculpturing and can roll into a ball due to the underside of the abdomen being concave. These chrysidids belong to the nomative subfamily, Chrysidinae.
However, there are two other chrysidid subfamilies, Amiseginae and Cleptinae, which are not often collected. I’d collected a species of Amiseginae in Arkansas (Amisega kahlii, which parasitizes stick insect eggs) and knew it wasn’t that subfamily, but had never seen a cleptine chrysidid before. Could it be Cleptinae?
Luckily, a few years ago I bought a copy of Bohart and Kiimsey’s (1982) “Synopsis of Chrysididae in America North of Mexico”, which has keys to the subfamilies and species of cuckoo wasps in North America, as well as distribution and biological information. Working through the keys, I found that yes, this is indeed a cleptine, specifically Cleptes purpuratus. The species is known from California, Nevada, and western Utah, so while this specimen was collected a bit east of the known range of the species, it’s within reason. They parasitize species of Neodiprion , which are sawflies that feed on pines and other conifers.
All-in-all, a really neat beast that is a new species and subfamily for the Frost collection and me personally.
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