Subject: what is this?
Location: Southern Illinois
March 28, 2015 6:48 pm
Went on a walk through a wooded area in southern Illinois and saw this insect. I’m not quite sure what it is and I’ve looked all over the internet. Picture taken 3/28/15.
Wow, this one has us confused. It seems to resemble the Black and Red Horntail, Urocerus cressoni, but there are too many inconsistencies for us to be sure. The Black and Red Horntail is described on BugGuide as being: “head, thorax and wings black, abdomen red (amount of red variable), two pale spots behind the eyes, antennae black with white tips.” Additionally, the black and white legs are evident in images on BugGuide. We cannot make out the “pale spots behind the eyes” in your image, and it also appears that the antennae are tipped in black. There is no obvious ovipositor, so it could be a male of the species, however, March is many months earlier than all the sightings documented on BugGuide. With all that said, we do not believe this is a Black and Red Horntail, but we cannot provide any other possibility at this time. We are posting your image and we hope to get some input from our readership.
Eric Eaton Responds
This is a tough one. Near as I can tell, though, it is a parasitic wood wasp in the family Orussidae:
They are common, but not seen very often. They are related to sawflies, but instead of being vegetarians in the larval stage, they are parasites of wood-boring insects, especially beetles. This one might be ovipositing.
The curly antennae are the best clue here, but the angle is awkward and I’d like to see other images, if there are any, before offering a definitive ID. I’ll stand by Orussus sp. for now, though.
author, Kaufman Field Guide to Insects of North America