Great Black Digger Wasp (Sphex pensylvanicus)

J drew this to my attention. Normally I would pass this insect by, having tipped a hat to it as one does, as being just another mud-wasp which we often see beside the garden pond. But … it was enormous, longer than my standard top-joint-of-the-thumb definition of an inch and so it was worth taking seriously. About one and half inches long I would say.

GBDWs it turns out are quite widespread but have only appeared in Quebec in the last couple of decades. Judging by size alone this specimen was a female and quite unconcerned by my presence. They do sting – I read – if truly annoyed and sting is painful but there is no swelling. Well, that’s good to know.

Of particular interest is that Sphex pensylvanicus was the subject of the first article on an insect written by a native of the New World when observations were presented to the Royal Society in 1749 by Peter Collinson.

Quote: Adult females of S. pensylvanicus build an underground nest which they provision with various orthopteran insects, particularly of the genera Microcentrum, Amblycorypha and Scudderia. Prey are stung three times, once in the neck and twice in the thorax, and are paralyzed by the wasp’s sting, although they can survive for weeks. The prey are then carried to the nest. While collecting their prey, the females are vulnerable to kleptoparasitism, in which birds, including the house sparrow (Passer domesticus) and the grey catbird (Dumetella carolinensis), steal the prey that the wasp has collected.

This wasp is an important pollinator of plants including the milkweeds. It has also been reported on wild carrot which perhaps explains its presence as this specimen was located just beside a fairly extensive carrot patch in the garden.

What a good morning this has been – most productive.