Two Great Black Wasps nectaring on Swamp Milkweed, Asclepias incarnata. Although here's a pair, they just happen to be drawn to the same plant. This species is one of the so-called solitary wasps and generally are loners. Like butterflies, they are drawn to palatable nectar such as is produced by milkweeds. another name for them is "katydid-killer". They make subterranean burrows with small chambers at the end, and after stinging and immobilizing a katydid, haul it back to the burrow and drag it within. Presumably eggs are then laid inside the katydid's tissues. Better to keep the host alive and essentially paralyzed, so when the young wasps hatch, the larvae have a fresher meal. Not sure I'd want to come back as a katydid and have that be my fate.
Speaking of katydids, here's one - potential Great Black Wasp prey. I photographed this Greater Angle-wing, Microcentrum rhombifolium, at Bigelow Cemetery, subject of the last blog entry. It is on the foliage of Scurf-pea, Orbexilum onobrychis, which is common in this tiny prairie remnant. In an amazing bit of evolution, these insects have developed a morphology that exactly matches that of a leaf, from overall shape to the venation of the wings, which matches viens on a leaf.
You've heard these. They are common nighttime singers nearly everywhere, making a rapid series of metallic clicks, or sometimes a single rasp. Some are singing outside my window as I type. Go here to hear a Greater Angle-wing.