The Hunting Wasps may be the most impressive insects I know. Which is not saying a lot with my limited knowledge. I am still highly enamored with the robbers but the wasps have some impressive facts associated with them. And Henri Fabre has made them a thing to be read about with his fine books. I have begun identifying them over the past few summers. My current working list of eastern US species is here. And a key to the tribes of Arkansas with genera is here

Here is a .pdf file link that is a key to the ant, bee and wasp suborders:

This is an Ammophila. Which apparently means 'sand-loving' but this is a poor name because many different genera of wasps seem to favor sand for their nesting places. Most of the Ammophila species look exactly like this. And this wasp was almost five centimeters long. I have twelve species listed in this genus on my probable Arkansas list (see the list). So it is likely one of those. I favor A. procera with the three marks on the side of the thorax.

The Ammophila are all caterpillar hunters and it was, in fact, an Ammophila that Fabre performed his famous dance with, wherein he dug up the caterpillars at the direction of the wasps. As he said, it was "like a pig after truffles."  Note the two white lines on the thorax like dragonfly markings. I don't know if these are distinctive to only a few of the species or not. I'll get back to you.

Same wasp, forward view showing the active flower frisking and the big round face. Some fairly impressive spikes on those legs as well. And here is a series of shots from a colony event, same species: wasp colony.

This is another Ammophila from Camp and it appeared distinctly different from the above. Note the absence of any marks on the side of the thorax. And whereas the probable A. procera always looked gray and dirty this one is very clean and dark. May be A. nigricans. Thought it was a male at first but I think I can see the tarsal rake on the foreleg. And this would be a very bright orange for a male. The Lespedeza leaf hides the end of the abdomen.

This may be A. nigricans as well from Johnson County. Pretty dark-winged, on sand, with what looks like a bright green sawfly.

The Ammophila have sleeping groups sometimes and they can be found isolated and gripping a stem or grass stalk in a torpid mode. This one was just sitting quietly for Norm on a cool day. Looks a bit strongly marked for A. nigricans though the wings looks dark from this angle. There are, again, eight or nine species I have not seen in AR.

The late summer flowers of Eupatorium are often rich with these hunters along with all other nectar feeders. From the Buffalo river area in 2015. Probably A. nigricans again. 

The other fairly common Cat hunter in the area is this Eremnophila aureonotata, the only member of its genus in the east. Takes mostly large Notodonid moth cats. Also carries them belly up with its mandibles. Like a golden-faced green bodied Ammophila.  I have yet to see one with a cat.

And pair of Eremnophila in copula. Looks hard on the larger female. Males head looks about half the size of hers.

And another copulation in 2018 at Garvan gardens.  

This is another smaller species of hunting wasp which I found coming and going from the burrow which you can see opening in front of this female's face. This is the sandy soil near Toadsuck Park. I did not witness what kind of food item went in, but I believe this is in the genus Prionyx and therefore it should be using grasshopper species. This wasp was significantly smaller than the above fall creature.   

Facial shot of the same individual. Again her nest entrance is to the right. They remind me of busy dogs.

And it is almost as if this Prionyx knew someone was watching. There is no damn way she can get that to a burrow. But we are all impressed with a Prionyx taking down this massive Differential Grasshopper.

A spring cricket hunter which is in the Larrinae family. I thought it was a Tachytes but I believe now it is a Liris species after viewing one closely under a scope. I need more information on this genus to determine it further.  Silvery legs and three dorsal silver bands on the abdomen on this one. Sand loving apparently. There was almost a loose colony where this gal was hunting. Witnessed one dragging a cricket that was stolen promptly by a Tiger beetle (C. scutellaris scutellaris). (This and the associated genus Tachysphex and Tachytes use crickets for nest storage.)

A green-eyed animal truly in the genus Tachytes. Orthopteran hunters and several in the genus like to use old rodent burrows or nest near active Sphecius, Cicada Killer, burrows. This genus makes multi-celled nests, Tachysphex make single-celled nests. All are in the Larrinae.  Many in this genus have green eyes and we may have 15 or 16 species in our area alone. Big genus.

Another Tachytes. Nectaring in late summer and buried in Eupatorium pollen. Another silvery banded species. Tough group to separate in photos so far.

And 2017 in the yard. Perhaps an Isodontia relation. It was hopping short flights across the leaf litter trying to find a launch point or a tree or human to climb. Certainly carrying a young Katydid and not the leaf-winged species.