Around two dozen of these captured in restored emergent marshes, mostly at this NWR and mostly in sweeps of flowering rush, Butomus umbellatus. Very large population of Hibiscus moscheutos at the location. Almost all specimens had the same coloration on tergites, with one large spot on T2 and a faint, very small spot on T4. Ventral side of F3-4, somewhat F2, are concave and shiny, and F4 has a projection. I couldn't find any females among the specimens to compare unfortunately. Three years later I am finally getting around to sifting through my crabronids, and I hope to turn up something interesting!