There have been 2 or 3 of these wasps hanging out in our garden for the last few weeks. They are on the same plants as several Tachinid flies and the occasional honey bee, Syrphid fly, & Calliphorid fly. They appear to be Sphex ichneumoneus, but the femur of the hind legs appears to be almost black, while in the photos on this site & in a couple of books I checked, the femur is orange, as the rest of the leg.