for sharing your expertise. Could I impose and ask what the morphological differences might be, names imply that one has bumps and the other has streaks. Might be worth putting specimens under a scope. The inquery about biters came about because recently at this location "something" became active and becomes apparant when a small trickle of blood is noticed. A slice similar to tabanids, haven't noticed any suspects, yet. Guess I was trying to blame a new kid on the block. For the record, the 6mm excludes antenna and the wing beyond abdomen tip.

You are right, E tubrculatus has a small hump on the base of the hind femur, which is very hard to see in the female and better visible in the male. E strigatus has stripes, like most Eumerus species, so it is not a very distinctive name. The best way to tell them appart are the male genitalia and sternites, which are very different and very telling. The new name for tuberculatus is funeralis (sometimes somebody finds an older name, which has then priority). Check out the pics in the European Eumerus key:
http://home.hccnet.nl/mp.van.veen/KEYS/Eumerus/eume_key.html

About those antenna. Those are the only two species of Eumerus I have listed for the eastern US.

Yes, there is one more species from the West, E. narcissi, Smith 1928, described from California! And it is clear that it is not native to America, but so far nobody found it in Europe. Must be from Turkey or the Middel East originally.