Unfortunately, the best advice has already been said. Dodge, and pick them off from range. Also be aware of what's around you as well, making sure to kill fuel rod users and plasma pistol users so they can't get extra damage or stun you long enough to get blown to hell by the wraith.
Also, if the scorpion gets too damaged at any point, you could probably hijack a wraith.
You can't call him out for being wrong when he never intended to be right - Stephen Colbert "Bad Mojo" is not a diagnosis - Dr. Foreman, House, M.D.