Hi
The best stuff we ever found was "Everglades Extra Strong" which was bought at the ranger station in Everglades City - they really need it there! Only problem was that after applying it and handling my video camera, the plastic camera case started to melt where it had been handled - dread to think what they put in it.
Seriously, my wife is a "must bite" for every insect known to man so, in preparation for our Italian lakes trip I have ordered one of the Fiamma door screens, We will see if that keeps the little b*******s out. I also bought her one of those electronic fly swats so she can lie in bed swiping them. It's a very labour intensive way of getting rid of them but very satisfying when they explode in a blue flash against the mesh.
Gaspode