http://www.emeraldashborer.info/
Not sure if it's in this article and I can't find direct links to it, but infected trees can and have been saved by Merit (can't spell the chemical name). I have seen numerous pictures of trees in SE Michigan that have been treated and turned around.
Here's the wbsite and contact info for the guy that discovered EAB and has been arguing with the MI Dept of Ag on treatment methods. Dept of Ag has insisted on elimination of ash trees, Dr Roberts has proved to them that treatment is possible.
http://www.msu.edu/~robertsd/
I'll see if I can find that info.