We use 3 injections systems depending on DBH, location of tree on property, etc. Wedgle, Mauget and Arborjet (Tree I.V.). The product we use is imidicloprid. We have found that Ashes uptake better AFTER leaf-out, which means we don't start injecting (w/the passive systems) until about the 3rd week of May. The trees we've done since about 2000 or 2001 are doing very well, our loss has been fairly low. We also do soil injection and spray foliage twice (early June and early July for adult females) on some of our high value trees.