I think that I have Zimmerman moth in my white spruce. The top has been dying back with the "shepard's hook" look for several years now. Evidently, I am trimming the top out too late to get rid of the caterpillar, so I was looking for chemical control. I thought that I remembered that "Merit", which used to be used for EAB, was listed for Zimmerman. Is this correct, or is there something better? Thanks, Liz Cramer