Yesterday I found the top 18" or so of a fairly young pecan tree -- it was about 5' tall -- lying on the ground. I thought at first that some person must have accidentally cut the top out, but on closer inspection it looked like something might have chewed a little channel about 1/8" tall and deep all the way around the roughly 1/2" diameter stem and that the middle had then broken out. Do I really have some kind of terrorist bug at work? At least it did its work high enough that tree can regrow from well above the graft. I'm familiar with cutworms in the garden, but I haven't noticed anything like this with trees before.