fwiw, I've had green "worms", but they typically eat from from the leaf edge inward; those didn't leave squarish looking holes in the middle of the leaf. I've also had the little black "hop worms", and they start at random spots on the leaf but usually away from the edges, but again, they didn't leave that squarish looking damage patterns. I've had very few snail attacks (almost none, really) and didn't leave that type of pattern behind.
I'll be interested in reading what the culprit turns out to be, as I'm experiencing a bit of the same thing here, mostly on my Chinooks but a little on the Centennials and the Cascades. Haven't applied anything yet as I'd prefer to know what I'm trying to nuke and not just thrash about.
In my case, whatever it is, it's definitely nocturnal. My plants are over 20' tall now, but I can inspect any/all parts because they grow from below my first story deck up to about 10' above my second story deck. I've run the Chinooks from crown to tip and couldn't find any critters. At all - even good ones. So I'm betting they're late night eaters. I'm going to wander out tonight with a flashlight just before bed to see if I can spot the li'l bastids...
[edit] Another data point: no poop. Whenever I've seen caterpillars or "worm" damage there's always poop pellets to be found. But not a single pellet in this case.
It'll be flashlight time in a couple of hours...
Cheers!
