Couple other pics in the daylight..

Stems are not perfectly smooth. There will be some 'lands and grooves' on any of them (yes, I watch too much CSI!). Other than rodents, I have never encountered any pests that may chew on woody portions of any tree. And those markings or signs of damage would be obvious.

Unless you find clear evidence of insects, don't spray. First, you have no idea what to spray for and second, Japanese maple foliage is extremely sensitive to most spray applications (including such benign products as hort oil and insecticidal soap). You can do more damage to the tree by spraying than by just leaving it alone or hosing down with plain water.

Thanks for the response. Glad I didn't spray anything. Perhaps I'll just hose it down with water and see what happens. I knew stems aren't perfectly smooth of course, but perhaps this pic shows it best...each of those markings is literally a pit, or indention in the tree..like someone took a small chisel and is slowly scraping/chipping away at the branch...who knows...and those stems also happen to be losing all their leaves....as long as it's not a disease or something, I guess I don't really care. Thanks!

It kinda does look like something was eating at it.....

But i dont know what. They look like little nicks on the stem.

Yeah. I can't say I've ever seen anything like it, I guess I'll just let it alone...idk. I only have a month warranty on the tree, so I hate to let it go and have the tree slowly decline though.

uhmmmmm ... there are no leaves on those branches as i see ...

prune them out ... all kinds of things can grow on dead branches ...

ken

Right...but those branches had leaves 3 weeks ago. Whatever is doing that to the branches is making the leaves fall off. There are a few branches that it's starting on, that still have their leaves....if I cut all of those branches off, I'm afraid that'll be like 25% of this tree..at least...tree is about 6'. Should I cut ALL effected branches off, or just ones that have lost their leaves?

Can we see clear pics of the branches in question in daylight? Or at least where there is some decent contrast? I'm not sure you should do anything yet - I can't imagine anything other than squirrels or rabbits nibbling on the branches (that's not an insect thing at all) and would like to see things much more clearly before I arrive at a conclusion and make suggestions. There is no indication the branches in question are dead - merely without leaves at the moment. And that could change quickly.

I did fine a caterpillar on it, but doubt this guy's the culprit..

Here is the overall tree

Thanks! Those pics helped a lot. Something is definitely chewing on the stems. but no insect I am aware of will do that. Squirrels will eat leaf buds and they will harvest bark from JM's for their nest so I guess it is also possible they might nibble on the stems as well. I doubt it would be anything larger - tree is too young and flexible to support a larger critter. And bunnies can't reach that high :-)

Try spraying with a squirrel deterrent or hot pepper spray, avoiding the foliage as much as possible. The nibbling has removed whatever leaves were there but you should see some releafing as well.

Thanks for the tips. So you don't suspect any diseases?, that's what I'm mainly worried about!

Maybe it had scale insects at one point.......

No disease and scale can't put in notches like that. Those are tooth marks.

Some of the damage is on the stems and looks like it is on the side facing the sun, right?
Some other damage looks mechanical or by an animal.
The tree is young and is adjusting to it's location. I'd leave it be for now.
Spraying an insecticide won't help because an insect isn't causing the damage as far as I can tell from here. :-)
Mike

The damage is mostly on the north side of the branches for whatever reason. So not sure if sun plays a factor or not.

Mmmm, wrong side for sun. So much for that theory.
Mike

JMs have yummy sap to some animals. Something was enjoying a sweet snack.

This year sapsuckers started pounding holes in my Linden trees, could it be something like that, they do a lot in a short period of time.

Did you ever figure out what was notching your tree? I'm having a Fireglow put in soon so am perusing the forums (fora?) to learn more. You have a beautiful tree and I hope it's been thriving over the last two years!

Probably deer

Deer usually just lightly browse my Japanese maples. I've never seen them bypass the leaves and go for the stems. When it comes to deer, all I can do is generalize. They have a mind of their own.