thats weird ...

animal damage is usually vertical ...

i just cant contemplate what is making horizontal scratches.. so shallow ... and it isnt bugs ...

frankly ... it suggests vandalism ...

the grey stuff is lichens.. and harmless .. some peeps pay money to have it applied ...

a 40 foot tree planted last year??? can that be a typo??? ... i didnt realize dogwood got 40 feet.. but anything is possible ....

cant say much about black bugs.. w/o seeing one ...

do let us know what the nursery guy says ...

ken

Hi & welcome to Gardenweb!

Agreed, that damage looks mechanical. Are you sure the bugs you saw were eating bark, not the lichen?

At the top of the pic, are there 2 holes in the trunk?

The damage does look mechanical, but I'm wondering if it could possibly be woodpecker damage. Usually woodpecker damage shows up as many, many holes very close together. Sometimes the holes run vertically and sometimes horizontally. If the rows of holes are drilled close enough together, short sections of bark could be stripped from the tree. Especially if someone brushed over the area with something or maybe hit the area with a strong stream of water.

If you look very closely, each stripped place seems to have small circular areas within it. That could be from woodpecker holes drilled very close together. A sharper and closer photo would be helpful.
Art

I suspect that this post has been forgotten about....but if not, I'd like to know at what height on the trunk this damage occurs.

dog chain???

ken