Help with Japanese Maple

[Mark-O]

I live in Los Angeles, CA and have a almost 6 year old Japanese Maple tree. It seems to have done well and appears beautiful and healthy. However, over the past year I noticed a groove in the bark and pealing and it appears to have occured in multiple areas. Yesterday I oberved a different problem-what appears to be a pin hole in a different area of the trunk. Is this from an insect? Is there anything I can I do about these two issues?

 

[Jason Douglas]

Very interesting discoloration at the margins of 1 and 4. Perhaps one of the paint/crust decay fungi in family Xylariaceae? Definitely a borer exit hole in the center there.
Other pics are more typical of winter sunscald/SW disease. These damaged areas are also prone to borer attack, commonly flatheaded apple tree borer on maples in my area but can't attest to those in your area.

 

[Mark-O]

Thank you for the response. Anything I can do to treat the bark or borer?

 

[Jason Douglas]

Perhaps opaque cover during the winter. Systemic insecticides will control some borers, cover sprays with strong rates of pyrethroid insecticides coinciding with adult flying and egg laying will control others.