Pitted roof sheathing

Has anyone ever seen this? This is a representative sample of the condition of the majority of roof sheathing. It looks like bores, as if created by small insects, but is very evenly distributed and no signs of insect parts could be seen anywhere in the vicinity.

A few sheets of sheathing are not affected at all; suspect they were replacements during the last re-roof approx 20 years ago. Also suspect the affected sheathing to be original (38 years old) and free of any fire retardant, increasing my suspicion of insect activity.

I’m no WDO expert but could that be insect damage done prior to installation… while in storage?

My thought also. Most likely outside, not elevated, not covered/protected, for a long period of time. Kind of like you would find on an owner-built job site.

Be my guess as well. Beatles???

White pocket rot

Rolling stones???