The osage was cut early this year. I am thinking something hatched out of it by the looks of it. its sawdust for sure on the osage. We have had osage post for 60 years in one of our pastures and they still stand. I designed this yard fence, to my husbands chagrin, though not embarrassment. He is going along with the plan. Ive been collecting the post from southern Iowa since early spring. I am just now noticing the sawdust exit holes on the post, that I did not see before. Both the new set, and the set from the spring are now sawdusty. They both came from the same farm/timber. The other logs I got elsewhere do not have this sawdust.
the last 2 photos show a nearby locust firewood pile, cut in early spring 2020, and cut and split that summer. Is this termite damage? if it is it has been out through the Iowa winter, so likely all dead, from my understanding.
Yeah, your frass I'd much more coarse and you have the carpenter ant in the pic. Not sure what was under the bark. I haven't seen osage growing up here, and never felt with it enough when I was in TX to learn what likes to live under the bark.