I had some holes appear in SYP flooring, bought as #1 Common. My termite guy came all the way over to see and said not to worry, powder post beetle takes 2-10 yrs to emerge, and once you see the hole, they are gone. I guess my flooring was not kiln dried. A friend built a cabin from sawmill beams log cabin style, and the same pest guy said it was the worst infestation he'd ever seen, but they did not treat it. That was almost twenty years ago, and the house is still sound.