I was moving some of my firewood around today to get the wet stuff in the sun, and noticed that a lot of logs under the top layers had sawdust on them. Assume it's a pest of some sort. Ive seen bees occasionally burrowing in some older wood, but I don't see any holes in the logs immediately above the sawdust. I've read that there are beetles that can do this and also carpenter ants. Haven't noticed any ants while moving logs around. None of the wood is touching the ground or any structure, so doubt (hope) its not termites.

I obviously won't be burning this anytime soon, so is there anything I can apply to the pile to ward this off for the next few months, yet won't be an issue when cooler temps finally come and we start to burn some of it?

Squirt it with a malathion solution mixed as directed.
Good residual.

Yes, oak. Talked to the guy I bought it from and he said beetles as well, as it's likely what killed the trees that he cut up. I am not using this to cook, just for fires in the pit.

Not really concerned unless it's a risk to the garage/house/pergola it's stacked next to.

These are a couple of in progress bench seat tops I made for a mesquite ranch table many years ago. As Agrams said they attack the bark edge. When you work with mesquite and this much infestation you spend more time getting the wood epoxied than you do building.

Cover tightly with black plastic in full sun. No pesticides needed.

I realize that's probably hardy siding and not wood, but I wouldn't keep wood stacked near a structure like that.

That is a normal thing in my woodpile which is 95% mesquite, and for me it is the flat head borer.

TLDR- do carpenter ants nest/burrow into cedar fencing?

Letterman...Took your advice, as best as I could (not direct sun) and covered the entire rack with a tarp. Apparently wasn't tight enough or enough sun because I'm still seeing dust on the ground. I have a smaller rack that is close to the pit that had some older logs and some of the smaller sticks from a recent tree pruning. Moved some of it today and there was sh|+pile of ants all over it. I will say that I also saw some huge bees flying around the yard which I haven't seen in a long time, so I assume it's a combination.

Burned the small stuff and a few of the bigger logs I had with them, sprayed the empty rack and surrounding area with pesticide and now plan on moving the large rack behind the garage, and wrapping in black plastic. My only other concern is if I move it away from the garage, do I need to worry about the fence? No other place to put it other than the center of the back yard. I did just treat the entire lawn twice within the last month with insecticide (sod webworms getting after it in Houston).

Be sure your wood is not touching the siding! I had a similar problem years ago and ended up with damage to some siding which had to be replaced.

Definitely not touching before, and certainly not now with the tarp over everything.

Some time back my neighbor had the problem in his mesquite but not on the oak in his fire wood stack. He called l an exterminator who said that it was mesquite wood bores and they don't go to another type of wood such as oak, pecan apple etc. Since what you see is oak logs it probably is the same. The will often backfill the hole with the wood dust that you see there in the picture so you don't see their bore holes. I agree with CS78 in that I would be more afraid of pesticide smoke then the beetles. My neighbor burned his wood with no problems. Also his stack touched the back of his garage in places and not one hole is the siding.

That's kind of what I was thinking. The garage is detached, nothing touching the structure, and it's all off the ground laid across the cedar runners connecting the ends of the rack. I haven't seen any ants on the ground, along the two cedar boards, or trails going into the garage, and if they don't like the heat, they want no part of my garage right now anyway.

I'm in the process of power washing my driveway and patio. I wonder if some high pressure water would do anything, or just spread them around... I have definitely decided to not spray anything on the wood itself.

Burned through that pile and as of Friday, I have a matching pile of relatively fresh cut oak. I'm taking the letterman/black plastic approach from the get go and will report back.

I keep my woodpile far away from the house and let those beetles go to town most the year. Then during the winter I move the stack closer to the house a little at a time. Move some, burn some, repeat.

No pesticides. Fire kills them nicely but I typically find them gone before moving the wood in winter.

The wood burns a hell of a lot better when the air has all those tunnels to move through.