Termites or something else?

There is only one piece of wood affected that I can find. This is a old 2x4 that runs along the sill plate between the house and garage.

The damaged area are full of very very fine sawdust, almost like powder.

I've had a few professionals look at this and got a very mixed bag of answers.

One said termites, one said it's definietly not termites, one didnt know but said it looks old, and one said powder post beetles, but looks like old damage.

If it's old, I dont remember seeing it a few months ago when I drilled that very board to run wire. I'm sure I would of seen it.

Theres no signs of any bugs that I can see.

The dust in the cobwebs is from picking at the damage with a screwdriver.

Note the little pellet looking piece siting on the board in the last pic.

 

The evidence in photo does not look like termite, nor does your description of fine powder sound like termite. Subterranean termites bring mud into the wood; they do not make sawdust of any consistency. Just for confirmation, wet the powder and you will see if it is mud or sawdust. You sound positive, though.

Being fine dust, it is also not carpenter ant. I'm sure it is a wood boring beetle larvae that did the damage. Possibly powder post beetle. Do you see pin holes in the wood? If so, it is ppb's. No pin holes mean it is a larger wood-boring beetle. Look for oval shaped holes; they are the emergence holes for the adult beetle. Their gestation period can be up to several years and it takes a long time to do any damage. I suspect that this was there when you drilled, you just coincidentally missed it.

Is the evidence spread throughout that joist, but not in others? That would be a good sign, as re-infestation has not occurred. Probably no treatment necessary.

Do internet search for large wood boring beetles. Some re-infest if the conditions are conducive, others do not re-infest no matter what. What part of the country are you in?

 

That nails it then.

I just had one more opinion, within 15 seconds of looking at the wood he said powder post beetle, then he also pointed out the pin holes.

So out of 5 professionals that looked at it, only 2 got it right. One even wanted to give me a $1500 termite treatment!