Termite and Wood Boring Insects - 1/4" hole in underside of deck

I noticed this morning that there is something boring 1/4" holes into the joist and planks of my deck. So far there are about 5 or 6 but I have no clue what they are from or how to treat them. The holes look like someone took a drill to it. I didn't really see any type of pest. Any one got an idea of what this may be or what to treat with. Thanks,

RM

Sounds like a wood boring bee - carpenter bee, although I don't recall having seen them bore into PT wood. They bore into the wood and lay their eggs.

They make an insecticide specific for this bee. If I remember correctly, it's a powder you shoot up into the hole. After treating the hole you are suppose to seal it up with a plug or wood dowel.

I usually try to spray both the bees and the holes when I see them. Generally with regular bee spray but I have used carberator cleaner if it was handier :D It pays to keep after them because they don't just bore a hole straight end - they will turn and make a tunnel and exit somewhere else :eek:

Here's a link to another recent discussion re: carpenter bees: http://forum.doityourself.com/showthread.php?t=344559

While I have not seen them get into new PT, I have seen them bore in 10 year old PT. Since they don't eat it, only sweep it out, I don't think it bothers them much. I don't think the pupae mature. The holes are the unsightly part.