Black vine weevil, of little consequence to the trees. When you say "infested" with carpenter ants, this is because you see them walking on the trees? Or are they actually nesting inside them, with piles of sawdust being made at the bases of the trunks? The latter would definitely indicate a problem (I think carpenter ants are usually found in quite dead wood) - as does heavy sap production.

You should have a certified arborist look at them.

This post was edited by bboy on Thu, Sep 19, 13 at 3:06

We have active nests at the base of the trees, and yes, piles of frass.
Thank you for the beetle id, I was looking at pics of the usual suspects on the internet and striking out.

Carpenter ants gnaw into wood that is in suitable condition, eject the fragments as they are not food for them. "Nests at the base" makes me wonder if you are talking about something else, such as thatch ants. Anyway, if it looks like you have something boring the trees out that is not to be ignored, whatever specific insects are involved.

how close to your home.. are these 'rotting at the base hundred foot trees'???

does it really matter what kind of ants they might be???

hire a pro

ken

Hi Ken, Yes, uphill from the house and 30 feet away. They'll take out the master bedroom if they fall, and just to make things more interesting, the one closest to the house is rotten at the base. DH just discovered that. The largest Douglas fir is about 2.5X the height of the power pole next to it. That tree dropped branches during the ice storm and took out power to the whole neighborhood. I believe that these trees belong in a forest, not in a residential area, but my city has a tree ordinance, so I need the city arborist to authorize removal.

Regarding the ants: carpenter ants are prevalent here. Most everybody has a pest control company come out once a year to spray. We found and removed several carpenter ant nests - one in a sad, old azalea; and the telephone pole has an active nest. They live for years, breed prolifically, and establish satellite nests, so it's a tough battle. (I had to do some homework after the water heater started sinking into the floor!) We might have thatch ants too, but I haven't seen the mounds.

Regarding the ants: carpenter ants are prevalent here. Most everybody has a pest control company come out once a year to spray.

Lived here all my life ( and most recently in the heavily wooded areas of Kitsap county) and have yet to call out a pest control company for ants. Did find moisture ants (tiny little creatures about 1/4 the size of carpenters) in a bathroom wall of a house we were renting once but the shower was falling apart so pretty much to be expected there.

If you see ants, they are a symptom, not the cause of the problem. Thatch ants will feed off the sap and carpenter ants will nest into the rotting wood. You could have Doug fir beetles - they are a very common source of both the sawdust, frass and weeping sap. There are also various fungal diseases loosely grouped as sap rots. None of these are good things.......best to get a certified arborist out to diagnose the tree and suggest treatment (maybe) or removal (likely).

Hi Gardengal. I understand what you are saying about symptom versus cause, especially after the water heater incident. Laminated root rot was recently diagnosed in Douglas Firs nearby, and we may have beetles. I'll have an arborist come out and check on these trees.

By the way, I see carpenter ants daily here: Squak Mtn. One of my neighbors has two stumps with active nests and he also has railroad ties for steps, and the carpenter ants are there, too.