[Stonehenge]

I noticed this Austrian looking like it was in a state of decline. When I took a closer look I found these areas of swelling all over it's branches.

If you look at the pics, it appears that the swelling appears to have started on one side of the branch and then spread around the perimeter of the branch (notice the meeting point of the swelling in the first picture). Of the 4 Austrians in this planting bed, 2 of the others show no signs of this swelling and no signs of decline. Another shows a few of these swelled nodules and is starting to show some decline.

In one of the pcitures you can see where I was trying to see what was inside the nodules by scraping with a pocket knife, then burrowing in. That one seemed pulpy in the middle, while the third picture shows what another looked like when I took a hand saw to it. Seemed solid throughout. I also noticed what appear to be holes in some of the nodules - possibly larvae escaping, or something else trying to get in?

I'm interested to see if anyone knows what this is, and if I can suggest a treatment.

[martinjohn]

It may be Pine-Oak Gall Rust?

[dan deutekom]

I would say that this is Pine-Pine Gall Rust. (AKA... Pine-Oak Gall Rust AKA...Western Pine Gall Rust) No cure. Cut it down and burn it. You can perhaps prevent it's spread to unaffected trees by spraying with a fungicide (I would have to look up which ones) but with older trees this is doubtful and impractical. Chances are that the other trees near this one are also infected. It takes a few years for the symptoms to develop after infection.