Spruce bark beetles

Asked October 27, 2018, 11:03 AM EDT

I lived on the hillside above Anchorage during the 80's - 90's. We had several mature trees attacked by the beetles. We sprayed the lower 40 feet of each tree, but the tops died, At the time, it was thought the the beetles wouldn't attack above 40'. I kept them well watered, so that helped. I did notice that one mature tree which had a 2'x2' plywood sign on it with 2 each 3" galvanized nails into the tree, was never attacked. I'm wondering if the nails had anything to do with fending off the beetles?

Anchorage Alaska spruce bark beetles

1 Response


Thanks for your question. It is unlikely that the nails in the tree helped protect the tree from attack by spruce beetles. Some trees may be more or less susceptible to attack by the beetles for a variety of different reasons. Without seeing the tree or knowing more about the growing conditions, I can't speculate why this tree was not attacked.

Spruce beetles can attack above spray lines. If you are thinking of having trees treated again, I would recommend treating them until the trunks are less than 5 inches in diameter when possible.