Expert: Jim Hyland - 8/24/2007

Question
We are in Maine. There are 5 white pines lining the edge of our yard. One of these is infested with a worm. There are small holes, 2 mm., over the entire tree into the bark. We can hear these worms "crunching" from as far as 30 feet away. The bark peels easily from the tree and the worms are under the bark. This tree went from apparently healthy to dead in approximately 1 month. The worms are white, ringed and have large "pinchers" on thier head. They range in size from about 1 inch to 3 inches, approximately 1/4" in diameter. So far, the other trees do not appear to infested. Can you tell me what these worms are?

Answer
These are pine sawyers , a longhorned beetle. They infest a pine that has been killed by some other cause. These beetles are no the cause of the trees dying but come in after to feed on the inter bark. I would think the pines were killed by a bark beetle. One of the signs of bark beetles is numerous exit hole on the bark about the size of number 8 shot gun shot. These holes are where a beetle has emerged from the bark. If I had to guess which bark beetle I would think Ips Engraver. If you hear the crunching sounds the tree is dead. Here is a web link to Ips bark beetles.    http://www.fs.fed.us/r6/nr/fid/fidls/f122.htm

The bark beetle have left the tree so control is not needed. If other nearby pines are having the needles turn yellow then you may want to spray the bark with an insecticide called onyx. I would call the state of Maine Forestry department and ask one of their Foresters to check the trees for you. Their phone number should be in the local phone book.