Question
QUESTION: I have a pine tree that is at least eighty years old, we had an unusually dry summer; this tree is suddenly dropping green needles. Alot of them, they are coating the drive and walks. I have two other pines, the same age which are not dropping needles. I have also lost two other pines of similar age in the past three years but the dropped brown needles not green. Do I need to be concerned? Is there something I can look for or do? I am very worried, please help.

ANSWER: Usually when a pine tree starts to drop green needles it is a sign of the tree dying. I have seen it with bark beetle attacks in dry weather. In this case the beetles have cut the water supply by girdling the cambium layer under the bark and the tree is already stressed due to the drought and the tree turns loose of the green needles. Check the trunk for signs of doring dust or small pitch tube resembling wads of gum. This would mean bark beetles have infested the tree.

Look at the ends of the branches and see if the green needles are dropping from the ends or further back on the branches or all over. IF the needles at the ends of the branches are not effected the tree will live, Drought itself can case the green needles to drop. About all that can be done for a tree this size is wait and see if it will make it. You could if the weather has been dry (near drought conditions) water the tree. This would mean letting the water hose run slow for 6-8 hours on the root system.

May want to contact the local office of the state Forestry agency and ask one of their foresters to come out and check the pine.

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QUESTION: Thank you for your help. I wanted to ask if it is bark beetles, can anything be done.

Answer
If you catch it soon enough. before the beetles construct their galleries under the bark cutting the flow of water to the needles, you can spray the trunk as high as you can reach with an insecticide called Onyx or Merit. These two insecticides will be absorbed into the bark killing the insects under the bark. For this tree it maybe too late but Pines nearby can be sprayed to prevent the beetles form moving to them. IF you still have some green needles on the tree I would try the spray but as you well can see getting the spray up High on the trunk on large trees will be a challenge.  

There is a  soil applied insecticide but this only works when the trees are growing which is the spring and summer. By now the tree have slowed down and not moving water up as they did in the spring. This insecticide is called Bayer Advanced Tree and Shrub Insect control. Check with your local garden type store for these products.