Question
We live Southeast Ohio.  We have a blue spruce that is being killed by worms.  The are starting from the bottom branches and moving up.  The use the dead needles to make little hanging nests and I belive one worm lives in each nest.  What kind of worm is this and how do I save the tree?  Thanks for any info.  Keely

Answer
These are bagworms. The insect caterpillar lives in the bag and eats the needles and makes the bag out of some of them. It is hard to get an insecicide into the bag so the best method of control is to pick off the bags and destroy them. You can spray the foliage with an insecticide BT and the caterpillar will feed on the sprayed foliage and die this works best on the smaller instars (stages) of the bagworm. A contact insecticide will work if you can spray the bags. If the tree is not too tall, picking them off works best for older caterpillars. By the way if any in your family are fishermen the caterpillars are good fish bait.