Question
i have a blue spruce and "christmas tree type" of pine in my yard.  both approx
18'-20' high.  a "tree and shrub" sprayer stopped to tell me i had pine worms
and he would spray both trees for $50.00.  i have no idea if he's legit.  he
showed me where needles had come off and there are a lot of falling needles.  
can you help, please.  thank you

Answer
Spruce and pine both shed needles. There is not any insect called a "pine worm". There are caterpillar type insects that may eat the foliage but this does not cause the needles to drop. There are foliage diseases that could cause the needles to drop sooner than normal but these do not harm the tree. It has been my experience that when any one shows up at your door to spray the trees saying they are dying it is not needed. I would call the local office of the State Forestry agency and ask one of their Forester to come out and take a look or at least advice you IF here is a problem with pines in your area.  This is a free service on most states. I would say it is not needed.