Question
Help!  I have 4 large (~50-60 ft) pine trees that are ~30 yrs old. One appears to be dying.  The needles are brown and dry and falling.  We have noticed small holes in the bark of the tree and saw a few dark ant-looking bugs.  Any help would be appreciated.  We live in upstate NY.

Answer
Are all the needles of the tree losing needles dying or just the older ones and there are green needles near the end of the branches. IF so this is just normal needles drop (pines have tow sets of needles on them and one set will drop and make the tree appear to be dying.
IF all the needles are dead on a tree then it is dead. The usual cause to this type death is bark beetles. If so you should see pitch tubes (wads of pitch scattered over the tree trunk). If you see these then I would spray the trunks as high as you can reach with an insecticide called Onyx. This will kill the beetles in the bark and prevent others from attacking for up to three months.
If none of this fits I would suggest you call the NY state Forestry agency and ask one of their Foresters to come take a look. this is a free service in most state. Here is the web link to their contact page and you can contact the nearest office to you. Or you can find their number in your local phone book.

http://www.dec.ny.gov/about/558.html