What is the chemical content of pine trees?

Why are all of our pine trees dying?

• My husband and I own a twin home with about 50-60 tall pine trees in back. Last summer we noticed that 10-15 trees had died and my husband cut them down. Now this year we had to take down 18 more. My dad said that he thinks it is some kind of pine beetle. When we cut this bunch down we inspected them. The bark is gone on most of the tree. There are little holes into the trunk and engraved trails around the outside. But when my husband cut them down he noticed that all of them had large amounts of ants in them. These ants have black or dark brown heads and rears and then red middles. (we live in Minnesota) Could that be what is killing our trees, or are they just using the tree after the beetles leave? We haven't found any kind of beetle. Let me know what you think, and if there is anything we can do. The remaining trees have really flaky bark. Could it be that they are just dying of age, and then the ants are taking over? Also, the trees only have needles way at the top of the tree. All branches below are bare. Any help would be much appreciated! Sorry about the novel!

• Answer:

  sounds like beetles,,go out late evening before dark and listen for "chewing" sounds. needles at top mean the trees are to thick,planted to close together,and are only getting sun at top branches.as im sure you can tell i aint no expert-just learned from experience-if it is beetles take all the trees out,replant some nice hardwoods at proper spacing