Posted by Debby Jeffries on September 16, 2006

Q: Our sugar maple, red maple, and crabapple trees have holes in the trunk and insects that are boring into it. The red maple has died. What can we do to save the other trees. Also some of our trees have a green mold like growth on the trunks, but appear to be healthy. Any ideas as to what that might be and should I do anything about it?

Habitat: forest/open woods

State: Indiana

Habitat: forest/open woods

A: It's very common for trees to have some borers, it's when those numbers are really high that a tree is compromised. The best way to keep borers at bay is to keep your trees in a healthy condition - borers are especially attracted to stressed trees. Unfortunately there are many different kinds of stresses in the environment for trees today so this is not always easy.

Your "green mold" sounds more like lichens to me. Lichens are two organisms (algae and a fungus) that live together in a special symbiotic relationship. Lichens grow on rocks, the ground, and bark of trees and do NO damage to the trees at all. In fact, I find them quite beautiful. Take a look at some different kinds of lichens on the web and see if what you have looks like one of the many kinds of lichens growing in North America. If this is what you have, you'll know that your air is reasonably clean where you live - lichens don't grow well in polluted air. Hope this helps and thanks for asking.

John Wiessinger ( September 17, 2006)