Often when trees get
older, they begin to lose large areas of bark. Upon
closer inspection, you may discover tiny "galleries"
or tunnels on the bottom side of the bark pieces.
This is evidence that the tree has been invaded by
bark beetles. A good entomologist can identify the
species of insect (and thereby also the species of
the tree) based on the configuration of these
galleries.
Bark beetles find
there way beneath the bark and lay their eggs. When
the young hatch, they begin to feed and this is what
creates the galleries or grooves on the wood and the
inside of the bark. Generally, these beetles are
only interested in older trees that are likely to
have some loose bark. Rarely do you find them on
young, healthy trees.
By themselves, most
bark beetles are just part of nature's long term
goal to recycle a tree. They are part of a group of
insects and diseases that start to work on elderly
trees.
If all they did was
eat, the beetles would be of small concern but they
also tend to carry disease organisms with them from
tree to tree. For example, bark beetles are a major
vector for moving
Dutch elm disease through a
population of mature elm trees.
