of more than $100,000,000 annually to the forest products of the
United States. A great number of destructive insects are
constantly at work in the forests injuring or killing live trees
or else attacking dead timber. Forest weevils kill tree seeds and
destroy the young shoots on trees. Bark and timber beetles bore
into and girdle trees and destroy the wood. Many borers and
timber worms infest logs and lumber after they are cut and before
they are removed from the forest. This scattered work of the
insects here, there, and everywhere throughout the forests causes
great damage.

Different kinds of flies and moths deposit their eggs on the
leaves of the trees. After the eggs hatch, the baby caterpillars
feed on the tender, juicy leaves. Some of the bugs destroy all
the leaves and thus remove an important means which the tree has
of getting food and drink. Wire worms attack the roots of the
tree. Leaf hoppers suck on the sap supply of the leaves. Leaf
rollers cause the leaves to curl up and die. Trees injured by
fire fall easy prey before the attacks of forest insects. It
takes a healthy, sturdy tree to escape injury by these pirates of
the forests. There are more than five hundred insects that attack
oak trees and at least two hundred and fifty different species
that carry on destruction among the pines.

Insect pests have worked so actively that many forests have lost
practically all their best trees of certain species. Quantities
of the largest spruce trees in the Adirondacks have been killed
off by bark beetles. The saw-fly worm has killed off most of the
mature larches in these eastern forests. As they travel over the
National and State Forests, the rangers are always on the watch