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 for signs of tree infection.

Whenever they notice red-brown masses of pitch and sawdust on the bark of the trees, they know that insects are busy there.

Where the needles of a pine or spruce turn yellow or red, the presence of bark beetles is shown.
Signs of pitch on the bark of coniferous trees are the first symptoms of infection.