INSECTS AND DISEASES THAT DESTROY FORESTS Forest insects and tree diseases occasion heavy losses each year among the standing marketable trees.

Insects cause a total loss 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.