CHAPTER VI

THE CARE OF TREES



STUDY I. INSECTS INJURIOUS TO TREES AND HOW TO COMBAT THEM

In a general way, trees are attacked by three classes of insects, and
the remedy to be employed in each case depends upon the class to which
the insect belongs. The three classes of insects are:

1. Those that *chew* and swallow some portion of the leaf; as, for
example, the elm leaf beetle, and the tussock, gipsy, and brown-tail
moths.

2. Those that *suck* the plant juices from the leaf or bark; such as the
San José scale, oyster-shell, and scurfy scales, the cottony maple
scale, the maple phenacoccus on the sugar maples, and the various
aphides on beech, Norway maple, etc.

3. Those that *bore* inside of the wood or inner bark. The principal
members of this class are the leopard moth, the hickory-bark borer, the
sugar-maple borer, the elm borer, and the bronze-birch borer.

The chewing insects are destroyed by spraying the leaves with arsenate