ouraged in every possible way. Add to these facts the
marvelous fecundity of the insect tribe, and the increase is less
remarkable. Loss from these orchard pests has now run up into the
millions. It has been estimated that the loss in the United States
from wormy apples alone is over $11,000,000 annually. Thus has the
necessity for fighting these enemies of good fruit arisen.

In order successfully to combat an insect or a disease it is very
necessary to have a somewhat detailed knowledge of its life history
and to know its most vulnerable point of attack. It is impossible to
work most intelligently and effectively without this knowledge, which
should include the several stages of the insect or disease, the point
of attack, the time of making it, and when and with what it can be
most easily destroyed. The number of insects and diseases which affect
the apple is so great that it is simply out of the question to treat
them all in detail here. We have therefore selected nine insects and
three diseases as those pests of the apple which are most common and
whose effects are usually most serious. The essential facts in their
life histories and their vulnerable points will now be pointed out.
The method of study may be taken as applicable to any other pests
which it may be necessary to combat.

INSECT PESTS.--Of the many insects which affect either the tree or the
fruit of the apple, the nine selected probably inflict the most damage
and are the most difficult to control of all those in the Northeastern
States. According to their method of attack all insects may be divided
into two classes: biting and sucking. Biting insects are those which
actually eat parts of the tree, as the leaves or fruit. These are
combated by the use of stomach poisons as we shall see in the
following chapter. Sucking insects are those which do not eat the tree
or fruit directly, but by means of a tubelike proboscis suck the
juices or sap from the limbs, leaves or fruit. Of the biting insects
the five which we shall discuss are: (1) codling moth, (2) apple
maggot, (3) bud moth, (4) cigar case bearer, (5) curculio. The four
sucking insects discussed are: (6) San Jose scale, (7) oyster shell
scale, (8) blister mite, and (9) aphis or plant louse.

1. THE CODLING MOTH, the most insidious of all apple pests, is mainly
responsible for wormy apples. The adult is a night flying moth with a
wing expanse of from one-half to three-quarters of an inch. The moths