certain that they are free from the San Jose
scale. If, however, it should in any way gain access to your orchard,
you can prevent its spreading by thorough spraying with what is known as
the lime-sulphur mixture. This mixture has long been used on the Pacific
coast as a remedy for various scale insects. When it was first tried in
other parts of the United States the results were not satisfactory and
its use was abandoned. However, later experiments with it have proved
that the mixture is thoroughly effective in killing this scale and that
it is perfectly harmless to the trees. Until the lime-sulphur mixture
proved to be successful the San Jose scale was a most dreaded nursery
and orchard foe. It was even thought necessary to destroy infected
trees. The lime-sulphur mixture and some other sulphur washes not only
kill the San Jose scale but are also useful in reducing fungous injury.

[Illustration: FIG. 150 SAN JOSE SCALE]

[Illustration: FIG. 151. SINGLE SAN JOSE SCALE
Magnified]

There are several ways of making the lime-sulphur mixture. It is
generally best to buy a prepared mixture from some trustworthy dealer.
If you find the scale on your trees, write to your state experiment
station for directions for combating it.

[Illustration: FIG. 152. THE CODLING MOTH
_a_, burrow of worm in apple; _b_, place where worm enters; _c_, place
where worm leaves; _e_, the larva; _d_, the pupa; _i_, the cocoon; _f_
and _g_, moths; _h_, magnified head of larva]

=The Codling Moth.= The codling moth attacks the apple and often causes
a loss of from twenty-five to seventy-five per cent of the crop. In the
state of New York this insect is causing an annual loss of about three
million dollars. The effect it has on the fruit is most clearly seen in
Fig. 152. The moth lays its egg upon the young leaves just after the
falling of the blossom. She flies on from apple to apple, depositing an
egg each time until from fifty to seventy-five eggs are deposited. The
larva, or "worm," soon hatches and eats its way into the apple. Many
affected apples ripen too soon and drop as "windfalls." Others remain on
the tree and become the common wormy apples so familiar to growers. The
larva that emerges from the windfalls moves generally to a tree, crawls
up the trunk, and spins its cocoon under a ridge in the bark. From the
cocoon the moth comes ready to start a new generation. The last
generation of the larvae spends the winter in the cocoon.

[I