will harm the young branches
with their tender bark. (3) Encourage the residence of birds. Urge your
neighbors to make war on the larvae, too, since the pest spreads rapidly
from farm to farm. Regularly sprayed orchards are rarely troubled by
this pest.

[Illustration: FIG. 160. THE TWIG GIRDLER AT ITS DESTRUCTIVE WORK
_a_, the girdler; _b_, the egg-hole; _c_, the groove cut by girdler;
_e_, the egg]

=The Twig Girdler.= The twig girdler lays her eggs in the twigs of pear,
pecan, apple, and other trees. It is necessary that the larvae develop in
dead wood. This the mother provides by girdling the twig so deeply that
it will die and fall to the ground.

_Treatment._ Since the larvae spend the winter in the dead twigs, burn
these twigs in autumn or early spring and thus destroy the pest.

=The Peach-Tree Borer.= In Fig. 161 you see the effect of the peach-tree
borer's activity. These borers often girdle and thereby kill a tree.
Fig. 162 shows the adult state of the insect. The eggs are laid on peach
or plum trees near the ground. As soon as the larva emerges, it bores
into the bark and remains there for months, passing through the pupa
stage before it comes out to lay eggs for another generation.

[Illustration: FIG. 161. BORER SIGNS AROUND BASE OF PEACH TREE]

_Treatment._ If there are only a few trees in the orchard, digging the
worms out with a knife is the best way of destroying them. You can know
of the borer's presence by the exuding gum often seen on the tree-trunk.
If you pile earth around the roots early in the spring and remove it in
the late fall, the winter freezing and thawing will kill many of the
larvae.

=EXERCISE=

How many apples per hundred do you find injured by the codling
moth? Collect some cocoons from a pear or an apple tree in winter,
place in a breeding-cage, and watch for the moths that come out. Do
you ever see the woodpecker hunting for these same cocoons? Can you
find cocoons that have been emptied by this bird? Estimate how many
he considers a day's ration. How many apples does he thus save?

[Illustration: FIG. 162. PEACH-TREE BORERS, MALE AND FEMALE
Female with broad yellow band across abdomen]

Watch the curculio lay her eggs in the plums, peaches, or cherries.
What per cent of fruit is thus injured? Estimate the damage. Let
the school offer a prize for the greatest number of
tent-caterpillar eggs. Watch such