Life history:  This insect appears in the form of a red-headed,
    yellow-colored caterpillar during the latter part of May, and in
    June and July.  The caterpillars surround themselves with silken
    cocoons and change into pupae.  The mature moths emerge from the
    cocoons after a period of about two weeks, and the females, which
    are wingless, soon deposit their eggs on the bark of trees, on
    twigs, fences, and other neighboring objects.  These eggs form white
    clusters of nearly 350 individual eggs each, and are very
    conspicuous all winter, see Fig. 101.

Remedies:  There are two ways of combating this insect:  (1) By spraying
    with arsenate of lead for the caterpillars during the latter part of
    May and early June. (2) By removing and destroying the egg masses in
    the fall or winter.

[Illustration:  FIG. 101.—­The Tussock Moth. (After Dr. E.P.  Felt.)

1.  Caterpillar. 2.  Male moth. 3.  Female moth laying eggs. 4 Cocoons. 5.  Cast skins of caterpillar. 6.  Work of young caterpillar. 7.  Male pupa. 8 and 9.  Girdled branches.]

THE GIPSY MOTH

Life history:  This insect, imported from Europe to this country in 1868,
    has ever since proved a serious enemy of most shade, forest, and
    fruit trees in the New England States.  It even feeds on
    evergreens, killing the trees by a single defoliation.

The insect appears in the caterpillar stage from April to July.  It feeds at night and rests by day.  The mature caterpillar, which is dark in color, may be recognized by rows of blue and red spots along its back.  After July, egg masses are deposited by the female moths on the bark of trees, and on leaves, fences, and other neighboring objects.  Here they remain over the winter until they hatch in the spring.  The flat egg masses are round or oval in shape, and are yellowish-brown in color.  See Fig. 102.

Remedies:  Spray for the caterpillars in June with arsenate of lead and
    apply creosote to the egg masses whenever found.

THE BROWN-TAIL MOTH

Life history:  This insect was introduced here from Europe in 1890 and
    has since done serious damage to shade, forest, and fruit trees, and
    to shrubs in the New England States.

It appears in the caterpillar stage in the early spring and continues to feed on the leaves and buds until the last of June.  Then the caterpillars pupate, the moths come out, and in July and August the egg clusters appear.  These hatch into caterpillars which form nests for themselves by drawing the leaves together.  Here they remain protected until the spring.  See Fig. 103.

Remedies:  Collect the winter nests from October to April and burn them. 
    Also spray the trees for caterpillars in early May and especially in
    August with arsenate of lead.