Life history:  The elm leaf beetle, Fig. 100, is annually causing the
    defoliation of thousands of elm trees throughout the United States. 
    Several successive defoliations are liable to kill a tree.  The
    insects pass the winter in the beetle form, hiding themselves in
    attics and wherever else they can secure shelter.  In the middle of
    May when the buds of the elm trees unfold, the beetles emerge from
    their winter quarters, mate, and commence eating the leaves, thus
    producing little holes through them.  While this feeding is going on,
    the females deposit little, bright yellow eggs on the under side of
    the leaves, which soon hatch into small larvae or grubs.  The grubs
    then eat away the soft portion of the leaf, causing it to look like
    lacework.  The grubs become full grown in twenty days, crawl down to
    the base of the tree, and there transform into naked, orange-colored
    pupae.  This occurs in the early part of August.  After remaining in
    the pupa stage about a week, they change into beetles again, which
    either begin feeding or go to winter quarters.

Remedies:  There are three ways of combating this insect:  First, by
    spraying the foliage with arsenate of lead in the latter part of
    May while the beetles are feeding, and repeating the spraying in
    June when the larvae emerge.  The spraying method is the one most to
    be relied on in fighting this insect.  A second, though less
    important remedy, consists in destroying the pupae when they
    gather in large quantities at the base of the tree.  This may be
    accomplished by gathering them bodily and destroying them, or by
    pouring hot water or a solution of kerosene over them.  In large
    trees it may be necessary to climb to the crotches of the main limbs
    to get some of them.  The third remedy lies in gathering and
    destroying the adult beetles when found in their winter quarters. 
    The application of bands of burlap or “tanglefoot,” or of other
    substances often seen on the trunks of elm trees is useless, since
    these bands only prevent the larvae from crawling down from the
    leaves to the base and serve to prevent nothing from crawling up. 
    Scraping the trunks of elm trees is also a waste of effort.

[Illustration:  FIG. 100.—­The Elm Leaf Beetle. (After Dr. E.P.  Felt.)

1.  Egg cluster, enlarged. 1a.  Single egg, greatly enlarged. 2.  Young larva, enlarged. 3.  Full grown larva, much enlarged. 4.  Pupa, enlarged. 5.  Overwintered beetle, enlarged. 6.  Fresh, brightly colored beetle, enlarged. 7.  Under surface of leaf showing larvae feeding. 8.  Leaf eaten by larvae. 9.  Leaf showing holes eaten by beetles.]

THE TUSSOCK MOTH