the inner layers of the bark,
which thereby became loosened from the wood beneath. The grubs rarely
exceed three-quarters of an inch in length. They have no feet, and they
resemble the larvae of other species of Saperda, except in being rather
more flattened. They appear to complete their transformations in the
third year of their existence.

"The beetles probably leave their holes in the bark during the month of
June and in the beginning of July, for, in the course of thirty years, I
have repeatedly taken them at various dates, from the fifth of June to
the tenth of July. It is evident, from the nature and extent of their
depredations, that these insects have alarmingly hastened the decay of
the elm trees on Boston Mall and Common, and that they now threaten
their entire destruction. Other causes, however, have probably
contributed to the same end. It will be remembered that these trees
have greatly suffered, in past times, from the ravages of canker-worms.
Moreover, the impenetrable state of the surface soil, the exhausted
condition of the subsoil, and the deprivation of all benefit from the
decomposition of accumulated leaves, which, in a state of nature, the
trees would have enjoyed, but which a regard for neatness has
industriously removed, have doubtless had no small influence in
diminishing the vigor of the trees, and thus made them fall
unresistingly a prey to insect devourers. The plan of this work
precludes a more full consideration of these and other topics connected
with the growth and decay of these trees; and I can only add, that it
may be prudent to cut down and burn all that are much infested by the
borers."

[Illustration: 101. Elm Tree Beetle.]

The Three-toothed Compsidea (Fig. 101), is a rather flat-bodied, dark
brown beetle, with a rusty red curved line behind the eyes, two stripes
on the thorax, and a three-toothed stripe on the outer edge of each wing
cover. It is about one-half an inch in length.

[Illustration: 102. Elm Tree Borer.]

The larva (Fig. 102) is white, subcylindrical, a little flattened, with
the lateral fold of the body rather prominent; the end of the body is
flattened, obtuse, and nearly as wide at the end as at the first
abdominal ring. The head is one-half as wide as the prothoracic ring,
being rather large. The prothoracic ring, or segment just behind the
head, is transversely oblong, being twice as broad as long; there is a
pale dorsal corneous transversely oblong shiel