Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1902-03-22

on the visible evidences of the spruce de-
stroyerS work, together with methods to
prevent their future invasion of living
timber
Or. Hopkins conducted investigations
during the past summer in the heart of
the Northwestern Maine woods, in locali
ties where the spruce were dying by the
thousands The infested living, dying
and dead trees all bore evidence of hav-
ing been killed by the beetle The adult
varies in length from 3-16 to SIG of an
inch, and in width from Lie to PIG of an
inch. The larva, when Matching from the
egg, is a minute, white, legless grub,
which feeds on the inner bark and in
creases in size until it has attained a di-
ameter equal to that of the adult. AS to
the life history of the beetle there is but
one brood in a season, and the period of
development from the egg to the adult is
about seventy-five days. Their destruc-
tive work begins when they emerge from
winter quarters, about the middle of June
and continues until the first of Septem-
ber The broods of the beetle do not re-
main in dying or dead tree more than
one year after it commences to die. DR..
Hopkins estimates that an average of
three pairs of beetles to the square foot
of bark on ten to fifteen feet of the trunk
of an averaged sized tree are sufficient to
| kill it. s..,-..
I 80 far as known the beetle attacks
| only spruce. The most striking and i'm
portant feature is it's habit of attacking
| only the larger trees. 1t is rarely found
| in trees below ten inches in diameter. A
l af xx.hi hal
covered from slight attack. as well as
| those that were infested by different
stages of the insect, indicated quite
clearly that the first entrances are made
in the bark of a healthy tree at a point
from six to ten feet from the base.
1.-The entrance gallery is started prob
ably by the male beetle, and gradually
| extended upward to one side through
the inner bark. The male is then joined
by a female, and together they excavate
a broad gallery. often growing the sur
| face of the wood for distance of six to
| twelve inches. Along the side of this gall
lery the eggs are placed singly in small
cavities, protected by a mass of borings
cemented with gum. After all is finished
| the adults may go on to irregular borings
| at the further end, apparently for an
abiding place, before they die
| THE leaves of dying tree infested by
| this insect change from dark, healthy
| green to a pale or gray hue and soon fall
| Infested trees present by their reddish
appearance a striking contrast with the
healthy foliage, and are thus easily re-
| cognized.
Three practical methods for mitigating
the ravages of the spruce destroying
beetle and reducing future losses to the
vast amount of timber have been deter
mined on as follows: First to regulate
the winter logging operations so that as
| many of the dying and infested trees as
possible can be cut and the logs there.
from placed in rivers. ponds and lakes,
between October l and June /. Vast num-
bers of insects will thereby, be drowned or
| so far removed from the large standing
spruce that they can do no harm; sec
ond. to regulate the summer operations 80
that as many of the infested trees as
possible can be cut while the bark will
peel; third, to girdle healthy trees in
June to attract the beetles away from
| timber that II is desired to protect. The
use OF girdle tapped trees has the ad-