The Portland daily press., 1883-07-23
THE DYING HACKMATACKs.
What DR.. A. s. Packard Has Discovered

The Sunday Herald publishes an interview
with Prof G. V. Riley OF the U. s. Entomo-
logical Commission in the course of which the
following was said regarding the investigation
OF DR.. Packard Of the cause of the destruction
of spruce trees which has attracted 80 much
attention
"What have you to say of the injury to the
hackmatack?"
A good deal has been said OF the dying Of
these spruce trees during the past two or three
years, number of different theories being
held. So requested DR.. A. s. Packard, who
is one of the special agents OF the chronological
division, and is preparing for the department
special report on forest tree insects, to give
particular attention to the subject I have
just left him at Brunswick, and, after thor
ough examination, we are of one mind or the
subject, and indeed there is no reason for the
ory." The injury is entirely due to the work
of a false caterpillar or saw fly larva-a worm
about three-fourths Of an inch long when full
grown, with black head, pale green body,
with darker green side stripes and ten pairs Of
prolegs The insect may be known as the
spruce saw fly. 1t passes the winter in a
tough brownish cocoon in the moss and turf
is black, with some four of the abdominal seq
ments reddish yellow. 1t issues from the CO.
coon In June, and the female lays her eggs In
the terminal young shoots. making about
dozen incisions in each, and thus causing the
shoot to curl in characteristic manner. A
few eggs may even now be found unmatched,
but the bulk of them hatch In June, and by
the present time of year most Of the worms
have left the trees and spun up
"But have not other explanations been offer
ed of this injury?"
"Oh, yes! Where facts and close observa-
tion are wanting, theories abound. The chief
of these are change of climate and 'old age.'
Some, high in authority, have adopted this last
but there is no sense in it. Trees die OF old
age gradually and individually This kind of
decay Is easily recognizable in any Species and
In forest is not particularly perceptible be-
cause younger trees gradually take the place
of the failing ones. YourIhackmatacks OF all
ages are being killed by the worm, which,
while partial to old trees, spares neither youth
nor age. Occasionally tree dies from some
other cause, as by borers, for Instance, or inju-
ry by fire; but such trees are conspicuous from
their brown dead leaves which are not eaten
off,
sor?''
"It extends throughout New England and
into New York. and DR.. Packard, who has had
good opportunities of getting at the facts,
thinks that about two-thirds Of the trees
throughout this whole extent are already de-
stroyed.
"Have you any remedy to recommend?'
Man is impotent to stem such widespread
injury. Trees can be saved, but the element
of cost will disarm all attempts ON large
scale. Smaller trees could be easily protected
by spraying them with water impregnated
with arsenic in some one OF the now well
known forms, as, for instance, one pound Of
London purple to so or 100 gallons OF water, or
one pound of Paris green to 40 gallons of water.
A Qartain 0unnftv of HQur should ha etirrad in
to give greater adhesiveness. These liqui DIS
sprayed on to the trees will kill all the worms
that hatch shall publish in the forthcoming
annual report of the department an account of
some improved methods of applying them to
trees by means of special spraying nozzle at
tached to rubber tube which is passed thu ough
a long bamboo rod and connected with force
pump in a barrel or tank drawn by horses. A
large number OF trees can be poisoned in a COM
paratively short time, and with minimum
quantity of material II had grove of young
spruces should certainly adopt this method Of
saving them. 1t occurs to me that something may
be done alsoln the sway of raking up old leaves
and moss on the ground on which the cc3oons
are formed, and burning them during the fall of
the year. However, these methods are only
valuable in limited areas, and we shall doubt
less have to await natures own remedy, name
ly, the incres5e of the insects natural enemies,
or some meteorological influence that may in
juriously affect it. Whenever a species be-
come a corresponding scarcity and immunity
from it is very apt to follow swiftly. Whether
this change viii occur before all the trees are
killed or not, it is impossible to say"
"You have no IDEA of the value Of thu trees
destroyed?"
II have not any statistics of the damage in
New England, but il is very great and impor-
tant."
docs not the injury extend to other ever
green trees?"
mo, notice good deal of injury and of
dying wigs and branches among the white
pines, the tips, or whole branches and some
times small trees being brown and dead. But
this has no connection with inject work, nor
does it result from the effects OF ire. have
examined it closely, and have come to the con-
clusion that it results from the exceptional
drouth that has prevailed for the last three
years combined with the severity of the past
winter. The ground got dried out to an unus-
al depth, and when the roots of coniferous
tree once cry they perish"