The Powder River County examiner and the Broadus independent. [volume] (Broadus, Mont.) 1919-1935, 1920-03-26

LII H. tions Of insects affecting
Ell - forest resources. according
~ ~ to the annual report of the
N chief Of the bureau of en-
8ARJ tomology, United States de-
partment Of agriculture.
The report says of western field work
IAN especial investigation of the in
sect damage to crude spruce products
for airplane stock in the states OF
Washington and Oregon showed that
the greater part if not all of the dam.
age could be prevented by proper
methods of logging and production
with little or no additional cost.
"Exhau>tive studies of insect investi.
CATION and control were continued in
the Sequoia and Yosemite national
parks. Much new information has been
gained. and the methods of gathering
and compiling field data have been
standardized.
~ special study was completed on
the INTERPOLATION Of forest fires and
insects on IN area Of about 1000 acres
IN southern Oregon. This area has heen
under observation since 1914. and the
fire had burned over about 500 acres
in 1918 The records show that pre>i-
GUS to the fire the insects had killed
4S5.OOO hoard feet of timber. The fire
killed 10000 feet. and subsequently
the slightly tire-njured as well as the
uninjured trees in the burned area
were killed by beetles. which were at
tracted from the surrounding areas.
1t was noticed that the infestntiOn in
| the burned area increased more than
| 1000 per cent. hut it was found that
| the infestation in the surrounding
areas decreased. 1t was also found that
| the hrOOds Of the beetles in the fire
scorched trees failed to develop to
| much beyond the original number that
attacked the trees. So the fire did not
| contribute to an increase Of the beetles
| in general area or to the starting
or extension of an epidemic of beetles.
! This result is of extreme interest and
hardly to be expected.
THE most careful study ever made
| Of the history of an epidemic infesta.
ton of tree-killing beetles was com.
! pleted and a report submitted during
the year. In the Rogue river area IN
about 5000 acres near Ashland. Ore.
the western pine beetle in 1914 caused
the death Of 346OOO hoard feet of pine
timber. In 1918, 1,Gl3,OOO board fee,
were killed: 1.3S3.O0O feet in 1916. and
6os.OOO in 1917. A count of the young
and matured stages Of the beetles tina,
developed in an average foot Of bark
and also IF the number of exit hole.
through which the beetles emerged t.
attack other trees. showed that there
was Il notable decrease in number,
during the development of the broods
each year in the infested trees on nc
count of the increase of natural ell
emieS and other disturbing factors
This helps explain why these beetle
epidemtcs rise and fall within Il linn
tied period Of years. and 1t explains
how the western forests of yellow
pine are naturally protected from tota
destruction. These facts are especial,
significant in connection with the an
plication of the percentage principle OF
control. as by aiding the natural forces
which work against the abnormal in
crease and epidemic shows the impor
lance Of prompt recognition ant
prompt treatment of threatened out
break IN order to prevent the grea
loss Of timber which would occur befor,
natural control became operative.
Another special study was made o
the number Of all stages of the west
ern pine beetle in $40 square feet n
infested bark selected from g. trees
which represented an average infesta
zion within an area of approxim,tel,
G square miles. 1t was shown tina
there is large percentage Of mortal
ity between the young and maturet
stages in the developing brootls. bu
that normally an average of about IL,
beetles to the square foot of bark de
veloped to the adult. or reproductiv,
stage. which would be $4,000 beetles