Nature Notes From Crater Lake
Volume 3, No. 2, August 1930
Bugs -- Part II
By Earl U. Homuth
The first effort in control with funds
provided in 1925 was begun in May with the arrival of Mr. J. E.
Patterson. A stand against the invasion was made on the southern front.
Infested trees were felled and burned upon the snow. Tall stumps now
standing give evidence of the difficulties encountered. The great masses
of snow will not support a man's weight until, by alternate thawing,
freezing, and packing, it becomes sufficiently solid. This is usually
about May 15. Caterpillar tractors were used to gain access to infested
areas from the roads, and here camps were established. The excessive
cost under these conditions was not taken into consideration when
appropriations were made; as a result the work was, and still is
considerably hampered.
The first season's work seemed a
complete failure, and seemed to establish the epidemic as beyond
control, and to indicate that the people of Oregon and California must
prepare to watch, helplessly, their forests disappear. Three successive
years' work were so discouraging that in 1928 no appropriation was made
for control work.
Nevertheless, in Crater Lake National
Park a great deal of study and thinking and planning was done. Obviously
a new method of attack must be developed. A group under the direction of
Mr. J. E. Patterson, associate entomologist of the Bureau of Entomology,
having suffered reverse, were not yet defeated.
Several results of their tireless
efforts developed. It was discovered that a beetle emerging from a
certain species of tree, returned to that species to breed. Thus a
beetle developing in the lodgepole pine returned to the lodgepole; if in
a yellow pine, it returned to the yellow pine. As ninety percent of the
trees attacked were lodgepoles, effort could be expended upon areas
where lodgepole were exclusive or at least predominant.
Another important discovery was the
fact that larvae hatched in a thin-barked tree would die if the felled
tree were exposed to a sun temperature of 85 degrees F. for a period of
one hour. A longer period of time would be necessary if the temperature
was lower, but allowing for this, the result would be the same. The
lodgepole is a thin-barked tree.
Based upon these new discoveries a
systematic, definite, and strenuous effort was again innaugurated to
control and eradicate the infestation. When we consider the great areas
of forest to be covered, the character of the terrain and the conditions
in early season, the difficulties to be encountered may be appreciated.
The results attained, however, have been encouraging. A few figures
indicating these results will be added later. The method of operation
will be first considered.
A preliminary survey is first made of
an infested area. An expert entomologist is generally called upon to
assist in this. From his study will be obtained the information
regarding the number of men necessary to carry out the program, and the
time necessary. Since the beetles begin to fly -- to leave the trees --
about July 1 and nothing can be accomplished for the season, thereafter,
time is also of the substance of this project.
The work is divided into four parts:
spotting, falling, rolling, and the keeping of records. The spotting
crew is usually made up of two spotters and a compassman. The felling
gang consists of three men in a crew, two fallers and a limber. The
rolling crew calls for four peavy men, one axeman, and a checker.
Records are kept by the spotting crew.
With the Spotting crew, the compassman
is in charge and should be thoroughly familiar with both compass work
and spotting. Also he should have a general knowledge of the area to be
covered, so as to take full advantage of the topography of the region.
Base lines are established (since in this park no governmental land
survey has been made) and these equally divide the area; they are
generally run north and south or east and west to facilitate running
lines with a compass. Spotters should be capable men, physically, with a
thorough knowledge of the work. Previous experience with a falling crew
is invaluable, since this gives experience in determining a good "bug"
tree.
Strips are systematically run thru the
area from the base line. The compassman stays in the middle of the
strip, with spotter "A" on his left and "B" on his right. They stay
abreast of each other. In an area where trees are scattered, an extra
spotter may be assigned to the middle of the strip. Where infested trees
are numerous, the extra spotter is not necessary. With two spotters in
the crew the strip does not exceed three hundred feet.
When an infected tree or a group of
trees is discovered, the spotter finding them calls "Bugs". The group
stops. He then blazes on both sides of the tree and puts a number on the
blazes. These numbers are in sequence, each spotter having a series, as
from 1 to 100 or 1001 to 1100. When the series inn his note book is used
he obtains a new series from the compassman. When he has finished
marking a group of trees, he calls the inclusive series in the group to
the compassman, who then enters the group and the numbers upon his map.
The crew moves on to the outer limit of
the area, then turns and runs another strip parallel to the first, and
continuing this until the entire area is covered.
The Fallers should be experienced men,
both in falling and limbing. Each crew is furnished with a map entering
the location and the numbers of the trees. They pass thru the strips,
cutting as they go. They fall the tree in as nearly a north-south line
as possible, which allows the maximum effect of the suns' rays, this
being the entire object of the treatment. Shade from other trees is, of
course, considered. The tree is limbed as far as necessary to prevent
shading. The stump is peeled. In case of the White Pine, the bark is too
thick to permit the heat of the sun to penetrate; therefore the bark is
peeled from these trees.
As each tree is felled, the number of
the tree is written on the stump, and also on a pad which is turned in
to the "spotters" in the evening.
The Rolling crew, of peavey men and
axemen are taken from the falling crews, and the checker should be a
spotter, or someone familiar with the region. The checker carries a map
and leads the crew to the trees, each of which is rolled half over, thus
exposing the remaining surface to the sun. This rolling is of course
done after sufficient time has elapsed to allow for the destruction of
beetle larvae on the surface originally exposed. The rolling must be
done accurately to allow all surfaces to be finally exposed. The number
of each tree rolled is recorded, and these numbers also turned in to the
spotters each evening.
The records, as mentioned, are kept by
the spotting crew. After each number in the original record, a check is
placed when that number is turned in by the Fallers and later by the
Rolling crew. This system checks up on trees missed.
A daily report is prepared as to total
trees spotted, cut, and rolled, and these figures complete a final
report. These final reports are useful in planning work for future
years, in estimating future costs, and by comparison with previous
years, in determining on the basis of percentage the effectiveness of
the work.
A system of tags has been suggested to
avoid duplication of numbers, misreading of numbers of other normal
errors. Each tag would have three stubs, one stub to be retained when
the tree was spotted, one when felled, and one when rolled.
In conclusion a few facts will be given
concerning the work actually done during the two years in which
appropriations have been available.