The Glasgow courier. [volume] (Glasgow, Mont.) 1913-current, 1920-05-21
ACTIVITIES
BEING INVESTIGATED
Stebbins Explains P~eculiarities of the
Pale Western CutwOrm Which Is
Troubling Eastern Montana.

No insect in recent years has proved
to be as serious a pest to grain in
northern Montana as the pale western
cutworm, which caused extensive in
jury in this section during the past
three years, according to A. l.. Strand
Of the Montana experiment station,
who is making an examination of
fields in the northern district to de-
termine if possible what may be ex-
pected from this pest during the sea-
son of 1920.
The cutworm, differing from the
more common species in that it feeds
exclusively beneath the surface of the
ground, was first known in the south
ern part of Alberta where in 1912,
close to $4,000 acres of grain were
totally destroyed. Since 1915 when
it commenced it's activity in Teton
county, it has been the cause of i'm
mense losses throughout northern
Montana, with the greatest losses sus-
tanned during the last three years.
Insect parasites have always been
the chief reason for the periodic album
dance and then the sudden disappear
ance of most insect pests. An increase
in the pest is accompanied by much
greater increase in the insect para
sites which then hold the destructive
insect in check. However, this pale
western cutworm has been found to
be practically immune from such par
asites, probably explained by it's re-
naming at all times beneath the sur
face of the ground where it feeds on
the tender lower part of the stems
and thereby not subjecting itself to
attack by parasitic insects.
Consequently birds, principally if
not entirely the small horned lark, has
been observed to be the chief natural
check on this particular pest. Thous-
ands of small excavations made by the
birds in digging out the worms were
a common sight last season through
much of the worm infested territory.
However loyal the work of the birds
it is believed that their efforts were
not sufficient to alleviate much dam
age this season. The moths, or par
ents of the worms, which appear dur
ing the latter part of August are
known to have emerged in consider
able numbers and when it is consid-
cred that each female deposits from
300 to.400 eggs, the possibility of this
insect maintaining itself in the fields
car readily be appreciated.
Experiments, both in Canada, and
Montana, designed toward the control
of this pest have proved to be only
moderately successful. By seeding
into the ground bran poisoned with
paris green and made attractive to
the worms by the addition of molas-
SEES mixed with water and salt, which
mixture is dried out before being run
through the drill, has given fair re-
suits. Small patches where the worms
are abundant can be treated ir this
manner and given some protection hut
the cost of labor and materials makes
it impracticable on large acreages.
The length of time the worms remain
active, from the last of April to the
middle of June, is a feature in the
habits of this species which makes it
a greater problem and adds to the
difficulty of finding a suitable means
of control.
There is a possibility that the late
season together with the heavy fall
of moisture during April, which would
a rapid Matching of such eggs
as did not hatch last fall, may prove
a decided benefit but it is not thought
that any weather conditions, which
We have had, have absolved the pos
sibility of cutworm damage this year
to any great extent.
MURRAY E. STEBBINS,
County Agricultural Agent.