The county record. [volume] (Kingstree, S.C.) 1885-1975, 1922-08-17
Fight the Cotton Leaf Worn.
By B. r. Coad.

During the last week of July the
Delta Laboratory began to receive
scattered reports of the cotton leaf
worm or, as it is sometimes called,
the cotton army worm alabama
argillacea Hubn.) from the states OF
Louisiana and Texas. These reports
have increased rapidly until 1t IS
now obvious that we may expect Sc
..ous trouble from this pest IN the
next few weeks. This species does
not overwinter in the United States.
1t is a native of tropical America and
as the adult moth is very powerful
hier, it migrates into the United
States whenever it reaches degree
of great abundance in its native home.
Normally the first generation pro-
duced by the migrating moths in the
United States is limited to the south
western coastal regions of the Gulf
of Mexico,and is not sufficiently
abundant to do serious damage. The
progeny of this generation move
northward and eastward, and as a
rule, by the third generation, the en-
tire cotton belt is infested. Gener-
ally these generations are fairly well
defined. The present infestation,
however, is very peculiar in that the
first generation has spread over a
remarkably large territory and in un-
usual abundance. Reports to date
show the state of Louisiana to be
completely infested, and the majority
of Texas is likewise. At least the
southern half of Arkansas is now in
tested, and a scattering occurs prac-
tically all over the state Of Mississip-
pi. In addition, scattering reports
have been secured from southwestern
Tennessee and western Alabama.
Throughout much of this territory
the worms have already reached de-
foiating abundance and are serious
ly injuring the cotton in local spots,
which is very unusual for the first
generation and indicates an abnor-
mally heavy infestatien in the next
generation, which may be expected
to start to develop within the next
ten days. In addition an examina-
ton of majority OF fields shows a
rem rkable variation in the size Of
the yorms, the same field often yield
ing all stages from newly hatched to
fully matured ones which have web
bed up. This seems to indicate a
continual immigration of moths and
the probability of more or less con-
tinous damage of a rapidly increasing
nature, rather than distinct genera
tions as has usually been the case in
the past.
Possibility of Damage.
The question of just how much
damage these worms can do is very
important one IN determining on con-
troll measures. At some points the
cotton crop is already so mature that
the worms can do little or no harm,
but this area is very limited. The
majority of the territory where the
worms are now present in defoliat-
ing abundance is still susceptible to
serious injury. Of course, the heay-
lest invasion will not develop for
some two weeks yet, and there will
be much more cotton which will be
beyond damage at that time. How
ever, there will still be an enormous
amount of cotton which can be Sc
riously injured by the worms even
after the first of September, owing
to the fact that so much Of the cot
ton crop is from one to three weeks
late in maturity. The question OF
whether or not to attempt to control
the worms is going to be an indlvld-
ual one for each grower to decide.
Many fields are already so thorough
ly infested with weeviis that defolia-
ton by the worms can do no harm,
and many more fields will reach this
condition within the next two weeks.
Before deciding on whether or not
to poison the worms the grower should
examine his fields closely and note
especially the condition of the bolls.
If there are many bolls present less
than two-thirds grown and still un-
infested with weevils, and the worms
start operations in threatening num-
bers, it will generally pay to poison
them. Of course, when field is
completely infested by weevils and
practically all of the younger bolls
punctured, defoliation by worms is
really more of benefit than harm,
but it should always be remembered
that defoliation by worms forces
premature opening of many bolls
=