Atlanta semi-weekly journal. (Atlanta, Ga.) 1898-1920, 1918-09-13
weevil by Poison

Weevn by Poison
The boil weevil has now been with
us for many years and in that time has
spread from the Mexican border to
about two-thirds of the way across the
state of Georgia. Both state and fed
eral governments have spent large
sums of money in an attempt to combat
its progress. 1t has. however, steadily
moved forward from year to year until
II has now covered the greater part of
the cotton belt and has inflicted ire
meudous losses on the farmers of the
south. As in the case of all devastating
agencies of this character. however. II
has been accompanied by some compen-
sating influences. In fighting IT, Tor
instance. il has been shown that bet
ter method of farm practice is neces-
saT-v that a more thorough preparation
and fertiIiza tion must be undertaken,
that the planting of earlier maturing
varieties is necessary, and that rola-
ton and diversified farm practice must
be instituted The benefits which are
already flowing out of the changes thus
brought about have probably more than
compensated our people for the losses
suffered up to the present time. I'm
doubtedly il will be necessary to In
stitute and continue the plans now in
more intensive basis as the years go by,
hut il is encouraging to observe that
after all the energy and effort which
have been put forth to control this in
sect to an appreciable degree through
pofscuiug, some substantial progress in
this direction seems to have at last
been attained. Hence it will not be IN
apDropriate to direct attention to what
has been done and to the possibilities
which apparently lie ahead through the
use of certain poisons in spraying cot
tor for mitigating or controlling IN
large measure the ravages which the
bolI weeviI has inflicted up to the pres
emit time.
The experiment in question was in
stituted and has been conducted py
members of the staff of the U. ). de-
partment of agriculture. The work has
been prosecuted in the south and in
rieIds where 'weevil infestation was
very bad. OF course, the experiments
are still in their initial stages. but
enough has been done to indicate the
latent possibilities of this plan of fight
ms the weeviI, and it is hoped that
the results of the Investigations this
year may throw new light on this prop
csitiou. Only recently, for instance, it
has been fully established that the
weevil stops occasionally from his work
Of puncturing cotton squares and bolls
and goes out to duench his thirst from
the dewdrop or raindrop on the cotton
plant While he is doing this he can,
OF course, be easily destroyed, provided
some cheap and effective means of pois-
oning the plant can he discovered. The
fact that arsenicals can be used as a
powder spray and thus poison the wee
wills water supply has only recently
been discovered and is a fine example Of
how valuable the application of scien-
tiffe investigations, through the. .solu-
ton of our agricultural problems, mas
become. Anything which will lessen the
weevil damage to measurable degree
viii. of course. add millions of dollars
10 the income of southern farmers and
NJ the same time will insure the pro-
ductiOn Of an adequate supply of the
greatest clothing staple known to COM
merce.
In a study OF the habits of the
weeviI the bureau of entomology of the
United States department of agriculture
observed that they regularly obtained
supply of water from rain or dew
collecting in drops on the leaves of the
cotton plants. Having discovered this
fact. the question naturally arose as to
the practicability of poisoning the water
which the weevil drinks. The dust spray
having been developed, it occurred to
the investigators that through the use
of an application of a very finely pow
dered poison to the leaves of the cotton
plants when :hey were moist with rain
or dew. the end they had in view could
be accomplished. 1t has, of course, been
known for a long time that it would be
comparatively easy to poison the weevil
provided he could be induced to consume
the poison. 1t has only recently realized,
however that he could possibly be in
duced to consume the poison through
taking il in the form of his drinking
water While these experiments, as al
ready pointed out. are not regarded as
conclusive, il has certainly been demon
atrated that through the use of dust
sprays in the manner indicated weevil
damage can be greatly reduced and
yields of from $50 to 1000 pounds more
OF seed cotton per acre obtained than
would be possible if the poison dust
sprays were not used. In field tests made
in Arkansas last year on large scale
on late planted cotton il was found that
weevil infestation had become so bad
by the latter part of July that the
plants had ceased to bloom, also that
the crop would apparently be destroyed
mature bolls on the plants. AS soon as
the top crop stopped developing the
Geevils attacked the more mature hollis
and poisoning was instituted to save
them. Treatment was made from Au-
gust % TO September ! on several hun
dred acres. A single poison spray was
applied and ten days later it was found
the weevil infestation had been reduced
so that only Sc per cent of the squares
were punctured. An examination of
the field before the spray was applied
revealed the fact THAI Sc per cent of
the hollis were punctured. Not only did
thin spray have the effect of reducing
the weevil damage very materially, but
as a result of the destruction of this
pest the plants began making a new
growth and development, and even if
the spraying had no other effect il
would Immediately supply the weevils
with a source OF food they prefer to
the hard maturing bolls and so permit
the hollis to open and develop under the
most favorable conditions. In the early
experiments the tri-plumbic form Of
lead arsenate was used. This, however.
was found TO be not as effective as was
anticipated and the di-hydrogen form of
lead arsenate was substituted therefor.
More recent tests indicate that a high
grade Of calcium arsenate is still more