Yorkville enquirer. [volume] (Yorkville, S.C.) 1855-2006, 1922-06-23
BOIL WEEVIL INVASION
Proceeding This Year on Larger
Scale.
VIGOROUS POISONING is NECESSARY
More WeeviIs Brought Over 6-Efp5,
Winter Than UsuaI-lnsects Should
Be Killed in Buds Where Possible.

-
partment of Agriculture sats- Delta
Laboratory, Tallulah, Alatamag con-
tains information that should receive
the attention of cotton growers Of this
section.
For the past few weeks 1--WE have
been accumulating records on the
emergence of the boil weevil from
nearly all of the cotton states and are
finding universally, as we forecasted
some months ago, that the number, of
over -wintered weevils is far. greater
than usual; in fact, in many districts
where accurate counts have been made
it has been found that we have in the
fields now as many weevils as are or
dinarily present month later when
the first summer bred brood has start
ed to appear. With anything like nor.
NAL weather conditions this is going
to mean tremendously rapid increase
in the weevil damage, and this win
have an important bearing on the pro-
gram to be followed by those using
calcium arsenate for the control OF the
weevil.
In the first place 1t should be re-
membered that we recommend starting
poisoning when from ten to fifteen per
cent. of the cotton squares have been
punctured by the weeyil. AS general
rule this condition does not arise un-
til after the newly bred weevils have
started to emerge from the squares.
This year, however, we have found
many fields where there are already
sufficient weevils present to DESTROY
practically all squares as fast as
formed In other words, such cotton
will never start blooming unless the
weevils are controlled, and from the
very outset so per cent. or more Of
the squares are punctured. Under
such conditions ii is undoubtedly go-
ing to be necessary to poison earlier
than ever before. OF course, there Is
no advantage in poisoning the cotton
before the squares form, as the weevils
are continuing to emerge from hiber-
nation during this period and further
more they are doing the crop no harm.
However, where such a heavy infes-
tation occurs it will be advisable to
make the first application just as soon
as the cotton startsasquaring freely, or
about the time the plants average
from to squares each. The regular
poisoning schedule should be started
at that time and continued along the
lines OF the usual recommendations
for controlling this early infestation Of
weevils.
Another very important effect OF
this heavy infestation will be felt later
in the season. When the weevils first
emerge from Information and reach the
cotton field they move around very
little as long as they can find an ample
supply OF unpunctured squares for
their use, but just as soon as the In
festation becomes sufficiently heavy to
puncture practically all squares ,i these
weevils start to move in search Of
fresh pastures. In an ordinary season
this means that you usually have only
the weevils bred in your own cotton
to contend with until some time from
the latter part Of July to the last of
August, depending on the locality.
This year, however, this movement OF
migration Of weevils will probably
start several weeks earlier than usual
Consequently, it will not only be-
necessary for you to start poisoning
earlier to controT your own infestation,
but you should also expect that, before
you have had time to mature the fruit
which your plants have set during this
period of protection, you will begin to
experience an immigration of weevils
from Imprisoned cotton. OF course,
this condition would not arise If every
one in district was successfully
poisoning his cotton; but this will not
be the case this year, and just as soon
as all squares in the imprisoned crops
are punctured the migration to the
poisoned fields will commence. This
means that every day large crop Of
new weevils will move into these pois-
oned fields, and it is going to take con-
tinuous, thorough poisoning to protect
to maturity the crop which has been
allowed to set by the earlier applica-
tions.
These two facts mean just this:
Successful weevil control this year is
going to require more effort and more
poison per acre than has ever been the
case in the past. On Che other hand,
wherever the land Is sufficiently fertile
TO justify such an effort, there is much
more assurance of profit from the
operation than is usually the case. The
increase in the cost per acre brought
about by the increased number of ap-
plications necessary will be far more
than compensated for by the fact that
the weevil damage without poisoning
will be far greater than normal, and
thus the margin of profit on the opera
ton is tremendously increased In
other words, a heavy weevil infesta-
ton such as we have this year means
Il greater expenditure per acre for