The farmer and mechanic. [volume] (Raleigh, N.C.) 18??-19??, 1909-05-25
Can Weevils in Corn Be Killed by Fumiqa-
ton With Carbon Bisulphide?
question is1

. TIC EullOI. lnlS Qu0SC1On
asked oy farmers every year, espe
ciany during May and June, when tn
presence Of weevils is discovered
What is the answer? Usually tn
recommendation is made to use car
bon misulphide, a foul smelling liquid
costing at the retail druggists price
about thlrty-fiVe cents a pound. Let
ters OF inquiry received by eXperme
stations, agricultural departments an,
agricultural papers, are usually an
sWered in a manner somewhat as fol
lows:
Use carbon bisulphide at the rat
of one and one-half to two pound
Tor !. 900 cubic feet. This iiQuit
evap0rates rapidly and the vaDor i
much heavier than air SO that it viii
sink readily through the infeste,
corn. The bottom and sides of tn
corn crib. box, or bin must be mad
tight. hut the top may be covered Will
blankets or boards. Fumigate a
least = hours exposing the carbon
bisuGp1ide in shallow dishes on tol
OF the corn in order to secure rapit
evaporation. The feeding value o.
terminating power of the grain will
not oe injured, etc
No, and the WeeVils will not be in
jured either.-the writer feels like
adding.
1t = not often that an experiment
station worker deems it advisable Oh
necessary to warn farmers agains
using = remedy that hundreds of peo-
pie have recommended. Recent eX-
perime1ts, however, have forced the
writer % doubt the value of carbon
hlSulpnlde as a remedy for corr
WeeVils, under ordinary farm condi-
tions. The trouble is With the corr
cribs and grain boxes, not with the
carbon hisulphide. The farmer does
not usually have time to make care
ful experiments, but depends on the
recOn7n1 endatiOns of prominent writer's
who nave supposedly known what
they were writing about The fact is
however. that most of us have failed
to emp hasize the fact that the vapor
Of carbon bisulphide must be abso-
lutely confined. Former recommen-
dations have undoubtedly been mis-
leading and have Very probably re
suited in the useless expenditure OF
hundreds of dollars worth of this
fumigaLihg agent.
What Are the Facts?
1t : known that the adult corn
weeVils and in fact nearly all insects
may be killed by using one pound OF
carbon bisulphide for 1000 cubic feet
of space. for 80 hours, if the space is
absolutely air tight. allowed no es-
cape Of the poisonous vapOr. But
can corn cribs or grain boxes be found
that are air tight. or that can be made
so without prohibitive expense? No,
not one in q thousand. The question
then *. how much leakage occurs,
and how much material must be used
to overcome this loss? The writer
results recently secured, show con-
ClusiveIy that perfect results cannot
be Obtained by the use of 20 pounds
for q hours. in 1000 cubic feet OF
spoce. in grain boxes that are appar-
emily tight, ard, furthermore, in corn
cribs. I IS a practical lmpOsSlblllty,
without pains, trouble and eX-
penSe, 10 make them tight enough to
hold the poisonous vapOr. Even
where the sides and bottom of a grain
bin are tight it is almost impossible
to make the top equally so, and TINS
source Of loss must be taken into con-
The fumes of carbon
bisulpblde, although 2.64 times heavier
than a5r. are still liable to diffuse ike
any gas and in actual experience 1t
was found that they escape rapidly
through blankets or coverings usually
recommended for putting over corn
that = being fumigated.
The Common Corn Wecyils.
The TWO most common and best
know0 species Of corn weevils are,
first, the fy-weeyil, a small moth IN
It's aGQlt stage, more correctly nalHeo
the AnSoumOis grain moth, ana sec
ond, the small, b1ackish, hard winged
WeeVil, known as the rice-WeeVil more
abundant in eastern than in western
North Carolina. During May ana
June, the fly weevils, (moths) When
disturbed, often rise in great mum bers
from infested corn The rice WeeV1l
is more readily overlooked because
of It's small size and retiring habits.
destructive corn pest, known