January 1947 E-708 (Revision) /
.. 7 RY
STATE L -5. )ARDUnited States Department of Agriculture
ATAT F agricultural Research Administration
Bureau of Entomology and Plant Quarantine
A NEW TREATMENT FOR SCREWWORM IN LIVESTOCK
By C. S. Rude and 0. H. Graham
Division of Insects Affecting Man and Animals
A new treatment for sorewworm-infested livestock has been developed
at the Menard, Tex., laboratory. Although not superior to smear 62, which
was developed at the same laboratory a few years ago and since that time has
been the recommended treatment, it is nevertheless a satisfactory substitute
and should be used if satisfactory materials are not available to make smear
62. Turkey red oil, one of the ingredients of smear 62, has been scarce in
recent years, and many of the supplies obtained have been off-grade.
The new remedy, which is called BQ smear 82, is composed of the following
ingredients (figures in parts by weight):
Triton X-300 (sodium salt of an
alkylated aryl polyether sulfate)..2
The grade of lampblack used in this formula is that ordinarily sold
by lumber yards and paint stores for tinting paints. Lampblack appears to
increase the killing action of benzene and to impart a greater efficiency
to diphenylamine for protecting the wound against infestation. The com-
mercial grade of the other ingredients is used.
The diphenylamine is dissolved in the benzene, preferably by placing
the two substances together and allowing them to stand 12 to 24 hours.
Solution can be hastened by placing the container in a vessel of hot water
and leaving the container uncovered. An open flame should never be used,
since benzene is highly inflammable.
The Triton X-300 formerly produced contained 20 percent of active
ingredient, whereas the present commercial product contains 30 percent.
It will take some time to determine whether this change will affect the
performance of the formula. However, the 30-percent material may be
diluted to 20 percent by adding 1 volume of water to 2 volumes of the
more concentrated product.
The Triton X-300 and the n-butyl alcohol should be placed in a
tight container and agitated vigorously until thoroughly mixed.
This mixture should be added to the diphenylamine-benzene solution
and the combined mixtures shaken again. The lampblack should then
SThis revision should be substituted for E-708, issued in December 1946.
be stirred in gradually. Mixing should be continued until the
compound is smooth in texture.* The resulting smear should be of
about the same consistency as thin pancake batter. It is then
ready for use.
Use of the Remedy on Wounds
The smear should be applied to the screwworm-infested wound
with a 1-inch paint brush, care being taken to push the material
well down into the pockets made by the maggots. The area around
the wound where blood and wound exudate have made the animal
attractive to flies and susceptible to infestation should be
It is not necessary to remove the dead worms from the wound.
However, many of the larger dead worms may be removed by wiping
with the brush. If the worms are removed, the wound should be
re-treated before the animal is released.
To protect uninfested wounds, such as those caused by shear
cuts, castration, dehorning, docking, and wire cuts, it is
sufficient to cover the raw tissue and surrounding area thoroughly
with a coating of the smear. In treating castration wounds some
of the material should be pushed slightly into the openings on both
sides of the scrotum.
This remedy kills screwworms quickly, and after its application
large numbers of them may drop out of the wound, carrying a consider-
able amount of the protective chemical with them. For this reason
it is a good practice to make a second application from 24 to 48
hours after the first to insure proper coating of the wound. There-
after, under average conditions, regular treatments twice each week
should be given until the wound is healed. It is recommended that
infested animals be kept in a hospital pasture where this schedule
may be followed. Vhen flies are unusually active and abundant,
more frequent treatments may be necessary.
Precautions in Preparing and Using This Smear
Prepare the remedy well away from open flames and do not have
lighted cigarettes or cigars around during the process.
The benzene in the smear is highly volatile and will evaporate
quickly if left in an open container. It is therefore advisable
that the smear be kept tightly covered in a cool place when not In
use. It is also recommended that only enough for a few days' use
be removed at a time from the larr supply container. Even while
animals are being treated, the container should be kept covered as
much as possible. In case the smear, thr.Li,,] evaporation, becomes
too thick for easy application, additional benzene may be stirred in
to restore its original consistency.
,When infestations near the eyes are being treated, avoid gett1
the smear into the unaffected parts of the eyes, as the material is
irritating. If this is done accidentally, it is advisable to ;ash
the eyes immediately with water.
Do not add oil, grease, or an, other substance to the forulua,
or its efficiency will be greatly :-,i'vh r x., if ot ;ttirely destroyed.
UNIVERSITY OF FLORIDA
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