ST, F Lkn
December 1946 E-708
United States Department of Agriculture
Agricultural Research Administration
Bureau of Entomology and Plant Quarantine
A NEW TREATMENT FOR SCREWORMIS IN LIVESTOCK
By C. S. Rude and 0. H. Graham
Division of Insects Affecting Man and Animals
A new treatment for screwworm-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 satis-
factory 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 EQ smear 82, is composed of
the following ingredients:
Parts by weight
Benzene *..... . .......*........** ....35
Triton X-300 (sodium salt of an
alkylated aryl polyether sulfate)... 2
Lampblack.............e o .... g.o......21
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 commercial 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 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
be stirred in gradually. Mixing should be continued until the
compound is smooth in texture. The resulting smear should be of
about the sae 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 materia,:l
well down into 'he pockets made by the maggots. The area around
the wound where blood and wound exudate have made the animal
attractive to ies and susceptible to infestation should be
It is not necessary to remove the dead worms from the wound.
However, rnman v- f the larger dead worms may be removed by vip;
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 b- shear
cuts, castration, dehorning., dock-4-, and wire outs, it is
sufficient to cover the raw tissue and surrounding area thorir Ily
with a coating of the smear. In treating castration wounds so(lt
of the material should be pushed slightly into the openings on both
sides of the scrotum.
This r-emed, kills sorewworms 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 reb.on
it is a good practice to make a second application from 24 to 4
hours after th first to insure proper coating of the wound, ere-
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 freqi,-nt treatments may be necessary.
Prec -itons in preparing and Using This Smear
Prepare the r'-Nmdi well away from open flames and do not have
lighted ci. arti.es or cigars around during the process.
,-ie bn- in the smear is highly volatile and will evaporate
quickly if lel in an open container. It is therefore advisable
that the smear 'e kept tightly covered in a cool place when not in
use. It is a,. recommended that only enough for a few days' use
be removed at time from the larger supply container. Even while
animals are be ig treated, the container should be kept covered as
much as possible. In case the smear, through 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 getting
the smear into the unaffected parts of the eyes, as the material is
irritating. If this is done accidentally, it is advisable to wash
the eyes immediately with water.
Do not add oil, grease, or any other substance to the formula,
or its efficiency will be greatly impaired, if not entirely destroyed.
UNIVERSITY OF FLORIDA
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