December 1946 S-708 
 
 United States Department of Agriculture 
 Agricultural Research Administration 
 Bureau of Entomology and plant Quarantine 
 
 A NEW TREATMENT FOR SCREWWORKS IK LIVESTOCK 
 
 By C. S. Rude and 0. H. Graham 
 Division of insects Affecting Man and Animals 
 
 A new treatment for screwworm-inf ested 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 sinoe 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 reoent 
 years, and many of the supplies obtained have been off-grade. 
 
 Preparation 
 
 The new remedy, whioh is oalled EQ smear 82, is composed of 
 the following ingredients: 
 
 Parts by weight 
 
 Diphenylamine .32 
 
 Benzene 35 
 
 Triton X-300 (sodium salt of an 
 
 alkylated aryl polyether sulfate).., 2 
 
 n-Butyl alcohol. 10 
 
 Lampblack. 21 
 
 The grade of lampblack used in this formula is that ordinarily 
 sold by lumber yards and paint stores for tinting paints. Lampblaok 
 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 
 
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 be etirred 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-inf ested 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 
 thoroughly painted. 
 
 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, oastration, dehorning, dock^g, and wire outs, 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 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 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, tuider 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. Mien flies are unusually active and abundant, 
 more frequent treatments may be necessary. 
 
 Precautions in Freparing and Using This Smear 
 
 Prepare the remedy well away from open flames and do not have 
 lighted cigarettes or cigars around during the process. 
 
 x he 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 oovered 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 larger supply container. Even while 
 animals are being treated, the container should be kept covered as 
 
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 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 
 
 3 1262 092sW 546^