E-447 Issued September 1938 (Revised) Revised February 1942 United States Department of Agriculture Bureau of Entomology and Plant Quarantine in Cooperation with the Texas Agricultural Experiment Station THE CONTROL 0?^ CATTLE LICE 1/ By 0. G. Babcock and E. W. Laake , Division of Insects Affecting Man and Animals Cattle, are subject tc infestation by several species of lice. In Texas three species are common. Tv/c of these, the long-nosed cattle louse or so-called blue louse (Linognathus vituli (L.)) and the short-nosed cattle louse 2/ (Haematopinus eurysternus (Nitzsch)), have sucking mouth parts and obtain their food by drav/ing blood from the host animal. The last-named Icuse is much larger than the other species and appears to be more resistant than other cattle lice to ordinary applications of insecti- cides. It has the habit of congregating in patches on the neck, dewlap, head, poll-, ears, tail, escutcheon,' etc. Several of the ' large yellowish eggs are attached to each hair. Considerable areas may be covered with these eggs. Upon hatching, the young lice soon attach to the skin and remain relatively quiet until they are full-grov/n, at which time they begin crawling about, mate, and seek new locations or hosts. The other species, the biting, or so-called red louse of cattle (Bovicola bovis (L.j), has mouth parts fitted for chewing and obtains its food by gnawing at the skir.'s surface: One or all species of lice may be present on calves or cows at any given time and may seriously retard the growth of calves. Lice may be found upon almost any part of the animal. In heavy infestations the entire body is likely to be affected. Blue lice are easily seen c white or light-colored skin of cattle; they are conspicuous on the ncoe or face of cattle of the Hereford breed. Cattle lice do not live apart from the host in pens or pastures but spend their entire lives on the animals. They pass from one host to another readily v;hen the animals come in contact with each other. When a lousy animal is rubbed by ar.cther, the sexually mature lice instinctively move outward on the hair and may attach themselves to the hair of any cow or calf that comes in direct contact with the host animal. In this way ycung calves become infested- very soon after birth. When lice find a new host they crawl about for a time, but soon settle down to feed and reproduce. The eggs arp attached firmly to the hairs, and the young lice that hatch from them resemble the adults but are light colored. 1/ Prepared especially for 4-H Club Members. 2/ Sometimes known locally as the gray louse or the black louse - 2 - CONTROL Where large numbers of cattle or calves are to be treated, dipping is recommended, but where only a few are involved, as is generally the case with animals under the care of 4-H Club members, other methods are simpler and more economical. The most practical of these laethcds for 4-H Club members appears to be the application of powdered insecticides by hand. Hand Applications Derris and cube powdar containing 5 percent of rotenone are probably the most efficient insecticides for the destruction of all species of lice on cattle. The powder should be diluted in the proportion of 1 to 10 with some material like kaolin, wheat flour, talc, or .325-mesh wettable sulfur. A sufficient amount of the mixture should be used to dust the animal thoroughly. The quantity required will vary with the size of the animal. The powder should be applied evenly over the body and v/ell rubbed in by hand on all hairy parts of the animal, including the tail. Although this mixture will not kill all the eggs of cattle lice, it appears to be considerably more efficient in this respect than insecticides formerly recommended. When an insecticide does not have good egg-killing properties and more than one treatment is required to control the insects, it is desirable to space the interval between treatments to coincide as closely as possible with the incubation period of the eggs. With the wettable sulfur and cube or derris powder mixture, usually one treatment, or two treatments given 12 to 14 days apart, will rid an anim.al of the long-nosed and red lice; but if the short-nosed cattle louse is also present the best procedure is to give two treatments separated by an interval of 17 or 18 cays. After the second treatment the animals should be examined frequently, and if live lice are found a third treatment should follow the second in about 18 days. Another schedule of treating which has given good results where all three kinds of lice are present is: Second treatment 12 to 14 days after first. Third treatment 17 to 21 days after first. Wettable sulfur that will pass through a 325-mesh screen, or finer, used by itself, is effective in killing the long-nosed cattle louse and the red louse when thoroughly dusted and rubbed into the hair. One or two pounds of the sulfur is required per animal, and it should be applied dry. Two applications, 12 to 14 days apart, are usually necessary, but sometimes one treatment will rid an animal of these species. Commercial sodium fluoride applied as a powder in the same way as derris, at the rate of 1 to 2 ounces per animal, is effective for killing biting lice. It may also be applied as a wash, using 1 ounce to a gallon of water. This material is poisonous and therefore should not be allowed to get into drinking water or feed. Also it should not be applied closely around natural openings in the body and head of animals, and care should be taken not to apply it too freely. - 3 - Dipping and Spraying Wettable sulfur plus cube or derris powder (containing not less than 5 percent of rotenone). at the rate of 100 pounds of sulfur and 10 pounds of cube or derris to 1,000 gallons of water, used as a dip, will control biting and sucking cattle lice. Previously it has been considered that under normal conditior.s the insecticidal potency of the cube or derria powder in this dip deteriorates rapidly after 5 to 7 days and that it was necessary to add another charge of this material to the dip if it had been exposed longer than this period. It has been found recently, however, that in the vicinity of Dallas and Fort Worth, Tex., during the months of November and December cube powder in the dip does not lose its strength as quickly as formerly supposed. All the motile forms of long- and short-nosed cattle lice were killed in a dip that was exposed for 18 days in a regular dipping vat, and in which several hundred animals had been dipped. ?;ettable sulfur, when used alone as a dip at the rate of 100 to 150 pounds to 1,000 gallons of water, will control the long-nosed cattle louse and the red louse. Arsenical dip is also effective in killing both biting and long-nosed sucking cattle lice when used in a regular dipping vat, The dip should test 0.18 to 0.20 of 1 percent of water-soluble arsenic. 3/ In cases where animals are infested with short-nosed as well as long-nosed and biting lice the best results with arsenical dip are obtained when all infested cattle are dipped at least three times at intervals of 15 to 16 days. Special care should be taken not to allow any livestock to have access to the vat or the dip except in the regular course of dipping, as the animals are likely to drink the dip and become poisoned. Where it is necessary to treat only a few animals, they may be thoroughly sprayed with a solution containing the same ingredients and in the same proportion as those used in the dips. When arsenical dip is sprayed, care should be taken that neither the animal nor the operator breathes the spray. The operator should also be careful not to get his clothing wet with the spray. The number of treatments and the interval between Ihera should be the same in dipping or spraying animals as these reccinmended under "Hand Applications." 3/ For details concerning arsenical dipping, see Farmers' Bulletin 909, U. S. Department of Agriculture, "Cattle Lice and How to Eradicate Them," by Marion Imes. Ilimln,^,'?.^,'7^ °^ FLORIDA fSlimii 3 1262 09223 0381