348 SANITARY ENTOMOLOGY 



range are frequently so heavily infested as to produce injurious effects. 

 One's attention is usually attracted to the lice on account of the rubbing 

 and biting of the animals which may in some cases become almost a 

 mania. The hair is frequently rubbed off in spots so as to expose the 

 skin in the regions where the lice are most abundant, notably around the 

 base of the tail and on the neck. 



Control Measures. — On farms where comparatively few horses are 

 kept the lice can most conveniently be brought under control by careful 

 grooming of the animals, and an occasional light application at grooming 

 time of lard with a small amount of kerosene added or raw linseed oil. 

 This treatment would undoubtedly answer in the case of army horses, al- 

 though it would probably be advisable in such instances as well as on 

 ranges where horses are raised extensively, to install dipping vats and 

 dip all animals twice at an interval of two weeks. The standard arsen- 

 ical solution is the best for this purpose. This treatment is also effective 

 against cattle lice. 



Where biting lice alone are concerned sodium fluoride can be applied 

 very conveniently and will give complete control with one application 

 at a very low cost. A powder gun may be employed and each animal 

 should be generally dusted using about one ounce. This is especially 

 adapted to the treatment of animals in the winter when the greasing or 

 wetting of the host is undesirable. It is the winter season, too, when 

 the lice are most abundant and injurious. 



IMPORTANT BIBLIOGKAPHICAL REFERENCES 



Bishopp, F. C, and Wood, H. P., 1917. — Mites and lice on poultry. 



U. S. Dept. Agr., Farmers' Bull. 801, pp. 1-26, May. 

 Bishopp, F. C, and Wood, H. P., 1917. — Preliminary experiments with 



sodium fluoride and other insecticides against biting and sucking lice. 



Psyche, pp. 187-189, December. 

 Hall, Maurice C, 1917. — Notes in regard to horse lice, Trichodectes 



and Haematopinus. Joum. Am. Vet. Med. A^soc, vol. 51, n. s., vol. 4, 



pp. 494-504, July. 

 Herrick, G. W., 1915. — Some external parasites of poultry. Cornell 



Exp. Sta., Bulletin 359, pp. 229-268, April. 

 Imes, Marion, 1918. — Cattle lice and how to destroy them. U. S. Dept. 



Agr., Farmers' Bull., pp. 1-27, February. 

 Lamson, G. H., Jr., 1916. — Some lice and mites of the hen. Conn. Agr. 



Exp. Sta., Storrs, Conn., Bull. 86, pp. 171-196, March. 

 Lamson, G. H., Jr., 1918. — Cattle lice and their control. Conn. Agr. 



Exp. Sta., Storrs, Conn., Bull. 97, pp. 1-17, November. 



