ENTOMOLOGY

.848 SANITARY ENTOMOLOGYrange are frequently so heavily infested as to produ~e injurious effects.One's attention is usually attracted to the lice on account of the rubbingand biting of the animals which may in some cases become almost amania. The hair is frequently rubbed off in spots so as to expose theskin in the regions where the lice are most abundant, notably around thebase of the tail and on the neck.Control Measures.-On farms where comparatively few horses arekept the lice can most cQIlveniently be brought under control by carefulgrooming of the animals, and an occasional light application at groomingtime of lard with a small amount of kerosene added or raw linseed oil.This treatment would undoubtedly answer in the case of army horses, althoughit would probably be advisable in such instances as well as onranges where horses are raised extensively, to install dipping vats anddip all animals twice at an interval of two weeks. The standard arsenicalsolution is the best for this purpose. This treatment is also effectiveagainst cattle lice.Where biting lice alone are concerned sodium fluoride can be appliedvery conveniently and will give complete control with one applicationat a very low cost. A powder gun may be employed and each animal'should be generally dusted using about one ounce. This is especiallyadapted to the treatment of animals in the winter when the greasing orwetting of the host is undesirable. It is the winter season, too, whenthe lice are most abundant and injurious.IMPORTANT 1I111LIOGRAPHICAL REFERENCESBishopp, 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 withsodium fluoride and other insecticides against biting and sucking lice.Psyche, pp. 187-189, December.Hall, Maurice C., 1917.-Notes in regard to horse lice, Trichodectesand Haematopinus. Journ. Am. Vet. Med. Assoc., vol. 51, n. s., vol. 4,pp. 494-504, July.Herrick, G. W., 1915.-Some external parasites of poultry. CornellExp. 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. Stn., Storrs, Conn., Bull. 97, pp. 1-17, November.