Imes (M.). Cattle Lice and how to eradicate them. — U. S. Dept. Agric.,'^'^ 

 Washington, D.C., Farmers' Bull. no. 909, February 1918, 26 pp., 

 14 figs. [Received 17tli May 1918.] 



The cattle lice dealt with in this bulletin are Haematopinus eury- 

 sternus (short-nosed cattle louse), Linognathus vituli (long-nosed cattle 

 louse) and Trichodectes scalaris (common biting louse of cattle). The 

 life-histories of these species have been previously dealt with [see 

 this Review, Ser. B, v, p. 168]. When separated from their hosts 

 the biting lice live about 7 days, the sucking lice only about 4 days. 

 Newly hatched lice Uve only 2 or 3 days, unless they find a host. The 

 longevity of the lice and the viabiKty of their eggs when separated 

 from the host have an important bearing on the problem of eradication. 

 Parasites becoming dislodged from animals drop in stables and pastures, 

 and though they die within a week or so, eggs so dislodged may con- 

 tinue to hatch if the weather is mild and thus be the means of tem- 

 porarily infesting the premises. All infested stables should be cleaned 

 and then disinfected by spraying with any of the coal-tar creosote 

 dips diluted to suitable strength. 



There are many insecticidal dusting powders containing naphthaline 

 and pyrethrum that are helpful in keeping the parasites in check 

 during the season when the weather is too cold for dipping or spraying, 

 but they are not recommended as successful remedies for eradicating 

 cattle lice. Hand appUcation may be useful when a few animals 

 only have to be treated ; effective remedies of this description include : 

 (1) cottonseed oil and kerosene in equal parts ; (2) |- pint kerosene 

 to 1 lb. lard ; (3) crude petroleum ; (4) any of the dips recommended 

 for use in dipping. 



Spraying and dipping operations are described ; the necessary 

 apparatus is explained and a plan of dipping plant is included. 

 Instructions are given for preparing an arsenical dip composed of 

 4 lb. caustic soda (85 per cent, pure), 8 lb. white arsenic (99 per cent, 

 pure) in fine powder ; 8 lb. sal soda crystals ; 1 gal. pine-tar ; water 

 sufiicient to make 500 U.S. gals. 



One treatment with arsenical or coal-tar creosote dip is usually 

 sufficient to eradicate L. vituli and T. scalaris, but for H. eurysternus 

 the animals should be given two treatments at 15-16 days interval. 

 After the second dipping the cattle should be examined frequently, 

 and if any lice remain aUve, a third treatment should be given about 

 16 days after the second. 



Creel (R. H.) & Simpson (F.). Rodent Destruction on Ships. — U.S. 

 Public Health Service, Washington, D.C., Reprint no. 423 from the 

 Public Health Reports, 7th September 1917, 7 pp. [Received 

 6th May 1918.] 



Tests recently carried out at New Orleans imder natural conditions 

 to determine the relative efficiency of sulphur dioxide and cyanide 

 gas as fumigants for destroying rats in ships showed that cyanide 

 fumigation resulted in the destruction of 95 per cent., whereas sulphur 

 dioxide destroyed only 77 per cent. , notwithstanding the fact that the 

 duration of the exposure to sulphur fumes was 6 hours, compared 

 with 1| hours or less when the cyanide was used. The method by 

 which these data were obtained was that of trapping the rats on 



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