38 



Tick Eradication. — Jamaica Dept. Agric. Ann. Rept. for Year ended 

 31st March 1918, Kingston, 1918, pp. 24-26. [Received 

 5th December 1918.] 



As the result of Professor Newstead's visit to Jamaica in 1909 to 

 study the tick problem, a very successful liquid for spraying cattle 

 waf- introduced in which arsenic in the form of Cooper's Dip was 

 added to a solution of paraffin-naphthaline or paranaph. In 1913, 80 

 per cent, sodium arsenite was adopted as the source of arsenic and 

 has proved to be the cheapest, most convenient and most effective 

 form to use. A new, single -solution dip has been put on the market 

 ■containing sodium arsenite and certain en\ulsifying ingredients, but 

 this, though having the practical advantage of greater simplicity in 

 jjreparation, has only 80 per cent, of the efficiency of the above mixture. 



At the beginning of the tick eradication campaign, the only method 

 employed was that of spraying, but in 1913 it was recognised that 

 dipping tanks were necessary for dealing with large herds of cattle, 

 and in 1915 a tank was constructed at a cost of £25, though subsequent 

 modifications and improvements brought its cost up to £00. In 1918 

 several planters decided to erect tanks, and a commission for the 

 erection of seven has been received from a single proprietor. 



The departmental dipping liquid is based on a standard content 

 of 2 lb. of 80 per cent, sodium arsenite per 100 gals., experience having 

 shown this to be the optimum strength for tick-destruction in Jamaica, 

 and the emulsifying effect is obtained by the addition of 3 lb. paranaph 

 per 100 gals, liquid. The pre-war cost of this solution was Is. Id. per 

 100 gals., or less than one-sixth that of the proprietary dips on the 

 market. During 1917 the whole of the herd on the Government 

 Stock Farm was dipped IG times, or about every 3 weeks, the average 

 cost of dipping for the year being only two-pence per head. Regular 

 dipping is carried out as a preventive measure, the occurrence of 

 ticks on cattle being rare, though there is always the risk of infestation 

 from neighbours' lands and from horses and mules. 



The dipping of horses and mules in a cattle dipping tank is somewhat 

 risky, and though it has been safely dene on the stock farm, control 

 of the tick is generally eifected in this case by spraying and painting 

 wdth sheep-wash. At tlie same time ticks derived from equines do 

 not impart tick-fever and they are therefore not dangerous to cattle. 



A remarkable feature of dipping is the way in which long-haired 

 cattle are completely freed from ticks, no previous clipping being 

 necessary, as is the case when spraying is carried out. 



For use as a spray the standard wash consists of : — Sodium arsenite 

 1 oz., paranaph 2 qts. or 5 lb., water 12 qts. An economical commercial 

 wash for use as a spray consists of : - Sodium arsenite 3^ oz., paranaph 

 1 lb., water 10 gals., tank or rain water being used if procurable. The 

 -dip for use in dipping tanks contains sodium arsenite 2 lb., paranaph 

 3 lb., water 100 gals. 



EiTCHiE (A. H.). Annual Report of Entomologist. — Jamaica Dept. 

 Agric. Ann. Rept. for Year ended 31st March 1918, Kingston, 1918, 

 pp. 34-40. [Received 8th December 1918.] 



In the rice-growing districts the drainage of the land, if carried 

 out extensively, would act as a considerable control of mosquitos 



