ECONOMIC ZOOLOGY ENTOMOLOGY. 257 



systonintic arrangeniont tbo ticks are divided into 2 subfamilies, Argasinjip, 

 and Lvodinje. A considerable number of species are referred to these families 

 as occurring in Great Britain. These include Argaa reflextis, Ornithodorus 

 megninl, Ixodes hexagonus, I. ricinus, and species of Hyalomma, Ilifmaphy- 

 salis, Dermacentor. and other genera. 



How to get rid of cattle ticks. A. D. Melvin (U. »S'. Dept. Agr., Bur. Anini. 

 Indus. Circ. 97, pp. .'/. fig 1). — Attention is called to the importance of active 

 cooperation between local officials in various States south of the Texas fever 

 quarantine line and the Bureau of Animal Industry for the purpose of eradi- 

 cating ticks. 



The eradication i>f licks is believed to be possible if all suggested precautions 

 are taken. Cattl(> and premises may be freed from ticks by hand picking the 

 cattle and destroying the ticks, after- which the cattle maj' be thoroughly 

 greased. Infested cattle should be examined every other day, attention being 

 given to the inside and back portion of the thighs, wher(> the ticks are liable to 

 be most numerous. For greasing the cattle, crude oil is recommended, or 

 cotton-seed oil, fish oil, or lard. Whei-e a farmer owns but a few head of cattle, 

 the cattle may be picketed on tick-free i)asture and occasionally moved, taking 

 care to avoid these localities for 9 months thereafter. 



Another method recommended is the rotation system and requires two fields. 

 The cattle are removed from the pasture by September 1 and no animals are 

 allowed on this pasture until March 15 of the following year. Before the 

 cattle are allowed to go back into the original i)asture they should be carefully 

 examined for the presence of ticks. 



Tests of dips as lice killers, L. L. Lewis {Oklahoma Sia. Bui. 72, pp. 8). — 

 The importance of dips in combating parasites on cattle has long been recog- 

 nized, and a number of these dips were tested by the author in controlling lice 

 and cattle ticks. 



In experiments with coal-tar ])repnrations it was found that the dips were 

 more effective when used at temperatures of TO to 80° F. than when applied 

 cold. Lice were usually found dead within from 3 to 10 hours after cattle and 

 horses were dipped. Hogs may be regularly dipped, like other animals, or a 

 wallowing vat may be provided containing a small (juantitj- of crude oil on the 

 surface of the water. ^Yhen this is done, the hogs keep themselves free from 

 lice. Most of the coal-tar dips, which were tested, failed to kill the lice eggs, 

 but kerosene emulsion was more effective in this respect. 



Farmers who own but a small number of cattle will find it too expensive to 

 construct vats especially for dippping. For these small owners it is desirable 

 that cattle be regularly insjiected about every 2 weeks from July to September, 

 and hand treated with crude petroleum or kerosene emulsion, after the large 

 ticks have been picked off. 



The effectiveness of pasture rotation in controlling ticks is also mentioned 



The economical preparation of the sulphur-lime spray, R. W. Thatcher 

 (WasJiiiigtoii Shi. Bill. 7il. pp. 16). — It is considered that the efficiency of the 

 lime-suli)hur wash is demonstrated and that at present experiments may well 

 be directed toward the i)reparation of this insecticide more cheaply. 



A chemical study was made of the reactions which take place in the prepara- 

 tions of the lime-sulphur wash according to various formulas. From this study 

 it appears that lime-sulphur wash contains 2 sohiltle compounds, viz. penta- 

 sulphid and thiosidphate of calcium. The relative amounts of these 2 com- 

 l)ounds are about the same in sprays prei)ared by any of the formulas and are 

 not influenced by the presence or absence of salt. Blue vitriol, on the other 

 liand, combines with the pentasulphid compound rendering it insoluble. Cal- 



11125— No. 3— Otj M 5 



