REPORT OF THE ENTOMOLOGIST 225 



SESSIONAL PAPER No. 16 



is thoroughly done, the warbles in any given locality can be reduced to harmless' 

 proportions. Further, by the employment of a special man, the cost has been shown 

 to be very small, in Denmark from two to five cents per head. 



The best method of destroying the maggots is that of sqvieezing them out of the 

 warbles which can be easily done when they are ripe. The first examination and des- 

 truction should take place in April, and two others in May and June respectively. If 

 the skin is hard it may be softened by washing with a solution of salt and water, 

 using half a pound of salt to three gallons of water. The maggots may also be des- 

 troyed by smearing the warbles with a mixture of equal parts of kerosene and pine tar 

 carefully mixed. This mixture fills up the breathing pores of the maggot which dies 

 in consequence. This method, however, is to be less recommended than that of squeez- 

 ing out the maggots, and it should not be confused with the summer smearing of the 

 backs of the cattle which was formerly recommended, but which has been shown to be 

 useless as a preventive. Wherever it is possible cattle should be allowed to have access 

 to shade trees and water in the summer as the warble flies dislike water and are most 

 active in bright sunshine. 



TICKS ON HORSES. 



In the spring of 1910, and again in the present year (1911) specimens of ticks 

 were received which Dr. Nathan Banks kindly identified for me as Dermacentor albi- 

 pictus Packard. Mr. G. E. Parham of Penticton, B.C., found them on horses. 

 Through the co-operation of the Veterinary Director General of this Department, 

 further specimens were received from Mr. Ransom, of Vancouver, B.C., who took them 

 from a horse in quarantine at Huntingdon, B.C. This horse had been imported from 

 Elgin, Oregon, and had been running wild all winter. Dr. A. E. Moore, of the Veter- 

 inary Branch, also brought specimens obtained from elks imported into Quebec from 

 Wyoming, U.S.A. A study of the life history of this species was begun in 1910, but 

 the records unfortunately were lost. Egg laying commenced at the end of April, and 

 single females deposited from 3,000 to 5,000 eggs during the succeeding months of 

 May and June. These eggs were deposited in the characteristic manner and began to 

 hatch early in July. The young six-legged ' seed ticks ' soon climbed up the leaves of 

 grass and collected in large numbers on the tips of the leaves awaiting an opportunity 

 to reach the hairs of the host. When they reach the host such as a horse or elk they 

 crawl over the hair and attach themselves to such a place as the inside of the thighs. 

 Here they moult and now have eight legs. The males are more active than the females 

 which, after mating, increase in size and drop to the ground to deposit their eggs. 

 This species occurs throughout the northern parts of the United States where it has 

 been found on cattle, horses and certain wild animals such as the elk, upon which it is 

 common, and the moose. It has also been found on the beaver. 



Two methods of eradication are possible, namely, the destruction of the ticks on 

 the host and in the pasture. They may be destroyed in the pasture either by excluding 

 the horses and cattle for a certain length of time, thus starving out the ticks, this 

 method being called the rotation method, or by allowing the horses to have access to the 

 infested pastures and afterwards destroying the ticks upon the hosts by treating them 

 with certain washes or dips. For the destruction of the ticks upon the host the United 

 States Department of Agriculture* as the result of a long series of experiments 

 recommended an emulsion of crude petroleum made according to the following 

 formula : — 



Hard soap 1 lb. 



Soft water 1 gallon. 



Beaumont crude petroleum 4 gallons. 



* U.S. Dept. Agric. Farmers Bulletin No. 378. 1909. 

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