38 PROTECTION OF PLANTS. 1917-18 



together and dangling loosely on each side of the animal. These nets are quite 

 satisfactory in warding off G. intestinalis, which, as has been stated, is not partic- 

 ular as to the region where it strikes. For haemorrhoidalis, western farmers gener- 

 ally protect their horses' noses by a wire-screen muzzle, which has the disadvant- 

 ages of being clumsy and also of interfering with respiration. A nose-band of 

 leather, cut into strips of about three-sixteenths of an inch wide and buckled on 

 to the head-stall so that the strips hang down loosely, will nonplus the attacks of 

 haemorrhoidalis as it "strikes" up from below. By attaching a canvas flap from the 

 nose-band to the throat, it will be found that the animal is amply protected 

 against nasalis. 



References. 



1. Curtice, C. The Larvae of Hypoderma hovis, DeGeer. Insect Life, 



V. 2, Jan. and Feb. 1890, pp. 207, 208. The Ox-warble of the United 

 States. Jour. Comp. Medicine, v. 12, 1891. 



2. Schaupp, F. G. In "The Ox Bot in the United States," by C. V. Riley. 



Insect Life, vol. IV, p. 306, 1892. Schaupp is the anonymous observer 

 referred to by the author. See, Hadwen Jour. Econ. Ent., vol. X, No. 4, 

 p. 447, 1917.' 



3. Carpenter, G. H., Hewitt, T. R., The Warble-flies. Fourth Report on 



Experiments and Observations as to Life-history and Treatment. 

 Jour. Dept. Agr. & Tech. Instr., Ireland, vol. 15, no. 1, pp. 105-132. 



4. Hadwen, S. Warble-flies, the Economic Aspect and a Contribution on the 



Biology. Bull. No. 16, Health of Animals Branch, Dept. of Agr. Canada, 

 1912. 



5. Hadwen, S. The Seasonal Prevalence of Hypoderma hovis in 1915. 46th 



Ann. Rept. Ent. Soc. Ont., 1915, pp. 108-115. 



6. Hadwen, S. A Further Contribution on the Biology of H. lineatum. Bull. 



No. 21, H. of A. Branch. Dept. of Agr. Canada, 1916. 



7. Hadwen, S. and Bruce, E. A. Observations on the Migration of Warble 



Larvae through the Tissues. Bull. No. 22, ibid., 1916. 



8. Hadwen, S. and Bruce, E. A., Anaphylaxis in Cattle and Sheep Produced 



by the Larvae of H. hovis, H. lineatum and Oestrus ovis. Jour. Amer. 

 Vet. Med. Assoc, vol. 4, n.s.. Vol. LI, No. 1, pp. 15-41, 1917. 



9. Clark, Bracy. Observations on the Genus Oestrus. Trans. Linn Soc, 



London, 1797, vol. 3, pp. 289-329. 



10. Clark, Bracy. An Essay of the Bots of Horses and Other Animals. London, 

 1815. 



