1910.] Prevention of Damage to Hides, etc. 623 



of some experiments carried out for the Irish Department of 

 Agriculture and Technical Instruction by Professor G. H. 

 Carpenter and Mr. J. W. Steen, and has resulted in a sub- 

 stantial reduction in the prevalence of the fly. In 1907, 2,090 

 maggots were squeezed out of 194 cattle on the farm where 

 the investigation was being conducted, an average of 1077 

 per beast. In the spring of 1908, 132 of these cattle were still 

 on the farm, and had been left throughout the summer of 

 1907 without any kind of dressing or protection against the fly. 

 From these cattle 586 maggots were squeezed out, an average 

 of 4*44 per beast, and this reduction was thought to be due 

 to the destruction in the previous year. In 1909, however, the 

 proportion rose to 7*77, while in 1910 it was 7*52. The con- 

 clusion arrived at is that systematic maggot destruction in the 

 spring will reduce the liability of the cattle to infection to a 

 certain extent, but that the benefit will be limited until similar 

 steps for the destruction of the maggots are taken on neigh- 

 bouring farms. For this reason the cattle grazing on the 

 outskirts of the farm suffered much more than those near the 

 centre of the farm. 



The Board would suggest that Agricultural Societies and 

 Farmers' Clubs should urge their members to adopt this plan, 

 which is certain in its results, and more effective than the 

 use of strong-smelling dressings with the idea of deterring 

 the flies from laying their eggs. The use of these dressings, 

 though they have long been recommended, appears in the 

 light of recent investigations to be of doubtful efficacy. As 

 was stated in this Journal in November, 1906, p. 484, Pro- 

 fessor Ostertag, the German authority, does not approve of 

 the method, and said that no case was known to him where 

 good results had been attained by it. Ostertag expressed the 

 view that the only useful means of combating the warble fly 

 is to extract the immature bots from the warbles and destroy 

 them. This may be done, he says, by opening the warbles 

 with a sharp knife and removing the bots ; the scar in the 

 hide will heal over smoothly and loss will not occur as is the 

 case when the bots themselves drill the holes. 



The Life History of the Warble Fly is described in Leaflet 

 No. 21, but there are several points in this connection on 

 which considerable uncertainty prevails, and the matter is at 



