116 APPENDIX. 



Applications to Destroy the Fly. — A great deal has been said 

 daring the summer concerning the merits of a proprietary substance, 

 consisting mainly of tobacco dust and creosote, known as "X. 0. Dust,'' 

 and manufactured by a Baltimore firm, as an application to cattle, and 

 it has received an indorsement from Prof. J. B. Smith, entomologist of 

 the New Jersey Experiment Station. We are convinced that this sub- 

 stance has considerable merit as an insecticide, and know from experi- 

 ence that it will kill many of the flies when it touches them, although 

 they die slowly, and a few may recover. The substance costs 2.5 cents 

 a pound, and is not lasting in its efifects. Where it is dusted through 

 the hair, the flies on alighting will not remain long enough to bite, but 

 two days later, according to our experience, they are again present in 

 as great numbers as before. A spray of kerosene emulsion directed 

 upon a cow would kill the flies quite as surely, and would be cheaper, 

 but we do not advise an attempt to reduce the number of the pests by 

 actually killing the flies. 



How TO Destroy the Eakly Stages. — Throwing a spadeful of lime 

 upon a cow-dung will destroy the larvae which are living in it, and as in 

 almost every pasture there are some one or two spots where the cattle 

 preferably congregate during the heat of the day, the dung which con- 

 tains most of the larvae will, consequently, be more or less together, and 

 easy to treat at once. If the evil should increase, therefore, it will well 

 pay a stock raiser to start a load of lime through his field occasionally, 

 particularly in May or June, as every larva killed then represents the 

 death of very many flies during August. We feel certain th^ this 

 course will be found in many cases practical and of great avail, and 

 will often'be of great advantage to the pasture, besides. 



Kansas Notes. — The Horn Fly occurs in France, and perhaps 

 elsewhere in Europe. It was first noted in America in 1887. Dr. 

 S. W. Williston, in an article entitled "A New Cattle Pest, " 

 American Naturalist, vol. xxiii, p. 584, says : 



On October 5, 1887, I received from Professor Cope specimens of a 

 fly taken from the cattle of Mr. Thomas Sharpless, of West Chester, Pa., 

 with the information, shortly afterward, that the flies had been observed 

 during the year at that place in small swarms. . . . The flies, I was 

 also told, were observed the same year on the land of Mr. George Pim, 

 of Marshallton, Chester county. I am thus particular in giving the 

 facts as told to me, for this is the first record, of which I am aware, of 

 the introduction from Europe of a cattle pest that bids fair to extend 

 itself over the whole United States, and be as troublesome as its nearly 

 related pest, the well-known Stable Fly, or Cattle Fly. also European 

 originally. Stomoxys calcitrans Linn. 



In September, 1887, specimens were sent to Dr. Riley from 

 Camden, N. J. The following year the pest was reported from 

 the same place, and also from Harford, Md. 



