BUREAU OF ENTOMOLOGY. 335 



near Sonora. It is the purpose to put into actual practice on the 

 ran<^e these control principles which have been more or less fully 

 worked out, and observe the results. These practices consist mainly 

 of (1) carcass burning, (2) trapping of flies, (3) poisoning of flies, 

 (4) avoidance of screw-worm attack through various modified range 

 practices, and (5) the development of a satisfactory larvicide and 

 repellent for use on w^ounds. 



During the latter part of the year an active cooperative arrange- 

 ment was entered into with the Texas experiment station. In the 

 future the field work will be carried on at the Texas substation No. 

 14, near Sonora, Tex. 



The difHculty of securing an effective and convenient bait for use 

 on the ranges has been largely solved by the production of dried 

 gut slime. The fresh slime, a by-product of the meat-packing houses, 

 has been used with much success as a blow-fly bait for several years. 

 The discovery that this product can be greatly concentrated and 

 made available for shi])ment through drj'ing and at the same time 

 retain most of its attractive principles is an important step forward. 



Considerable progress has been made in the development of more 

 eflicient repellent mixtures for wounds. 



Horseflies.— The investigation of the horsefly problem in the South- 

 west, in coope'ration Avith the Xevada experiment station, was discon- 

 tinued with the close of the last season. The life history and habits 

 of the principal species were rather fully studied. Many control 

 measures suggested w^ere found to be impracticable under ranch con- 

 ditions. It was rather conclusively shown that the drainage of the 

 swampy areas and the substitution of more intensive cultivation of 

 the farmed areas, substituting alfalfa, grain, etc., for the native grass 

 meadows, will be necessary to reduce materially the losses from these 

 flies. 



Ox loar'hles. — Work on the two destructive species of ox warbles 

 has been continued in various parts of the United States. Further 

 experiments have been carried out which will prove that the larvae 

 hatch antl penetrate through the skin on the heels or elsewhere where 

 the eggs are laid. ^loreover, these larvse, at least in part, go to the 

 gidlet of the host before passing to the subcutaneous tissues of the 

 back. A large amount of information on other points in the life 

 history, seasonal history, distribution, and injuriousness of the pests 

 has been obtained. Experiments have also shown that the larvae 

 can be effectually and economically destroyed by placing certain com- 

 ])()unds in the holes in the hide on the backs of cattle. 



PouJtrii panmltis. — A species of mite {Liponyssiis sylv'iarum), not 

 heretofore known as a poultry pest, has been found to occur in inju- 

 1-ious numbers in several flocks of chickens in different parts of the 

 United States. An effective control method has been develojied. and 

 eradication pVoved possible through its actual accomplishment in 

 one heavily infested flock. 



The depluming mite of fowls has been studied and a simple and 

 effective remedy found. 



Insects ami hog cholera.— T)\\v\u<i, the sunnner of 101!) an agent 

 was assigned to cooperate with the Bureau of Animal Industry in 

 studying the possible transmission of hog cholera by insects. Earlier 

 work of the Bureau of Animal Industry showed that both the house 



