UNITED STATES DEPARTMENT OF AGRICULTURE 



!n cooperation with the Nevada Agricultural Experiment Station 



DEPARTMENT BULLETIN No. 1218 



y^HftffiW. 



Washington, D. C. 



July 21, 1924 



HORSE-FLIES: BIOLOGIES AND RELATION TO WESTERN AGRICULTURE. 



By J. L. Webb and R. W. Wells, Entomologists, Investigations of Insects 

 Affecting the Health of Animals, Bureau of Entomology. 



With a Description of the Mature Larva of Tabanus punctifer, by Adam G. 

 Boving. Entomologist, Bureau of Entomology, and a Description of a New 

 Species, by James S. Hine, Professor of Zoology and Entomology, Ohio State 

 University. 



CONTENTS. 



Page. 



Historical 1 



Injuriousness and abundance 3 



Antelope Valley 4 



Breeding methods and equipment 6 



Oviposition cages 8 



The feeding cone 9 



Species involved 9 



Tabanus punctifer Osten Sacken 10 



Tabanus phaenops Osten Sacken 20 



Tabanus insuetus Osten Sacken 26 



Tabanus monoensis, n. sp 29 



Chrysops spp 31 



Page. 



Natural enemies of tabanids 31 



Parasites 31 



Predators 32 



Protection of animals 33 



Repellents 34 



Repressive measures 34 



Poisoning tabanid* 34 



Drainage 35 



Literature cited 36 



HISTORICAL. 



Blood-sucking flies of the family Tabanidae are very serious pests 

 to horses, cattle, and other domestic animals. In certain cattle-grow- 

 ing sections of the United States, particularly where swampy areas 

 exist, tabanids are pests of great economic importance. 



In 1915, requests were received from cattlemen, through S. B. 

 Doten, director of the Nevada Agricultural Experiment Station, for 

 an investigation of the conditions favoring and the methods of con- 

 trolling an abundance of horse-flies which were causing serious losses 

 on ranches in Nevada. In that year J. H. Clemons, land commis- 

 sioner for the Union Land and Cattle Co.. one of the largest cattle 



1 F. C. Bishopp, of the Bureau of Entomology, directed the investigation, and Director 

 S. B. Doten, of the Nevada Agricultural Experiment Station, cooperated. Most of the 

 determinations were made by Prof. J. S. Hine. The junior author conducted the field 

 work in 1919. In the field, Rufus Ogilvie assisted in' I'M 7. Noble Waite in 1918, and 

 Harold Whalman in 1919. 



II. W Wells, the junior author, resigned July 24, 1923, 



67881 



