UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 597 
Contribution from the Bureau of Entomology 
L. O. HOWARD, Chief 
| Washington, D.C. PROFESSIONAL PAPER April 9, 1918 
SOME BIOLOGICAL AND CONTROL STUDIES 
OF GASTROPHILUS HAEMORREOIDALIS AND> 
OTHER BOTS OF HORSES 
By 
W. E. DOVE, Scientific Assistant 
Insects Affecting Domestic Animals 
CONTENTS 
S 
Page Page 
EISEGUCHIOMN tat sGites sys ek ees) ve le 1 | Natural Protection of Horses .... 14 
Brief Life History of Gastrophilus .. 2 | Seasonal History of Gastrophilus. . . 15 
EEARCENCAE raf rania lich; aioe et ais 2 | Gastrophiius kaemorrheidalis Linn . 16 
Species Differentiation . . . . 2... 3 | Gastrephilus nasalis Linn... . - 29 
Distribution in the United States and Gastrophilus intestinalis DeGeer. . 32 
Probable Dispersion . . . «© s « « 5 | Effect of Death of Host upon Gastro- 
Larval Collections and Rearing Tech- leet RO PAER ES). WIA WSIS og 37a! heh whit hath want eet 
EES thes Sea ea aoa es ial ey colt Ba @ COMPEON Stes 5:5 sce iar at a eget 
Larval Infestation and Injuries. .. . G6. | Samimary> to 2-00) 6a whine eh et See 
Bot-fly Annoyance. . . ». «© » « « « 13 | Bibliography . . . . - © «© © © « ec 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1918 
PEYOTE TOR 
Dee Wenn en ees 
TAMPA BAP OM Poo os 
