February, '13] BISHOPP: STABLE FLY 113 



cases be connected with the transmission of septicemia in man, glanders 

 in horses and other animals and certain other maladies. In this 

 country the recent work of Brues and Sheppard on the apparent 

 etiological relation between Stomoxys and poliomyelitis and the work 

 of Jennings and King pointing toward the connection of the stable 

 fly with pellagra transmission has had the effect of greatly stimulating 

 the interest of entomologists as well as medical men in the study of 

 this insect, and its possible relation to the transmission of various 

 diseases, the etiology of which has not been fully elucidated. As is 

 now generally known, the conclusions of Brues and Sheppard have 

 been greatly strengthened by the work of Rosenau which demon- 

 strated that the stable fly can transmit poliomyelitis in monkeys. 

 The results of Rosenau have been corroborated by experiments along 

 the same line conducted by Anderson and Frost of the United States 

 Public Health Service. 



An Unusual Outbheak of the Stable Fly 



About August 14 reports of the occurrence of this species in unusual 

 numbers began to be received from several points in north Texas. 

 The flies appear to have become seriously numerous about August 

 12, and from that date until the end of August the outbreak continued 

 at maximum severity. The abundance of the insect gradually became 

 less until the middle of October, although an unusual number of flies 

 were present from that date until about the middle of November. 



An investigation quickly determined the fact that the flies were 

 breeding in great numbers in straw stacks. The relation between 

 straw and the abundance of the stable fly in this outbreak very closely 

 simulated that described by Professor Iches as occurring in Argentina 

 in 1898, although at the time this investigation was made Professor 

 Iches' work was unfamiliar to the author. 



Territory Affected 



A survey of the territory made by the writer, assisted by Mr. J. D. 

 Mitchell, showed that the great abundance of the fly was practically 

 co-extensive with the area where grain was extensively produced this 

 year. The abundance was found to be largely governed by the number 

 of straw stacks in a given district. Although flies were found to be 

 exceptionally numerous in areas where practically no oats or wheat 

 were grown, usually such localities were not removed distantly from 

 grain growing areas. The center of greatest abundance was in Gray- 

 son, Cook, Collin and Denton counties in northern Texas, however, 

 the severe injury extended as far south as Hill county and west to 

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