114 ■ JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 6 



Wichita county. In Oklahoma the outbreak was much less severe 

 and, as in Texas, appeared to be confined to localities where grain 

 was extensively grown. 



Character of Injury and Losses 



Injury to live stock was brought about in a number of ways. Prob- 

 ably the "worry" due to the attack of great numbers of the flies was 

 the most serious and this Avas a contributing factor to all of the losses 

 sustained. During the period of greatest abundance all live stock were 

 compelled to keep up a constant fight against the flies from daylight 

 until dark. Whether the animals were being driven in small towns, 

 on country roads, worked in fields, or kept in stable or pasture, the 

 flies sought them out and kept up a continual attack. In many cases 

 both horses and cattle became so weakened from this continual worry 

 that they largely gave up fighting and flies swarmed on them in 

 countless numbers. In a number of such cases animals that were not 

 given attention succum])ed to the injuries. The loss of blood during 

 the outbreak was by no means a small matter as in many instances 

 as high as a thousand flies were estimated to be present upon a single 

 animal at one time. It was also found that as fast as the flies became 

 filled with blood they would leave the host for a period in order to 

 digest their meal and then renew the attack. It will thus be seen 

 that the blood supply of animals in the worst infested territory must 

 have been heavily drawn upon. 



Another, and probably the most important source of loss through 

 the actual death of animals, was the bringing on of acute Texas fever 

 in cattle which already harbored the disease organism in their blood. 

 The development of the disease in these animals was analogous to that 

 which some times occurs in herds which are shipped long distances, 

 exposed to very unfavorable climatic conditions or otherwise weakened, 

 thus bringing on acute Texas fever. In the instances observed the 

 animals were greatly weakened from fighting the flies as well as from 

 loss of blood, thus the disease was given a good opportunity to take 

 hold. 



The lessening of the milk supply in all milk cows throughout the 

 affected area was an important source of loss. Dairymen who kept 

 close account of their milk production found that after the advent of 

 the flies their milk output was reduced from 40 to 60 per cent, and in 

 a few cases the cows were completely dried up. Reliable dairymen 

 also assert that since the subsidence of the severe invasion the cows 

 have never returned to their normal milk production. 



The loss of flesh in all animals in the fly zone was very noticeable. 



