344 DISEASES OF CATTLE. 



horns. In this position the wings are held nearly flat down the back, 

 overlapping at base and diverging only moderately at tip; the beak is 

 held in a nearly horizontal position, and the legs are not widely spread. 

 In the active sucking position, however, the wings are slightly elevated 

 and are held out from the body, not at right angles, but approaching 

 it. The legs are spread out widely, and the beak, inserted in the skin 

 of the animal, is held in nearly a perpendicular position. The fly, before 

 inserting its beak, has worked its way through the hairs close to the 

 skin. While feeding, however, the hair, which can be seen over its 

 body, does not seem to interfere with its speedy flight when alarmed, 

 for a fling of the tail or an impatient turn of the head will cause the 

 flies to rise instantly in a cloud for a foot or two, returning as quickly 

 again and resuming their former positions. The horns are not the only 

 resting places, for with the horns covered by them for two inches above 

 their base, toward nightfall vast numbers will also settle upon the neck 

 where they can not be reached by the head or tail. When feeding they 

 are found over the back and flanks and on the legs. During a rain 

 storm they flock beneath the belly. When the animal is lying down a 

 favorite place of attack seems to be under the thigh, and belly around 

 the bag. With certain animals the dewlap becomes badly attacked, 

 while in others this portion of the body is about exempt. Certain cat- 

 tle, again, will be covered with flies and will lose condition rapidly, 

 w^hile others are but slightly affected. 



The amount of injury done by this pest is not so very great; it is 

 stated that the flies alone will never cause the death of an animal. They 

 reduce the condition of stock considerably, and in the case of milch 

 cows the yield of milk is reduced from one-fourth to one-half. Their 

 bites seldom produce sores by themselves, but large sores have been 

 made by the cattle in rubbing themselves against trees, fences, etc., in an 

 endeavor to allay the irritation caused by the bites, or in spots where 

 they could not rub by licking constantly with the tongue, as about the 

 udder and on the inside of the thighs. These sores are usually difficult 

 to heal, as from the continued irritation by the flies and the repeated 

 licking by the animal, the sore is maintained. 



Treatment. Almost any greasy substance applied to the skin and 

 horns of the animal will keep the flies off for several days. For this 

 purpose common axle-grease, whale oil, carbolized oil, etc., may be 

 used. 



Prevention. The flies are propagated from eggs laid in the droppings 

 of cattle by the female flies. Thus a new generation of flies is pro- 

 duced about every two weeks. It is recommended by Prof. C. V. Eiley, 

 entomologist for the U. S. Department of Agriculture, that a spadeful of 

 lime should be placed upon each dropping of the cattle in the field, to 

 destroy the larva? after they leave the egg, and previous to their trans- 

 formation into the fly. By doing this twice a week the number of sub- 

 sequent flies could be materially lessened, possibly the pest altogether 

 eradicated. 



