438 EXTERNAL PARASITES OF ANIMALS 



effective for four or five days. Where the flies have produced sores, 

 treat them with a weak solution of carbolic acid. On the range 

 where large numbers of animals are to be treated, dip them in a 

 dipping vat provided with a splash-board which will throw the 

 spray down on the animal and kill most of the flies. Use any of 

 the oily dips recommended for the Texas-fever tick. 



CATTLE LICE (Hcematopinus spp. and Trichodectes scalaris). 

 Cattle are especially liable to become infested with lice during the 

 winter and early spring. They acquire a generally unthrifty look, and 

 the flow of milk is greatly lessened. On young stock the injurious 

 effects are more noticeable ; lousy calves are thin and do not make 

 the proper growth. 



Treatment. When the weather will permit, spray or wash infested 

 animals with a 10 per cent kerosene emulsion or the nicotine-and-sulfur 

 sheep dip as used for sheep scab. 



SOUTHERN BUFFALO-GNAT (Simulium pecuarum) . A small black 

 gnat or punkie occurring in the lower Mississippi Valley, where it causes 

 immense loss to the live-stock interests. The larvae are aquatic, and 

 are able to develop only hi swiftly running waters. The gnats appear 

 in great swarms in early spring and attack cattle, mules, horses, sheep, 

 and other animals in countless numbers. They feed by sucking the 

 blood and at the same time inject a poison into the wound, causing 

 great distress and producing an acute inflammation. Animals in poor 

 condition from exposure or lack of food are frequently killed. 



Treatment. Protect the animals by smudges producing a dense 

 smoke, or keep them in dark stables until the swarms of gnats have 

 disappeared. Working teams can be protected by using train-oil or 

 the cotton-seed oil and tar mixture advised, under HORN-FLY. To 

 reduce the irritation caused by the bites, rub the animal thoroughly 

 with water of ammonia and give internally a mixture of 40 to 50 

 grains of carbonate of ammonia in a pint of whiskey, and repeat 

 the treatment every three or four hours until relieved. 



SCREW-WORM FLY ( Chrysomyia macellaria) . Whitish maggots, 

 three-fourths inch in length when full grown, infesting sores and wounds 

 of animals in the Southern States. The eggs are laid on the wounds 

 in masses of 100 or more by a bright, metallic green fly a little larger 

 than the house-fly. The maggots enter the wound, feed on the putrid 

 matter within, and as they increase in size burrow into the flesh, fre- 



