Diptera. 989 



The blinding gadfly (Chrysops coecutiens) is a fly 9 mm. long with broad 

 spreading wings and sharply defined abdomen; it flies especially about the head of 

 the animals, and occasionally causes inflammation of the eyes and ears. 



h. Flies (Muscida) in the restricted sense. Most insects 

 belonging to tliis class merely annoy the animals and hinder 

 them from eating at pastnre or they cause waste of food. Some 

 of their representatives also cause considerable disturbance of 

 health. 



In inhabited places the house fly (Musca domsstica) is frequent everywhere; 

 it occurs in large numbers in stables and in the brushwood about meadows; other 

 flies are the M. corvina which sucks the sweat, the M. vomitoria (vomiting fly), 

 the M. cada,verina which is parasitic on dead animal bodies, the Sarcophaga carnaria 

 (meat fly) and the Sarcophaga magnifica, the female of which deposits its larvae, 

 that are born alive, on wounds and swellings as well as in the ears, and in the 

 vagina of female animals. In a case observed in a goat by Wirth the larvae of the 

 Sarcophaga magnifica were found in a necrotic patch of the vagina; fever was also 

 present. 



The larvfc of Lucilia caesar and L. sericata, which belong to 

 this class, produce the fly larvae disease of lambs; this is 

 prevalent especially in Holland and New Zealand. The larvae 

 of these species of flies are hatched from the eggs that have 

 been deposited in the perineal region of lambs suffering from 

 diarrhea. They cause violent itching, wander from here to the 

 root of the tail and to the sacral region, where they riddle the 

 skin and produce an inflammation which still more exhausts the 

 weakened animals. According to Gilruth the larvae at times 

 pass through the abdominal wall into the abdominal cavity. 

 The fly larva disease was observed by Graber in Grermany (Pr. 

 Mt., 1877, 78, 82) and by Jordal in Norway (Norsk Vet.— 

 Tidskr., 1905, 121). 



In America the larvae of Lucilia macellaria establish them- 

 selves on wounds, whose healing process they disturb, and even 

 wander into the nasal cavities. According to Jerwolajew (B. 

 t. W., 1905, 676, Rev.) the '' Welfare fly" in Russia deposits its 

 eggs on wounds on sheep and cattle, where the liberated larvae 

 destroy the tissues, and at times this destruction extends so 

 deeply in the umbilical region as to produce hernia. 



The treatment consists in removing the larvae of the flies 

 with forceps, applications of 5% carbolic acid or creolin solu- 

 tion, in painting with 5% carbolated oil, or in the introduction 

 of creolin suppositories (creolin 1 part and cacao butter 20 

 parts). The removal of flies from the stables is attempted by 

 establishing conditions unfavorable to their life (sharp draughts, 

 partial exclusion of daylight, fly nets, etc.), by mechanical de- 

 struction of flies and their broods and by keeping off the flies 

 from animals in the open (by blankets, etc., by substances hav- 

 ing an objectionable smell). 



The stinging fly (Stomoxys calcitrans), belonging to the same family, 

 takes up its al)ode in stables and may be recognized because it rests on 

 the walls with the head directed downwards ; it attacks the feet of horses, 



