26 PARASITOLOGY. 



Melophagus Ovinus (Alallos — wool, phagein — to eat). 



Synonyms. — S;heep-tick ; louse-fly. 



Description. — The head is small and sunken in the thorax. 

 It is provided with a tubular-shaped proboscis adapted for 

 piercing the skin and sucking t'he blood. The thorax is 

 distinctly separated from the abdomen, and is provided 

 with three stout pair of legs, which are covered with hair. 

 The last segment of each leg is provided with, a bi-dentated 

 claw. The abdomen is large, and glofoalar in shape. 



Life Cycle. — The female lays eight to ten young in 

 the form of pupae. The pupal case is ovoid in 

 shape and brown in color, and is cemented to a few 

 fibres of wool. These hatch in about four weeks. 



Animals Infested. — They are found most abundant 

 on long-wooled sheep. After shearing they have a 

 tendency to leave the sheared sheep for the lambs. 



Fig. 2— Melophagus Ovinus. Fi^. 3— Melophagus Ovinus 



a, Head with Piercing' Rostrum Pupa. 



b, Thorax, with 3 Pair of Legs. a, Pupa. 



c, The Large, Globular Abdomen. b. Wool Fibers. 



They live upon blood of the host, and grease or yolk 

 of the wool. At point of puncture there is injected 

 a small quantity of poison, which causes irritation 

 and swelling. 



Symptoms. — The infested sheep rubs, scratches and 

 bites itself. When present in large numbers these 

 parasites cause unthriftiness and debility. 



Treatment. — The sheep dip or kerosene emulsion 

 will kill them. 



Gastropliilus Equi (Gaster-stomach) (Equi — horse) (Phileo — to love. J 



Synonyms. — Horse bot-fly; oestrus equi ; gad-fly. 

 History. — They were described by the earliest 

 writers and are universally found. 



Description. — A fly about the size of a honey-bee ; 



