INSECT PARASITES. 3"> 



the young, either larva or pupa, when expelled from 

 the parent's body is nearly equal to it in size. 



0. pallida (fig. 10) has a small, oval, tough body, 

 sliffhtly hairy and bristly, tawny in colour, paler 



Fis-. 10. 



Ornithobia pallida. 



beneath. Eyes large, oblong, and brown. Mouth 

 (which is formed for suction) is not long ; it consists 

 of a pair of hairy hard valves, which enclose a slender 

 stiff tube, the sucking-tube, which is formed by the 

 union of two setiform pieces. There are very short 

 antenna?, and stout wings, grey in colour with dark 

 brown veins. The legs are robust and wide apart ; 

 claws long, curved, and black. About J of an inch 

 long. 



0. avicularia (fig. 11) is greenish in colour, more 

 or less varied with tawny. The thorax has a reddish- 

 brown dorsal stripe. Wings ample, rather long, 

 grey with black veins. Legs stout and bristly. 

 Sliohtlv larger than the former and more hairy. 



Both these Diptera crawl about upon the fowls and 

 fly from one to another. They generally infest the 

 nostrils and ears, crawling into them and setting up 



d2 



