162 APPLIED ENTOMOLOGY 



have dropped out as a result of the feeding of these insects. Birds nor- 

 mally dust themselves, working the dust in among their feathers, where 

 it is claimed it gets into the spiracles of the lice and suffocates them. 

 Apparently the greatest injury to the fowls does not come from the feeding 

 on the feathers and scales, but from the irritation produced by the 

 scratching of the skin caused by the tarsal claws of the parasites as 

 they move about, and this must be quite severe, for birds considerably 

 infested become dull and act sick, and are certainly less able to resist 

 disease than usual. 



The eggs of the lice are attached separately to the feathers or hairs 

 of the host, and hatch into nymphs, which on the whole considerably 

 resemble their adults. They feed, molt, grow and become adult in a 

 few weeks. 



FIG. 155. Female Chicken Body Louse (Menopon biseriaium Piag.), greatly enlarged. 

 (From U. S. D. A. Farm. Bull. 801.) 



Though these insects are widely distributed on many kinds of birds 

 and on a number of mammals, they are of importance from an economic 

 standpoint mainly on the domesticated birds such as chickens, turkeys, 

 geese, ducks and pigeons, though occasionally dogs, cattle and horses 

 become infested. 



Seven different kinds of biting-lice are fairly common on domestic 

 fowls. Of these, some prefer the head for their location, others the body 

 (Fig. 155), etc., though not found exclusively in those locations. Four 

 kinds are often present on turkeys and quite a number occur on geese 

 and ducks. Pigeons and guinea fowls have several species. 



