CHAPTER XXIII 



THE MALLOPHAGA 



The Mallophaga are generally called bird-lice but as they feed by biting 

 off particles of feathers, hairs and scales of the skin, from the animals on 

 which they live, the name biting-lice would be better as it would dis- 

 tinguish them more accurately from a large number of very similar 

 insects found in many cases on the same animals, which feed by sucking 

 the blood of their hosts, and which are called sucking-lice. 



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1 -ictBaissXli 





Fig. 154. — Samples of Mallophaga or Biting Lioe, greatly enlarged: hair lines show 

 actual length. (After Kellogg.) 



The bird-lice or biting-lice (Fig. 154) are very small insects ranging 

 from about one-twenty-fifth to one-tenth of an inch in length, rather 

 whitish in color, much flattened and with an external shell which is 

 unusually hard for such small insects. They are wingless and are rarely 

 found off the bodies of the birds and mammals on which they live. 

 Development from the egg is gradual, through a series of molts which 

 finall}' produces the adult. 



The group may be described thus : 



Small, wingless insects, usually with a large head; mouth parts for 

 biting. Body quite hard, flattened. Parasitic on the bodies of birds and 

 some mammals. Metamorphosis incomplete. 



About fifteen hundred kinds of Mallophaga are known, most of them 

 living on birds, where they feed on feathers and skin scales. On mam- 

 mals, hairs replace the feathers as their food. When abundant, bare 

 areas on the bodies of birds appear where the feathers have been eaten or 

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