CHAPTER XVI 

 ORDER MALLOPHAGA* 



The Bird-Lice 



The members of this order are wingless parasitic insects with chewing 

 mouth-parts. Their development is without metamorphosis. 



The bird-lice resemble the true lice in form, being wingless, and 

 having the body more or less flattened ; certain species that infest 

 domestic fowls are well-known examples. These insects differ from 

 the true lice in having chewing mouth-parts. They feed upon feath- 

 ers, hair, and dermal scales, while the true lice, which constitute the 

 order Anoplura, have sucking mouth- parts, feed upon blood, and 

 infest only mammals. 



The Mallophaga infest chiefly birds, and on this accoimt 

 the term bird-lice is applied to the entire group; a few genera, 

 however, are parasitic upon mammals. Some writers term the Mallo- 

 phaga the biting lice, which is a more accurate designation ; but the 

 name bird-lice is more generally used. 



The bird-lice are small insects. The more common species range 

 from I mm. to 5 mm. in length. The mouth-parts are on the imder 

 side of the head, the most anterior .part of the head being a greatly 

 enlarged clypeus ; they are of the mandibulate type; and paragnatha 

 ("furcae maxillares") have been found in several species (Snod- 

 grass '05). There is a pair of "simple eyes" located in the lateral 

 margins of the head. The structure of these eyes has not been de- 

 scribed; but judging from their position they are probably degenerate 

 ommatidia and not ocelli. The front legs are shorter than the others 

 and are used to convey food to the mouth. 



There is an interesting correlation between the habits of these 

 insects and the structure of their feet. The tarsi of those species 

 that feed on mammals are one-clawed and fitted for folding against 

 the tibice; they are organs well adapted for clinging to hairs. Those 

 species that feed on birds have two-clawed tarsi and are better fitted 

 for running. The above distinction is not quite accurate, as a few 

 two-clawed species feed on kangaroos, wallabies, and wombats. 



*Mall6phaga: mallos (/taWis), wool; phagein {(payeiv), to eat. 



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