CHAPTER 8 



FEATHER LICE (MALLOPHAGA) 



(/xaAAoV^WOOL, </)ayos'= eating) 



Tell me what company thou keepest, and I'll tell 

 thee what thou art 



Cervantes 



THERE WERE no Hcc in the Garden of Eden. Such loathsome creatures 

 must have been created after the Fall. " Can we believe that man 

 in his pristine state of glory, and beauty, and dignity, could be the re- 

 ceptacle and prey of these unclean and disgusting creatures?" So mused 

 Henry Denny when compiling his Monographia Anoplurorum Britanniae, 

 the first and only book to be written on the Mallophaga of Britain. To- 

 day, it is generally believed by entomologists that the feather lice are 

 derived from free-living ancestors which were not unlike the Psocida or 

 book-lice in form and habit. These ancestral Mallophaga probably lived 

 under moss and stones and on the bark of trees, feeding on any organic 

 debris they could find. Book-lice have been taken from the bodies of 

 caged animals, such as white mice, where they were possibly feeding on 

 skin debris, and it is not difficult to imagine that the free-living ancestral 

 Mallophaga might have visited the bodies of resting reptiles. When the 

 reptiles which gave rise to the early birds gradually evolved a feather 

 covering, a hitherto untouched source of food became available. 

 Originally, feathers must have proved a hard and indigestible diet, but 

 one which enabled the insect to occupy a new habitat with an almost 

 unlimited food supply and without competition. Gradually the 

 ancestral Mallophaga became more and more closely adapted to these 

 new conditions so that eventually they could live and breed only in the 

 warmth and shelter provided by the body of their host. The Mallo- 

 phaga, the feather or chewing lice, are found on all birds and many 

 mammals, but not on man. It is usually believed that they first became 



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