PART TWO 



Bird Fleas and Feather Lice 



INTRODUCTION 



Sir, there is no settling the point of precedency 

 between a louse and a flea. 



Dr. Johnson 



BIRD FLEAS and feather lice do not sing. Nor do they fly about 

 flashing brilliantly coloured wings in the sunshine. It is scarcely 

 surprising that in Britain bird and butterfly enthusiasts number 

 thousands, but the collectors of fleas and lice can be counted on the 

 fingers of one hand. 



The Mallophaga and Aphaniptera are small, drab insects of in- 

 significant appearance and without obvious aesthetic appeal. In the 

 mind of ordinary men and women they have loathsome associations of 

 dirt, disease and furtive scratching. Moreover, they are too small to 

 study with the naked eye and the finer structures on which their classi- 

 fications are based have to be examined with the aid of a microscope. 

 From the scientific aspect however, they are of great interest, not only 

 as carriers of deadly disease but as insects closely adapted to the 

 parasitic mode of life. 



Both bird fleas and feather lice prey upon avian hosts, and their 

 mode of life has imposed upon them certain well known features 

 associated with parasitism. Thus both are wingless, both have failing 

 or poorly developed eyesight, and both have claws adapted to clinging. 

 In addition they have developed a very resistant integument, and can 

 consequently survive a nip from the host that would squash or fatally 

 injure many insects of similar size. The Ceratophyllid bird fleas and a 

 certain number of species of Mallophaga also share a rather curious 



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