CHAPTER X 

 EXTERNAL PARASITES 



Fowls heavily infested with any of the external parasites 

 are unprofitable, and many kinds of external parasites, when 

 in enormous numbers, as is often the case, cause death of the 

 infested bird. 



In order to treat birds and rid them and their premises of 

 parasites it is essential to know something of the life history 

 and of their habits. 



Among the more common external parasite infesting birds 

 may be mentioned lice, chiggers, air-sac mites, fleas, chicken 

 bugs, chicken ticks, and ringworm. 



LICE 



Lice are a group of biting insects. Their bodies are fiat and 

 their mouth parts are arranged for biting. They live upon 

 secretions of the body, epidermis, and feathers. The insect 

 consists of three parts — a head, a thorax, and a body. The 

 head is provided with jointed antennae or feelers. In most 

 lice of birds the antennae are provided with five joints. The 

 eyes are located just back of the antennae. In some species 

 the thorax is long and narrow, in others it is short and globular. 

 The thorax is provided with three pair of legs. Each free 

 extremity of the legs are provided with two bristles each, or 

 with one or two claws, which enable them to hold onto their 

 host. The body and legs are more or less covered with bristles. 



Varieties. — Each kind of bird has its own peculiar hce, 

 which Uve upon that particular kind of bird and no other. 

 On chickens there is found quite commonly two distinct 

 varieties. These are scientifically known as the Menopon 

 biseriatum and the Menopon pallidum. The former is the 

 larger of the two, and is commonly known as the large head 



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