EXTERNAL PARASITES 



51 



larva goes through several moults, finally maturing into the 

 adult, sexual, eight-legged parasite. 



Symptoms of Dermanyssus Infestation. — This par- 

 asite lives in the poultry houses and dove-cotes, 

 hiding in the straw of nests, cracks and crevices ®f 

 the roosts, and other places of concealment in the 

 daytime. It is the most common and most injur- 

 ious of mites and is present in every poultry house 

 unless it is kept unusually clean. It comes out at 

 night and makes its attack. Few of these parasites 



Fig. 14 Fig. 15 



Fig. 14. Dermanyssus Gallin.e 

 A, Conical-shaped rostrum. B, palpus. 



Fig. 15. PuLEX Avium 

 A, AntenriK. B, stylette. C, hooklets on free extremity of leg. 



are to be found on the birds (chickens and pigeons) 

 in the daytime, but at night they may be numerous. 

 Birds so harassed at night cannot sleep or rest 

 and soon become emaciated. The laying hens 

 will leave their nests and even cease laying. Birds 

 may be found dead under the roosts in the morn- 

 ings from the attacks of these mites. 



These parasites may also attack horses and 

 other animals kept close to the quarters of infested 

 birds ; they cause irritation, the animal scratches. 



