164 ENEMIES AND DISEASES OF POULTRY 



other causes combined. The following are the principal 

 specific effects resulting from parasites: (1) They re- 

 duce the vitality of poultry; (2) they lessen egg pro- 

 duction; (3) they deduct from the table qualities of fowls 

 intended for market poultry; (4) they interfere with 

 the proper performance of the natural duties of incuba- 

 ting and brooding; (5) they cause the loss of parts 

 of a fowl's body; (6) they infest poultry with other and 

 additional varieties of parasites; (7) they infect poultry 

 with fungous and bacterial diseases, 



Rapidity of Reproduction of Poultry Parasites. The 

 exact time required for poultry parasites to produce 

 . new generations cannot be stated definitely. Under 

 favorable conditions, however, all kinds of poultry para- 

 sites are very prolific and will increase to an alarming 

 extent. Salmon states that the third generation from a 

 single louse may number more than 120,000, and all of 

 these may be produced within a period of 8 wk. Such 

 a rapid increase being possible, the result of intro- 

 ducing into a flock a fowl that is thoroughly infested 

 with parasites can readily be surmised. Such a fowl is 

 sure to do injury. 



Poultry parasites multiply particularly fast in damp, 

 filthy, unsanitary places surroundings that are unfavor- 

 able to poultry even when not infested with parasites. 

 Poultry parasites, however, will also develop rapidly 

 in clean places if the air is allowed to remain hot 

 and moist for any length of time. 



PARASITES ATTACKING DOMESTIC FOWLS 



The parasites that are found occasionally on domestic 

 poultry are: Large chicken louse (Goniocotes abdomi- 

 nalis) ; lesser chicken louse (Goniocotes hologaster). The 

 Goniodes dissimilis and the Goniocotes burnettii are rarely 

 found on fowls. 



A louse that is sometimes found on fowls and which 

 does considerable damage to the feathers when present 

 in large numbers is the variable chicken louse, or 

 feather louse (Lipeurus variabilis) . 



