32 



Dissemination studies are few. Besides spreading from bird to bird 

 (Cameron, 1938), Foulk (1964) found that four main methods of poultry 

 flock infestation are by infested hatcheries ar\d contract started-pul 1 et 

 farms, infested trucks and crates used to carry infested birds, infested 

 personnel, equipment, or egg crates, and infested v/ild birds that enter 

 poultry houses. While Hartman (1953) believed northern fowl mites to 

 be carried by sparrows, Foulk (1964) was unable to infest chicks with 

 northern fowl mites from sparrows. Mites have also been carried from 

 farm to farm on filler flats that have not been fumigated after use 

 (Anonymous , 1 968) . 



Since the northern fowl mite has been found on the Norway rat and 

 the house mouse in poultry houses (Hall ana Turner, 1976; Miller and 

 Price, 1977), it is assumed that these rodents may aid in mite dis- 

 seminat ion . 

 Effects on the Host 

 Patent effects of northern fowl mite infestation 



The most obvious sign of a northern fowl mite infestation is 

 feathers in the vent area which have become matted and discolored 

 (Yunker, 1973) from the eggs ana excretion of the mites (Metcalf et al. 

 1962). Examination of birds reveals mites and usually evidence of 

 skin irritation and feather plucking (Anonymous, 1967). In more severe 

 cases, the skin becomes thickened and scabby (Anonymous, 1959; Metcalf 

 et al., 1962; Yunker, 1973) due to secondary infection of the bites 

 (Cameron, 1933). 



While northern fowl mites seen crawling en freshly laic chicken 

 eggs are an indication of a mite infestation, the number of mites 



