Dispersal of the northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), and the chicken body louse, Menacanthus stramineus (Nitzsch), among thirty strains of egg-type hens in a caged laying house.

From September 1978 through Februrary 1979, dispersal of uncontrolled, naturally occurring populations of the northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), and the chicken body louse, Menacanthus stramineus (Nitzch) was studied on 30 strains of egg-type pullets reared to 20 weeks old on four growing rations before being housed for egg production. Hens representing all 30 strains and each of the four feeding regimens had mites. The northern fowl mite spread from initial infestations down the entire length of the house in 1 month; after four months, the chicken body louse had spread approximately two-thirds the length of a cage row in the house. Populations of the northern fowl mite increased from very light to extra heavy within 1 month and then began a slow decline.