Chemical control of Ornithonyssus sylviarum on caged layer hens

Manual application of aqueous solutions of malathion, carbaryl and permethrin controlled northern fowl mite, Ornithonyssus sylviarum Canestrini and Fanzago, on caged layer hens for at least 118 days. Azamethiphos sprayed manually provided acceptable control for a shorter period. Machine application, particularly of azamethiphos, but also malathion, provided lesser control. The addition of surfactant increased the wetting ability of the sprays but interfered with the efficacy of azamethiphos.