Systemic activity of coumaphos, famphur, crufomate, ronnel, and phosmet given orally to hens for control of the northern fowl mite, Ornitbonyssus sulviarum (Canestrini and Fanzago).

Coumaphos (O-(3-chloro-4-methyl-2-oxo-2H-1-benzopyran-7-yl)O,O-diethyl phosphorothioate), famphur (O-[p-(dimethylsulfamoyl)phenyl] O,O-dimethyl phosphorothioate). crufomate (4-tert-butyl-2-chlorophenyl methyl methylphosphoramidate), ronnel (O,O-dimethyl O-(2,4,5-trichlorophenyl) phosphorothioate) and phosmet (O,O-dimethyl phosphorodithioate S-ester with N-(mercaptomethyl) phthalimide) were administered as systemic acaricides (either single or multiple oral doses or as feed additives) for control of the nortnern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), on caged White Leghorn hens. None of the treatments controlled the mites, but some hens were poisoned.