Cnemidocoptic Mite Infestations in Wild Birds

¹ Division of Zoonoses and Wildlife Diseases, Ontario Veterinary College, Guelph, Canada

During 1965 many wild birds were examined for the lesions of "scaly leg" disease, caused by mites of the genus Cnemidocoptes. Mite infestation was found in redwinged blackbirds (Agelaius phoenicus), common grackles (Quiscalus versicolor), cowbirds (Molothrus ater) and in two new hosts for the mite, a black-capped chickadee (Parus atricapillus) and a crested flycatcher (Myiarchus crinitus). The mite was identified as closely related to Cnemidocoptes jamaicensis (Turk 1950). Mites were transmitted from diseased to healthy red-winged blackbirds by cage contact but nine other wild bird species appeared not to be susceptible during an observation period of six months, even when mites were applied to scarified skin. Attempted transmission to chickens was not successful during an observation period of six months. Male and female mites were observed in copulation. The progress of the disease, pathological findings and the histopathology of "scaly leg" disease in wild birds is described.