SOURCES OF NORTHERN FOWL MITE (ORNITHONYSSUS-SYLVIARUM) INFESTATION IN ONTARIO EGG-PRODUCTION FACILITIES

In the poultry industry, northern fowl mites are generally thought to survive poorly one they have left the bird. However, several researche rs have found mites infesting equipment or surviving off-host for up t o 2 wk. Our work demonstrates that large numbers of mites can be found on cage equipment in poultry houses, and if an acaricide application is not a part of the cleanout program at the end of the production cyc le, there is a good chance that mites will survive to infest the next flock. A province-wide inspection of 16- to 18-wk-old pullets indicate d that a new mite infestation was more likely to originate from the pr oduction facility than the pullet rearing facility. However, a previou s investigation found a pullet flock infested with mites, indicating t hat pullet facilities were not completely free of responsibility. In o rder to reduce the chance of future infestations of northern fowl mite s, it is necessary to incorporate an acaricidal treatment to prevent t hem from surviving cleanout procedures in egg production facilities an d, if necessary, pullet rearing facilities.