On June 7, 2019, CFIA inspectors conducting routine plant health surveys at the Harold Mitchell Nature Reserve in Wainfleet, Ontario detected several hemlock trees, which they strongly suspected were infested with hemlock woolly adelgid (HWA), Adelges tsugae. On June 12, 2019, the CFIA confirmed that the suspect samples were positive for HWA. This second site is located approximately 40 km away from the Niagara Glen Nature Reserve, where HWA was previously confirmed to be present between 2013 and 2015 and again in 2019.
Both the sites are under Notice of Prohibition of Movement, which were imposed after the initial detection. A delimitation survey has been completed. Official control measures are being applied to prevent the introduction of HWA into non-infested areas of Canada.
Hemlock woolly adelgid is a regulated pest under the Plant Protection Act. Hemlock woolly adelgid is considered present only in British Columbia and in Nova Scotia (five counties) and is subject to official control in Canada.