Michigan Department of Agriculture and Rural Development Director Jamie Clover Adams today announced that Hemlock Woolly Adelgid (HWA) has been eradicated from three counties across the state – two sites in Macomb County, two sites in Ottawa County and multiple locations within Emmet County.
HWA is a small, aphid-like insect that uses its long, siphoning mouthparts to extract sap from hemlock trees. Native to eastern Asia, HWA was discovered in Virginia in 1951, and has since spread over an area from Georgia to Maine, decimating hemlock stands.
HWA was first detected in Emmet County in 2006 when it was found in hemlock nursery stock grown in West Virginia and planted for residential landscaping in the Harbor Springs area. HWA was detected at the Macomb and Ottawa county sites in 2010.
“Thanks to diligent survey and our partnership with the Michigan Department of Natural Resources and our nursery industry, I’m happy to announce MDARD has successfully eradicated this destructive pest from these communities,” said Clover Adams. “However, we continue to ask you to examine your hemlock for the presence of white, cottony masses on the underside of branches where the needles attach. If you suspect HWA, contact MDARD immediately.”
To report suspected HWA, email MDA-Info@michigan.gov or call 800-292-3939.
The infestations were believed to have originated from hemlock nursery stock originating from HWA-infested areas of the U.S. The infested trees at each site were removed and destroyed. Nearby trees were treated with pesticides and surveyed annually over the course of at least three years.
Over 100 million hemlock trees are present in Michigan forests, providing valuable habitat for a diversity of animals, including birds, deer, and fish. These trees are critical to the ecology and aesthetics of Michigan’s northern forests.
Michigan law restricts the movement of hemlock into the state, and includes a complete ban on the movement of hemlock from infested areas.
For more information on the HWA quarantine or other exotic pests, go to www.michigan.gov/exoticpests.