Hemlock Woolly Adelgid

Hemlock woolly adelgid (Adelges tsugae) is a small invasive insect native to Asia that is a threat to the health and sustainability of eastern hemlock (Tsuga canadensis) and Carolina hemlock (Tsuga caroliniana). Hemlock woolly adelgid, which is related to aphids and scales, feeds on the hemlock's tissues and the build-up of large populations can result in the decline and death of hemlock trees.

Hemlock woolly adelgid has been expanding its range in New Hampshire since it was initially detected in1999. This pest is now found in more than half of the towns in the state (120) and every county except Coös. This pest can be introduced into new areas by birds and other wildlifeand through human activities - namely themovement of infested nursery stock and forestry products. Spread of hemlock woolly adelgid on nursery stock and forestry products is prohibited by existing nursery stock (RSAs 433:28-433:30) and forestry (RSA 227-K:17) regulations which prohibit the sale of nursery stock and forestry products infested with dangerous plant pests. Hemlock woolly adelgid is also a prohibited invasive insect in the state (Agr 3802.01)-it is not permissible to transport live hemlock woolly adelgid except for purposes of destruction. Hemlock woolly adelgid and other hemlock pests threaten the landscape and natural hemlocks of New Hampshire. Plant Industry conducts inspections of nursery stock, Forests and Lands responds to detections of hemlock woolly adelgid in forested settings with survey, cultural controls, pesticide applications, best management practices recommendations and a bio-control program. Nurseries and foresters should use best management practices to reduce their risks. The public should learn how to identify this pest and report it (NHBugs.org) where it is found. Landscape hemlocks should be protected from drought, and when infestations are suspected, they should be confirmed by a tree car professional who can offer assistance on managing tree health.

• USFS Hemlock Woolly Adelgid Pest Alert
• UNH Cooperative Extension Hemlock Woolly Adelgid Fact Sheet
• HWA Quarantine Eliminated 2018
• HWA Best Management Practices for Nurseries