New Hampshire
Forest Health Update

Hemlock Woolly Adelgid populations have declined around the state and were difficult to find in some areas that had previously been heavily infested. This is most likely weather related as hwa winter mortality rates were very high the past couple of years. Surveys for 2019 were done in 23 towns that border infested areas in NH. Towns surveyed included Marlow, Stoddard, Sullivan, Nelson, Harrisville, Roxbury, Dunbarton, Allenstown, Pittsfield, Barnstead, Gilmanton, Belmont, Tilton, Laconia, Effingham, New Hampton, Center Harbor, Northfield, Canterbury, Boscawen, Sandwich, Tamworth, and Ossipee. New infestations were detected in Sullivan, Harrisville, Roxbury, and Allenstown.

(Click on maps for higher resolution pdfs.)

Elongate Hemlock Scale surveys for 2019 were done in conjunction with HWA surveys. Towns surveyed included the towns surveyed for HWA and the towns of Dublin, Jaffrey, Candia, Madbury, Lee, Barrington, Marlborough, Bennington, Hancock, and Deerfield. New infestations were detected in Jaffrey, Candia, and Deerfield.

Our winter visual survey for emerald ash borer is now complete and infestations were detected in six new towns: Newton, Chester, Nottingham, Barrington, Farmington, and Rochester. As the size of the overall infestation increases in New Hampshire more people are being forced to make difficult decisions about how to care for their forested and landscape trees. It is important to remember that to manage your trees in the face of the advancing wave of this destructive pest it is critical to know where you stand in relation to known outbreaks and that the best tool to find this information is the Infestation Location and Management Map which can be found at www.nhbugs.org . This map is regularly updated with the latest detections and can be used in conjunction with other information on the NHbugs website about insecticide treatments for ornamental trees and management recommendations for forested trees to decide what action you will take in response to emerald ash borer, along with the appropriate time to initiate your response.

In the upcoming months we will continue to monitor the spread of EAB within the state using purple prism traps. We will also be initiating several new locations to carryout biological control releases which remains our best tool for long term management of emerald ash borer.