NHBugs

Protecting trees and forests

Recommendations for homeowners and landowners

Management zones

Generally infested area
Emerald ash borer is in this zone, though not necessarily in all ash trees.

Potential expansion area
Emerald ash borer isn't known to be in the area, but the area is within 10 miles of the outer limits of the known infestation. There is a high probability emerald ash borer will spread naturally to this zone within a few years.

Alert area
Emerald ash borer isn't known to be in the area and it is more than 10 miles from the known infestation.

Quarantine
All of Merrimack County is quarantined regarding the movement of ash products and all hardwood firewood. To learn about the quarantine.

Definitions

Diameter at breast height (DBH)- Diameter of a tree at 4.5 feet above the ground

High-value ash- A tree valued for economic, ecological, aesthetic or cultural reasons.

Sentinel tree- A high-risk ash, normally with a large crown, exposed to sun. Used to monitor for EAB.

Sink sites- Low-value ash within 1/4 mile of high-value ash where trees are girdled to attract EAB away from high-valued ash.

Trap tree- A low-valued ash girdled to attract EAB and monitored by the N.H. Division of Forests & Lands.

The long term management of emerald ash borer in New Hampshire involves actions by state and federal agencies, homeowners, forest landowners, communities and others, including:

  1. Regulation and the enforcement of quarantines by the N.H. Dept. of Agriculture, the N.H. Division of Forests and Lands and USDA Animal and Plant Health Inpsection Service,
  2. Outreach and public education by UNH Cooperative Extension and others, and
  3. Management of emerald ash borer (EAB) populations and ash trees by state agencies, homeowners, forest landowners, communities and others.

From the experiences in the rest of the country, we know we won't be able to eradicate emerald ash borer from New Hampshire. Our goal is to slow the spread of ash mortality. By doing so we will:

  1. Give time for natural predators introduced biocontrols (predators and parasites) to establish control.
  2. Allow communities to plan and budget for ash tree management or removal.
  3. Allow forest landowners time to maximize economic returns from ash silviculture.
  4. Allow all of us to enjoy native ash trees for as long as possible.

Management zones, based on risk of infestation by EAB, are established for all of New Hampshire. Homeowners and landowners can take action depending on location (see map):

  1. Generally infested area
  2. Potential expansion area (within 10 miles of the infestation)
  3. Alert area (beyond 10 miles of the infestation)

Recommendation are given by zone for urban and forested landscapes:

Generally infested area for urban landscape:
  1. Inventory your trees by species, size and value.
  2. Evaluate ash trees for signs of EAB infestation. Report a suspect tree or insect or call 1-800-444-8978.
  3. Consider insecticide treatment options for any high-value ash.
  4. Consider removing low-value ash trees while they’re still healthy. Use the material locally as the quarantine allows.
  5. Cut all known infested trees. Use the material as locally as possible, preferably on-site. Handle the material as the quarantine regulations require.
Generally infested area for forest landscape:
  1. Inventory your trees by species, size, location and value.
  2. Evaluate ash trees for signs of EAB infestation. Report a suspect tree or insect or call 1-800-444-8978.
  3. Remove infested trees for on-site consumption or treatment based on quarantine regulations.
  4. Remove as much of the large ash (greater than 12” diameter at breast height, dbh) as possible, leaving smaller ash.
  5. Identify high-value ash trees that warrant protection.
  6. Create sink sites where ash trees will be used to lure beetles away from high-value ash trees. Cut and destroy ash in the sink site when infested.
  7. Identify highly susceptible sentinel ash trees and monitor every year.
  8. Create two trap trees in each stand containing more than 5% ash stocking.
Potential expansion area for urban landscape:
  1. Inventory your trees by species, size and value.
  2. Evaluate ash trees for signs of EAB infestation. Report a suspect tree or insect or call 1-800-444-8978.
  3. Consider removing low-value ash trees while they’re still healthy.
  4. Consider preventative insecticide treatments for high-value trees.
  5. Identify large sentinel ash trees and monitor every year.
Potential expansion area for forest landscape:
  1. Inventory your trees by species, size, location and value.
  2. Evaluate ash trees for signs of EAB infestation. Report a suspect tree or insect or call 1-800-444-8978.
  3. Remove as much of the large ash (greater than 12” diameter at breast height, dbh) as possible, leaving smaller ash.
  4. Identify high-value ash trees that warrant protection.
  5. Identify areas of ash trees suitable for creating sink sites where ash trees will be used to lure beetles away from high-value ash. Cut and destroy ash in the sink site when infested. 
  6. Identify highly susceptible sentinel ash trees and monitor every year.
  7. Create two trap trees in each stand containing more than 5% ash stocking.
Alert area for urban landscape:
  1. Inventory your trees by species, size and value.
  2. Evaluate ash trees for signs of EAB infestation. Report a suspect tree or insect or call 1-800-444-8978.
  3. Consider removing low-value ash trees while they’re still healthy.
  4. Identify large sentinel ash trees and monitor every year.
Alert area for forest landscape:
  1. Inventory your trees by species, size, location and value.
  2. Evaluate ash trees for signs of EAB infestation. Report a suspect tree or insect or call 1-800-444-8978.
  3. Identify high-value ash that warrant future protection or harvest.
  4. Identify highly susceptible sentinel ash trees and monitor every year.
  5. Create two trap trees in each stand containing more than 5% ash stocking.