Join the Hunt for the Emerald Ash Borer in Maine

May 26, 2022

The Maine Forest Service (MFS) invites you to join us in tracking the spread of emerald ash borer (EAB). We are looking for volunteers outside the area of Maine known to be infested by EAB for our Girdled Trap Tree and Green Funnel Trap networks. We especially seek volunteers with ash trees (Fraxinus spp.) located in Oxford, Androscoggin, and Sagadahoc counties. However, sites in other places outside of known infested areas are also welcomed. These methods will only draw EAB from the immediate area.

Why do these networks exist?

The information from these surveys will help the MFS and our partners better understand where EAB is and support planning and management to respond to this destructive invasive forest pest. These surveys augment monitoring using purple prism traps and biosurveillance. They are supported in part by funding from the USDA Animal and Plant Health Inspection Service and Forest Service.

Girdled Trap Tree Network

Trap trees are perhaps the most powerful tool for towns, landowners and managers, land trusts, and others to monitor for EAB in their specific areas. Trap trees have often detected EAB one to two years before any external signs of infestation. This allows more time for land managers to plan and manage their forests, and cities and towns make decisions about public ash trees and management of ash near public infrastructure ahead of ash tree death.

A trap tree is created by removing a cylindrical section of bark from around the trunk in late spring. The tree stays alive throughout this growing season but is stressed, causing it to release scents into the air, making it attractive to EAB in the area. If present, EAB are more likely to come to this tree than a random ash.

A trap tree should be:

  • Any species of ash (Fraxinus spp.) can be used (not mountain ash).
  • Open to sunlight on at least one side. Trees such as those at the edge of road, field or stream, or above the canopy, are much more attractive to EAB and make better trap trees.
  • Healthy prior to girdling.
  • Four to 10 inches diameter at about 4.5 feet from ground level.

Details on how to girdle a trap tree are available on our website. If you girdle an ash tree for EAB monitoring, please use the online form, EAB Trap Trees 2022, to report it to the MFS. You can also reach out at or (207) 287-2431 if you have trouble with the form, have questions about selecting or girdling a tree, or if you need assistance. Those who let us know that they are girdling an ash tree will receive information in on how to fell and section trap trees and information on processing them to look for EAB.

Green Funnel Trap Network

Interested in monitoring for emerald ash borer, but not ready to sacrifice your ash tree?

The MFS is seeking volunteer cooperators to monitor a limited number of green funnel traps for the presence of emerald ash borer. If you have an ash on your own property, or nearby in which you could request permission to place a trap and monitor through the growing season, we'd love to hear from you.

An ideal tree for a trap:

  • Is away from powerlines and other hazards that might impede trap hanging (often traps are hung by hurling a weighted line high up into the tree canopy).
  • Gets plenty of sunlight such as trees on a forest edge or in an open area.

Please fill out this form to express your interest in monitoring a green funnel trap. We will begin deploying traps late May through late June. MFS staff will install the trap in a tree on sites selected for participation and provide all materials and training for biweekly or weekly trap collections.