Pests and Disease

Report Browntail Moth sightings with our SeeClickFix tool.

The Browntail Moth Caterpillar has tiny poisonous hairs that cause dermatitis similar to poison ivy on sensitive individuals. People may develop dermatitis from direct contact with the caterpillar or indirectly from contact with airborne hairs.

The hairs become airborne from either being dislodged from the living or dead caterpillar or they come from cast skins with the caterpillar molts. Most people affected by the hairs develop a localized rash that will last for a few hours up to several days, but on some sensitive individuals the rash can be severe and last for several weeks. 

The rash results from both a chemical reaction to a toxin in the hairs and a physical irritation as the barbed hairs become embedded in the skin.

Helpful Links

• Maine Department of Agriculture, Conservation & Forestry (Link)
• Maine CDC Browntail Moth InformationI

The City of Bangor's Emerald Ash Borer Response Plan

One of the greatest threats the trees of Bangor face is Emerald Ash Borer (EAB). EAB is an invasive beetle from Asia that was introduced into the U.S. in 2002, and reintroduced to the mid-Atlantic region in the years following. Since then, it has spread north through New England, and was found in Maine in 2018. As of 2025 it has been found as far north as Exeter in Penobscot County, and in Aroostook county from an introduction made through Canada.

To learn more about EAB in Bangor you can visit the City’s EAB StoryMap. You can view the City’s EAB Response Plan here Version Options Pests and Disease Headline. If you believe you may have found EAB in Bangor, please report it using SeeClickFix, or call the Forestry Division at 207-992-4514. The Forestry Division is also requesting that privately owned ash trees be reported so that they can have a better understanding of how many privately owned ash trees are in the City.

There is currently an Ash Wood Quarantine active in Maine to reduce the spread of EAB. It is requested the residents of Bangor do not move ash firewood into or out of the City. 

If you have ash trees on your property that you would like to protect from EAB, you can find a list of licensed pesticide applicators from the tab below. You can use the Private Ash Treatment Guide from the MFS to help make decisions on how to best manage your ash trees. Injected insecticides are the best method to treat trees, and foliar sprays are not recommended. 

Helpful Links

Emerald Ash Borer (EAB) : Forest Health & Monitoring : Maine Forest Service : Maine Agriculture, Conservation, Forestry (DACF)

EAB Quarantine FAQ Revisions_May2024.pdf

How to ID Ash Trees (video)

Emerald Ash Borer | Animal and Plant Health Inspection Service

Hemlock Wooly Adelgid (HWA) is a scale insect that feeds on hemlock tree species. They can be found on the underside of hemlock needles, and form egg sacs that almost look like lint balls. Their feeding causes needle-loss and decline, and a large enough infestation can eventually kill a tree.

HWA is not yet detected in Bangor, but has been found in 60 coastal and Southern Maine towns, per the Maine Forest Service. Bangor is in a hemlock quarantine area, so no hemlock trees or wood products should be moved into or out of the City to slow its spread.

There are few Eastern hemlocks found as street or park trees in Bangor, however, Brown Woods, Prentiss Woods, and the City Forest have large populations of Eastern hemlock. Their loss would drastically change the landscape of these areas. You can learn more about HWA and how to identify it on the MFS HWA webpage.  

Helpful Links

Hemlock Woolly Adelgid | National Invasive Species Information Center

Hemlock Woolly Adelgid - Acadia National Park (U.S. National Park Service)

Hemlock Woolly Adelgid Overview: Forest Health & Monitoring: Maine Forest Service: Maine DACF

Red pine scale is an invasive insect that can devastate red pine trees. It has been detected in at least three Maine counties and, as of February 2026, there is concern that it will eventually spread to Penobscot County and Bangor. 

Red pine scale (RPS) is a scale insect native to Asia that is believed to have been introduced to the U.S. in the 1930s. It feeds on nutrients in red pine trees by inserting their sucking mouthparts into the upper branches and twigs. This feeding interrupts the flow of nutrients and water to the needles of the trees, leading to canopy decline and eventual death. RPS was first detected in Maine in Hancock County on Mount Desert Island in 2014. Since then, it has also been found in Washington County and York County. Over 1,800 acres of red pine mortality have been detected by the Maine Forest Service and are directly attributed to RPS.

The City of Bangor has 131 red pine street and park trees. These trees will continue to be monitored for signs and symptoms of RPS; however, they are of relatively low concern because they are a low percentage of the urban canopy. What is of greater concern are the thousands of red pine trees planted in plantations across the City’s publicly owned properties and parks in Bangor and Winterport. These are monocultures of red pine that are highly susceptible to RPS infestations and much more difficult to monitor on a regular basis. Additionally, because of the density of the plantings and closure of the forest canopy, in most of these plantations there is little to no tree regeneration growing underneath to succeed the overstory red pine trees.

Chemical treatment of publicly owned red pine is not a viable option for managing RPS in the City. For this reason, active management through invasive plant management, thinning, harvesting and replanting these red pine plantations is the chosen course of action. Invasive plant management will occur first and involve the use of mechanical, cultural and chemical controls. Other treatment efforts will follow.

Helpful Links

• City of Bangor Red Pine Scale Response Plan, February 2026 (PDF)

Spruce budworm (SBW) is a native moth species in Maine. The caterpillars defoliate balsam fir and spruce trees. At high enough populations, this can cause significant loss of fir and spruce trees. This is mostly concerning for large land managers and timber producers, as it leads to large financial losses. Populations occur at low levels almost continuously within spruce-fir forests, and losses are minimal. However, when populations reach outbreak levels—which occurs every 40 or so years—intervention is necessary to avoid major monetary loss.

SBW is carefully monitored for in northern Maine, and to varying degrees across the rest of the state. It is not of great concern for the City, unless you have private property with high volumes of spruce or fir. If you are concerned about SBW, you can reach out to a member of the Forestry Division at 207-992-4514.

To learn more about SBW, see the Maine Forest Service Spruce Budworm webpage.

Helpful Links

• Return of the Spruce Budworm to Maine
• Spruce Budworm in Maine: Forest Health & Monitoring: Maine Forest Service: Maine DACF
• Spruce Budworm Early Intervention Strategy Shows Promise in Maine
• Spruce Budworm Maine | Maine SBW Task Force