Browntail moth has been in Maine since 1904 and has been in an outbreak phase over a broader area since 2015.[1] The Maine Forest Service has found it in all 16 counties, including Cumberland County.[2] Populations can be heavy on one street and light on the next, so the best way to know about the trees around your South Portland home is to look for winter webs. The Maine Forest Service also keeps a map of known populations.[3]
In 2026, Maine CDC reported higher browntail moth populations in parts of Cumberland County, along with parts of Androscoggin, Hancock and Oxford counties, even as populations statewide have been steadily decreasing over the past couple of years.[4] The Maine Forest Service’s 2026 aerial survey found localized defoliation mainly along the western shores of Sebago Lake.[5]
Why browntail moth is a problem
Our browntail moth services in South Portland
Spray or injection?
Both are used for browntail moth in Maine. Near wells, the Maine Forest Service advises using tree injection rather than foliar spray or soil drench, to reduce off-site movement.[6] Speed and length of protection vary by product: some act within minutes and others take weeks, and injected products can remain active in trees anywhere from two weeks to two years.[6] One thing to avoid: insecticide capsules sold as Acecaps are not registered for use in Maine.[3]
Within 250 feet of the mean high tide mark along coastal waters, and upriver to the first bridge, additional rules apply to browntail moth treatments.[3] Like much of coastal Maine, South Portland has many properties close to the water, so treatment has to be chosen with care.
Want the full picture? Read our complete guide to browntail moth treatment in Southern Maine.
Browntail Moth help near South Portland
Tree Medics is based in Biddeford and works throughout Southern Maine. We also offer browntail moth services in nearby towns:
See all tree care in South Portland.
Sources
- Maine Forest Service: Browntail moth management overview
- Maine CDC & Maine Forest Service: Browntail moth hairs pose risk during spring outdoor activities
- Maine Forest Service: Browntail moth information, treatment timing and map of known populations
- Maine CDC Health Advisory: Browntail moth (May 2026)
- Maine Forest Service: Forest & shade tree conditions, August 2026
- Maine Forest Service: Browntail moth frequently asked questions
