RLHT Installs Spruce Budworm Pheromone Traps 

RANGELEY - You might remember the spruce budworm (SBW) infestation that attacked Maine nearly 40 years ago. Once again, Maine is threatened by this small insect that may have the potential to make a big impact on Maine’s working forestlands.

The SBW is a native insect whose population cyclically explodes leading to massive feeding on maturing fir and spruce trees. In Maine, the SBW may also attack black and red spruce, larch and hemlock. Additionally, planted trees such as Douglas fir, Norway spruce and Colorado blue spruce can also be part of its diet. An entire tree can be defoliated within a two- to four-year window, reducing forest value and increasing the potential of wildfires as a result of dying timber acting as fuel.

Adult SBW emerge as moths in July and swarm about the trees. They are grayish-brown, marked with white and black spots. They are about 1.5 cm long with a 2.5 - 3 cm wing span and are often referred to as "millers." By late July, the female moths lay her eggs in light green masses of about 20 eggs each on the underside of fir needles or on spruce needles. A single female lays a total of approximately 200 eggs. These two stages are the most common form of identification by the human eye.

Outbreaks or single trees can be controlled on the ground using pesticides approved by the EPA and the Maine Board of Pesticides Control.

Due to our warming climate trend, some researchers suggest that it’s possible the anticipated outbreak will be a less severe outbreak than which occurred in the 1970s. Regardless, the key is early detection, as it may be the best plan on preventing massive tree die off and other major forest disturbances.

Rangeley Lakes Heritage Trust, working with our foresters at Seven Islands Land Management Company and the state, have installed 15 SBW traps on five separate RLHT parcels. These strategically set pheromone traps are designed to lure, trap and kill any potential budworm. These traps will be collected by late August and turned into the Maine Forest Service for evaluation of any SBW populations.

This potential threat to our forests is real, but we are being proactive in an effort to be reactive, should it occur. To learn more about the SBW, we urge you to visit the Maine Forest Service here.