The Maine Forest Service Division of Forest Health and Monitoring coordinates a network of roughly 350 spruce budworm monitoring sites using pheromone lures in spruce-fir forests across Maine. Insects, like the spruce budworm, use pheromones signals to find each other and mate. The traps use a pheromone lure, which attracts and traps nearby male spruce budworms. Pheromone traps are set strategically throughout Maine during the moth flight season (June-August). The traps are collected in late August and turned into the Maine Forest Service for evaluation of spruce budworm populations. The Maine Forest Service produces yearly maps based on those trap collections. A subset of long-term trap sites has been monitored since the early 1990s and has helped track spruce budworm population fluctuations over time. More information on the Pheromone Trap Network can be found in the Spruce Budworm Annual Reports that the Maine Forest Service produces.