In 2019, pheromone trap captures peaked at an average of 67 moths per trap following a mass migration event from Canadian SBW outbreak areas. In the years following, the statewide average decreased to 36 in 2020, 16 in 2021, and remained at 16 moths per trap in 2022. In 2023, we observed another slight decrease, with the statewide average dropping to 13 moths per trap across 354 monitoring sites. This drop is primarily driven by the fact that 12 percent of sites statewide (43 sites) captured zero moths in 2023. The percentage of sites averaging more than 200 moths per trap also increased in 2023 but remained low at just one percent. The geographic locations of these sites in the higher bracket may be important since there appears to be some degree of concentration in far northwestern Aroostook County. This area warrants closer attention during the upcoming 2024 monitoring season.”
– Maine Forest Service, 2023 SBW Annual Report
Report takeaways:
- The statewide average of spruce budworm caught in pheromone traps slightly decreased in 2023 primarily because of 43 sites recording 0 moths
- Elevated (50-300+ moths per trap) sites were found on the Canadian border near Saint Pamphile. This area is close to an ongoing outbreak in Quebec and warrants closer attention during the 2024 monitoring season
- The Spruce Budworm Lab is still working to release finalized maps of Maine’s 2023 L2 populations, which paint a more accurate picture of potential defoliation and damage from budworm populations. More samples are being processed this year due to higher L2 numbers being recorded at long-term monitoring sites
Michael Parisio is a Forest Entomologist with the Maine Forest Service and has coordinated the pheromone trapping network and spruce budworm monitoring programs and reports since 2019.