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Submission information
Insecticide and biocontrol treatments at Maquam Wildlife Management Area, Swanton, VT
Green, white and black ash within the site were becoming infested with EAB. Parasitoid releases began in 2023 and continued into 2024. Injections of emamectin benzoate were conducted in 2025 on black ash (male and female) at the site. Both treatments occurred to maintain ash on the landscape at this important WMA. Injected trees will be monitored for canopy health annually and will be re-treated as needed.
Site Location
Swanton, Vermont
Wildlife management area (state-owned) in northwest corner of Vermont; nearly bordering Lake Champlain
44.905965
-73.157757
From Swanton, take Rt. 78 west across the Mississquoi River and take a left at the stop sign onto S River St. Take the next right onto Lake St. (Rt. 36), and follow for 1.5 miles to the parking access for Swanton Beach. Upon exiting vehicle, backtrack on Lake St. approx. 0.1 miles to a small pulloff with gate across logging road. Follow logging road and navigate via GPS to treatment site.
Site only accessible on foot
State of Vermont – Fish and Wildlife Department
+1(802) 878-1564
Stand Information
20 ac. = treatment area; 32 ac. = treatment area + untreated area with mortality
Ash
emerald ash borer
emerald ash borer
Pre-treatment Conditions
https://anrmaps.vermont.gov/websites/wma/maps/Maquam%20Bay.pdf
EAB presence
Silviculture Prescription
Multiple ash species impacted by EAB. In an effort to keep ash on the landscape, a total of 12 biocontrol releases occurred between 2023-2024, and 12 ash trees were injected with emamectin benzoate (4%) in 2025. Treated trees will be monitored annually and re-treated when appropriate. Establishment of biocontrol parasitoids will be assessed starting in 2026.
Trying to keep ash on the site
Trying to keep ash on the site
- forest health
EAB parasitoids (larvae, pupae, eggs) for 3 species (Tetrastichus planipennisi, Oobius agrili, Spathius galinae)
ArborJet Quik-Air injection system and plugs
Tree-Age G4 (4% emamectin benzoate)
Power drill
Biocontrol releases – received shipments from USDA-APHIS PPQ and released as directed, either by affixing bolts to trees, opening cups containing adults, or affixing egg containers (“oobinators”) to trees Injections – measured DBH to inject proper amount, drilled corresponding number of holes on or near root flares, installed plugs, injected insecticide
Post-treatment
yes
Miscellaneous
32
$1,370 for staff time and chemicals. Injection system = $2800
Will re-treat in 2027 or 2028 depending on tree condition
Statistics
Contact Information
Josh Halman
VT Dept. of Forests, Parks and Recreation