Cornwall Swamp WMA - SAP-Ne Demonstration Site (Cornwall, VT)

The Vermont Department of Forests, Parks, and Recreation observed a high density of black ash at the site that is threatened with becoming infested with EAB. Injections of emamectin benzoate were conducted in 2026 on black ash (male and female) at the site. Treatments occurred to maintain ash in the landscape at this important Wildlife Management Area. 18 trees were injected in 2026; 20 trees will be treated in 2027 followed by another 12 trees in 2028. Injected trees will be monitored for canopy health annually and will be re-treated as needed.

Cornwall, Vermont

Wildlife management area (state-owned) in central Champlain Valley of Vermont; near Otter Creek River.

43.915921

-72.712223

From Middlebury, Vermont take route 30 south for 8.5 miles. Take a left onto Swamp Road and go 0.5 miles to small parking lot on left.

The site is accessible only on foot.

State of Vermont – Fish and Wildlife Department

+1 802-878-1564

98 acres

Ash

Red Maple-Black Ash Seepage Swamp

emerald ash borer

emerald ash borer

Emerald ash borer

Black ash is threatened by EAB. In an effort to keep black ash on the landscape, 18 black ash trees were injected with emamectin benzoate (4%) in 2026, 20 black ash will be treated in 2027, and 12 more in 2028. Treated trees will be monitored annually and re-treated when appropriate. Biocontrol parasitoids will be proposed for release in 2026 and releases will then occur in 2027 and 2028. Establishment of parasitoid releases will be assessed starting in 2029.

Trying to keep ash on the site.

Trying to keep ash on the site.

Management objectives are to maintain genetic diversity and to slow the decline and mortality of the black ash on site. Dominant and codominant trees with no less than 30% dieback will be targeted for insecticide treatments. Insecticide treatments will be done using Tree-age G4 emamectin benzoate (4%) insecticide. An ideal ratio of 1:3 male to female trees will be treated to maintain seed production and regeneration on site. A spatial and temporal treatment rotation will be implemented annually to always have a subset of trees with insecticide treatment occurring each year. This will maximize the treatment effect of reducing EAB population density in and around treatment zone while increasing staff efficiency.

• forest health
• invasive species

Arborjet Quik-Jet Air injection system and plugs

Tree-age G4 (4% emamection benzoate)

Power drill

Injections – measured DBH to inject correct amount, drilled corresponding number of holes on or near root flares, installed plugs, injected insecticide.

yes

In 2027 20 trees will be treated and then in 2028 12 trees will be treated. Biocontrol parasitoids will be released in 2027 and 2028.

Josh Halman

VT Dept. of Forests, Parks and Recreation