Green ash tree marked for harvest

If a site with green ash trees meets certain criteria, the USDA returns in late summer to peel back bark of trees. That's the emerald ash borer larval-evaluation method USDA uses to determine emerald ash borer-infestation levels. The department then marks each tree to be harvested.

The U.S. Department of Agriculture’s Biological Control Facility continues to seek landowners to donate living ash trees to support laboratory production of parasites that combat the emerald ash borer.

“A vital part of our program is to harvest green ash trees infested with the emerald ash borer,” said Paul Nelson, field team-leader at the emerald ash borer biological-control rearing facility at USDA’s Animal Plant and Health Inspection Service in Brighton, Michigan. “Harvesting the wood allows us to capture the beetle in its adult form, which is then used to replicate populations of the parasites.”

The facility uses trees between 8 inches and 20 inches in diameter at breast height to support its production process. The facility needs green ash trees only. It also needs trees that are still living. Ash trees typically show significant signs of decline but retain some leaf canopy throughout the summer and shouldn’t be completely dead. Nelson will conduct landowner site visits after leaves have budded in spring.

“Our focus area looks to be properties in northern Sheboygan County, Fond du Lac County and Door County” he said. “If the site meets most of our criteria, I would return in late summer to peel back bark of trees one by one. That’s the emerald ash borer larval-evaluation method we use to determine infestation levels. We mark each tree to be harvested based on that methodology.”

The USDA subcontracts and pays for the harvests. Sites also are remediated to the best of a contractor’s ability to pre-harvest conditions, Nelson said.

The USDA requests donations of 50 or more ash trees. It will harvest trees weekdays between 8 a.m. and 4:30 p.m. Contact or 734-732-0025 for more information.