MADISON, Wis. -

The emerald ash borer continues to be a concern for the city. Madison Mayor Paul Soglin met with city of Madison forestry crews Friday to demonstrate a new way to treat infested trees.

The emerald ash borer are beetles that can move into a tree, leading to its eventual death. Invested trees were first found on Madison’s Northside November 2013.

Soglin and forestry crews demonstrated a chemical injection treatment of ash trees that will protect trees against the emerald ash borer. The chemical treatments will be injected into healthy trees. Small holes are drilled around the tree and the injection is placed inside.

There are nearly 22.000 publicly owned ash trees on Madison streets, and an unknown number of trees in parks and private property, according to the Forestry Department.

The Ccty of Madison hopes to save 65 percent of trees over the next several years.

“The work is complex. It takes time. Our work is affected by the seasons and we have to be as efficient as possible so we can treat the maximum number of trees as quickly as possible,” said Soglin.

Madison is one of 30 municipalities using tree trunk injections, according to the Forestry Department.