Under imminent threat of invasion by a wide-reaching army of emerald ash borers, West Chester has set up a thorough, first-in-the-state defense strategy that itself is spreading across the commonwealth and beyond.

The 2013 pilot program has since garnered federal grant funding to continue scouting out ash trees in the borough’s most important parks and proactively treating some trees with “an injectable, systematic insecticide to ward off the borer,” according to an announcement from state Sen. Andy Dinniman, who heralded the approach’s success on Arbor Day.

“For 26 consecutive years, West Chester has received the Tree City USA Award for its commitment to maintaining the health, beauty and diversity of trees throughout our parks, neighborhoods and the downtown,” Dinniman said. “I want to thank all the staff and volunteers for their ongoing efforts in safeguarding our trees and preventing invasive species like the emerald ash borer from jeopardizing our rich natural heritage.”

West Chester is surrounded by infestations — in 56 of Pennsylvania’s 67 counties and 25 of the 50 states — that, without action, will girdle an ash tree’s living tissue just beneath the bark, cutting off its supply of water and nutrients to the branches and leaves.

“You never know when the infestation is going to happen,” Pennsylvania Department of Conservation and Natural Resources Forest Health Manager Donald Eggen said. “We don’t have a good survey tool for detecting low populations. It can be percolating and then it appears and it’s here. They also start up high in the trees and by the time they get down to the bottom it’s too late.”

West Chester University and the West Chester Borough Urban Forester are also involved in the partnership.

Read more about their plan in official documents here.