GREENFIELD, Ind. (AP) _ A central Indiana city's main park is facing the loss of more than half its mature trees because of damage from the emerald ash borer.

The invasive beetle originally from Asia has been found in ash trees throughout Indiana and last month prompted workers to cut down a 75-foot tree in Greenfield's Riley Park.

City naturalist Joe Whitfield tells the Daily Reporter and WRTV he knew the trees would eventually start dying and that it could be devastating for the 40-acre park.

City workers marked each of the park's 125 ash trees two years ago. They've been monitoring them for damage and tried insecticide treatments on some.

Officials say the city's newer parks don't have ash trees because they knew the emerald ash borer would eventually show up.