An invasive beetle that kills ash trees is moving further into Louisville. The emerald ash borer was found earlier this month in Shawnee Park.Arborists have known the emerald ash borer was in Jefferson County for awhile, and have been preparing. But the discovery of one in Shawnee Park is the first sign of the beetle in the Metro Parks system and shows the pest is moving west.As its name suggests, the emerald ash borer infects ash trees and eventually kills the tree. Once a tree is infected with emerald ash borers, there’s little that can be done. But city arborist Mark White says the city is working to identify the area’s bigger, more significant ash trees, and is taking steps to protect them.“The main thing is for us to continue to plant trees, plant the desirable trees, the right tree in the right place,” he said. “But at this time you will not see the city planting more ash trees until we can figure out how long this ash borer is going to be around.”About seven percent of the trees in downtown Louisville are ash trees. But White adds that it’s important to keep the problem in perspective.“A lot of people are panicking but we’ve had the same thing years back with our dogwood trees when we had the dogwood borer,” he said. “We had the same thing with our crab apple trees when we had the crab apple borer, and we have plenty of those around today.”The spread of the emerald ash borer can be slowed by not transporting firewood out of infested areas.