OMAHA, Neb. (AP) — The City of Omaha has begun preparing for an infestation of the emerald ash borer.

Mayor Jean Stothert said Friday that she will budget $1 million a year in the city’s five-year capital improvement program, beginning in 2017. The city has begun preparing for the expected infestation by cutting down unhealthy ash trees and buying tree-removal equipment.

City Parks Director Brook Bench says the city has hired a four-person tree-trimming crew devoted solely to ash trees.

The insects are native to Asia and were first spotted in the U.S. in 2002, when they showed up in the Detroit area. The emerald ash borer has killed millions of trees. Once infected, trees typically die within five years.