Oak Creek Carries On Tough Fight Against Emerald Ash Borer

The city of Oak Creek is treating more ash trees over the next few weeks as it enters Year 4 of the fight against the invasive emerald ash borer. 

The fight has proven tough, with many trees infested despite Oak Creek's efforts. City Forester Rebecca Lane says trees were probably more infested than the city realized when it began treatments, and last summer's severe drought also played a big role. 

Oak Creek is switching chemicals and its method of application for the latest round of treatments, which begin this week and continue through July 4. 

The city is also in the fourth year of the Legacy Tree Project, in which it receives five years of treatment for about 125 ash trees. 

The emerald ash borer is a species of beetle native to Asia that was accidentally introduced to Canada and the United States during the 1990s. It is a highly-invasive, destructive insect that feeds on the sap of ash trees, which are common in Oak Creek and throughout Wisconsin. Once an ash tree is infested with ash borer larva, it can die within a year.