The Wisconsin Agriculture Department says it has hung nearly 7,000 sticky, purple traps in ash trees across the state in search of the emerald ash borer.
Program manager Jennifer Statz says the tree-killing beetle has been found for the first time in Crawford County.
Statz says the traps indicate the infestation found near Victory in southwest Wisconsin this spring may be larger and more established than first suspected.
The emerald ash borer's larvae attack and destroy ash trees. The bug has been found only in southeastern and southwestern Wisconsin.
The beetles have destroyed trees in 11 other states and two Canadian provinces.