GREENFIELD, WI (WTAQ) - The emerald ash borer has been spotted in the Milwaukee suburb of Greenfield.

State agriculture officials said Thursday that the tree-killing beetle was confirmed along South 43rd Street.

They said the finding was not unexpected, because ash trees had distinctive “S”-shaped galleries that provide evidence that the borer’s larvae had grown underneath. Also, officials said the ash borer was discovered earlier in neighboring Greendale, also in Milwaukee County.

The bug has killed millions of ash trees in the eastern half of the U.S. – and it’s been confirmed in 13 counties throughout the southeast half of Wisconsin.