State officials want to determine whether a tree-killing beetle has spread beyond a quarantined area in Northern Virginia.

The Virginia Department of Agriculture and Consumer Services said Monday it will install 3,500 traps across the state to determine the extent of the emerald ash borer infestation.

Commissioner Todd P. Haymore said the survey's findings will help local officials develop plans to manage the beetle.

A quarantine was issued in 2008 for Arlington, Fairfax, Fauquier, Loudoun and Prince William and the cities of Alexandria, Fairfax City, Falls Church, Manassas and Manassas Park after the emerald ash borer was found in Fairfax County.

The beetle feeds on the layer of wood just beneath the bark of the ash tree, cutting off water and nutrients.