MADISON - Wisconsin officials are expanding their quarantine after finding the emerald ash borer in Washington County.

The tree-killing, Asian insect has been already been detected in Ozaukee County and nine other states.

It lays its eggs inside ash trees. Larvae hatch and chew through the tree's fluid-conducting vessels, killing the tree.

The state Department of Agriculture, Trade and Consumer Protection says three tiny, green beetles were found Aug. 1 in Newburg in southeastern Wisconsin. A Michigan lab confirmed they were emerald ash borers and notified the state Wednesday.

The state quarantine bans the moving of firewood, ash nursery stock, timber and other items likely to be invested with ash borers out of Washington and Ozaukee counties.

(Copyright 2008 by The Associated Press. All Rights Reserved.)