UPDATE: Seven more counties added to emerald ash borer quarantine

MADISON (AP) — Wisconsin agricultural officials have added seven more counties to the state's emerald ash borer quarantine.

The Department of Agriculture has found the destructive insect in three of those seven counties — Columbia, Grant and Monroe. The rest are in close proximity, which include Richland, Iowa, Lafayette and Green.

That brings the total number of counties under quarantine to 29.

For businesses handling wood products, it means they must work with ag officials to assure the products are pest free before shipping to non-quarantine counties. For citizens, it restricts the movement of firewood.

Since the emerald ash borer was first discovered in North America, it has killed tens of millions of ash trees in 18 states.