The natural range of Agrilus planipennis, or the emerald ash borer, is eastern Russia, northern China, Japan, and Korea. Before June of 2002, it had never been found in North America.
New Jersey's first confirmed case of an invasive beetle that kills ash trees has surfaced in Somerset County.
A landscaper checking unhealthy trees in Bridgewater discovered insect larvae that are the emerald ash borer.
The beetle was first discovered in Michigan in 2002 and is present in 23 states, including New York and Pennsylvania.
The state Agriculture Department says larvae from the metallic green insects cut off the flow of nutrients and eventually kill ash trees.
The state will examine trees in the surrounding area to determine the extent of the infestation.
Officials say pesticides are available to protect trees.
Homeowners can prevent the spread by using locally-sourced firewood instead of bring wood in from other areas.