Meanwhile, the quarantine zone is being expanded into a part of Clark after an infested tree was found in northwestern Linden two months ago, according to the state Department of Agriculture.

Personnel began looking at the industrial area after individual trees in parts of Linden were infested without large numbers of trees surrounding them showing signs of the beetle. Computer modeling suggested the beetles may have been coming from the industrial area, which at the time was outside the existing quarantine zone. A subsequent survey of that area found additional infestation.

As of mid-May, 579 infested trees have been detected in Middlesex and Union counties and 529 trees have been removed. In addition, 16,614 high-risk host trees have been removed from the area since November 2004.