Beetles keep hemlock tree attackers at bay

A U.S. Forest Service survey shows hemlock trees are still abundant despite an insect infestation that has decimated the trees in some areas.

New Jersey is employing a secret weapon—beetles that are helping to prevent the hemlocks in New Jersey from being wiped out.

Raised at the New Jersey Department of Agriculture’s Beneficial Insect Lab, the beetles attack the insect called woolly aldegid that kills hemlocks by sucking the sap from the trees.

Those beetles are making a difference, said Mark Mayer, the lab’s supervising entomologist.

“I wouldn’t call it a complete success story yet because we don’t have this beetle in all the hemlock stands in the state,” he said. “But where we have released it, and there still is hemlock woolly adelgid, the beetle is doing very, very well.”

As the number of beetles increases, Mayer anticipates more hemlocks will thrive. He said all the rain this summer has helped by preventing the attacking insects from draining the trees’ moisture.