WATERBURY – Several hundred tiny beetles from Idaho, called Laricobius nigrinus, are scheduled to be released later this week in a Brattleboro forest infested with hemlock woolly adelgid. Hemlock woolly adelgid is an Asian insect that recently moved into Windham County. It damage hemlocks by sucking sap from their twigs.
Laricobius nigrinus is a predator of hemlock woolly adelgid native to the Pacific Northwest. It has already been widely released in the eastern United States, including in our neighboring states of Massachusetts, New Hampshire and New York.
The beetles are being released as part of a research project being conducted by Dr. Dave Mausel from the University of Massachusetts. It is hoped that they will not only survive the winter, but also reproduce. According to Dr. Mausel, “We believe this predator has real promise, and could turn the tide against the adelgid.”
Follow-up measurements will be taken to determine whether these beetles, collected from Idaho, are more tolerant of cold winters than beetles of the same species collected from the Pacific coast.
“People are rightly concerned about releasing predatory beetles into the environment,” said Barbara Burns, Forest Health Program coordinator for the Vermont Department of Forests, Parks, and Recreation. “We believe this beetle is unlikely to become a problem … and it has the potential to help save our hemlocks.”
Beetles in the genus Laricobius feed only on adelgids. Laboratory tests conducted before this beetle was first released in 2003, showed that this species thrives only on hemlock woolly adelgid. If they don’t have adelgids to feed on, they will die out.
Hemlock woolly adelgids were first discovered in Vermont forests in 2007. Since then the beetle has been detected in the towns of Vernon, Guilford, Dummerston, Townshend and Jamaica. Feeding by the hemlock woolly adelgid leads to twig dieback and, eventually, tree mortality.
![Vermont Division of Forestry [photo]](../img/top_banner.jpg)
