What will be the fate of our Hemlocks in the Eastern US?

Healthy Hemlock


Or this?

Or this?

The imported Hemlock Woolly Adelgid (HWA) has brought widespread destruction to our native hemlocks in the eastern US. The loss of the hemlock would be an ecological disaster for our mountain coves and waterways, as well as our neighborhoods and parks. As a keystone species, on which many others depend, hemlocks provide critical shelter and habitat for a whole range of animal species including birds, amphibians, fish and mammals. And there are no apparent successors, native or otherwise, that could fill the critical ecological niche of the hemlock. So all hemlock-dependent ecosystems would be threatened by the hemlock’s demise.

The threat of hemlock loss is real, but it is not inevitable. USDA-approved biological control agents, primarily predator beetles, exist that can reduce the threat of HWA to our native hemlocks and allow the long-term survival and recovery of our native hemlock ecosystems. This recovery process is already in evidence in both wild and residential hemlock areas. But it requires human involvement to introduce the predator beetles. Public hemlocks already have their advocates at USDA, but hemlocks on private lands will only survive with your help.

The HWA predator beetles approved for release in the eastern US are so highly specialized that they cannot reproduce without adelgids present. So they are not a potential destructive force for other insects or plants. And USDA-sponsored genetic research has identified the origin point of our HWA import in Southern Japan, which is also the origin for the predator beetle – Sasajiscymnus tsugae (aka St or Sasi). And this predator beetle, with millions of USDA-sponsored releases on public lands,  is now also available to protect hemlocks on private lands as well.

The purpose of this site is to emphasize the important role for private citizens’ and landowners’ involvement in saving our native hemlocks from the Hemlock Woolly Adelgid. Whether your HWA-threatened hemlocks are in a neighborhood, a local park, or a wild cove or waterway, you can do something to protect them and to contribute to their long-term return to health and survival. And you can do this without resorting to short-term chemical treatments involving environmentally dangerous insecticides.

To learn more about the history and biology of our Hemlock Woolly Adelgid problem, go to Bio Control

To learn how to get predator beetles to help your hemlocks, go to How to Help