Biological Control of the Hemlock Woolly Adelgid
What will be the fate of our Hemlocks in the Eastern US?
Some observers have compared the possible loss of our Eastern and Carolina hemlocks with the loss of the American chestnut.
The loss of the majestic chestnut was a shock to our Eastern woodlands, especially to human and livestock populations that were dependent on its bountiful nut production. However, its place in the natural ecological structure was soon occupied by mast-producing oaks and hickories.
But the loss of the hemlock would be an ecological disaster for our mountain coves and waterways. 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 its demise.
Another important difference is that while both trees were attacked by invasive organisms from Asia, there is still no effective treatment for the chestnut blight. But there is an effective, USDA-approved biological control agent for HWA with over 3 million released on public lands. And this predator beetle - Sasi (Sasajiscymnus tsugae) is now also available to private individuals and groups.
The purpose of this site is to emphasize the important role for private involvement in saving our hemlocks from HWA. Whether your threatened hemlocks are in a neighborhood, a local park, or a wild cove or waterway, you can do something to to contribute to their return to health and long-term survival.