Maryland Protects Hemlock Trees at Patapsco Valley State Park from Devastating Pest

State Planting New Trees, Fighting Invasive Insect with Native Beetles

ANNAPOLIS, MD – Representatives from the Maryland Departments of Agriculture and Natural Resources, and the State Park Service’s Maryland Conservation Corps, today gathered at Patapsco Valley State Park to kickoff a collaborative, multi-year project that will restore populations of hemlock trees lost to the hemlock wooly adelgid, a small invasive insect.

This innovative restoration project will bring hundreds of new hemlock trees to Patapsco Valley and Cunningham Falls state parks, areas that have seem major hemlock declines due to hemlock wooly adelgid. Additionally, the project will create a hemlock hedge insectary at Big Run State Park, which will be used to establish populations of tiny predatory beetles for bio-control against the pest.

“The hemlock wooly adelgid has devastated Maryland’s hemlock trees, which are an integral part of our state’s ecosystem,” said Agriculture Secretary Joe Bartenfelder. “This is a very important project and I am confident that our partnership with state and local agencies and Pennsylvania will go a long way toward restoring our state’s hemlock forests.”

Maryland will receive 500 trees per year for the next few years from Penn Nursery near State College, Pa., as part of an agreement with Pennsylvania Department of Conservation and Natural Resources. In exchange for the trees, Maryland will send Pennsylvania bio-control beetles collected from hemlock forests in Maryland.

“Hemlock trees provide shade and wildlife habitat, improve air and water quality, and enhance visitor experience. We are planting at strategically chosen sites where both park users and the environment will see the most benefit,” Natural Resources Secretary Mark Belton said. “We are thankful for our partners, and for the young men and women of the Maryland Conservation Corps, and are grateful for the opportunity to share in the conservation, management and stewardship of our state’s natural resources.”

The Maryland Conservation Corps, which engages young adults in natural resource management and park conservation projects, has helped the state carry out a variety of hemlock enhancement projects over the past five years, including treating hundreds of infected trees in Western Maryland. As part of this project, corps members from across the state will be planting approximately 220 hemlock trees at Patapsco Valley State Park and 220 trees at Cunningham Falls State Park and 60 trees at Big Run State Park that will provide a myriad of benefits once they mature.

Without any natural controls in Maryland, such as predators or disease, hemlock wooly adelgid populations were able to go unchecked for a number of years resulting in hemlock decline and death. Recent use of biocontrol beetles has helped to establish a natural predator within the state, slowing the devastation caused be hemlock wooly adelgid.

The hemlock forests of Maryland are part of a unique and often fragile habitat and contribute significantly to the natural beauty and character of the state’s public lands. Hemlocks are usually found growing in riparian areas or in steep cove forests in the state’s northern and western tier counties. It is estimated that more than 42,000 acres of such forests exist in Maryland.

“Cooperation between states dealing with the impacts of the hemlock wooly adelgid is essential to our efforts,” said Don Eggen, forest health manager with the Pennsylvania Department of Conservation and Natural Resources.

Through the U.S. Forest Service’s Hemlock Wooly Adelgid National Initiative, the Maryland Departmetn of Agriculture has released five different species of predators (Sasajiscymnus tsugae, Laricobius nigrinus, Laricobius osakensis, Scymnus coniferarum, Scymnus sinuanodulas) totaling 49,358 beetles in 27 locations in Harford, Baltimore, Frederick, Washington, Allegany and Garrett counties. Of the species released, Laricobius nigrinus has already been established at seven of the 10 release sites.  The other three sites are the most recent release locations and population levels have not met the requirements to be considered established. The department will continue to release this species, along with Laricobius osakensis and Scymnus coniferarum, and monitor for establishment. Sasajiscymnus tsugae and Scymnus sinuanodulas were never recovered after release and have been dropped from consideration for bio-control releases in Maryland.

In addition to the biocontrol beetles, the Maryland Department of Agriculture has been using insecticide since 2004 to implement a prevention and suppression program in cooperation with the Maryland Forest Service’s Hemlock Wooly Adelgid Initiative. In the coming weeks, the department’s Forest Pest Management Program will be injecting and treating several thousand hemlocks throughout the state, and will cooperate with the Maryland Department of Natural Resources and Maryland Conservation Corps to treat over 5,000 trees in Wolf Swamp in Garrett County.

For further information, contact Bob Tatman, Maryland Department of Agriculture, Forest Pest Management Program at (410) 841-5922.

Additional information about the hemlock woolly adelgid can be found on the following websites:

• mda.state.md.us/plants-pests/forest_pest_mgmt/cooperative_forest_health_program/hwa.php
• http://na.fs.fed.us/spfo/pubs/pest_al/hemlock/hwa05.htm
• fs.fed.us/foresthealth/technology/pdfs/FS_hwa.pdf

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