Destructive Invasive Species from Gypsy Moth to Sea Lamprey Topic of Yale Forest Forum at Yale University

A small number of invasive plant and animal species inflict massive economic and ecological damage throughout the United States. In fact, 79 plant and animal species found beyond their geographic range caused direct economic losses of $97 billion from 1906 to 1991, according to the Office of Technology Assessment. The European gypsy moth, a pest introduced nearly a century ago in the Northeast that spread rapidly to forests in other regions, inflicted $764 million in damages in one recent year alone.

The public is invited to join the Yale Forest Forum on Wednesday, May 6, 3-5:30 p.m. in Bowers auditorium of Sage Hall, 205 Prospect St., for a free panel discussion that will examine a new national strategy to control invasive species. Titled “Alien Invasive Species: A Public Dialogue Exploring New Solutions to an Old and Persistent Threat,” the event will be followed by a reception 5:30-6:30 p.m.

“A federal interagency initiative on invasive alien species is currently under development and will provide guidance for increased awareness, cooperation and efficiency in efforts to manage damaging, non-indigenous species throughout the United States,” said John C. Gordon, dean of the Yale School of Forestry and Environmental Studies.

Dr. Bill Brown, science adviser to U.S. Secretary of the Interior Bruce Babbitt, will present the key points of the federal initiative, which include establishing a national coordinating council for invasive species; increasing efforts to identify, monitor and restrict introduction of new invasive species; promoting collaboration between federal, state and regional interests; and educating a wide range of audiences.

Representatives from conservation organizations, agricultural interests and industry will respond and make recommendations on the new strategy. Panelists will include John Kahabka, New York Power Authority; Elizabeth Chorneski, The Nature Conservancy; Herb Manig, American Farm Bureau; and a representative of the forest-products industry.

Invasive alien species come in many forms, from ornamental plants to small insects, said Gary Dunning, director of the Yale Forest Forum. Purple loosestrife (Lythrum salicaria) produces an attractive purple flower and was likely introduced to New England as an ornamental in the early 1800s. Loosestrife reproduces prolifically and is replacing a rich diversity of native plants, as well as animals dependent on indigenous vegetation, in wetlands throughout the nation, he said.

Another invasive alien species is the balsam woolly adelgid (Aldelges piceae), a small sucking insect that drains the sap from fir trees, killing them slowly over several years. Introduced from Europe, the balsam woolly adelgid has destroyed three-quarters of the spruce-fir forests in the South and endangered several other plant and animal species dependent on these forests.

U.S. fisheries have been significantly degraded by non-indigenous species as well, Dunning said. In the mid-1900s, the parasitic sea lamprey (Petromyzon marinus) found its way into the Great Lakes through newly constructed canals and decimated the regions recreational and commercial fisheries. Today, approximately $10 million is spent annually to control predation by the lamprey.

“If you are a forest, water resource, farm or park manager, or a horticulturist or conservationist, then invasive species are likely to become an increasingly complex management issue for you,” Dean Gordon said. “The Invasive Alien Species Forum at Yale will provide land managers with current and useful information on the policy, management strategies and available resources that are evolving to meet this challenge.”