Feb. 24, 2006

Invasive wasp, Southern Hemisphere forest devastator, found to be 'well-established' in upstate New York

Last year while sifting through insects from a trap from Fulton, N.Y., E. Richard Hoebeke, a Cornell University expert taxonomist, discovered a single specimen of an alien woodwasp that devastates conifers. It was the first such woodwasp, Sirex noctilio Fabricius, ever found in the wild in the United States.

Hoebeke and Cornell work with the Cooperative Agricultural Pest Survey Program (CAPS), whose primary objective is the early detection of exotic plant pests.

The announcement of Hoebeke's discovery triggered a "rapid response" from federal and state plant pest regulatory officials. By season's end, Hoebeke had identified 85 specimens from traps, and hundreds more emerged from bolts of wood collected from the field.

That's bad news for conifers nationwide. This invasive species has devastated up to 80 percent of pine trees in areas of New Zealand, Australia, South America and South Africa. If established in the United States, it would threaten pines coast-to-coast, particularly in the pine-dense states of the Southeast.

After the identity of the single specimen was confirmed last winter, Hoebeke worked with the U.S. Department of Agriculture's Animal and Plant Health Inspection Service (APHIS) and Forest Service and New York State Departments of Agriculture and Markets and Environmental Conservation to set out a large dragnet, placing multiple traps in areas that could be harboring the woodwasp within a 20-mile radius of ground zero in Fulton. When that wave of traps produced woodwasps, the dragnet was extended to a 50-mile and then a 70-mile radius. By season's end, 576 traps were set out.

"We found specimens in traps from Oswego, Onondaga, Wayne, Cayuga and Seneca counties," said Hoebeke, a Cornell senior extension associate in entomology who has examined tens of thousands of insects sent to him from agencies and scholars over the past 25 years. APHIS has officially designated Hoebeke a "national identifier" for the woodwasp, the point person to identify specimens of this invasive species.

"The species is evidently well established in at least a 50-mile radius around Oswego," said Hoebeke. "If it gets established further, the potential damage from this exotic woodwasp could be monumental."

In a ground survey in May 2005, Hoebeke and colleagues found trees on the State University of New York-Oswego campus, 11 miles from Fulton, that seemed to have been damaged by the alien. They cut down eight trees, which were teeming with suspicious-looking larvae. The larvae were sent to an APHIS plant protection and quarantine facility where more than 900 adults emerged. Additional larvae were submitted to a Forest Service laboratory for species confirmation utilizing molecular sequencing techniques.

"That's when we knew we had a bigger problem," said Hoebeke. "We now think that the pest has certainly been here for at least five to seven years prior to its discovery. Now we hope to determine just how extensive it is and what we need to do about it. The biggest fear is that this species may spread to the Southeast where pine production constitutes a major industry of economic importance."

Hoebeke and his colleagues at various government agencies are now gearing up for a major survey this spring within a 150-mile radius of Oswego with more than 2,200 traps across New York and into northeast Pennsylvania and western Vermont. Canada is expanding its own survey along the St. Lawrence River due to a reported detection of this pest last summer.

The woodwasp, which is native to Europe, Asia and northern Africa, where it rarely is a pest, kills pines and sometimes several other types of conifers by introducing a toxic mucus and spores of a toxic fungus when the female lays her eggs through the bark and into the sapwood of the tree.

"Because S. noctilio has established in New York, a rapid response to contain and control the infestation is under development among federal and state cooperators," said Hoebeke. This initiative benefited from the recommendations of an expert science advisory panel convened earlier this year. A biological control method using a parasitic nematode has been remarkably effective in other countries in the Southern Hemisphere where the woodwasp has been accidentally introduced, he said.

Hoebeke and his colleagues suspect that the members of this invasive species have hitchhiked into the United States in wooden crates used to import marble and tile.