July 16, 2007

The Michigan departments of Agriculture (MDA) and Natural Resources (DNR), along with the U.S. Department of Agriculture (USDA), today announced the confirmation of Sirex Woodwasp in Macomb County. A single specimen was collected from a trap on July 6 and later identified by the USDA.

Sirex Woodwasp is a wood-boring insect native to Europe, western Asia, and northern Africa and is a potentially serious pest of commercially produced pine trees. It was first detected in North America in Oswego, N.Y. in 2004, and has since been found throughout central New York, northern Pennsylvania, and southern Ontario.

The larvae of this exotic pest are responsible for damaging the tree. It severs the trees' conductive tissues, interrupting the transport of water and nutrients. Adult females lay their eggs in two- and three-needled pine trees, including: Austrian, jack, red, and Scotch pines.

"At this point, we don't know whether this is part of an established Michigan infestation," said MDA Director Mitch Irwin. "We don't anticipate this pest to have a major economic impact on the state's nursery, landscape and Christmas tree industries. We will, however, vigorously monitor this exotic pest and its potential to impact our forest systems."

The trap is one of more than 250 trapping locations established throughout Michigan through a cooperative effort that includes the USDA, MDA, DNR, Michigan Technological University and Michigan State University. This work is part of an international effort to delimit the extent of the infestation in North America.

"Since the Sirex find in New York we have been monitoring Michigan's pine resource," said DNR Director Rebecca A. Humphries. "The network of traps and trap trees established across Michigan will provide excellent data. This information will be used by the workgroup to assess and develop a pro-active response."

Sirex Woodwasp is not expected to significantly impact healthy landscape pine trees in the state. Its impact on vigorous, well managed pine plantations in Michigan, while not yet fully defined, is likewise not anticipated to be severe.

For more information on this pest, please visit www.aphis.usda.gov.