U-M campus under ash borer quarantine

ANN ARBOR, Mich.—The University of Michigan's Ann Arbor campus is under quarantine for the emerald ash borer. By imposing the quarantine, U-M joins with its neighbors in Washtenaw County and the adjoining counties of Wayne, Oakland, Macomb, Livingston and Monroe in attempting to stop the spread of the highly destructive wood-boring beetle.

Adult beetle

This exotic species of beetle from the Northern China/East Russia area can spread so quickly and cause such great damage to so many ash trees that experts consider the entire Michigan ash population at risk. Larvae feeding just under the bark cause severe damage. "They can quickly girdle a tree causing dieback and eventual death within a few years," says Tom O'Dell, a senior horticultural assistant at U-M's Matthaei Botanical Gardens.

Marvin Pettway, U-M's supervisor of forestry and horticulture says the quarantine prohibits movement of ash trees, limbs, logs, firewood and untreated ash lumber to areas outside the quarantined counties.

"The Ann Arbor campus of the University of Michigan has a highly diversified forest of trees with well over 150 species planted on 700 acres," Pettway says. "The ash tree accounts for approximately 900 of the 17,000 inventoried landscape trees on campus—5.3 percent of the campus forest. Michigan Department of Agriculture experts are predicting 75 percent mortality of all ash trees in the quarantined area in the next four years."

There are many means being considered to stop the spread of the beetle. Currently the United States Department of Agriculture's Forest Service is conducting research on the ash borer at Matthaei. This study involves treating trees with insecticide and studying the number of living and dead larvae found in untreated and treated trees.

The ash borer problem is expected to cause more devastation than the Dutch elm disease did nearly four decades ago. "This exotic pest most likely will be the most dramatic and destructive tree pest problem ever in Michigan," says Pettway. "The negative effects of this insect are much greater than what we recently experienced with the European gypsy moth."

Pettway and his crew have been working closely with officials of the city of Ann Arbor, to bring this scourge under control. They have adopted a plan of attack against the ash borer similar to that of the city. They will:

· Educate the campus community about the borer via radio, local cable television, print media and the internet

· Monitor the health of campus ash trees on the Ann Arbor campus, marking infested trees for removal

· Remove infested and dying ash trees from the campus forest in a timely fashion

· Improve the existing capabilities for wood disposal of dead and dying trees

· Replace dead campus trees in a timely manner.

Heavily infested ash trees

The emerald ash borer probably invaded southeast Michigan in pieces of untreated wood from its native home in Asia. In a similar way, it can infest ash trees hundreds of miles away—through movement of infested firewood.

Since infested ash trees can be found in Washtenaw and its surrounding counties as well as on the U-M campus, Pettway warns all residents of Southeast Michigan, "Don't move ash firewood out of the quarantined area. Don't repeat the process by taking it on vacation with you. In addition to it being against the quarantine law and punishable by fines and/or imprisonment; imagine how your favorite vacation spot would look with some or all of the trees gone."

Related links:

Matthaei Botanical Gardens >

U-M Trees and Forestry Department >

Contact: Joanne Nesbit
Phone: (734) 647-4418
E-mail: mjnesbit@umich.edu