YOUR GARDEN — Plant Information

Pests, Problems, and Diseases

Emerald Ash Borer

State-Wide Quarantine Enacted to Fight the Emerald Ash Borer

On November 21, 2006, the USDA's Animal and Plant Health Inspection Service announced the expansion of its Emerald Ash Borer (EAB) quarantine to include the entire states of Illinois, Indiana and Ohio—more than doubling the previously quarantined area. The quarantine becomes effective December 1, following the issuance of a federal order. To date, the EAB is responsible for the death and decline of more than 25 million ash trees in the United States. As of November, the areas infested with the EAB have exceeded 40,000 square miles.

The USDA estimates that if the EAB is not contained or eradicated, it has the potential to cost state and local goverments approximately $7 billion over the next 25 years to remove and replace dead and dying ash trees. The new quarantine order restricts the interstate movement of ash nursery stock and green lumber, as well as other ash material such as firewood. Due to the difficulty in distinguishing between species of hardwood firewood, all hardwood firewood is affected.

The Chicago Botanic Garden is in the quarantine area for the emerald ash borer. No firewood will leave the Garden during the quarantine.

For more information, visit www.emeraldashborer.info.

Source: The Animal and Plant Health Inspection Service, USDA.

Susceptible Plants
White, green, black, pumpkin, and several horticultural varieties of ash, whether healthy or stressed.

The emerald ash borer poses a significant threat to the urban and rural forests of Illinois, though it presents no direct threat to public health.*

Since the emerald ash borer was first confirmed in the Midwest in the summer of 2002, more than 25 million ash trees are dead or dying.

Fraxinus americana (White ash)

Description & Symptoms
The emerald ash borer, Agrilus planipennis, is a slender, elongated (3/4-inch), bright green beetle in the same genus as the bronze birch borer. Most likely, this pest arrived in Michigan from Chicago at least five years ago, probably in ship cargo. By the summer of 2006 it had spread into Illinois.

Emerald ash borer larvae

Emerald ash borer

The beetle deposits its eggs on the surface or cracks of ash tree bark, and the hatched larvae feed on the tree's phloem and outer sapwood. Within several weeks, larval feeding creates S-shaped galleries in the tree's inner bark and wind back and forth, becoming progressively wider and girdling the truck and branches as larvae grow. Adult beetles emerge headfirst, creating very small (3-4 mm) D-shaped exit holes that leave minimal evidence of infestation until the canopy begins to die back. Then the tree declines in the second growing season and is usually dead by the third.

The symptoms of emerald ash borer infestation resemble ash decline or damage from the native ash-lilac borer and the two-lined chestnut borer, making detection difficult.

Ash bark

Ash bark damage

Damage
(See above.)

Treatment & Solutions
PHOTO: emerald ash borer

The Emerald Ash Borer Team for the State of Illinois has developed a comprehensive strategy to assess resources, minimize risk, identify infestations, and collaborate to contain them. As part of the team's effort to monitor the beetle's spread, purple traps, which are sticky and baited with a compound that simulates a distressed ash tree, are being used throughout the state to attract the cunningly deceptive creatures. Small and stealthy in its behavior patterns, the emerald ash borer remains extremely difficult to detect.

For more details about efforts to monitor the spread of the emerald ash borer in Illinois, visit http://www.agr.state.il.us/eab/data/200804104243.pdf.

*Information throughout this pest alert was compiled by the Emerald Ash Borer Team for the State of Illinois, including among other groups the City of Chicago, Cook County Forest Preserve, Illinois Departments of Agriculture and Natural Resources, the USDA Forest Service, Michigan State University, Purdue University, the University of Illinois, and The Morton Arboretum.

Anyone who suspects a tree is infested should call their county Extension office. The Illinois Department of Agriculture offers a toll-free hotline at (800) 641-3934 for Extension-confirmed infestations. For additional information, visit www.emeraldashborer.info, or call the Plant Information hotline at (847) 835-0972.