Urgent Call to Save Maryland’s Ash Trees
Emerald Ash Borer
Contact: Dick Bean, Maryland Department of Agriculture
410-841-5920 | beanra@mda.state.md.us
ANNAPOLIS, MD (March 4, 2004) - Emerald ash borer (Agrilus planipennis), an exotic pest from Asia, was confirmed in ash trees at a nursery in Prince George’s County in August of 2003. The emerald ash borer (EAB) is a serious invasive insect that, prior to the Maryland detection, had only been detected in the U.S. in Michigan (2002) and Ohio (2003). The insect feeds on and kills ash trees, an important neighborhood and landscaping tree, in one to three years after infestation. In Michigan, over six million ash trees have died and thirteen counties are under state and federal quarantines due to the emerald ash borer.
Dick Bean, a survey entomologist with Maryland Department of Agriculture (MDA) says, “We must act now to prevent the emerald ash borer from becoming established in Maryland.” The Maryland Invasive Species Council agrees, and has named the emerald ash borer as their March, 2004 “Invader of the Month.”
Nursery records and regulatory investigations by MDA and the U.S. Department of Agriculture (USDA) determined that the Maryland nursery received 121 ash trees in two shipments from Michigan in April, 2003. The Michigan grower has since been prosecuted and heavily penalized for violating state and federal plant pest movement laws. In Maryland, all but three of the 121 trees from Michigan are believed to be accounted for and have been destroyed. The MDA has removed from the nursery an additional 389 ash trees that were exposed when the beetles emerged sometime after they arrived in early April and began laying eggs. Of these 389 trees, 71 were found to contain EAB larvae.
The emerald ash borer belongs to a group of insects known as metallic wood-boring beetles. Adults are dark metallic green in color, 1/2 inch in length and 1/16 inch wide. Larvae are creamy white in color and are found under the bark. The presence of the emerald ash borer typically goes undetected until the trees show symptoms of being infested – usually the upper third of a tree will thin and then die back. This is usually followed by a large number of shoots or branches arising below the dead portions of the trunk. Other symptoms of infestation include: D-shaped exit holes in the bark where adults emerge, vertical splits in the bark, and distinct serpentine-shaped tunnels beneath the bark in the cambium, where larvae effectively stop food and water movement in the tree, starving it to death.
MDA is in the process of completing a delimiting survey within a ½-mile radius from the nursery where the infested ash trees were located. All ash trees within the buffer will be removed by mid-April in an eradication effort to eliminate the possible spread of this potentially devastating insect to other ash trees in Maryland. The predicted flight distance is believed to be less than ½ mile. The Maryland Department of Natural Resources Forestry, Wildlife and Heritage will be providing vouchers for tree replacement for trees that fit certain criteria removed from within the ½ mile buffer.
Any ash trees that originated at the nursery between April 2 and Sept 1, 2003 are considered “exposed” to emerald ash borer and may harbor larvae. ADULT EMERALD ASH BORERS ARE EXPECTED TO EMERGE FROM EXPOSED ASH TREES IN MAY OF 2004. MDA has been identifying and removing exposed ash from landscaping jobs. At the time this was written, 89 at-risk trees have been removed from 13 sites landscaped with exposed ash. Two hundred and six larvae were found in 15 of these trees, more than enough to start a raging population! “It is urgent that anyone who purchased ash trees from Ed's Plant World in Brandywine, MD in 2003 contact MDA as soon as possible, before emerald ash borer adults can emerge,” says Bean.
For additional information on the status of emerald ash borer in Maryland, and to learn to recognize symptoms of attack, visit the official website: http://mda.maryland.gov/plants-pests/Pages/eab.aspx. To report suspected emerald ash borer infestations in Maryland contact MDA’s Plant Pest Survey and Detection Program at 410-841-5920.
For more information about the Maryland Invasive Species Council and other Invasive Species of Concern in Maryland, visit www.mdinvasives.org or call 410-841-5920.
photos available electronically on request