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Emerald ash borer makes life exciting for area trees
Purple triangular-shaped boxes have been spotted in different locations hanging from the trees. One was spotted in Rady Park and two more on the side of Belvoir Rd. in Fauquier County. Perhaps you have seen one in your neck of the woods too.
These purple boxes are chemical attractive traps for the emerald ash borer (EAB), an insect that is a new pest in the area. This small green metallic beetle has caused the death of millions of ash trees in Michigan and surrounding states and provinces.
This new pest comes as an accidental import from China. The first EAB was found in the Detroit area in 2002. In 2004 EAB was found and eradicated from Virginia. However, in 2008 a new infestation was found in Fairfax County. These purple traps are part of an expanded and aggressive monitoring, containment, and hopefully, eradication program.
The eradication program is a combined effort of several different state and federal agencies, including Virginia Cooperative Extension, the U.S. Forest Service, the Virginia Department of Agriculture and Consumer Services, the Virginia Department of Forestry, and the U.S. Department of Agriculture's Animal and Plant Health Inspection Service.
The traps have a sticky surface on the inside of the three sided open box. This sticky substance also includes a chemical attractive substance that smells like a stressed or dying ash tree. The insects are more attracted to stressed trees because their defences are weaker. Periodically, in the summer, the traps are checked to see if any of the EAB have been caught. If they are found in a box, then there will be a futher search of the area for other EAB and other control measures will be taken. This may include removing and destroying infested trees.
The Emerald Ash Borer lays its eggs on the bark of ash trees between May and July. The eggs hatch in 7-10 days and then the tiny larva burrow into the bark of the tree. The larva spend the rest of the summer feeding on the phloem tissue of the tree. This S-shaped feeding under the bark is what is deadly to the tree. The tree is unable to get water and nutrients needed from the soil.
The insect winters over inside the tree and then emerges as an adult in May, June or July to mate and lay a new set of eggs. The EAB is deadly to white, black, and blue ash varieties. It is also deadly to the horticultural cultivars of those species as well. Green and white ash are the varieties that live in the woods of Fauquier County and their cultivars are planted in many lawns and gardens in the area. It is not deadly to mountain ash and prickly ash, as these are in different plant families.
Ash trees that are infected with Emerald Ash Borer will show signs of individual branches dying, usually in the upper third of the tree, or they my have a large flush of new and vigorous growth at the base of a dead branch or base of the trunk. There may also be cracks in the bark directly over the larval feeding gallery. These symptoms are similar to those of other borers that attack ash trees. When the adults exit the inside of the tree, they leave a D-shaped hole that is one-eighth of an inch in diameter. This damage is unique to EAB.
The Emerald Ash Borer is not very mobile. It is spread long distances through nursery stock, wood chips, firewood, or other ash wood products. Because of this characteristic, a quarantine has been put into place. Fauquier County along with Prince William, Loudoun, Fairfax and Arlington counties are in the quarantine area. This means that one may not transport ash tree products from Fauquier to Culpeper, Rappahannock, Stafford, or Clark counties. Ash tree products can be taken from Fauquier to Loudoun or Prince William because they are within the quarantine area.
While the purple traps are primarily focused in the quarantine area, according to the Virginia Department of Agriculture website, every county has a few traps.
Culpeper Extension Agent Carl Stafford reported that according to forestry agent Adam Downing in Madison, "he thinks the Emerald Ash Borer is already here by virtue of the tree waste, tree trimmings, and land clearing materials that come into our county."
Stafford is concerned. "Despite the moratorium on the quarantined counties to the north, the “bug” is likely to make its way out into the state and ruin our Ash trees," said Stafford. "The traps will help us monitor its presence."
According to calls received at the Culpeper Extension Office, there have been reported sightings "we have traps up in Culpeper," said Stafford. [This is] an important subject that people need to learn about."
The local extension offices have several different publications with information on the Emerald Ash Borer. There is also a sample of the purple trap hanging in the entrance to the Fauquier Extension Office. If you have any other questions about EAB, contact you local extension office or http://www.emeraldashborer.info/.
Carl Stafford is the Extension Agent for Culpeper County and can be reached at ccstaffo@vt.edu or (540) 727-3435. Tim Ohlwiler is the Horticulture Extension Agent for Fauquier County. He may be reached at tohlwile@vt.edu or (540) 341-7950.
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