Gypsy Moth Defoliation Increases 46 Percent in Virginia
Officials with the Virginia Department of Forestry (VDOF) say that the gypsy moth returned with a vengeance this year, defoliating 112,340 acres of forest across the Commonwealth – an increase of almost 39,000 acres over last year’s total. Nearly 70,000 acres of defoliation occurred across the George Washington – Jefferson National Forest close to the West Virginia state line. An additional 11,750 acres affected Shenandoah National Park.
(PressZoom) - Officials with the Virginia Department of Forestry (VDOF) say that the gypsy moth returned with a vengeance this year, defoliating 112,340 acres of forest across the Commonwealth – an increase of almost 39,000 acres over last year’s total. Nearly 70,000 acres of defoliation occurred across the George Washington – Jefferson National Forest close to the West Virginia state line. An additional 11,750 acres affected Shenandoah National Park.
The most heavily impacted area was the GW National Forest in Augusta County extending into southern Rockingham County, which, combined, saw almost 43,000 acres of heavy defoliation – an area covering approximately 30 square miles. Another heavily impacted area for the third year in a row was northwestern Giles County, where more than 15,000 acres of forest was defoliated, most of that being in the Jefferson National Forest.
VDOF Forest Health Specialist Dr. Chris Asaro said, “Most trees and forests can withstand one complete defoliation without experiencing significant losses. However, many areas that are in their second or third year of severe damage will see considerable tree mortality, particularly among oak trees, which are the preferred food of the gypsy moth.”
While oak trees are not in danger of disappearing from forests in Virginia, over time the gypsy moth will contribute to a reduction of oak populations in these forests.
“Other species, such as tulip poplar and maple, will grow in their place and become more dominant,” Asaro said. “Oak trees grew in abundance when the once-dominant American chestnut was obliterated from the eastern forest by the chestnut blight in the first half of the 20th century. Now, many of those same oak forests are aging and entering a stage of decline. The gypsy moth is helping to speed up the process,” he said.
Gypsy moths were introduced into the United States via Massachusetts in 1869 and have been slowly spreading southward ever since. The first defoliation in northern Virginia was recorded in 1984 and the moths continue to spread slowly southwestward.
“The US Forest Service and the Virginia Department of Agriculture and Consumer Services have been very effective at slowing the spread of the gypsy moth through widespread trapping and mating disruption techniques,” Asaro said. “But, inevitably, it will continue to spread.”
While gypsy moths can spread on their own, forestry officials say it is people that are largely responsible for the most significant spreading. Gypsy moths will lay eggs on almost any surface, including vehicles, campers, and firewood, which often transport them hundreds of miles from their point of origin.
“If there is a silver lining, it is that gypsy moth outbreaks are cyclic,” Asaro said. “Gypsy moth caterpillars often succumb to disease caused by a fungus and a virus, especially when cool, wet weather occurs during their feeding period in May.”
Dry spring weather predominated during 2005-2007, helping populations of gypsy moth to build up. This May, however, it was cool and wet at the right time.
“In some areas, caterpillar mortality from disease appears to be quite high,” Asaro said. “The caterpillars die only when they are nearly full grown and most of the defoliation is done, so the disease doesn’t have much of an effect for this year. On the other hand, dead caterpillars mean fewer adult moths will be around this summer to lay eggs. So, next year’s defoliation could be considerably lower.”
Asaro cautions that it’s still too early to say whether gypsy moth populations are on the decline. Egg mass surveys will be completed in late summer and fall will give us a better idea of what we can expect next year. Another wet spring in 2009 would likely help set us up for a population crash.
-30-
The Virginia Department of Forestry protects and develops healthy, sustainable forest resources for Virginians. Headquartered in Charlottesville, there are Forestry staff members assigned to every county to provide service to citizens of the Commonwealth. VDOF is an equal opportunity provider.
With nearly 16 million acres of forest land and more than 184,000 Virginians employed in forestry, forest products and related industries, Virginia forests provide more than $29 Billion annually in benefits to the Commonwealth.
Contact: John Campbell 434.220.9070 or 434.989.0665
Submitted by
n/a
Release Date
This news item was released on 2008-07-29. Please make sure to visit the official company or organization web site to learn more about the original release date. See our disclaimer for more information.
(c) PressZoom.com - Press Release Distribution Service - All Rights Reserved
