Gypsy moths: slowing the spread

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By Christopher Brooke, Reporter

One of the fronts in the battle against destructive gypsy moths will be fought in Middle Fox Creek in Grayson County this year.
The integrated pest management program to "Slow the Spread" of the foreign pest involves releasing pheromones on 1,000 acres in the Southwest Virginia county, among others, says Larry Bradfield, project manager in the Virginia Department of Agriculture and Consumer Services.
The goal is to confuse the flying males enough so they can’t find the stationary females to reproduce.
This effort “doesn’t kill anything,” Bradfield stressed. It just disrupts the mating cycle.


“Gypsy moth is a destructive, exotic forest pest that feeds on over 300 species of trees,” according to information from the Slow the Spread Foundation. “It was accidentally introduced into the United States in 1869 and is currently established throughout the northeast and parts of the upper midwest where it has defoliated 80 million acres since 1970.”
Gypsy moths feed on the leaves of more than 300 species of trees, with oaks being the favorite.
“Even though gypsy moths prefer oak trees it is not necessary to totally avoid planting oaks,” Virginia Tech researchers say. “The rule of thumb for homeowners is to plant several different kinds of trees.”
There are kinds of trees that gypsy moths avoid, including all ashes, flowering dogwood, American holly, locust, juniper, rhododendron, brambles, spicebush, sycamore and viburnums, according to information from Virginia Tech.
“Defoliation causes extensive tree mortality, reduces property values, adversely affects commerce and causes allergic reactions in sensitive individuals that come in contact with the caterpillars,” the info says.
Gypsy moth populations run in seven- to 10-year cycles, Bradfield said.
“They build up and then they crash,” he explained. “In the past three years, we haven’t had a large defoliation in Virginia.”
State officials expect more damage in upcoming years as the moths are once again in a building phase.
Records show that the pests have impacted 90 million acres nationwide since 1924.
“In Virginia, historical defoliation is nearly 5.5 million acres with a suppression cost of over $17 million,” according to information from Virginia Tech on gypsy moths. “These costs do not include the economics associated with tree mortality, reduced tourism and adverse recreational and residential impacts due to defoliation and the nuisance of large numbers of caterpillars in and around dwelling and public areas.”
Sensitive areas in the Jefferson and Washington National forests remain on the gypsy moth’s path.
A 2011 map showing trap yields from Virginia reports higher concentration of the moths, between 10 to 30, caught in traps at the eastern border of Carroll County, with a few in the northern portion of the county having around three to 10 moths.
West of that in Carroll, traps were more likely to have one to three moths in them and yields in Grayson County remain even lighter.
The federal government has teamed with 10 states to support the gypsy moth control program.
This year, affected areas will split funding of $7 to $8 million in funding, which will be allocated based on need, Bradfield said.
Benefits of the Slow The Spread program include holding the exotic insect in check enough to prevent infestation and damage to more than 100 million acres in 12 years, according to information from the effort.
Program participants expect to hold the line at western Virginia over the next three decades, as compared to projections without the treatments showing that gypsy moths would make it far south as Alabama and Georgia and cross the Mississippi River to the west.

DOWNLOAD MAP: This map shows higher gypsy moth yields right on the border of Carroll County.

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