County, state coping with gypsy moth woes

June 25, 2007|By JULIA COPLEY

The sound of a gypsy moth infestation is distinctive: It sounds like a gentle summer rain.

That's the sound of millions of gypsy moth droppings falling through the trees.

Weathering the worst gypsy moth outbreak in 12 years, Washington County is in the middle of a waste monsoon.

Bob Tichenor, chief of Forest Pest Management for the Maryland Department of Agriculture, has been dealing with gypsy moths for 25 years. He says their population seems to go through five-year cycles, and 2007 is right in the middle of a big one.

"We have defoliation from Cecil to Garrett (counties), and possibly some spots south," he said.

In Washington County, Tichenor supervised the treatment of more than 7,000 acres with anti-gypsy moth insecticides.

The adult gypsy moth isn't the troublemaker. Alive for only a few months, the adults breed, lay eggs and die in short order. It's the youngsters who wreak havoc.


When they hatch in April and May, larvae quickly grow through several stages called "instars." The first four instars are the most destructive for trees, as the caterpillars devour leaves and bark, sometimes leaving a tree without defense and its primary source of energy.

Although they prefer hardwood trees, especially oak, the insects are most devastating when they eat pine. Because the evergreen keeps its foliage year-round, it stores energy in the needles instead of in its roots, as deciduous trees do. This makes it harder for pines to recover when stripped of their greenery, said George Eberling, who works at the Indian Springs Wildlife Management Area as the Washington County forester with the Maryland Department of Natural Resources.

Eberling said Indian Springs' primarily hickory-oak forest is particularly attractive to the gypsy moth.

"The whole management area, up around Indian Springs and the hunt clubs, they've all been hit very hard," he said.

Eberling said he thinks that the worst damage is still to come. Because of the recent droughts, coupled with the gypsy moth outbreak, he said he expects that trees will try to conserve energy as much as possible. This means that their nut and seed production, or "mast," will be much lower than usual. And for the wildlife management area of Indian Springs, that means deer and turkeys will be affected this winter.

"This year probably won't hurt too bad, but the deer and turkey birth rates next year, they won't reproduce as much," he said.

According to the Department of Agriculture's Web site, the gypsy moth is native to Europe and Asia. It was introduced to North America in 1868 or 1869, when amateur entomologist Etienne Leopold Trouvelot tried to create a disease-resistant species of silkworm. The hardy gypsy moth seemed like a good candidate for cross-breeding, so he brought a few egg clusters from France to his home in Boston. Unfortunately, not only did the hybridization attempt fail, some of the gypsy moth larvae crept away and infiltrated the Boston suburbs.

Although the gypsy moth is preyed upon by rodents and predatory insects, its population has expanded exponentially since its release in the 1860s. Its expansion has been calculated at 21 kilometers per year in a southwestern direction extending from New England, according to the USDA Web site.

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