Gypsy moths eat W.Md. economy

Trees: Timber and tourism are vital in Garrett, Allegany and Washington counties, where caterpillars are devouring forests.

July 14, 2000|By Joel McCord | Joel McCord,SUN STAFF

GREEN RIDGE STATE FOREST - A wide swath of gray and brown cuts through the dark green of the forest on the west side of Town Hill here, testimony to the burst of gypsy moth caterpillars that stripped the leaves from oak, maple and hickory trees throughout Washington and Allegany counties this spring.

From the top of a Forest Service tower, you can see the path of destruction follow the stand of hardwoods to a notch in the mountain and wrap around to the east. A similar path traces the top of Warrior Mountain north to south.

The caterpillars defoliated 12,840 acres of trees this spring in western Washington and Allegany counties alone, says David Cohen, the state Department of Agriculture's regional entomologist for Western Maryland.

"That's much, much more than we've had out here in years. It just exploded," he says.

The outbreak has been so severe that economic development officials are worried about the effect the infestation will have on timber and tourism, the industries at the heart of the regional economy. They are pushing the state for a more aggressive spraying program.

The state needs to "get proactive and get ahead of the problem before it's so devastating," says Joyce Bishoff, of the Western Maryland Economic Development Task Force.

Bishoff and others are trying to organize meetings with state agriculture officials and local governments to deal with how to pay for spraying next spring when the new crop of gypsy moths hatches from the mud brown egg masses spattered over tree trunks and limbs as if someone had thrown them there.

"The tourists don't want to come here and see bare trees," says Tim Carney, of the Allegany County Economic Development Commission. "It's a shame to see a resource like that disappear."

Tourism is a $300 million-a-year business in Washington, Allegany and Garrett counties, and timbering is even bigger, although no solid figures are available.

Gypsy moths live to reproduce. The caterpillars hatch in the spring and feed on tree leaves until they are ready to spin their cocoons, usually in late June.

The moths that emerge are incapable of feeding - they live just long enough to mate, reproduce and die.

The damage the caterpillars cause is so catastrophic because they begin feeding after the trees have depleted all their leaf-making energy. Without leaves, there is no photosynthesis, which nourishes the trees and restores the energy used to make leaves.

It is unclear how many times a tree can survive such defoliation, says Robert Tichenor chief of forest pest management for the state Department of Agriculture. It depends on the size, genetic make-up and health of the tree.

"A lot of people say a healthy tree can withstand a couple bouts of defoliation," he says. "But I have seen indications it has to do with the individual tree. I have seen very healthy trees buy the farm on the first time they're defoliated."

Scientists can predict the following year's gypsy moth outbreak by counting egg masses on trees in the late summer and early fall.

Maryland scientists, who take their cues from the same forests every year, warned last year that gypsy moths were increasing, and sprayed even more acreage than they have in previous years.

But they still were caught by surprise.

"It got much worse much more quickly than we expected," says Tichenor. "We knew it was going to rain, but we didn't know it was going to be a flood."

It's been so bad, Cohen says, that his office has received hundreds of calls.

"We've had calls from people with one oak tree and people with 400 acres of oak trees," he says.

Some of the trees that had been stripped are pushing out tiny, light green leaves now, but "you have to wonder how many times they can do this," says Cohen.

State agriculture and natural resources officials aren't sure why the outbreak was so severe this year, but some have theories.

Bernie Zlomek, regional forester for the Department of Natural Resources, speculated that eggs were carried on the wind from north and west, adding to a cyclical increase in the moths.

An infestation of gypsy moths devastated thousands of acres of oaks in the early 1990s, but it died out in the middle of the decade, then began gaining strength again in the past two years.

The threat had been so minimal that the Department of Agriculture had not sprayed for the moths in Washington and Allegany counties since 1995, Cohen says.

A fungus of Japanese origin that has been in the forests since at least 1989 and kills gypsy moths almost exclusively has kept the creatures in check, but it failed this year.

"The fungus is where we got caught," says Cohen. "We thought it would kill the caterpillars and they wouldn't be much of a problem.

"But the caterpillars didn't die until they had already defoliated the trees."

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