Back from war on moths, ag crews await reports

June 13, 2006|by ARNOLD S. PLATOU

CUMBERLAND, Md. - Dave Cohen and three co-workers returned to their state Department of Agriculture office here Monday from the war zones of Western Maryland.

Cohen, the agency's entomologist for western Washington County, and all of Allegany and Garrett counties, together with three inspectors have been directing an aerial assault on newly-hatched gypsy moths found in more than 16,000 acres of woodland in the area.

The moths, in their caterpillar stage now, are voracious eating machines, devouring leaves and killing trees from late April through June. To combat them, Maryland sprayed a total of 25,500 acres in eight counties from mid-May through last Friday when Cohen and the others finished up in Garrett County.

At the end of July, Cohen said, they will begin returning to the treated areas to view the results, hoping to see shrivelled egg masses and caterpillars. "We sure hope that's what we will find," he said.


Still though, he said, they know there are gypsy moths that survived. "We've already been receiving calls," he said, adding that that's another part of the ongoing battle against the bugs.

"One thing we like to tell people, if you've had a problem this year, please let us know and we'll try to get out there and take a look at it," Cohen said.

No more spraying will be done this year, but the sightings reported now will be used in planning next year's assault, he said.

In Washington County, from west of Interstate 81 out past Hancock, 580 acres were sprayed by helicopters this year, Cohen said. Most of the area treated is on state-owned and privately-owned land between Clear Spring and Hancock, he said.

In the eastern half of the county, 2,271 acres were sprayed, said Tom Lupp, assistant regional entomologist for the state's central region which includes eastern Washington County. The treated sections were mostly along the South Mountain ridge in the Greenbrier State Park area, "plus a couple areas up around High Rock and Pen Mar," Lupp said.

In Frederick County, the treated areas totalled 1,867 acres. Most of that is on the eastern slopes of South Mountain in the Greenbrier region, and also in the Gambrill Park area and a section between Thurmont, Md., and Emmitsburg, Md., he said.

Farther out in Western Maryland, Cohen said, 2,001 acres were sprayed in Allegany County and 14,212 acres in Garrett County.

The totals seem remarkable given that in 2004, only 660 acres were treated in all of Maryland and last year, none were treated.

"It's just the nature of the beast," Cohen said. "It just varies from year to year. The gypsy moth population has the capability of going from high levels to low levels, and vice versa. It just so happened in this year, we found a lot of acres that needed to be treated."

Each egg mass can contain "hundreds of eggs and, in some areas, we can have hundreds of egg masses. So in a single area, the population can just take off," he said.

Lupp said aside from man's efforts to control the insect, there are the effects of nature.

"There are some diseases of the gypsy moth caterpillar that can have a significant impact and, in 2003, it was very wet and there's a fungus disease ... that kind of caused an areawide collapse of the population," Lupp said.

According to a news release from the state agency, the first defoliation by gypsy moths in Maryland occurred in 1980. Since then, gypsy moth caterpillars have defoliated 1.05 million acres of timber and residential trees in the state.

From 1982 to 2004, trees were sprayed on more than 1.7 million acres statewide "with an average effectiveness rate of more than 98 percent," the department said.

Lupp said much of the inspection later this year will be done from the air. "It's a way to see how well the spraying worked, (to see) if we prevented defoliation in the area we sprayed," he said.

The life cycle of the gypsy moth is a circle that extends through the winter months from one year to the next. Right now, the newly-hatched insects are in the caterpillar stage. They'll eventually turn into adult moths, which lay the egg masses in late June or early July, the state agency said.

The oval-shaped masses are about the size of a quarter, are raised in the center and are tan to light brown. Because the female moth deposits hairs and scales from her body in the mass, it appears slightly fuzzy, the state agency said.

The masses are left in protected places such as the underside of tree limbs, crevices in tree bark, ivy-covered tree trunks and buildings, the underside of lawn furniture, inside the wheel wells of campers and trailers, under the eaves of houses and storage buildings, on the foundations of houses, on woodpiles and even inside birdhouses. The mass adheres to the surface on which it was laid - it is not in a web, tent or bag.

They'll lay there through the winter, until the following spring when tiny caterpillars hatch.

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