By Dan Klepal
The Cincinnati Enquirer

The gypsy moth has been a terror along the East Coast for two decades, gobbling up about 1 million acres of old-growth forests from Massachusetts to Pennsylvania each year since 1980.

The moth is a native of Europe and Asia that was brought to the United States and accidentally released by a French scientist in the 1860s. It was first found in Ohio in 1971, and has largely been a problem in the north and northeast counties of the state since then.

But the gypsy moth has made inroads in the Tristate over the past few years. Starting June 23, biologists with the Ohio Department of Agriculture will begin trying to control the spread of the moth here by essentially trying to fool the males of the species.

Scientists have been able to produce a synthetic replica of the females' scent, called a pheromone, which they drop between two small pieces of plastic, making a scent sandwich.

They then put a drop of glue on the outside of the plastic "flakes'' and drop them from a crop duster in areas where the moths are known to live. Treatment in Hyde Park and just northeast of Hamilton in Butler County will begin early next week, depending on the weather.

The idea is to treat the areas before the males emerge from their cocoons, since they have only about a week to find a mate before they die.

"When the male comes out, his inclination is that there are females everywhere because he can't distinguish between flakes and the real pheromone being emitted by females," said Bill Pound, gypsy moth program manager for the Ohio Department of Agriculture. "He has to use that initially to track back to the females. So he's flying around everywhere trying to hone in on a female that doesn't exist.

"Our hope is that they will die very tired and frustrated deaths."

Slowing the spread

The pheromone treatments are part of a plan developed by the U.S. Forest Service in 1999 meant to slow the spread of the moth. The program is expected to:

• Decrease the new territory invaded by the moth each year from 15,600 square miles to 6,000.

• Protect forests, forest-based industries, urban and rural parks and private property.

• Avoid $22 million per year in damage and management costs.

The moth is destructive in its caterpillar stage, when they dine on tree leaves. The moths seem to especially like hardwood trees that are vital to the timber industry.

Pound said the moths can kill an adult tree in two or three generations. Diseased trees are particularly vulnerable.

"If you have a tree with one foot in the grave, one defoliation may actually kill that tree," Pound said.

"The primary hosts are the oak and cherry trees, which are high-value timber,'' he added. "Species not preferred are coming back, such as ash, maple and elm. A lot of these areas convert back to maple. So there's a real shift in the dynamics of the species of trees within wooded areas."

The moths have been spreading more quickly recently because of humans. Eggs can be attached to firewood stacks, moving vans, barbecue pits, outdoor lawn furniture or just about anything people might take with them on vacation.

The moths would normally be able to move only two or three miles per year, but in the last few decades have managed to spread 15 miles per year.

The treatment next week marks the first time pheromone has been used in the Tristate, although chemical treatment meant to kill the moth outright was used in the Hyde Park in 1994.

Pound said the best thing about the pheromone treatments is that the chemical is not a toxin.

"We're not killing anything with it," Pound said, "not even the moth."

E-mail dklepal@enquirer.com