While the summer heats up, Montgomery County is taking steps to protect its greenery from the pesky gypsy moth by conducting flyover pesticide treatments.

"We have a fairly small window of opportunity to make these aerial treatments," said Barry Robinson, an agent with the Virginia Cooperative Extension.

The gypsy moth, which is prevalent throughout the New River Valley, can lay several hundred to a thousand eggs that become foliage-damaging larvae, said Charles Putnam, coordinator of the Montgomery County Gypsy Moth Program.

The county conducted its first set of treatments in May as part of a contract administered by the Virginia Department of Agriculture and Consumer Services. Some 262 acres were sprayed with a natural insecticide by helicopters flying just above treetop level. This portion included two blocks May 10 on Brush Mountain and another two blocks May 18 on Poor Mountain.

Per the agreement, Montgomery County is responsible for at least 50 percent of the spraying cost, with federal funding paying for the rest. Last year, the county ended up paying 88 percent of the cost.

Putnam said the Montgomery County Board of Supervisors votes to approve the program on a yearly basis. The invoice for 2009 hasn't gone out yet, but he said he expects it to be below 88 percent.

He said the county paid $7,795 last year to spray 250 acres. Though the spray area is slightly larger this year, Putnam said the contract price is lower, and he expects more federal funds to be available, making the overall cost lower.

Putnam said the treatments were done successfully, despite facing setbacks.

"I checked the blocks after the spraying and they looked pretty good," he said.

On certain days, crews showed up to conduct the treatments but the weather was unsuitable. On another day the equipment malfunctioned.

According to the Virginia Cooperative Gypsy Moth Suppression Program, the gypsy moth arrived in the United States in 1869 through an experiment to improve the silkworm. The moths escaped containment and spread south and west from Boston. According to the VCGMSP, the moth won't be eradicated, and is a pest that must now be constantly controlled.

With Montgomery County rich in greenery, the gypsy moth can be a pesky inhabitant of the area's mountain ridges, Putnam said.

"The gypsy moth happens to be one of the most invasive alien species," he said.

Putnam said the DOF began reporting defoliation in Montgomery County in 2006, and in three years the county has seen 12,432 acres defoliated because ofthe gypsy moth, based on aerial sketch mapping and photo interpretation. He said this is a significant amount, but not a cause for alarm.

Shenandoah County recorded the most gypsy moth-caused defoliation of any county in one year in 1992, when 153,000 acres were defoliated.

The gypsy moth feeds on 300 species of trees and shrubs, according to the VCGMSP.

Robinson said because the moth is a pest while still in the larval stage, it must be controlled very early.

"We must do so when larvae are fairly young," he said.

Putnam said gypsy moth larvae go through either five or six stages of shedding -- five for males and six for females. To adequately eliminate the larvae, treatments should be done between the first and second stages, he said.

The natural insecticide used is sprayed onto the greenery, so that the larvae ingest it while feeding on leaves.

Ideal weather conditions for treatments are an average wind speed below 10 mph, humidity above 50 percent and temperature between 35 and 75 degrees, Putnam said. He said surfaces should not be very wet and precipitation should not be in the forecast for at least several hours.

Putnam said while his department has received numerous calls this spring from residents concerned about gypsy moths, they pale in comparison to the amount received last year. He said most calls are from residents living in wooded developments north of Blacksburg.

"Most people seem to have identified the gypsy moth prior to calling, and simply want to report it or find out more about the spray program," Putnam said.

While spraying is the only way to control the larvae in forestland, Putnam said property owners who notice gypsy moths can visit montva.com to learn about techniques for eliminating the pests.

These techniques include scraping egg masses into soapy water or coating them with horticultural oil to suffocate the eggs, Putnam said.

He said residents can identify the larva by looking at their backs -- older caterpillars have five pairs of blue dots followed by six pairs of red dots. Putnam urges residents to check the county Web site to view photos of the gypsy moth, their larvae and egg masses.

These eggs are often laid on trees, rocks, buildings, lawn furniture and firewood and are usually about the size of a coin, Putnam said. Additionally, residents are urged to contact the department if they notice a gypsy moth problem.