Biological and chemical warfare will come to Howard County in May, when the state sprays sections of the county to combat the leaf-eatinggypsy moth.
Most spraying will be in scattered pockets east of Route 29, with a few spots west of the highway. Residents in affected areas were sent letters in recent weeks to advise them of spraying locations and of the type of spray that will be used, said Mark Taylor, state gypsy moth coordinator.
The gypsy moth caterpillar can kill a tree -- or an entire forest-- by defoliating it, said Steve Parker, tree care supervisor for the county Bureau of Highways.
Stripped of its leaves, a tree uses the food it had stored for winter just to get through the summer. Thisweakens the tree, which may die or fall prey to other insects that kill it. Some trees can withstand more than one defoliation by the noisy, voracious caterpillars before they die.
"These little critterswill eat like crazy," said Parker. "They really have the best job inthe world because they eat all night and sleep all day."
The mostpopulous areas that will be sprayed are the Phelps Luck section of Columbia's Village of Long Reach, the Glenmar area northeast of Columbia, the area around Chestnut Hill near Route 40, and areas by the Orchards development near Ellicott City.
Of those, Glenmar is the only heavily populated area to be sprayed with Dimilin, a chemical that stops the leaf-munching caterpillar from forming a "new skin" and developing into an egg-laying moth. Taylor said that Dimilin is harmful only to animals that molt into other forms, such as crabs, but is no threat to people, plants or pets. The chemical will not be used within 250 feet of waterways.
Roughly 95 percent effective in ridding an area of the insects, it is more effective than Bacillus thuringiensis, a natural bacteria that is about 70 percent effective and can be used near waterways. The bacteria kills the caterpillar by paralyzingits stomach. The insect stops eating within two hours, and dies and falls from the tree within a few days.
Many Glenmar residents saidthey support the use of Dimilin.
Elinor Santor, of Elko Drive, said she put a sticky band, a strip that bogs down caterpillars from climbing up a tree, to protect her trees last year.
"It's a cost-benefit kind of a thing. I don't want to see the trees ruined," she said. "It's not that I like Dimilin. I don't like gypsy moths."
Several of her neighbors said they worry more about potential gypsy moth damage than the spraying.
Officials will hold an open session tomorrow, from 6 to 8:30 p.m. at Hammond High School, to answer questions about the spraying. Forms to request withdrawal from the spraying are available from the state by calling 829-9116.
Last year, county residents were not adequately notified of the spraying. As a result, callers, alarmed by aircraft swooping over their yards, flooded the county's emergency 911 lines. Officials said they hope the mailings and meeting will dispel residents' fears.
Taylor estimated that close to $168,000 will be spent to suppress the insect in Howard County this year. A quarter of the money is provided by the county, another quarter by the state, and the remaining half by the federal government. He said gypsy moth infestation has dropped by half statewide in the last year.
Taylor also advises home owners to destroy the gypsy moths' buff-colored egg masses and red-and-blue spotted caterpillars. The insects should be picked up and sent to the dump or dropped in a bucket of soapy water to kill them. Taylor cautions the public to wear gloves because some people are allergic to the hairs of the caterpillar or tree fungus.
Trees also can be protected with sticky barrierbands, available from hardware or home and garden stores, which prevent newly hatched caterpillars from climbing up the trees.
Bands should be placed about four feet from the ground; about a foot above the sticky band, a burlap band should be wound around the trunk.
Burlap offers shelter for the larger caterpillars that crawl down fromthe foliage to rest during the day. The homeowner should check the burlap while the pests are resting and either squash them or drown them in soapy water.
For more information on the gypsy moth and the spraying, call (800) 492-2106 or (301) 829-9116.