This spring has been wetter, and that could also help with limiting the larvae.
Garrett County administrator Monty Pagenhardt, whose section of Western Maryland was ravaged by the moths last year, said he hopes this year's rain and the added pesticides will provide a one-two punch.
"It was very bad last year, and this year was projected to be even worse," said Pagenhardt, whose county is chipping in $49,000 for spraying this year. "Right now we're having a wet spring, and that fungus thrives on damp moldy springs, and that will help, too."
Aerial surveys in the spring help officials judge which sections of the state should be targeted for spraying. Property owners whose homes will be sprayed receive warning letters recommending that people stay inside during the application.
The spraying started April 30 in Anne Arundel, Talbot and Worcester counties; continued this week in Baltimore County; and over the next month will move west across the state, from Carroll to Garrett counties, finishing in early June, according to state officials.
For a listing of the exact locations and dates of spraying, go to the Maryland Department of Agriculture's Web site at http:--www.mda.state.md.us/.
One of the compounds being used is Bacillus thuringiensis (known as Bt), a pesticide made from a naturally occurring soil bacteria that is toxic to insects.
Another is Dimilin, an insect growth regulator that can also be poisonous to aquatic invertebrates living in streams.
"Harmful if absorbed through skin or inhaled. Avoid contact with eyes, skin or clothing," warns the label on Dimilin. "Avoid breathing spray mist."
Tilley, the entomologist at the state Agriculture Department, said he has been spraying the chemicals for more than two decades and hasn't heard any complaints about human health problems.
But he added that people should stay inside, just to be careful. "People see the airplanes or helicopters flying by and they go out and look at it - and that's not a good idea," said Tilley. "The pesticides we are using are safe, but the best idea is to reduce your exposure."
Ruth Berlin, executive director of the Maryland Pesticide Network, a health advocacy organization, disagreed that the chemicals are safe.
"The truth is that no pesticide is safe," she said. "There is a growing body of research that pesticides affect the public health and the watershed, and people are becoming increasingly concerned."
The U.S. Environmental Protection Agency, however, says that Bt "presents little risk" to mammals. Dimilin "has been shown to be slightly toxic," but the danger is low enough that most spraying presents an "insignificant" risk to people, EPA says.
Baltimore County Councilman T. Bryan McIntire said it would be "disastrous" if the state stopped spraying: "I am very grateful that they are doing more spraying this year. But it's still not enough, because there are areas that still have a strong presence of the gypsy moths."
tom.pelton@baltsun.com
