An advisory panel recommended Wednesday that state agriculture officials spray pesticide over a 40-acre area in the wooded hills of Encino to eradicate a recently discovered infestation of gypsy moths, which ravage trees by eating their leaves.
The chairman of the panel, a five-member group of scientists and agriculture officials who have advised the California Department of Food and Agriculture on gypsy moths for more than a year, told about 20 Encino residents at a public meeting that the recent moth infestation is "a very serious problem." But infestation is localized enough to allow an eradication program to work, panel members said.
The meeting was called last month after agriculture inspectors discovered nine gypsy moths this summer, along with three "egg masses" containing 600 to 800 eggs each. State officials believe the moths were brought to California inadvertently by a family that moved from Massachusetts two years ago.
Some Hatched Last Spring
Five moths were found in the same area in 1985, although no egg masses were found then, according to E. Alan Cameron, a Penn State University entomologist and chairman of the panel.
Inspectors also found evidence of "three or four" egg masses that had hatched last spring, he said, and there are probably more egg masses waiting to hatch next spring in the infested area, a blend of forest and expensive homes near Royal Oak and Skytop roads.
Defoliated 2 Million Acres
The infestation "is perceived to be a very serious problem by the panel," Cameron said.
John Kegg, an official with the New Jersey Department of Agriculture who also is on the panel, said the moths have defoliated more than 2 million acres in the United States this year. In 1981, they took the leaves from more than 12 million acres of forest, mostly in the Northeast.
The group recommended aerial spraying early next spring, just after the eggs have hatched but before the young caterpillars, which each can eat as much as a cubic yard of leaves a day, have the chance to disperse widely among the trees.
The panel listed several spraying alternatives involving different pesticides. Its favored option is aerial spraying with the pesticide Dimilin, which kills caterpillars by altering their development before they turn into moths.
Residents expressed concern about what the moths could do if left unchecked, but they also asked about the effect of the pesticide spraying, which they were told would only affect insects.
"It's going to be a costly thing if we don't get rid of" the moths, said Encino homeowner Lillian Gendell. "I want to know when they're going to do it," she said of the spraying, "because I'm going to take certain precautions."
Don Henry, a Department of Food and Agriculture program supervisor, said the department probably will decide on a treatment method next month, hold another public meeting in January and spray in early March. Residents of the area will receive more than one notice of the spraying, he said.