The gypsy moth, the leaf-eating insect that has infested many areas in Maryland and Virginia, has landed in the District and may soon become a serious problem for some upper Northwest neighborhoods unless preventive measures are taken, according to the University of the District of Columbia's extension service.

"It's really bad right now, and we are getting dozens of calls a day from people wondering what to do," said Allen Jones of the Cooperative Extension Service, which provides agricultural information to the public. "But it's nothing like what it's going to be in a couple of years."

In this area the hungry gypsy moth caterpillars, which are identified by their rows of blue and red dots, feed on oak trees and can kill softwood trees after one defoliation. Two or more defoilations can lead to the death of hardwood trees.

Jones said that although the moths can be found in small quantities all over the District, they can be found in threatening numbers only in some upper Northwest neigborhoods bounded by Oregon Avenue on the east, Military Road on the south and Western Avenue on the west.

Some residents of this Chevy Chase area, where large houses are lined with oak trees, said they first started noticing the moth's voracious leaf-eating caterpillar a month ago.

"Those nasty bugs are the most revolting thing we've ever seen," said Ursula Shears, who lives on 32nd Street NW. "We have never had this problem before."

Shears and many of the residents in the area have wrapped their trees in burlap bands, a method that experts say can trap larvae and caterpillars as they ascend or descend a tree. On some streets each tree along the curb or on private property is wrapped in a burlap band.

"We received a notice from the city instructing us to use the burlap," said Barbara Frese, who lives in the 3300 block of Stuyvesant Place, "and my husband pulls hundreds of those awful insects off the burlap and puts them in bleach in order to kill them."

Although the city's tree service has sprayed twice in the area, Shears and many of her neighbors are having exterminators spray infested trees in their yards.

The caterpillar, which hatches after nine months, feeds on leaves, shade and fruit trees, and shrubs. It can eventually devour entire forests.

Anyone who wants more information on gypsy moths can call the extension service at 576-7419.