Virginia officials predict that there will be more gypsy moths in the northern part of the state next year and propose extending the quarantine area to slow the spread of the leaf eating pest.

Robert E. Bailey, an official with the Virginia Department of Agriculture and Consumer Services, said it would be "at least a couple more years" before the gypsy moth population is high enough to cause "heavy tree defoliation or mortality."

But Bailey and other state agriculture representatives, who held a briefing session Thursday with Northern Virginia community leaders, said it is vital to use this time to limit the damage as much as possible.

Although isolated gypsy moth outbreaks have been reported throughout the United States, the severest damage has occurred in the Northeast, where a record 13.1 million acres were defoliated in 1981.

Under regulations adopted by Virginia last April, parts of three Northern Virginia counties -- Fairfax, Fauquier and Loudoun -- fall under the gypsy moth quarantine.

The state agriculture department wants the quarantine extended next year to include those counties in their entirety, as well as Frederick, Warren, Clark, Stafford, Prince William and parts of Shenandoah and Culpeper counties.

Under the quarantine, articles such as firewood, cut Christmas trees and recreational vehicles cannot leave quarantine areas unless state-authorized inspectors certify that they are free of gypsy moths.