The recent survey - conducted in late June and early July - showed that 2,887 acres in 51 municipalities in 17 counties received moderate to severe damage, officials said.
Fifty-three acres were affected in Camden County, 23 in Gloucester County and six in Burlington County. Tree damage also was found in Atlantic, Bergen, Cumberland, Essex, Hunterdon, Mercer, Middlesex, Monmouth, Morris, Ocean, Passaic, Somerset, Sussex and Warren Counties. The most damage was found in Bloomingdale Borough and West Milford Township, both in Passaic County, which had a total of 1,087 acres of trees heavily damaged.
In 2012, 1,068 acres of trees in 21 municipalities in 10 counties were defoliated by gypsy moths - the lowest recorded defoliation since the department's Gypsy Moth Suppression Program began in 1970.
"Gypsy moth populations depend on conditions like weather and other factors," said Lynne Richmond, a spokeswoman for the state Agriculture Department. "We had a fairly wet spring that promoted the growth of fungus that's detrimental to them" - another factor in holding down the population, which has collapsed over the last several years.
Gypsy moth caterpillars lay their eggs on trees and emerge in May and early June. This year, no spray program was needed because of low populations.
The state has been monitoring the bugs and "aggressively responds when it sees their population getting higher," Richmond said. To qualify for the spray program, a residential or recreational forest must have an average of more than 500 egg masses per acre and be at least 50 acres in size. A single egg mass contains up to 1,000 eggs.
"We plot out spray blocks and propose them to the municipality in January," Richmond said. The towns pay for the program and "determine if they want to be part of it."
Contact Edward Colimore at 856-779-3833 or firstname.lastname@example.org.