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Photo of gypsy moth caterpillar - Click to enlarge
For Immediate Release: July 15, 2010
Contact: Lynne Richmond
(609) 633-2954

(TRENTON) – New Jersey Secretary of Agriculture Douglas H. Fisher today announced gypsy moth caterpillar populations remain low in the state, following an aerial survey to assess tree damage caused by the pest.

The New Jersey Department of Agriculture’s annual gypsy moth aerial defoliation survey showed 3,813 acres of trees experienced some level of leaf loss in the state this year, as compared with 91,890 acres last year and 339,240 in 2008.

“We are pleased to see a drop-off in the numbers of gypsy moth caterpillars this year, causing the least damage to forested areas of our state since 1999,” said Secretary Fisher.  “However, given the right conditions, populations can easily rise again, so the Department must continually monitor gypsy moth’s status to continue to control the spread of these tree-killing insects.”

The Department’s defoliation survey showed that this year, Cape May County was the most impacted by gypsy moth caterpillars, with 1,019 acres showing moderate to heavy tree damage.  About half that acreage was in Upper Township.  In general throughout the state, most tree damage was scattered and in heavily wooded areas.

An egg mass survey conducted last fall qualified one area for the Department’s annual spray program, in Mullica Township, Atlantic County.  But, the municipality opted out so no spray program was conducted this year. 

The 2009 Gypsy Moth Aerial Spray program included 15 counties, 55 municipalities and 11 agencies with spraying on 35,816 acres of wooded residential and park land, wooded areas along the Garden State Parkway and areas of Earle Naval Weapons Station.

The gypsy moth population reached its peak in 2008 with 339,240 acres defoliated before the population began to drop off last year through a combination of regular life cycle drop-off, beneficial fungus and natural predator increases combined with the Department’s aggressive spray program.

The Department of Agriculture will continue to closely monitor, survey and spray, where necessary, to control the spread of the gypsy moth in the future.  Towns that experienced tree defoliation this year will soon receive letters informing them that they can request the Department to conduct an egg mass survey this fall to determine if spraying is necessary in 2011 to control gypsy moth caterpillars.  To qualify, residential or recreational forests must have an average of more than 500 egg masses per acre, and be at least 50 acres in size to qualify for participation in the voluntary program.   

The Department’s gypsy moth suppression efforts are aimed at preventing the loss of trees and protecting forests, which are important wildlife habitats as well as filters for the air we breathe.  Since 2006, repeated defoliations by gypsy moth caterpillars led to the death of more than 30,000 trees throughout the state.

Two to three consecutive years of significant defoliation (defined as 75 percent or more) can kill an otherwise healthy tree. However, any gypsy moth defoliation can make trees more susceptible to other damage that can lead to the death of the tree.   Oak trees are the preferred host for gypsy moths, but the caterpillars can be found feeding on almost any tree in the vicinity.

To access the detailed 2010 New Jersey Gypsy Moth Aerial Defoliation survey and for more information on New Jersey’s gypsy moth suppression program, visit: