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Photo of a gypsy moth caterpillar - Click to enlarge
Proposed Spray Program Announced
For Immediate Release: January 6, 2009
Contact: Lynne Richmond
(609) 633-2954

(TRENTON) – The New Jersey Department of Agriculture is proposing treatment on 65,794 acres of forested land to suppress gypsy moth caterpillars in May and June of this year.

The number of acres proposed for treatment this year is about half of what was proposed in 2008, when 112,500 acres were targeted for spraying.  The number of acres actually treated last year was 93,814.

“New Jersey’s aggressive approach to suppressing gypsy moth caterpillars appears to be working evidenced by the much lower number of acres qualifying for the spray program this year,” said Acting Secretary of Agriculture Al Murray.  “Even though the expectation is that the gypsy moth population is decreasing, more than 65,000 acres is still a significant treatment area, demanding that we continue our cooperative effort with municipalities, counties, other state agencies and the federal government to protect the state’s trees from this voracious pest.” 

The Department today announced a proposed spray program in 98 municipalities and agencies in 17 counties. Burlington, Atlantic, Ocean and Sussex counties account for more than half the acreage proposed for treatment. In addition, the State Department of Environmental Protection is planning to spray about 1,908 acres in state parks and forests. 

More than 339,000 acres of trees were defoliated by gypsy moth caterpillars in spring 2008, however, the rate of increase in the gypsy moth population showed signs of slowing.  There had been a steady increase in population since 2004 when only 6,502 acres were defoliated.  In 2005, that increased to 44,131 acres; in 2006, it was 125,743; and in 2007, 320,610 acres of trees were stripped.

Following consecutive years of gypsy moth caterpillar defoliation, a tree mortality survey conducted by the Department of Agriculture and the Department of Environmental Protection’s Division of Parks and Forestry last summer observed a total of 30,902 acres of trees had died in 2007 and 2008.  Burlington and Ocean Counties experienced the largest number of tree deaths, mostly on federal and state forested lands.

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 qualify for inclusion in the cooperative gypsy moth suppression 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.  Municipal participation in the aerial spray program is voluntary.

Last year, the United States Forest Service provided $1,195.946 in 23 percent cost reimbursement funds to municipalities participating in the Department of Agriculture Gypsy Moth Aerial Suppression Program.  The Department is working with the state's congressional delegation to again secure federal cost reimbursement funds for the 2009 program.

For more information on New Jersey’s gypsy moth suppression program, visit:   Also, for national gypsy moth material, visit