HARRISBURG, Pa., March 7, 2013 /PRNewswire-USNewswire/ -- The Department of Conservation and Natural Resources will target eight counties in an aerial spraying effort to combat the effects of growing gypsy moth populations in northwest and north central Pennsylvania.

The gypsy moth is one of the most destructive forest pests in Pennsylvania. When the insect's population peaks, it may strip trees of foliage, leaving them weakened and susceptible to disease, drought and attack by other insects. A tree begins to suffer when 30 percent or more of its leaf surface is lost.

"After a three-year absence of severe gypsy moth damage in our state woodlands, the invasive forest pest has multiplied in some areas to the point where suppression efforts must be resumed," DCNR Secretary Richard Allan said. "Woodlands selected to be sprayed this spring were determined by the number and concentration of gypsy moth egg masses found, previous defoliation and ecological, historic or economic significance."

Gypsy moth numbers are at high enough levels that 43,124 acres of state forestland, state parkland and Pennsylvania Game Commission land will be sprayed in Cameron, Clarion, Forest, Jefferson, Lycoming, Potter and Tioga counties. Sixty five acres of private property also will be sprayed in Venango County.

"Spraying is a suppression and forest management effort that will protect trees from moderate to severe defoliation," Allan said. "The gypsy moth will continue its cyclic population with ups and downs, and we cannot eradicate the insect. It's too well-established, and is here to stay."

DCNR last sprayed for gypsy moths in 2009, when more than 178,380 acres in 25 counties were targeted across the state. In 2008 a total of 221,221 acres of private, state and federal woodlands were sprayed in 27 counties.

"Counties and cooperating agencies opt to enroll and share in the costs of treatment in this voluntary program," State Forester Daniel Devlin said. "Spraying was not needed in prior years because the gypsy moth's natural enemy, the fungus Entomophaga maimaiga, caused populations to collapse across the state.

"Spraying helps contain the widespread gypsy moth damage we've seen in the past, but the major controlling factor is, and will continue to be, the prevalence of this fungus in our woodlands," Devlin said.

Using helicopters, the spray program will begin in mid-April and end by June 1. Tree foliage will be treated at the rate of one-half gallon per acre with the biological insecticide, Bacillus thuringiensis (Bt), comprised of naturally occurring Bacillus spores which must be ingested by the caterpillar. No chemical insecticides are used.

Begun in 1972, forest insect spray programs are a cooperative effort among DCNR's Bureau of Forestry, county governments and the U.S. Department of Agriculture Forest Service's Forest Health Protection Unit. County governments share the cost of treating private residential and local government-owned lands for gypsy moth suppression.

DCNR is soliciting public comment on the proposed gypsy moth suppression program at a public meeting between 10 a.m. and noon Monday, March 11, in Room 7A, Rachel Carson State Office Building, 400 Market St., Harrisburg.

Written comment may be mailed to Kevin Carlin, forest pest suppression supervisor, Bureau of Forestry, Division of Forest Pest Management, Rachel Carson State Office Building, 400 Market Street, 6th Floor, Harrisburg, Pa., 17105, or emailed to [email protected].

Learn more about the gypsy moth at www.dcnr.state.pa.us (click on "Forestry," then "Insects and Disease" at upper left).

Media contact: Terry Brady, (717) 772-9101

SOURCE Pennsylvania Department of Conservation and Natural Resources