GYPSY MOTH ERADICATION

Our Concerns About Dimilin Use

The Maryland Department of Agriculture website states that:

"When such areas are threatened with defoliation, the Maryland Department of Agriculture, Forest Pest Management Section may propose aerial insecticide treatments to protect and preserve the forest and shade trees. Such treatments are conducted under the Maryland Cooperative Gypsy Moth Suppression Program. The USDA Forest Service, Maryland Department of Agriculture and local governments or landowners participate in this voluntary program. Although Maryland, like other states in the northeast, has suffered severe outbreaks of the gypsy moth, the Maryland Department of Agriculture, Forest Pest Management Section has been highly successful in protecting our forest heritage."

MPN shares concerns with other organizations and state governments about the aerial spraying of Dimilin for gypsy moth eradication. On January 29, the New Jersey Department of Environmental Protection (DEP) concluded a month-long review of the Department of Agriculture's (NJDA) petition to waive the state's ban on aerial-spraying of broad-spectrum pesticides. The state will uphold the ban, effectively blocking widespread use of the chemical Dimilin.

Dimilin is a restricted-use pesticide (available only to certified applicators) that has been unavailable for broadcast use for decades in New Jersey. For the past 20 years, in lieu of aerial spraying of Dimilin "also known as diflubenzuron" the pesticide specified in NJDA's request, New Jersey towns have used bacillus thuringiensis (Bt) , a bacterial agent. Despite expectations that gypsy moth populations will be higher in 2007 than in recent years, the state did not rescind the ban in Dimilin and chose to rely on Bt.

The Environmental Protection Agency (EPA) classifies Dimilin as "moderately toxic" to humans. Two breakdown products of diflubenzuron are carcinogenic according to EPA, p-chloroaniline (PCA) and p-chlorophenylurea (CPU). CPU is the major breakdown product found in water and therefore could be widely distributed in certain waterways following aerial application of dimilin.

Dimilin affects both gypsy moths and beneficial organisms, such as aquatic crustaceans and other molting insects.

According to the US Environmental Protection Agency, all the agency's "levels of concern" were exceeded when the agency looked at Dimilin's impacts on freshwater invertebrates (insects and related animals). EPA concluded that "Use of diflubenzuron is expected to cause adverse acute and chronic effects" to these animals. Similar effects were found for estuary fish. In turn, dimilin "may cause adverse effects" on the animals that feed on the aquatic invertebrates, gamefish, waterfowl, shorebirds, small mammals, reptiles, and amphibians.