ANDREWS AFB, Md. –
In conjunction with the U.S. Forest Service, the 316th Civil Engineer Squadron Environmental Flight is currently coordinating an aerial spray operation to mitigate a Gypsy Moth infestation in three areas around the base - a large portion of the golf courses, the wooded area surrounding the small arms range and another area off Tyler Road -- a total of about 215 acres.
"Andrews Air Force Base personnel observed some defoliated oak trees in the wooded areas of the installation and requested the US Forest Service complete a field survey to determine the cause and make recommendations," said Patricia Gray, Environmental Conservation and Planning chief, 316 CES. "The result of the survey indicated high counts of gypsy moth egg masses. If left untreated, the USFS estimated 215 acres could suffer heavy defoliation in 2008. Defoliation significantly weakens trees and can cause trees to die under stressful seasons or with repeated defoliation."
Spraying should take place during the first week of May.
"Timing of the treatment is determined by the growth of tree leaves and the growth of the gypsy moth larvae," said Ms. Gray. "Spraying would take place around the first week of May when the gypsy moth is in a larval stage and susceptible to the treatment."
The Gypsy Moth has been observed throughout the region, particularly in Maryland where the outbreak is said to be the worst in 12 years. In fact, the Maryland Department of Agriculture sprayed 50,000 acres of public and private land statewide in May 2007. So, not only will some of the Andrews wooded areas be sprayed, but the National Arboretum also plans to treat their resources on the same day.
"Treatment by aerial spray would occur in the early morning in order to meet the requirements for wind velocity, probability of precipitation, relative humidity, air temperature, and foliage wetness restrictions," added Ms. Gray. "The spray would be accomplished by a certified applicator in a Global Positioning System equipped helicopter flying [close] to the tree canopy."
According to Ms. Gray, these insects are normally found in temperate areas of Asia and Europe.
However, an accidental release of Gypsy moth larvae occurred in Boston during the late 1860's and over the past 140 years they have become an invasive species to North America. The adult male moth has two antennae and is tan and brown with a pattern resembling tree bark while the female is larger and lighter with no antennae. Older larvae are recognizable by the combination of 5 blue and 6 red pairs of spots down their hairy bodies.
"They are voracious eaters, especially of oak tree leaves," said Ms Gray. "Trees here have been significantly weakened by previous loss of leaves and dry seasons making them especially vulnerable this year. It is likely that many trees will be lost if they are not treated and are defoliated by the increasing population of gypsy moths."
To mitigate pest infestations, the Air Force practices integrated pest management to minimize the use of chemicals when possible.
In this case however, the USFS and AF entomologists involved have recommended the use of Dimilin(r) (diflubenzuron) because of the level of infestation and need for an effective treatment to save the weakened trees. Dimilin(r) is the most widely used chemical insecticide in gypsy moth suppression projects in the U.S. It works by inhibiting the molting process of the larvae.
Dimilin, the chosen pesticide, is registered by the EPA for use in residential areas. It is mixed with water and applied at a rate of 1 ounce per acre directly to the tree canopy. It is not harmful to people, mammals, birds, plants or finished surfaces at the rate applied. As with any chemical, precautions should be taken to avoid inadvertent exposure or ingestion.
For safety during spraying, and for 15 minutes afterward, people should remain indoors if located in a treatment area to let the product settle and dry. The applicator would fly the helicopter low to the tree canopy to target the leaves but incidental coating of cars, tools, equipment, etc. may occur within the area sprayed. After treatment individuals should wash these items when practical and wash their hands after handling coated materials, particularly before eating, drinking or chewing gum.
People here should know that the treatment helps AAFB retain the beautiful old oaks and other trees threatened by the gypsy moth. Personnel located within the treatment areas have the inconvenience of staying indoors during spraying and may choose to park further away. Other personnel should be aware of the action and not be alarmed by a low flying helicopter spraying trees in the designated areas.
"Practicing good environmental stewardship can make a difference," said Ms. Gray. "Gypsy moths love to lay egg masses in sheltered places under branches, on tree trunks, parked vehicles such as campers, RVs, and boats, firewood stacks, playground equipment, lawn furniture, and structures.
"The egg masses are tan and when found should be removed and destroyed by placement in rubbing alcohol, buried in the ground, or placed in the garbage. Leaving egg masses on the ground surface is ineffective. Mobile items like vehicles and lawn furniture should be inspected before relocating them during PCS moves. Firewood should never be moved to other counties or regions because it can transport gypsy moth eggs or other invasive species such as the Emerald Ash Borer. Quarantines are in effect for both of these species."
For more information, call 301-981-5151.