The Gypsy Moth in Virginia: History, Management, and Educational Programs

F. William Ravlin and Shelby J. Fleischer

In Virginia, the first gypsy moth was found in the Shenandoah National Park (Albemarle county) in 1969, probably transported on a visitor's vehicle. That area was treated with insecticide and the population was apparently eradicated. Isolated infestations continue to be identified and treated by the Virginia Department of Agriculture and Consumer Services gypsy moth control program. The natural spread of gypsy moths did not reach northern Virginia until about 1980. Since then the gypsy moth has continued its movement south and west and now covers approximately two-thirds of Virginia.

Movement of the Gypsy Moth in Virginia

Defoliation due to the gypsy moth in the United States regularly approaches two million acres. In Virginia defoliation began in 1984 with 374 acres. In 1992 almost 800,000 acres were defoliated and the gypsy moth could defoliate over a million acres during a single growing season by the year 2000. By 2010 virtually every county in Virginia will experience some level of gypsy moth impact.

Gypsy Moth Defoliation in the United States

Gypsy Moth Defoliation in Virginia

Gypsy Moth Impacts

Several years ago James O. Nichols, then Chief of the Division of Forest Pest Management, Pennsylvania Department of Environmental Resources, distributed excerpts from gypsy moth mail. Many of these excerpts proved to be quite amusing but all provide insight into the gypsy moth problem. For example:

"You money grubbers will find out that you can't take it with you. God will reap his just reward on you people and to these no good objectors to spraying. I am 78 and have worn out two brooms trying to get rid of these damn caterpillars."

"I don't not want any spraying on my property. Furthermore, P. O. Box ___ is an underground box not used by me. It belongs to criminal snakeface David _____ of Fort Washington who uses it in his illegal Russian espionage activities to defraud our government by using my name illegally -- he must be arrested."

"Who authorized any person to make judgements over me? How does any person obtain permission to tell me whether or not my land shall be sprayed? Since this is now in the hands of counsel, whose name shall appear on a temporary injunction order? To whom would we issue an arrest warrant? With whom would we start suit for damages? Thank you for your kind and helpful assistance."

Needless to say the gypsy moth is a people problem in addition to economic and environmental concerns. For one person a tree in their front yard may be worth well over $1,000, for another person, an entire woodlot may be worth much less. Trees are harvested to build furniture and houses, produce paper products, and others are ever-present symbols of history and heritage. No two trees have the same utility or value.

Even after gypsy moth control decisions have been made the control techniques themselves often become an issue. Pesticides in the environment are controversial and even more so when they are applied by aircraft, which is often the only feasible application technique. Determining what controls to use, where to implement controls, how to approach educational programs, and how to maintain support for gypsy moth management and Extension programs on a continuing basis are complex problems that must be addressed by Virginia's county administrators and taxpayers.

The goal of gypsy moth programs is to minimize the negative impacts associated with the presence of the gypsy moth. The most direct impact to counties will be significant defoliation of hardwoods, especially oaks, which comprise over 50% of the total species composition in many Virginia counties. Defoliation results in stress to trees, tree mortality, decreased growth, and reduced aesthetic quality. In addition, the gypsy moth creates a significant nuisance due to crawling larvae, larvae dropping fecal material, swarming of flying male moths, and the presence of egg masses laid on trees, houses, lawn furniture, and virtually anything providing a resting place for female gypsy moths. Other impacts include the disruption of county services such as dead tree removal along rights-of-way and an increased burden on Extension programs. In all cases where the gypsy moth initially invades, resources have been used to address increased homeowner, recreational, and producer related demands. Operational costs will be incurred to deal with problems associated with the gypsy moth no matter whether counties elect to implement a gypsy moth management program or not.

Regulatory and Management Approaches

Regulatory Program

The regulatory program in Virginia is implemented by the Virginia Department of Agriculture and Consumer Services (VDACS) in cooperation with U.S.D.A, Forest Service and U.S.D.A., Animal Plant Health Inspection Service. The goal of the regulatory program is to detect and eliminate gypsy moth infestations which are found outside of the regulated or the generally infested area (quarantined area). The extent of this area is revised annually and currently covers about one half of Virginia. Current quarantine maps are available from Virginia Tech and USDA APHIS.

Appalachian Integrated Pest Management

During the 1987 congressional hearings Robert C. Byrd (D-W.Va.) voiced concerns about gypsy moth range expansion and control within the Appalachians. Through Senator Byrd's efforts, the U.S. Congress 1987 Supplemental Appropriations Bill included funding for a project to demonstrate integrated pest management (IPM) technology against the gypsy moth. This project was entitled the Appalachian Gypsy Moth IPM Demonstration Project or AIPM. AIPM encompassed thirty-eight counties and almost thirteen million acres in Virginia and West Virginia. The objectives of AIPM were to slow the spread of the gypsy moth, minimize adverse effects caused by defoliation, evaluate the use of control activities against isolated populations, assess the feasibility of a coordinated county, state, and federal gypsy moth program, and develop a prototype IPM system that would be transferable to other areas of the United States. The principle components of AIPM included survey and monitoring of gypsy moth populations, decision making, control activities, evaluation, methods development, and education.

The Slow the Spread Project

After AIPM ended in 1992 a second regional gypsy moth IPM project began, the Slow the Spread pilot project (STS). The goal of the STS project is to determine the feasibility of using IPM strategies to slow the spread of the gypsy moth over a large geographic area (selected counties in Virginia, West Virginia, North Carolina, and Michigan). The objectives for STS are to 1) demonstrate that new and current technology can slow the rate at which gypsy moth populations are currently spreading, 2) assess the technological, economic, ecological, and environmental viability of implementing an operational STS program (one implemented over a larger area) and 3) implement a plan for integrating STS technology into a national strategy for suppression of the gypsy moth.

County Programs

Within the generally infested area state and federal mandates for meeting regulatory responsibilities diminish and responsibility for controlling gypsy moth populations fall to local governments and private individuals. Cost sharing for gypsy moth control in Virginia is available through state and federal agencies. All counties within the generally infested area have used the cost sharing funds and most have had to implement some level of gypsy moth management. This includes monitoring systems to determine when and where damaging populations exist and using a combination of chemical and nonchemical control tactics. Educational programs are one of the most important components of county programs. Because of the state-wide nature of the gypsy moth problem an Association of Virginia Gypsy Moth Managers (AVGMM) has also been formed. The purpose of AVGMM is to gather and exchange information, expertise, ideas, and when appropriate, resources in a coordinated effort to manage the gypsy moth in Virginia.

County Program Needs and Problems

As the gypsy moth continues to invade new areas, Virginia counties are faced with defining the appropriate gypsy moth programs, program maintenance and information management systems for making control decisions, strategic planning, and public education.

Defining the Appropriate Gypsy Moth IPM Programs. There is no one gypsy moth management approach that will suit the needs of all counties. What is logical and affordable for one county may be inappropriate for another. There are however, some guidelines and projections that can be made relative to infestation levels. Capturing male gypsy moths using pheromone-baited traps is a reliable way to determine the geographic extent of gypsy moth populations prior to an initial defoliation. Counties which have male moths that are generally distributed throughout their area will have approximately three years to put together a program. This does not mean that defoliation is imminent but that within a three-year period there is a high probability that reproducing populations will be found somewhere in the county (someone will find egg masses or larvae). Once this occurs homeowners will contact county offices, begin control activities, and pressure administrators and Extension agents to do something. Counties who become aware of the status of gypsy moth populations at the early stages will have the ability to develop appropriate budgets and programs prior to occurrence of defoliation.

A primary source of information to assist in initial program development is Virginia county Extension agents. Necessary Extension activities include working with the county administration to formulate a plan of action and educate residents that the gypsy moth is a significant problem, is imminent, and one that will not go away. Agents cannot carry out management activities or pay little more than cursory attention to public relations and education in the latter stages of gypsy moth infestation without assistance or without de-emphasizing existing programs in lieu of the gypsy moth problem. Extension can help initiate a coordinated management program through the formation of an advisory committee.

Program Development. In those counties where gypsy moth management becomes a priority, county administrators have hired and maintained a high level of expertise in gypsy moth program coordinators. These coordinators have had responsibility for program budget development and administration, public relations and implementation of control programs. They are sensitive to political and environmental concerns, and have skills in integrated pest management. In some counties, program coordinators have taken the lead in developing and distributing educational materials and programs delivered to county residents and public school programs. Successful educational programs are closely tied to Extension efforts. The close interaction between gypsy moth management programs and Extension is essential to a successful and lasting program. In addition to ties with Extension the gypsy moth program must also receive significant input from groups affected by the gypsy moth. This input can be facilitated by the formation of a county/city Gypsy Moth Advisory Committee. This committee would be comprised of representatives from public lands, local governments, homeowner associations, and industry to name a few. Annual activities for the Gypsy Moth Advisory Committee include program review, review of future management plans, and input into budget development.

Program Maintenance. The gypsy moth problem is one that Virginia must live with. The gypsy moth will not be brought under control in the foreseeable future and county governments and residents must begin the process of deciding if a gypsy moth management and education program will assume a priority position in budget decisions. In making this decision, county administrators must realize that the gypsy moth program activities occur year around, that the problems faced by program coordinators are extremely demanding, and that the problem will continue after years when defoliating populations have subsided. A maintenance plan must provide funding for the nondefoliating "off years" to insure that high quality gypsy moth program coordinators can continue with the program and that an early warning monitoring system be kept in place on a permanent basis.

Information Management. County resources must become available to develop a coordinated effort to centralize, standardize, and make available information necessary for making objective control recommendations for the wide range of social, economic, political, and ecological situations in Virginia. This approach would include the development and implementation of a county-wide gypsy moth monitoring system, management of relevant data bases, interpretation of monitoring system results, preparation of control recommendations, and using this information to proactively develop budgets for the overall gypsy moth IPM program. As a result of the monitoring system an extensive data base will be developed on gypsy moth densities through time, susceptibility and vulnerability of forest stands, and history and extent of defoliation and tree mortality. All information should be geographically referenced and compatible with data from other resource management programs being conducted in and around a particular county. Computer hardware and software must be made available and programs developed to maintain and access data necessary for making control recommendations in a timely fashion. This will facilitate the production of maps for program planning, description of the extent of the gypsy moth problem, and how the problem interacts with sensitive social, economic, and ecological situations.

Availability of "Silver Bullets"

When asked what is the most pressing need for managing the gypsy moth, many state and county gypsy moth managers have cited more new and more specific insecticides and better formulations of existing ones. Although this may provide more tools to control the gypsy moth on a local basis, the real need is for a unified approach to managing the overall gypsy moth problem. This approach must combine the objectives of all who will be impacted by the gypsy moth. With the inevitable change of the gypsy moth from exotic to endemic or generally infested status, federal and state funding assistance will be reduced or eliminated from counties. Counties must then develop management systems from which control decisions can be made. These decisions would then be based on high quality data derived from cost-efficient monitoring systems, with the interests of those who will be affected kept in the forefront. Recent outcries related to pesticide use in Virginia underscore the need to develop integrated pest management systems that take advantage of current technology, philosophy, and practicality. It is essential that the gypsy moth be considered in a long-term context, keeping in mind that there will not be any "silver bullets" available for many years to come.