Management
delta traps
Terry Price, Georgia Forestry Commission
Bugwood.org
Gypsy moth management practices vary depending upon the scale of the project. Here we provide some information that may be helpful to the small scale projects of homeowners, as well as the larger scale undertakings of those in the forestry professions. Also available is information on the various chemical and biological agents used.
Population Monitoring
milk carton trap
Gypsy moth population monitoring in Virginia typically is orchestrated through one or more state, local, or federal agencies. Pheromone-baited traps use a synthetic version of the gypsy moth mating pheromone to attract and capture male moths. This is the most efficient method of detection and monitoring and is the primary tool used in the National Slow the Spread Project (STS) and in the APHIS detection and eradication program. Pheromone traps are most useful in areas with low and/or building populations where moths have only recently been introduced. They are not useful tools for monitoring moths in generally infested areas.
Population assessment in generally infested areas is based upon egg mass surveys, the most accurate of which is the 1/40th acre fixed-plot method. With this method, one counts every egg mass within a circle with a radius of 18.64 feet (18ft 8in) and multiplies by 40. Populations are quantified based on the number of egg masses per acre. The relationship between egg mass density and damage varies a great deal, but a general threshold that can be used to indicate noticeable defoliation is 500 egg masses per acre. It's easy to see that if you average only 12.5 new egg masses per 40th acre plot, you are at the damage threshold. If you can easily count a dozen egg masses on a tree, it is safe to assume you have many more that are not visible. For more information, see:
- Gypsy Moth Egg Mass Sampling for Decision-Making: A Users' Guide
- New York state egg mass survey guide
Virginia Department of Agriculture and Consumer Services (VDACS) Cooperative Gypsy Moth Suppression Program
In Virginia, gypsy moth control activities are administered through the Virginia Department of Agriculture and Consumer Services (VDACS). In this program, Virginia uses federal gypsy moth suppression money to cost-share with qualifying counties and municipalities for expenses associated with gypsy moth management. Entities applying to the cost-share program must work through a gypsy moth coordinator and submit information about their proposed treatment areas to VDACS. Details on the Virginia Cooperative Suppression Program, as well as information about regulatory guidelines, can be found at the VDACS gypsy moth web site.
- Virginia Cooperative Gypsy Moth Suppression Program Guidelines for 2008
To learn more about the options available in your area, contact your local extension agent, forester, or county board of supervisors.