PROVIDENCE - The Rhode Island Department of Environmental Management (DEM) reports that moderate to high concentrations of gypsy moth caterpillars are expected this spring across the state. While a nuisance, the caterpillars do not pose a public health threat and will eventually die off naturally. As a result of the anticipated large numbers of caterpillars, widespread defoliation of trees and shrubs is also expected; however, these effects will be temporary. The vast majority of the state's impacted tree canopy is expected to recover.
Caterpillars have just begun hatching from egg masses. Once hatched, they will disperse with the wind on thin threads of silk. As the caterpillars grow, they will become increasingly noticeable on tree trunks and on the underside of leaves. The State will continue to monitor caterpillar populations and the resulting defoliation. At this time, the state does not plan to apply pesticide to control caterpillar populations. Widespread use of pesticides can be detrimental to the environment and harmful to other insects and wildlife. Homeowners interested in learning more about treatment options for infested landscape should contact a licensed arborist who also holds a state pesticide applicator's license.
In recent years, gypsy moth populations have been on the rise due to dry spring weather conditions. Last year, aerial surveys and ground sampling conducted by DEM documented the defoliation of close to 226,000 acres of forestland. An outbreak of gypsy moth in the mid-1980s defoliated 411,000 acres of Rhode Island forestland.
For more information on gypsy moths and expected impacts, visit www.dem.ri.gov/gypsymoths. Follow DEM on Twitter (@RhodeIslandDEM) or Facebook at www.facebook.com/RhodeIslandDEM for timely updates.