Managing gypsy moths in North Carolina

by | Jun 5, 2013

Gypsy moths and their egg masses. Image: J. Ghent, USFS,

The gypsy moth. While you may not have heard of it, the very name strikes fear in the hearts of people in states north of us who deal with this leaf-eating insect each year. It’s also why there are thousands of orange or green prism boxes hanging in trees throughout North Carolina. We want to keep the gypsy moth caterpillars, and the damage they cause, out of the state.

Originally from Europe and Asia, gypsy moths were brought to the Boston area in 1869 by an amateur entomologist hoping to improve the silk moth industry. The moths escaped into native forests and have since spread throughout the Eastern and Midwest regions of the United States, right to North Carolina’s doorstep. In the forests they invade, gypsy moth caterpillars eat the leaves of more than 300 species of trees and shrubs, sometimes causing tree death. And unlike most native insects, the gypsy moth doesn’t have a suite of naturally-occurring predators and diseases to keep their populations in check.

Gypsy moth traps (they can be green or orange). Image: Terry Price, Georgia Forestry Commission,

While the gypsy moth has been found in Virginia counties along the North Carolina border, it has not yet become established in North Carolina. Surveyors are placing about 10,000 traps throughout the state to monitor for emerging gypsy moth populations. If the traps indicate a population is large enough, NCDA&CS may opt to treat the population in order to eradicate it.  Five of these sites have been treated so far this year.

Fortunately, efforts to manage gypsy moth populations have been successful. Along with the U.S. Forest Service, several state agencies, including the NCDA&CS Plant Industry Divison and the N.C. Forest Service, are cooperating as part of the Gypsy Moth Slow-the-Spread Foundation.  This program was established to help limit the spread of this invasive pest. For every dollar spent through the foundation, four dollars are saved by delaying the onset of impacts from the gypsy moth.

You can help slow the spread of gypsy moth and other damaging invasive species in North Carolina. Many invasive species, including gypsy moths, are easily spread by humans through the transport of untreated wood products such as firewood. One of the best ways to avoid moving invasive insects is by buying firewood close to where you will burn it, rather than bringing your own. And don’t forget to keep an eye out for suspicious insects.

To learn more about the gypsy moth and its management in North Carolina, visit NCDA&CS’ Gypsy Moth Program website. Additional questions? Give us a call at 1-800-206-9333 or contact your local NC Forest Service county ranger.

Gypsy moth damage: complete tree defoliation by gypsy moth caterpillars. Image: M. Robinson, USFS,

Contributed by Matt Andresen, Gypsy Moth Program manager, NCDA&CS Plant Industry Division.