You Can Help Fight Gypsy Moths!

MADISON -- Gypsy moth caterpillar populations are approaching peak outbreak in some areas of Wisconsin. They’re also approaching a stage in their life cycle when they are especially vulnerable to simple efforts to remove them from trees.


By the middle of June, gypsy moth caterpillars are approximately half-grown (about three-quarters of an inch long) and are eating leaves and growing quickly. They’re making daily trips from the tops of trees where they feed during the night, down to the trunk and ground in order to avoid birds and other predators that can spot them during the day. They may also be spotted on the sides of homes or other structures.


It’s at this time, according to state forestry entomologists, that people with gypsy moth problems on their property should exploit this behavior and deliver a blow to the local gypsy moth population.


“Because the caterpillars are making this predictable daily migration, property owners with local gypsy moth problems can take some simple steps in an effort to knock back the numbers of caterpillars in their backyard,” said Andrea Diss, coordinator of the statewide Gypsy Moth Program for the Department of Natural Resources. “Normally the caterpillars hide in leaf litter, furrows in the tree bark, and other protected places. But with a strip of burlap, some string, and a pair of scissors, property owners can capture and kill many caterpillars each day for the next several weeks.”


Diss provides these simple instructions for making a gypsy moth caterpillar collection band:


1. Start with a piece of burlap, about 12 to 18 inches wide and long enough to wrap around the tree trunk at chest height. Burlap can be purchased at most fabric stores.


2. Place the fabric flat against the bark and tightly tie a string around the middle of the burlap.


3. Fold the portion of the burlap above the string down so that a double-layered ‘skirt’ is formed around the tree. Be sure that the flaps hang freely and that the caterpillars can easily get beneath them.


“As they move down the tree during the day, caterpillars will collect under the burlap and on the bark beneath the burlap,” Diss said. “Each day, in the late afternoon, remove the caterpillars by brushing them into a bucket of soapy water or snipping them in two with scissors. You should wear gloves when handling caterpillars because their long hairs can be irritating to some people.”


But in order for this technique to be effective, Diss added, the bands must be monitored every day.


The burlap bands should be left up from mid-June until early to mid-July, when the caterpillars pupate in preparation for developing into the moth stage.

For more information on how to make and use burlap bands or employ other control methods throughout the year and the life cycle of the gypsy moth, visit the Web site of the Wisconsin Cooperative Gypsy Moth Program.


FOR MORE INFORMATION CONTACT DNR's: Andrea Diss - (608) 264-9247.