MADISON (WKOW) -- According to the Department of Agriculture, Trade, and Consumer Protection, special traps will be set up to catch adult Gypsy Moths in 42 counties this summer.
The small orange or green boxes will be tied to trees by trappers working with the Wisconsin Gypsy Moth Slow the Spread Program. The program is preparing for the emergence and flight of the adult male gypsy moth. That is expected to happen in July.
Gypsy Moths are an invasive pest known to defoliate many species of trees and shrubs, especially Oaks. According to experts, the gypsy moth is most destructive during the larva or caterpillar stage. When they become moths, they spend their two-week life span looking for a mate and reproducing.
Trappers will set approximately 29,000 traps in 42 counties by the beginning of July. Traps will be used as a way to survey the gypsy moth population, not as a method of population control.
"Trapping tells us where the moths are and where they're not," said Chris Whitney, gypsy moth trapping coordinator. "Trapping also helps determine if an area needs spray treatment the following year or if an egg mass survey needs to be done after traps are taken down in the fall to better evaluate the population."
The program will use two different types of traps for this year's trapping: a triangular "delta" trap, which looks like a small birdhouse, and a milk carton trap, which looks like a milk carton with a roof. The delta trap can hold up to 20 moths. A milk carton trap can hold up to 1,500 moths.
All gypsy moths that are caught are males because female moths cannot fly. Male most find the females to mate by following a scent released by females. To catch the male gypsy moth, each trap has a string or strip that releases the female gypsy moth scent. The inside walls of the delta trap are coated with a non-toxic glue. When a male moth flies in, it sticks to one of the walls. The inside walls of the milk carton trap are not sticky, but a pesticide strip kills the moths that fly in.
The traps are not harmful to people, plants, or animals. When the traps are constructed properly, they should last until the moths stop flying in August. The traps do not allow birds or small mammals to get inside. The number and type of trap used will depend on where it is set in the state. Areas where gypsy moths are known to be found will see mostly milk carton traps. Those traps are set up one every nine square miles. Delta traps are usually set in the Western third of the state where gypsy moths are not very common. Delta traps are set one trap per one square mile.
There is no trapping in the eastern part of Wisconsin, because it is considered to be generally infested and trapping does not provide any usable data. People are asked to leave the traps alone. If a trap needs to be set up on private property and the owner is present, trappers will ask for permission to set the trap.
Trappers will wear fluorescent vests and carry identification. If the owner is unavailable, trappers will set the trap and leave an information sheet and phone number for the landowner to call for more information.
"Most landowners are very cooperative, and we appreciate that," Whitney said. "However, if a landowner wants a trap moved or removed, they should call the number listed on the trap."
If you'd like more information about the gypsy moth trapping program, call 1-800-642-MOTH (1-800-642-6684).