Gypsy moth trappers will be setting traps mid-May through early July to gather data that the Wisconsin Department of Agriculture, Trade and Consumer Protection will use to plan future gypsy moth treatments.

The department asks that property owners allow the trappers access to place the traps, and that the public not disturb the traps, according to a news release.

According to the statement: 

The traps are small orange or green boxes tied to tree branches. They are designed to catch male gypsy moths, not the immature gypsy moth caterpillars. The traps are used to estimate population levels, not to control the moths. The department does treatments in spring to control the caterpillars.

Trappers from the department will set about 11,000 traps total in 44 counties, mainly in western Wisconsin. The traps will stay in place until the male moths stop flying in August, when trappers will begin taking them down.

“Trapping tells us where the gypsy moths are and where they’re not,” said Michael Falk, gypsy moth trapping coordinator. “It helps determine if we need to do an egg mass survey in the fall to better evaluate the population, and if an area may need an aerial treatment the following year.”

Trappers wear fluorescent vests and carry identification cards. Each trap is labeled with a phone number that property owners can call if they have questions.

“Most landowners are very cooperative, and we appreciate that,” Falk said. “But, if a landowner wants a trap moved or removed, they can call the number listed on the trap, and we can move the trap.”

The traps catch only male gypsy moths, because they can fly and the females cannot. To find each other and reproduce, the females release a pheromone for the males to detect and follow. This pheromone is undetectable to other insects and is used as a lure in the traps.

“It’s important to leave the traps up during moth flight to get the data we need. Then, when the moth flight ends, we’ll take them down,” Falk said.

For more information, call the toll-free number 1-800-642-6684 or visit https://datcp.wi.gov/Pages/GypsyMoth.aspx.