Spongy moth traps to be set up in areas of Wisconsin

The Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) will be setting approximately 6,700 traps for the detection of spongy moths this year.

The traps will be placed in 36 counties in western and central Wisconsin from mid-May through early July. Trap locations are determined according to a grid- and data-based system. Most traps will be set along public roadside rights-of-way, but some may need to be set on private property where there’s evidence of a new spongy moth population nearby. The department is asking that all traps remain undisturbed once they are in place.

The spongy moth (formerly known as the gypsy moth) is a highly destructive invasive insect whose caterpillars feed on the leaves of over 300 tree and shrub species in the state, defoliating forests and even killing some plants if severe feeding persists across multiple seasons.

The department says even though spongy moth populations drastically decreased across the state again last season, there are still new outlier populations developing in western Wisconsin. Data collected from traps this season will be crucial in the program’s effort to pinpoint these new populations and limit their spread before infestations become large enough to cause damage to trees.”

The traps are described as small green boxes stapled to or hung on trees. The trap emits the scent of flightless female spongy moths to attract and catch adult male moths. The lure scent is undetectable to other insects, animals, and humans. Although these traps catch adult male spongy moths, the primary purpose is to gather data to inform future control efforts and does not have direct, meaningful impacts on the population of this invasive species.