Gypsy Moth Management

The National Slow The Spread Program

Since the U.S. Congress has funded the National Slow The Spread Program (STS) in the year 2000, ten states located along the leading edge of the main gypsy moth population have implemented a region-wide strategy with the USDA Forest Service to minimize the rate at which gypsy moth spreads into uninfested areas.

The National Slow The Spread Program uses education, detection, and control strategies to slow the spread of the pest across a 1,200 mile long gypsy moth frontier from Minnesota to North Carolina.

Northeast Iowa and southeast Minnesota are now considered to be in the 100 mile wide "transition zone" between generally infested gypsy moth areas and unifested areas. Gypsy moth is moving forward by natural spread into new areas in this zone.

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If you are an Iowa resident and suspect gypsy moth as a new introduction to your area, we would be interested in taking a closer look. Please let us know by visiting our Contact us page.

It is not economical, or environmentally feasible to completely stop the spread of gypsy moths; however, slowing their spread is economically and environmentally palatable. Focusing on newer and smaller gypsy moth infestations is more efficient than trying to contain a larger, more heavily infested area.

Slow The Spread reduces the progress of gypsy moth by at least 60%, which will prevent infestation of more than 180 million acres in the United States over the next 20 years.

What Are The Benefits of Slow The Spread ?

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How Slow The Spread Works

The management area, also known as the transition zone, is located ahead of the advancing front of the main gypsy moth population. The program focuses on early detection of low level gypsy moth populations, and then disrupts the normal build-up and spread of gypsy moth in those locations.

Gypsy Moth Mating Disruption

Mating disruption is a non-insecticidal treatment that is one of the key elements in the STS program. Pheromone flake treatments have been applied in northeast Iowa during June 2011, 2013, and 2016. Please visit for more details on the treatments used and listed locations.

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Link: Questions and Answers - Gypsy Moth Mating Disruption

Pheromone applications are a non-toxic method for managing low level gypsy moth populations by preventing male moths from finding mates. This is accomplished with tree canopy applications of the female gypsy moth pheromone, the powerful scent produced by flightless female moths, that is used to attract a mate.

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Airplane applied treatments are very economical and most often used. These products are designed to stick to tree foliage and can be used in urban areas as well as woodland areas. About 1/2 cup of flakes or liquid paste is used for 1 acre of land. The costs are currently being handled by the Slow The Spread Program at a cost between 5 to 6 dollars per acre.