Benefit-Cost Analysis of the Slow the Spread Program: An Update Through 2045
| Authors: | Sonia Bruck, Matthew Sloggy, Jane Foster, Michelle J. Thompson, Tom W. Coleman |
| Year: | 2026 |
| Type: | General Technical Report |
| Station: | Southern Research Station |
| DOI: | https://doi.org/10.2737/SRS-GTR-289 |
| Source: | USDA Forest Service |
Abstract
Spongy moth or Lymantria dispar (L.) (Lepidoptera: Erebidae), formerly known as gypsy moth, is a nonnative invasive defoliator pest to the United States. Introduced accidentally to the United States in the 1860s by an amateur entomologist, spongy moth spread quickly and large-scale efforts began soon thereafter to eradicate and limit its population and distribution. The National Slow the Spread (STS) Program, piloted in 1992 and fully implemented in 2000, currently operates in 11 States and monitors a buffer zone that stretches about 100 kilometers from North Carolina to Minnesota. Current management of spongy moth populations consists of large-scale suppression treatments and monitoring along the buffer zone. In this report, we build on previous economic assessments to aggregate the costs of the STS Program from 2007 to 2023 and quantify potential programmatic costs from 2024 to 2045. In addition, we compute the costs and costs avoided to human health, tourism and recreation, and willingness to pay for a public management program with and without the STS Program. We found that from 2007 to 2023, the benefit-cost ratio was between 1.60 and 2.31, and from 2024 to 2045, we expect a return of between 3.81 and 5.58. Findings suggest that continuation of the program under business-as-usual scenarios would result in net positive public benefits.