Homeowners, taxpayers pay billions to fight invasive pests

Results from a first-of-its-kind economic analysis, which estimates financial damage of importing foreign insects into the nation and trying to eradicate them once they establish, are reported in the journal PLoS ONE.

The authors, which include University of Central Florida Biologist Betsy Von Holle, looked at three types of invasive pests that feed on U.S. trees, the emerald ash borer, gypsy moth, and hemlock woolly adelgid. Using actual costs, researchers calculated the economic damages for five categories: federal governments, local governments, households, residential property value losses and timber value losses to forest landowners. The costs were staggering.

The costs of invasive forest insects to local governments is on average more than $2 billion per year and residential property value loss due to forest insects averages $ 1.5 billion a year. The federal government spends on average about $216 million a year.

"It is costing taxpayers billions as the government tries to eradicate these invaders," Von Holle said. "We're losing a variety of native species as a result of importing these pests. It's not just aesthetics. It's impacting our economy and our analysis shows just how much it is costing all of us, not just government."

Wood-boring insects such as the emerald ash borer and the Asian longhorned beetle alone cost local governments an estimated $1.7 billion. Approximately $830 million is lost in residential property values each year.

The research team was composed of scientists from U.S. and Canadian universities and the U.S. Forest Service. The team's analysis also can be applied to other countries that face similar problems.

"Obviously, international trade has tremendous benefits, but it also has costs," said Juliann E. Aukema, the lead author and a scientist with the University of California at Santa Barbara's National Center for Ecological Analysis and Synthesis (NCEAS). "The regulations we currently have aren't keeping the pests out. We need to strengthen regulations and enforcement of them to protect our forests and our economy."

Wood-boring insects are not the only troublesome pests. Foliage feeders and sap feeders cause an estimated $410 million and $260 million, respectively, in lost residential property value each year.

And the costs will likely continue as there is a 32 percent risk that a new invader will enter the country in the next 10 years, exacting even more damage.

In addition to the three pests used for the study, researchers also used an exhaustive database of established non-native forest insects, and a novel modeling approach to arrive at their results. The authors have developed an analytical framework that can be used in any country where data are available. The framework can be easily adapted for estimating costs in other natural resource sectors, including fire, disease, and water quality, at scales from municipalities to nations.

Co-authors include Brian Leung and Corey Chivers from McGill University, Montreal; Ken Kovacs of the University of Minnesota; Kerry O. Britton, Susan J. Frankel, Robert G. Haight, Thomas P. Holmes and Andrew M. Liebhold from the U.S. Forest Service; Jeffrey Englin from Arizona State University, and Deborah G. McCullough from Michigan State University. The Nature Conservancy supported the group's work.

Von Holle joined UCF in 2007 after working at the Smithsonian's Environmental Research Center, Harvard University and the American Association for the Advancement of Science. Von Holle has a bachelor's of science in Ecology, Behavior & Evolution from the University of California at San Diego and a Ph.D. in Ecology & Evolutionary Biology from the University of Tennessee at Knoxville. She has received multiple awards and grants from many institutions including the Florida Department of Environmental Protection and the U.S. Fish and Wildlife Service.

The California native also has published many articles. One paper, "Ecological resistance to biological invasion overwhelmed by propagule pressure" was identified by Essential Science Indicators as an Emerging Research Front, , which means it is one of the most-cited papers in a highlighted research area in the field of Environment/Ecology. . Essential Science Indicators is a resource that enables researchers to conduct ongoing, quantitative analyses of research performance and track trends in science.