Modeling the Risk of Emerald Ash Borer

Research Issue

Emerald Ash Borer (Agrilus planipennis, EAB), an invasive insect native to Southeast Asia, is responsible for killing millions of Ash (Fraxinus) trees throughout much of the Midwestern USA. It was first discovered near Detroit, Michigan in June of 2002, most likely imported in ash crates or pallets in the early 1990s.  As of March 2008, the insect occupies the states of Illinois, Indiana, Ohio, Maryland, Michigan, Pennsylvania, West Virginia, and parts of Canada.

Detection of EAB infestations is difficult when trees are first attacked, showing few signs that EAB is present. However, healthy ash trees are killed in 2-4 years. Outlier colonies also make tracking the natural spread of the insect difficult, since they are often attributed to human activities. Predicting where EAB will likely spread to can be a challenging process as they can use several human agents to infest ash trees in outlier zones beyond its inherent flight capability. 

Our Research

We have modelled the risk of spread for EAB in Ohio using a stochastic, spatially explicit cell-based model which incorporates the insect’s flight characteristics (Insect Flight Model) and external agents that enable EAB to “hitch a ride” (Insect Ride Model). The Flight Model calculates the risk of spread for any 270m-cell based on the basal area of ash within the cell (ash abundance) and estimates of EAB abundance based on the years since infestation. We assume EAB will kill all ash trees within a cell in 10 years after the initial detectable infestation. The Insect Ride Model weights the road network, wood products, population density, and campground information in a GIS and uses an ash abundance multiplier that alters the ash abundance input to the model. We combine both the Flight and Ride Models to yield a map of potential Modeling EAB Risk that is corroborated by detection trees and trees that have been confirmed infested.

Research Results

Research Publications

Prasad, A., L. Iverson, M. Peters, J. Bossenbroek, S. N. Matthews, D. Sydnor, and M. Schwartz. 32767. Modeling the invasive emerald ash borer risk in Ohio, USA  it’s mainly about roads. Landscape Ecology. doi10.1007/s10980-009-9434-9

Iverson, Louis R.; Prasad, Anantha M.; Sydnor, Davis; Bossenbroek, Jonathan; Schwartz, Mark W.. 2006. Modeling potential Emerald Ash Borer spread through GIS/cell-based/gravity models with data bolstered by web-based inputs. In: Mastro, Victor, et. al., comps. Emerald Ash Borer research and technology development meeting; 2005 September 26-27; Pittsburgh, PA. FHTET-2005-16. U.S. Department of Agriculture, Forest Service, Animal and Plant Health Inspection Service: 12-13.

Iverson, Louis R.; Prasad, Anantha; Bossenbroek, Jonathan; Sydnor, Davis; Schwartz, Mark. 2006. Modeling potential movements of the emerald ash borer in Ohio. In: Mastro, Victor; Lance, David; Reardon, Richard; Parra, Gregory, comps. Emerald ash borer and Asian longhorned beetle research and technology development review meeting; 2006 October 29-November 2; Cincinnati, OH. FHTET-2007-04. U.S. Department of Agriculture, Forest Health Technology Enterprise Team, Morgantown, WV: 15.

Research Participants

Principal Investigators

• Louis Iverson, US Forest Service – Northern Research Station Landscape Ecologist
• Anantha Prasad, US Forest Service – Northern Research Station Ecologist
• Matthew Peters, US Forest Service – Northern Research Station GIS Analyst
• Stephen Matthews, Ohio State University Wildlife Landscape Ecologist

Research Partners

• Jonathan Bossenbroek, University of Toledo
• Davis Sydnor, Ohio State University
• Mark Schwartz, University of California