Modeling the Potential Dispersal of Asian Longhorned Beetle Using Circuit Theory

Abstract

The Asian longhorned beetle (ALB, Anoplophora glabripennis) is an invasive pest species currently infesting major port cities in North America and Europe. There is limited knowledge regarding the pathways of movement across heterogeneous landscapes at local scales. This study models dispersal pathways using circuit theory in Worcester, Massachusetts, which has the largest ongoing ALB infestation in North America. Circuit theory–based dispersal modeling provides a means of predicting the movement of random walkers across a landscape comprising differential resistance to movement. Calibration of landscape resistance to ALB movement used a combined expert opinion and empirical approach, with 820 ALB presence points for calibration and validation. Results indicate that ALB typically uses nonhabitat land-cover types to connect suitable habitat patches. Circuit modeling was a better predictor of spatial patterns of dispersal than least-cost dispersal modeling, especially by predicting narrow corridors that connect large habitat patches. ALB dispersal modeling is difficult due to limited data availability and ongoing ALB habitat modification. This article contributes to knowledge of ALB dispersal patterns at local and regional scales, using empirically driven methods to provide spatially explicit predictions of high dispersal probability and habitat suitability for ALB, using the best data sets available. Key Words: Asian longhorned beetle, circuit theory, invasive species, urban forestry.