Spread of the emerald ash borer, Agrilus planipennis, in the Front Range region of Colorado

Abstract

Until it was discovered in Boulder, Colorado in 2013, the invaded range of the emerald ash borer, Agrilus planipennis, in the Western Hemisphere was entirely limited to natural and urban forests of eastern North America. Subsequently, this species has expanded its range through much of the Colorado Front Range region, utilizing non-native ash, Fraxinus spp. These host trees are widely planted there in urban settings but natural forests containing ash are lacking in the region. Here we use survey data to quantify emerald ash borer regional spread across the Colorado Front Range as well as its local spread in the city of Longmont, Colorado. Across the region, spread rate was estimated at 3.9 km/yr, but within Longmont the rate was only 0.25 km/yr. These rates of spread are lower than what has been reported from comparable spatial scales in eastern North America and the slower spread may reflect reduced host resource availability, successful implementation of management, or differences in environmental conditions.

Citation

Liebhold, Andrew M.; Ethington, Matthew W.; Stadsvold, Brett; Negrón, José F. 2025. Spread of the emerald ash borer, Agrilus planipennis, in the Front Range region of Colorado. Biological Invasions. 27: 42. 8 p. https://doi.org/10.1007/s10530-024-03512-1.