Spatio-Temporal Analysis of Xyleborus glabratus (Coleoptera: Circulionidae: Scolytinae) Invasion in Eastern U.S. Forests.
Authors:
Koch, F.H. Smith, W.D. USDA, FS
Source:
Environmental entomology. 2008 Apr., v. 37, issue 2, p. 442-452.
NALT Subjects:
Xyleborus ambrosia beetles forest pests invasive species ecological invasion geographical distribution spatial distribution temporal variation host plants Persea Sassafras albidum plant density climatic factors Eastern United States
Other Subjects:
Persea borbonia climate matching pest infestation
Issue Date:
Apr-2008
Abstract:
The non-native redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), has recently emerged as a significant pest of southeastern U.S. coastal forests. Specifically, a fungal symbiont (Raffaelea sp.) of X. glabratus has caused mortality of redbay (Persea borbonia) and sassafras (Sassafras albidum) trees in the region; several other Lauraceae species also seem susceptible. Although the range of X. glabratus continues to expand rapidly, little is known about the species' biology and behavior. In turn, there has been no broad-scale assessment of the threat it poses to eastern U.S. forests. To provide a basic information framework, we performed analyses exploiting relevant spatio-temporal data available for X. glabratus. First, we mapped the densities of redbay and sassafras from forest inventory data. Second, we used climate matching to delineate potential geographic limits for X. glabratus. Third, we used county infestation data to estimate the rate of spread and modeled spread through time, incorporating host density as a weighting factor. Our results suggest that (1) key areas with high concentrations of redbay have yet to be invaded, but some are immediately threatened; (2) climatic conditions may serve to constrain X. glabratus to the southeastern U.S. coastal region; and (3) if unchecked, X. glabratus may spread throughout the range of redbay in <40 yr. Disruption of anthropogenic, long-distance dispersal could reduce the likelihood of this outcome.
