Influence of Climatic Conditions and Elevation on the Spatial Distribution and Abundance of Trypodendron ambrosia Beetles (Coleoptera: Curculionidae: Scolytinae) in Alaska

摘要

The objective of this study was to model the influence of temperature and precipitation on the distribution and abundance of the ambrosia beetles in the genus Trypodendron. Although these beetles do not attack and kill healthy trees, their gallery holes and accompanying black and gray stain associated with symbiotic ambrosial fungi can cause significant economic losses to commercial logs and wood products. Beetles were collected along a 1,100-km latitudinal transect 4 times at 2-week intervals at 43 sites beginning early July using Lindgren-funnel traps baited with ethanol, alpha-pinene, and lineatin. Average annual temperature and precipitation were used to partition the state into 25 climatic zones. Large-scale patterns of beetle distribution were correlated with elevation and the temperature and precipitation zones. Results indicate that reasonably accurate predictions of beetle abundance can be generated using models based on trap data collected across several climate zones. Predictions derived from this latitudinal transect can be extrapolated to more remote areas using species environment relationships based on temperature and precipitation combinations. Partitioning large geographic areas using climatic zones offers a logical approach for predicting insect activity in remote areas, and if implemented on a long-term basis would be able to provide estimates of yearly and seasonal trends in the infestation. Such information would allow forest managers to evaluate the impact on forest ecosystem services and improve future assessments that predict the influence of a changing climate on insect pest migrations and their intensification during outbreaks.