Print PageInvasive bark- and wood-infesting insects of concern for the U.S. - Canada border region include the emerald ash borer (Agrilus planipennis), sirex woodwasp (Sirex noctilio), European oak borer (Agrilus sulcicollis), brown spruce longhorn beetle (Tetropium fuscum) and Asian longhorned beetle (Anoplophora glabripennis). The emerald ash borer, for instance, was detected in both the U.S. (Michigan) and Canada (Ontario) in 2002. To date, 15 U.S. states and two Canadian provinces are known to be infested and are totally or partially under quarantine for this invasive insect. International trade has been acknowledged as an important pathway for the initial introduction of these invaders into the U.S.-Canada border region. Bark- and wood-infesting insects are moved primarily in wood packaging material such as pallets and crating. Once established in a new country, they can spread naturally as well as through movement of logs, nursery stock, firewood, and domestic wood packaging material. Moreover, each of the insects listed above could be inadvertently moved across the U.S.-Canada border as well as within each country through trade involving these materials. Although such scenarios are generally recognized as forest health threats, invasion ecologists have limited understanding of the spatio-temporal trends and patterns of the movement of international goods into and within the U.S.-Canada border region. As a result, our capacity to anticipate invasions for purposes of prevention or early detection is severely limited.
Results/Conclusions
We present a synopsis of the initial emerald ash borer invasion in North America near the Detroit (U.S) –Windsor (Canada) region, emphasizing potential international trade pathways. Then, using a propagule pressure framework, we present a summary of the major spatio-temporal patterns of freight transportation in the U.S. that have implications for future insect invasions in throughout the U.S. Those patterns include a) the type of imported goods most commonly associated with invasive forest insects, b) the world regions of origin for those goods, and c) the final destination of imported goods. We also summarize the international freight transportation trends that have important implications for future invasions in the aforementioned region. Trends include a) an increasing amount of imported goods, b) the rise in the use of mega-vessels, c) the establishment of continental transportation corridors, and d) an increasing importance of inland ports. Finally, we discuss recent changes in bilateral regulations between the U.S. and Canada for firewood and wood packaging material.
