Studies of Ambrosia Beetles (Coleoptera: Curculionidae) in Their Native Ranges Help Predict Invasion Impact

Abstract Ambrosia beetles frequently invade non-native regions but are typically of no concern because most species live in dead trees and culture nonpathogenic symbiotic fungal gardens. Recently, however, several ambrosia beetle—fungus complexes have invaded non-native regions and killed large numbers of host trees. Such tree-killing invasions have occurred unexpectedly, and the mechanism of the ecological switch from dead trees to live trees has been left unexplained, or termed an “evolutionary mismatch.” We demonstrate that the mismatch hypothesis is not supported in the redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae), because this beetle is able to colonize live trees also in its native range and its symbiotic fungus acts as a pathogen in some native hosts. We further synthesized findings from recent literature and unpublished observations on several other invasive fungus-associated beetles such as Euwallacea fornicatus (Eggers) (Coleoptera: Curculionidae), Platypus qu...