North American Xyleborini north of Mexico: a review and key to genera and species (Coleoptera, Curculionidae, Scolytinae)

Abstract

Bark and ambrosia beetles (Scolytinae) are the most successful group of invasive wood borers worldwide, and the most invasive among them are species in the tribe Xyleborini. This haplodiploid, highly inbred, fungus-farming group is represented by 30 non-native species in North America, of which at least five are serious pests. The few identification resources for Xyleborini that exist are becoming outdated due to new species arrivals and nomenclatural changes. Here we present a new comprehensive key to Xyleborini currently known from the continental United States. Compared to the previous key, the following species have been added to the North American fauna: Ambrosiodmus minor (Stebbing), Ambrosiophilus nodulosus (Eggers), Anisandrus maiche Kurentsov, Coptoborus pseudotenuis (Schedl), Cyclorhipidion fukiense (Eggers), Dryocoetoides reticulatus Atkinson, Dryoxylon onoharaense (Murayama), Euwallacea interjectus (Blandford), Xyleborinus andrewesi (Blandford), Xyleborinus artestriatus (Eichhoff), Xyleborinus octiesdentatus (Murayama), Xyleborus bispinatus Eichhoff, Xyleborus seriatus Blandford, Xyleborus spinulosus Blandford, and Xylosandrus amputatus (Blandford).

Freeze stress of deciduous trees induces attacks by opportunistic ambrosia beetles

“…Xyleborini offspring are produced via haplodiploid reproduction and sibling mating subsequently occurs between the haploid males and diploid females. Their cryptic wood‐boring behaviour, fungus farming lifestyle, haplodiploid reproduction and sibling mating likely contribute to the invasion success of ambrosia beetles (Smith & Hulcr, ; Gomez et al ., ). A broad host tree range and association with weakened trees also likely promotes the establishment and proliferation of ambrosia beetles introduced into new habitats, with this relationship probably being facilitated by extreme climatic events producing an availability of weakened host resources (Ranger et al ., , , b).…”

“…Ambrosia beetles (Curculionidae: Scolytinae) in the tribe Xyleborini are among the most successful and destructive wood‐boring insects worldwide (Hulcr & Stelinski, ). Thirty non‐native species of Xyleborini are currently established in North America (Gomez et al ., ) and the Xyleborini also represent half of the exotic Scolytinae introduced into Europe (Kirkendall & Faccoli, ). After dispersing from their natal galleries, adult females tunnel into host trees tissues, where they establish and cultivate gardens of their nutritional fungal symbiont (Hulcr & Stelinski, ).…”

Ambrosiodmus rubricollis (Eichhoff) (Coleoptera; Curculionidae; Scolytinae) associated with young Tasmanian blue gum trees

“…Bark and ambrosia beetles (Scolytinae) are the most successful group of invasive wood borers worldwide, with special emphasis on species in the tribe Xyleborini, which includes important forest pests (Gomez et al, ). Ambrosiodmus rubricollis is an example of an ambrosia beetle native to eastern and southern Asia (Wood & Bright, ) that has been inadvertently dispersed by human activity to other continents.…”

“…Ambrosiodmus rubricollis is an example of an ambrosia beetle native to eastern and southern Asia (Wood & Bright, ) that has been inadvertently dispersed by human activity to other continents. The species is now widespread in the mid‐Atlantic and south‐eastern United States of America (Bright, ; Lightle et al., ; Rabaglia, Dole, & Cognato, ), and is also reported as introduced in Australia (Gomez et al, ; Wood & Bright, ), although the website of the Australian Government Department of Agriculture and Water Resources (PaDIL) classifies A. rubricollis as absent from the country (McCaffrey, ). In Europe, it was first detected in Italy in 2009 (Faccoli et al, ), and, more recently, in neighbouring Slovenia (Hauptman, Rekanje, Pavlin, & Jurc, ).…”

“…Adults emerging from the logs were hand‐collected and kept in plastic vials until identification. At the INIAV’s laboratories, eight insects were identified to the species level with the keys of Gomez, Rabaglia, Fairbanks, and Hulcr (), Faccoli et al () and Hulcr and Smith ().…”