Symbiotic Fungi Associated With Xyleborine Ambrosia Beetles (Coleoptera: Curculionidae: Scolytinae) and the Imperative of Global Collaboration

Abstract

Ambrosia beetles from the tribe Xyleborini are part of nearly all forest ecosystems. Because of their small size, haplodiploid mating structure, and protected lives inside the sapwood of woody plants, they have a unique ability to expand into new regions via inadvertent human transport. A small number of invasive xyleborines cause significant damage to forests, lumber concerns, and agricultural systems. Most ambrosia pests damage or kill trees by the accumulation of beetle attacks, one is known to cause tree death through the introduction of pathogenic fungus into susceptible Lauraceae trees. The relationships between ambrosia fungi and their beetle vectors range from mutualistic symbiosis to facultative association, but most remain unstudied. Unresolved taxonomies, convergent morphologies, and the difficulty of sampling ambrosia fungi over their entire global ranges make comprehensive surveys of ambrosia fungi difficult to achieve. Ambrosia fungi from Europe and North America are moderately well documented, however, we have yet to sufficiently document those from Africa, Asia, Australia, and South America. Worldwide cooperation to improve and standardize scientific study of the ambrosia symbioses is needed to better understand these impactful organisms.

Commodity risk assessment of maple veneer sheets from Canada

“…However, being a xyleborine species long time identified as Xyleborus validus (Wood, 1982 ) and considering its size, it may be assumed that the depth of its galleries into the wood is similar to that of Xylebous ferrugineus (up to 30 cm in depth). As other Euwallacea species, E. validus is in symbiotic relationships with Fusarium AF‐clade fungi and Fusarium oligoseptatum , as well as with Raffaelea subfusca (Aoki et al., 2018 ; Osborn et al., 2023 ). Euwallacea validus is also a vector of the pathogenic fungus Verticillium nonalfalfae on Ailanthus altissima and Acer pensylvanicum in the USA (EPPO, 2020 ).…”

“…are known as fungal symbionts of X. ferrugineus (Baker & Norris, 1968 ); more recently, also Ambrosiella sp. and Fusarium AF‐9 have been found as associated with the beetle (Mayers et al., 2015 ; Osborn et al., 2023 ). Xyloterinus politus attacks dying or recently dead trees, usually in the basal region of the trunk; it is also found on windthrows, recently felled trees and logs (Dodge, 1938 ; MacLean & Giese, 1967 ).…”

Identification of the ambrosia beetle Xyleborinus saxesenii (Ratzeburg, 1837) (Coleoptera: Curculionidae: Scolytinae) from frass and adult DNA by TaqMan Probe real‐time‐PCR

“…Rapid‐response tests are requested in such cases (Rizzo et al., 2021; Taddei et al., 2021) and when a threat of an invasive spread requires appropriate countermeasures (Allen et al., 2017). The threat posed by invasive ambrosia beetles, potential vectors of plant pathogens, requires global collaboration to minimize phytosanitary risks (Allen et al., 2017; Osborn et al., 2023; Turner et al., 2021).…”

A new widely distributed invasive alien species of Amasa ambrosia beetles (Coleoptera: Curculionidae: Scolytinae: Xyleborini)

“…Since the beetles feed on ambrosia fungal and not directly on host plant tissues, species are typically strongly polyphagous though some species and genera are specific at the family level (Ruzzier et al 2022(Ruzzier et al , 2023. The beetles have a strongly-female biased haplodiploid reproductive system with extreme inbreeding-diploid females mate with their haploid dwarfed and flightless brother inside of their natal gallery prior to dispersal (Smith & Hulcr 2015;Osborn et al 2023). The beetles' small size and cryptic nature allows them to be easily transported through global trade (Haack & Rabaglia 2013).…”

“…The beetles' small size and cryptic nature allows them to be easily transported through global trade (Haack & Rabaglia 2013). At least 49 (Johnson & Smith 2023;Osborn et al 2023, but see Smith & Cognato, 2021 xyleborine species have become established outside of their native region. These exotic species have caused significant major economic and ecological damage to trees in forests, orchards, nurseries as well as urban/suburban settings (Hughes et al 2017;Coleman et al 2019).…”