About this tool

Scope and background

Why is a tool for SE Asian xyleborines necessary?

The Xyleborini are the largest tribe within the Scolytinae – over 1300 species of ~6300 (Hulcr et al. 2015Hulcr et al. 2015:
Hulcr J, Atkinson TH, Cognato AI, Jordal BH, McKenna DD. 2015. Morphology, taxonomy, and phylogenetics of bark beetles. In: Vega FE, Hofstetter RW (Eds) Bark beetles: biology and ecology of native and invasive species. Elsevier, San Diego, CA, 41minus;84.). The tribe also includes some of the most destructive ambrosia beetle pests. In addition, Xyleborini includes more invasive species than any other group of Scolytinae. Interestingly, most of the species that are both pests and invasive are originally from Southeast and East Asia. Their pestiferous nature makes Xyleborini the most important scolytine group in terms of biosecurity and regulation. Unfortunately, the Southeast Asian fauna is vast, and until a recent monograph (Smith et al. 2020bSmith et al. 2020b:
Smith SM, Beaver RA, and Cognato AI. 2020b. A monograph of the Xyleborini (Coleoptera, Curculionidae, Scolytinae) of the Indochinese Peninsula (except Malaysia) and China. ZooKeys 983: 1-442. https://doi.org/10.3897/zookeys.983.52630) there was no comprehensive resource for identification of the species. Xyleborines also have a complicated taxonomic history. Nearly all species were originally described in a single genus, Xyleborus. Only in the late 19th and early 20th centuries were some genera carved out of Xyleborus (Wood 1989Wood 1989:
Wood SL. 1989. Nomenclatural changes and new species of Scolytidae (Coleoptera), part IV. The Great Basin Naturalist 49: 167-185. https://doi.org/10.5962/bhl.part.22642, Wood and Bright 1992Wood and Bright 1992:
Wood SL, Bright DE. 1992. A catalog of Scolytidae and Platypodidae (Coleoptera), Part 2: Taxonomic index. The Great Basin Naturalist Memoirs 13: 1-1533.), and it was not until recently that the genus-level classification of this group has become somewhat stabilized, particularly for the Asian fauna (Hulcr et al. 2007a; Beaver and Liu 2010Beaver and Liu 2010:
Beaver RA, Liu L-Y. 2010. An annotated synopsis of Taiwanese bark and ambrosia beetles, with new synonymy, new combinations and new records (Coleoptera: Curculionidae: Scolytinae). Zootaxa 2602: 1-47. https://doi.org/10.11646/zootaxa.2602.1.1; Hulcr and Cognato 2010, 2013; Beaver et al. 2014Beaver et al. 2014:
Beaver RA, Sittichaya W, Liu L-Y. 2014. A synopsis of the scolytine ambrosia beetles of Thailand (Coleoptera: Curculionidae: Scolytinae). Zootaxa 3875: 1-82. http://dx.doi.org/10.11646/zootaxa.3875.1.1; Smith et al. 2018aSmith et al. 2018a:
Smith SM, Rabaglia RJ, Beaver RA, Thu PQ, Cognato AI. 2018a. Attraction of ambrosia beetles (Curculionidae: Scolytinae) to semiochemicals in Vietnam with new records and a new species. The Coleopterists Bulletin 72: 838-844. https://doi.org/10.1649/0010-065X-72.4.838, 2018b; Cognato et al. 2020aCognato et al. 2020a:
Cognato AI, Smith SM, Beaver RA. 2020a. Two new genera of Oriental xyleborine ambrosia beetles (Coleoptera, Curculionidae: Scolytinae). Zootaxa 4722: 540-554. https://doi.org/10.11646/zootaxa.4722.6.2; Sittichaya and Smith 2020Sittichaya and Smith 2020:
Sittichaya W, Smith SM. 2020. Eggersanthus Sittichaya and Smith gen. nov., a new Oriental ambrosia beetle genus (Coleoptera: Curculionidae: Scolytinae: Xyleborini). Zootaxa 4779: 282-288. http://dx.doi.org/10.11646/zootaxa.4779.2.9; Smith et al. 2020bSmith et al. 2020b:
Smith SM, Beaver RA, and Cognato AI. 2020b. A monograph of the Xyleborini (Coleoptera, Curculionidae, Scolytinae) of the Indochinese Peninsula (except Malaysia) and China. ZooKeys 983: 1-442. https://doi.org/10.3897/zookeys.983.52630; Sittichaya et al. 2021Sittichaya et al. 2021:
Sittichaya W, Smith SM, Beaver RA, Thaochan N (2021) Revision of the xyleborine ambrosia beetle genus Microperus Wood, 1980 (Curculionidae: Scolytinae, Xyleborini) of Thailand; with four new species and four newly recorded species. ZooKeys 1074: 191-214. https://doi.org/10.3897/zookeys.1074.76235; Smith et al. 2022bSmith et al. 2022b:
Smith SM, Beaver RA, Sittichaya W, Cognato AI. 2022b. One hundred eighteen taxonomic changes among Xyleborine ambrosia beetles (Coleoptera: Curculionidae: Scolytinae). Zootaxa Zootaxa 5194: 151-175. ttps://doi.org/10.11646/zootaxa.5194.2.1; Osborn et al. 2022). The convoluted taxonomic history, the massive diversity, and the economic impact of Xyleborini necessitate a unified and current resource for their identification.

This tool is designed for identification of 35 genera and 339 of 367 recognized species of xyleborines. Morphological identification is only for females as the males are haploid, flightless, dwarfed, rarely seen, and unknown for the majority of the species (see Xyleborini ambrosia beetles). Males can be identified using molecular diagnostics.

Geographic region covered

This tool was designed to cover the countries in mainland Southeast Asia and East Asia that encompass both the Oriental and Palearctic faunal regions. This area has a high volume of international trade with the United States. Countries covered include India (northeastern), Nepal, Bhutan, Bangladesh, Myanmar, Cambodia, Laos, Thailand, Vietnam, China, Taiwan, Japan, and Korea. In addition to the introductions of the species through trade, this fauna is also significant because the climate of these countries is similar to that of the United States which increases the risk of establishment of exotic xyleborine species. As of late mid-2022, 34 xyleborines from this region have already become established in the U.S. (Gomez et al. 2018aGomez et al. 2018a:
Gomez DF, Rabaglia RJ, Fairbanks KEO, Hulcr J. 2018a. North American Xyleborini north of Mexico: a review and key to genera and species (Coleoptera, Curculionidae, Scolytinae). ZooKeys 768: 19-68. https://doi.org/10.3897/zookeys.768.24697, 2018b; Smith and Cognato 2022Smith and Cognato 2022:
Smith SM, Cognato AI. 2022. New exotic beetles found in the United States among pseudocryptic Cyclorhipidion species (Coleoptera: Curculionidae: Scolytinae: Xyleborini) revealed via a multigene phylogeny. Insect Systematics and Diversity Insect Systematics and Diversity 6(4), 2. https://doi.org/10.1093/isd/ixac014).

Specimen identification

Specimens from this tool were either collected by the authors or borrowed from a large number of worldwide institutions (see Acknowledgements for complete list). To ensure accurate identifications, we borrowed as many type specimens as possible and compared them to non-type material. This tool was developed in conjunction with a revision (Smith et al. 2020bSmith et al. 2020b:
Smith SM, Beaver RA, and Cognato AI. 2020b. A monograph of the Xyleborini (Coleoptera, Curculionidae, Scolytinae) of the Indochinese Peninsula (except Malaysia) and China. ZooKeys 983: 1-442. https://doi.org/10.3897/zookeys.983.52630) of the Southeast Asian fauna inferred from a combination of molecular and morphological characters. Many studies have already been published as a direct result of this project (Beaver et al. 2019Beaver et al. 2019:
Beaver RA, Sittichaya W, Liu L-Y. 2019. A review of the genus Immanus Hulcr amp; Cognato with a key to species (Coleoptera: Curculionidae: Scolytinae: Xyleborini). Zootaxa 4585: 378-386. http://dx.doi.org/10.11646/zootaxa.4585.2.11; Beaver and Smith 2022Beaver and Smith 2022:
Beaver RA, Smith SM. 2022. The bark and ambrosia beetles of Bhutan (Coleoptera: Curculionidae: Scolytinae and Platypodinae): a synopsis with three new species of Scolytinae. Zootaxa 5174: 1-24. https://doi.org/10.11646/zootaxa.5174.1.1; Cognato et al. 2020aCognato et al. 2020a:
Cognato AI, Smith SM, Beaver RA. 2020a. Two new genera of Oriental xyleborine ambrosia beetles (Coleoptera, Curculionidae: Scolytinae). Zootaxa 4722: 540-554. https://doi.org/10.11646/zootaxa.4722.6.2; Lin and Smith 2022Lin and Smith 2022:
Lin C-S, Smith SM. 2022 Four new species and five new records of xyleborine ambrosia beetles (Coleoptera, Curculionidae, Scolytinae, Xyleborini) from Taiwan. Taiwania 67: 285-301. https://doi.org/10.6165/tai.2022.67.285; Mandelshtam et al. 2019Mandelshtam et al. 2019:
Mandelshtam M Yu, Petrov AV, Smith SM, Cognato AI. 2019. Resurrection of Heteroborips Reitter, 1913 (Coleoptera: Curculionidae: Scolytinae) from synonymy with Xyleborus Eichhoff, 1864. The Coleopterists Bulletin 73: 387minus;394. https://doi.org/10.1649/0010-065X-73.2.387; Sittichaya and Beaver 2018Sittichaya and Beaver 2018:
Sittichaya W, Beaver RA. 2018. Cnestus quadrispinosus , a new species of xyleborine ambrosia beetle from Thailand and Borneo (Coleoptera, Curculionidae, Scolytinae, Xyleborini). ZooKeys 795: 31-37. https://doi.org/10.3897/zookeys.795.28384; Sittichaya and Smith 2020Sittichaya and Smith 2020:
Sittichaya W, Smith SM. 2020. Eggersanthus Sittichaya and Smith gen. nov., a new Oriental ambrosia beetle genus (Coleoptera: Curculionidae: Scolytinae: Xyleborini). Zootaxa 4779: 282-288. http://dx.doi.org/10.11646/zootaxa.4779.2.9, 2022; Sittichaya et al. 2019Sittichaya et al. 2019:
Sittichaya W, Smith SM, Beaver RA. 2019. Ten newly recorded species of xyleborine ambrosia beetles (Coleoptera, Curculionidae, Scolytinae, Xyleborini) from Thailand. ZooKeys 862: 109-127. https://doi.org/10.3897/ zookeys.862.34766, 2021; Smith and Cognato 2022Smith and Cognato 2022:
Smith SM, Cognato AI. 2022. New exotic beetles found in the United States among pseudocryptic Cyclorhipidion species (Coleoptera: Curculionidae: Scolytinae: Xyleborini) revealed via a multigene phylogeny. Insect Systematics and Diversity Insect Systematics and Diversity 6(4), 2. https://doi.org/10.1093/isd/ixac014; Smith et al. 2018aSmith et al. 2018a:
Smith SM, Rabaglia RJ, Beaver RA, Thu PQ, Cognato AI. 2018a. Attraction of ambrosia beetles (Curculionidae: Scolytinae) to semiochemicals in Vietnam with new records and a new species. The Coleopterists Bulletin 72: 838-844. https://doi.org/10.1649/0010-065X-72.4.838, 2018b, 2019, 2020a, 2020b, 2022a, 2022b, 2022c; Park et al. 2020Park et al. 2020:
Park S, Smith SM, Cognato AI, Beaver RA. 2020. Catalogue of Korean Xyleborine ambrosia beetles (Coleoptera: Curculionidae) with seven new species. Journal of Asia-Pacific Biodiversity 13: 210-228. https://doi.org/10.1016/j.japb.2020.01.002; Sittichaya and Smith 2020Sittichaya and Smith 2020:
Sittichaya W, Smith SM. 2020. Eggersanthus Sittichaya and Smith gen. nov., a new Oriental ambrosia beetle genus (Coleoptera: Curculionidae: Scolytinae: Xyleborini). Zootaxa 4779: 282-288. http://dx.doi.org/10.11646/zootaxa.4779.2.9; Wang et al. 2020Wang et al. 2020:
Wang J, Smith SM, and Cognato AI. 2020. Immanus virago , a new species from Borneo (Coleoptera, Curculionidae: Scolytinae: Xyleborini). The Coleopterists Bulletin 74: 438-440. https://doi.org/10.1649/0010-065X-74.2.438).