Summary of native geographic distribution of all 3,341 species of the most speciose animal genus Agrilus (Coleoptera: Buprestidae)

Abstract

We present a summary of the geographic distribution data of all 3,341 species of the jewel-beetle genus Agrilus taxonomically valid at the end of 2022. Our work is richly illustrated with maps and diagrams. The genus Agrilus is the most speciose in the Americas (1,292 species) and Asia (1,187 species). The Americas have the best-delimited fauna at the regional level, with 100% of Agrilus species unique to the region, followed by those of Africa (95.8%) and Asia (93.4%). Europe has the lowest percentage of unique Agrilus species on all levels (regional, subregional and country). Among the subregions, the genus Agrilus is the most speciose in South-Eastern Asia (784 species), South America (769), Central America (427) and Eastern Asia (342); on the other hand, Micronesia has a single species, Polynesia has six species and the Caribbean has 18 species. New Zealand has no Agrilus. Brazil (477 species), Mexico (317) and Laos (265) are the three countries with the highest number of Agrilus species. Among 3,341 Agrilus species, 2,924 (87.5%) are unique to one biogeographic realm or transitional zone, and 417 species (12.5%) are shared by two or more biogeographical realms or transitional zones. Three widely distributed Agrilus species found in four biogeographic realms or transitional zones (A. acutus, A. auriventris and A. occipitalis) are pests of cultivated plants Citrus, Abelmoschus, Corchorus, Hibiscus, Malachra, Urena, are likely native to Southeastern Asia and were dispersed by humans. The number of Agrilus species by biogeographic realm varies between 12 (Oceanic) and 1,115 (Neotropical). The genus Agrilus is most speciose in the following realms: Neotropical (1,115 species, 33.4%), Indomalayan (810, 24.2%) and Afrotropical (694, 20.8%). The percentage of unique Agrilus species by biogeographic realm or transitional zone varies between 15.2% (Nearctic–Neotropical transitional zone) to 95.7% (Afrotropical realm). The range of 2,803 Agrilus species (83.9%) lies within a single biogeographic realm: Neotropical (974 species), Afrotropical (665), Indomalayan (662), Palearctic (234) Australasian (174), Nearctic (86) and Oceanic (8). Agrilus species reported from the largest number of countries are A. viridis, A. cuprescens, A. pratensis, A. angustulus, A. biguttatus, A. subauratus, A. cyanescens, A. suvorovi, A. hyperici and A. graminis; they are all native to the Palearctic realm. French Guiana (1.81), Laos (1.12), Vietnam (0.54) and Malaysia (0.53) are the countries with the highest number of Agrilus species per thousand square kilometers. On the sub-country level, the Laotian provinces Houaphan (7.09) and Bolikhamxai (5.52), as well as the Thai province Mae Hong Son (6.55) have the highest number of Agrilus species per thousand square kilometers. Indochina, French Guiana and Mexico are the global hotspots of Agrilus diversity. Our estimates suggest that the true number of Agrilus species in subtropical and tropical zones is at least twice higher than is currently known.