Aoki, T., National Agriculture and Food Research Organization, Genetic Resources Center, 2-1-2 Kannondai, Tsukuba, Ibaraki  305-8602, Japan; Smith, J.A., School of Forest Resources and Conservation, University of Florida, Gainesville, FL  32611-0680, United States; Kasson, M.T., Division of Plant and Soil Sciences, West Virginia University, Morgantown, WV  26506, United States;  Geiser, D.M., Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University ParkPA  16802, United States; Geering, A.D.W., The Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Ecosciences PrecinctDutton Park  QLD 4102, Australia; O’Donnell, K., Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, US Department of Agriculture, Agricultural Research Service, 1815 North University Street, Peoria, IL  60604-3999, United States

The Ambrosia Fusarium Clade (AFC) comprises at least 16 genealogically exclusive species-level lineages within clade 3 of the Fusarium solani species complex (FSSC). These fungi are either known or predicted to be farmed by Asian Euwallacea ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) in the tribe Xyleborini as a source of nutrition. To date, only 4 of the 16 AFC lineages have been described formally. In the absence of Latin binomials, an ad hoc nomenclature was developed to distinguish the 16 species lineages as AF-1 to AF-16. Herein, Fusarium species AF-3, AF-5, and AF-7 were formally described as F. floridanum, F. tuaranense, and F. obliquiseptatum, respectively. Fusarium floridanum farmed by E. interjectus on box elder (Acer negundo) in Gainesville, Florida, was distinguished morphologically by the production of sporodochial conidia that were highly variable in size and shape together with greenish-pigmented chlamydospores. Fusarium tuaranense was isolated from a beetle-damaged Paŕa rubber tree (Hevea brasiliense) in North Borneo, Malaysia, and was diagnosed by production of the smallest sporodochial conidia of any species within the AFC. Lastly, F. obliquiseptatum was farmed by an unnamed ambrosia beetle designated Euwallacea sp. 3 (E. fornicatus species complex) on avocado (Persea americana) in Queensland, Australia. It uniquely produces some clavate sporodochial conidia with oblique septa. Maximum likelihood analysis of a multilocus data set resolved these three novel AFC taxa as phylogenetically distinct species based on genealogical concordance. Particularly where introduced into exotic environments, these exotic mutualists pose a serious threat to the avocado industry, native forests, and urban landscapes in diverse regions throughout the world. © 2019, The work of Kerry O’Donnell was authored as part of their official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 USC. 105, no copyright protection is available for such works under US Law.Takayuki Aoki, Jason A. Smith, Matthew T. Kasson, Stanley Freeman, David M. Geiser, and Andrew D. W. Geering hereby waive their right to assert copyright, but not their right to be named as co-authors in the article.