Scientific communication is facilitated by a data-driven, scientifically sound taxonomy that considers the end-user’s needs and established successful practice. In 2013, the Fusarium community voiced near unanimous support for a concept of Fusarium that represented a clade comprising all agriculturally and clinically important Fusarium species, including the F. solani species complex (FSSC). Subsequently, this concept was challenged in 2015 by one research group who proposed dividing the genus Fusarium into seven genera, including the FSSC described as members of the genus Neocosmospora, with subsequent justification in 2018 based on claims that the 2013 concept of Fusarium is polyphyletic. Here, we test this claim and provide a phylogeny based on exonic nucleotide sequences of 19 orthologous protein-coding genes that strongly support the monophyly of Fusarium including the FSSC. We reassert the practical and scientific argument in support of a genus Fusarium that includes the FSSC and several other basal lineages, consistent with the longstanding use of this name among plant pathologists, medical mycologists, quarantine officials, regulatory agencies, students, and researchers with a stake in its taxonomy. In recognition of this monophyly, 40 species described as genus Neocosmospora were recombined in genus Fusarium, and nine others were renamed Fusarium. Here the global Fusarium community voices strong support for the inclusion of the FSSC in Fusarium, as it remains the best scientific, nomenclatural, and practical taxonomic option available.

Ambrosia beetles frequently invade non-native regions but are typically of no concern because most species live in dead trees and culture nonpathogenic symbiotic fungal gardens. Recently, however, several ambrosia beetle—fungus complexes have invaded non-native regions and killed large numbers of host trees. Such tree-killing invasions have occurred unexpectedly, and the mechanism of the ecological switch from dead trees to live trees has been left unexplained, or termed an “evolutionary mismatch.” We demonstrate that the mismatch hypothesis is not supported in the redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae), because this beetle is able to colonize live trees also in its native range and its symbiotic fungus acts as a pathogen in some native hosts. We further synthesized findings from recent literature and unpublished observations on several other invasive fungus-associated beetles such as Euwallacea fornicatus (Eggers) (Coleoptera: Curculionidae), Platypus qu... Resumen Los escarabajos descortezadores frecuentemente invaden las regiones no nativas, pero normalmente no son motivo de preocupación porque la mayoría de las especies viven en árboles muertos y cultivan hongos simbióticos no patógenos. Recientemente, sin embargo, varios complejos escarabajo descortezador-hongo han invadido regiones no nativas y han matado un gran número de árboles hospederos. Tales invasiones que matan árboles han ocurrido inesperadamente, y el mecanismo del cambio ecológico de árboles muertos a los árboles vivos se ha dejado inexplicado, o denominado un “desajuste evolutivo”. Demostramos que la hipótesis de desajuste no es apoyada en el escarabajo descortezador de aquacatillo, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae), porque este escarabajo es capaz de colonizar árboles vivos también en su área de distribución nativa y su hongo simbiótico actúa como patógeno en algunos hospederos nativos. Además, se sintetizaron los hallazgos de la literatura reciente y observaciones no...

Shot hole borer (SHB)-Fusarium dieback (FD) is a new pest-disease complex affecting numerous tree species in California and is vectored by two distinct, but related ambrosia beetles (Euwallacea sp. nr. fornicatus) called polyphagous shot hole borer (PSHB) and Kuroshio shot hole borer (KSHB). These pest-disease complexes cause branch dieback and tree mortality on numerous wildland and landscape tree species, as well as agricultural tree species, primarily avocado. The recent discovery of KSHB in California initiated an investigation of fungal symbionts associated with the KSHB vector. Ten isolates of Fusarium sp. and Graphium sp., respectively, were recovered from the mycangia of adult KSHB females captured in three different locations within San Diego County and compared with the known symbiotic fungi of PSHB. Multigene phylogenetic analyses of the internal transcribed spacer region (ITS), translation elongation factor-1 alpha (TEF1-α), and RNA polymerase II subunit (RPB1, RPB2) regions as well as morphological comparisons revealed that two novel fungal associates Fusarium kuroshium sp. nov. and Graphium kuroshium sp. nov. obtained from KSHB were related to, but distinct from the fungal symbionts F. euwallaceae and G. euwallaceae associated with PSHB in California. Pathogenicity tests on healthy, young avocado plants revealed F. kuroshium and G. kuroshium to be pathogenic. Lesion lengths from inoculation of F. kuroshium were found to be significantly shorter compared with those caused by F. euwallaceae, while no difference in symptom severity was detected between Graphium spp. associated with KSHB and PSHB. These findings highlight the pest disease complexes of KSHB-FD and PSHB-FD as distinct, but collective threats adversely impacting woody hosts throughout California.

The phlebioid clade (Polyporales, Basidiomycota) accommodates numerous species of corticioid and polyporoid fungi of the Phanerochaetaceae, Irpicaceae, and Meruliaceae. The present study used morphological and phylogenetic approaches to revise the generic classification of the phlebioid clade and survey species diversity. The phylogenetic analyses were performed using sequences of multiple genes, including the nuc rDNA ITS1-5.8S-ITS2 (ITS), the D1-D2 domains of 28S rDNA (28S), the RNA polymerase II largest subunit (rpb1), the RNA polymerase II second largest subunit (rpb2), and the translation elongation factor 1-α (tef1). We overall recognize 57 genera including six new ones (Alboefibula, Cremeoderma, Gelatinofungus, Luteochaete, Phanerochaetella and Quasiphlebia). We describe 26 new species belonging to 15 genera (Alboefibula bambusicola, A. gracilis, Crustodontia taiwanensis, Cytidiella albomarginata, Efibula matsuensis, E. turgida, E. subglobispora, Gelatinofungus brunneus, Hydnophlebia aurantia, H. crocata, Irpex lenis, Mycoaciella efibulata, Phanerochaete alpina, P. crystallina, P. guangdongensis, P. rhizomorpha, P. spadicea, P. subcarnosa, Phanerochaetella formosana, Phlebiopsis odontoidea, P. yushaniae, Quasiphlebia densa, Rhizochaete chinensis, Roseograndinia jilinensis, R. minispora, and Scopuloides allantoidea), and present 18 new combinations belonging to 12 genera (Cremeoderma unicum, Crustodontia nigrodontea, C. tongxiniana, Cytidiella albida, Efibula intertexta, Hydnophlebia alachuana, Irpex laceratus, I. latemarginatus, I. rosettiformis, Luteochaete subglobosa, Luteoporia lutea, Phanerochaetella angustocystidiata, P. exilis, P. leptoderma, P. xerophila, Phlebiopsis alba, Rhizochaete lutea, Scopuloides dimorpha). Descriptions, illustrations and notes of new species and some new records are provided, as well as identification keys to genera of each family.

Species of Ceriporia (Irpicaceae, Basidiomycota) are saprotrophs or endophytes in forest ecosystems. To evaluate the taxonomy and generic relationships of Ceriporia and other related taxa, we used morphology and multigene phylogenetic analyses based on sequence data from nuc rDNA internal transcribed spacer ITS1-5.8S-ITS2 (ITS) region, nuc 28S rDNA (28S), and RNA polymerase II largest subunit (rpb1). Our results show that Ceriporia sensu lato is polyphyletic and distributed across multiple clades in the Irpicaceae, Phanerochaetaceae, and Meruliaceae. Some species previously considered in Ceriporia are now recovered in Meruliopsis, resulting in four new combinations: M. albomellea, M. crassitunicata, M. nanlingensis, and M. pseudocystidiata. Two new species of Meruliopsis are described: M. leptocystidiata from northeast China and South Korea and M. parvispora from Taiwan. Ceriporia arbuscula is described as a new species from Taiwan. Ceriporia mellita and Meruliopsis nanlingensis are newly recorded from Japan and Taiwan, and M. taxicola is recorded from Taiwan for the first time.