This article is the 15th contribution in the Fungal Diversity Notes series, wherein 115 taxa from three phyla, nine classes, 28 orders, 48 families, and 64 genera are treated. Fungal taxa described and illustrated in the present study include a new family, five new genera, 61 new species, five new combinations, one synonym, one new variety and 31 records on new hosts or new geographical distributions. Ageratinicolaceae fam. nov. is introduced and accommodated in Pleosporales. The new genera introduced in this study are Ageratinicola, Kevinia, Pseudomultiseptospora (Parabambusicolaceae), Marasmiellomycena, and Vizzinia (Porotheleaceae). Newly described species are Abrothallus altoandinus, Ageratinicola kunmingensis, Allocryptovalsa aceris, Allophoma yuccae, Apiospora cannae, A. elliptica, A. pallidesporae, Boeremia wisteriae, Calycina papaeana, Clypeococcum lichenostigmoides, Coniochaeta riskali-shoyakubovii, Cryphonectria kunmingensis, Diaporthe angustiapiculata, D. campylandrae, D. longipapillata, Diatrypella guangdongense, Dothiorella franceschinii, Endocalyx phoenicis, Epicoccum terminosporum, Fulvifomes karaiensis, F. pannaensis, Ganoderma ghatensis, Hysterobrevium baoshanense, Inocybe avellaneorosea, I. lucida, Jahnula oblonga, Kevinia lignicola, Kirschsteiniothelia guangdongensis, Laboulbenia caprina, L. clavulata, L. cobiae, L. cosmodisci, L. nilotica, L. omalii, L. robusta, L. similis, L. stigmatophora, Laccaria rubriporus, Lasiodiplodia morindae, Lyophyllum agnijum, Marasmiellomycena pseudoomphaliiformis, Melomastia beihaiensis, Nemania guangdongensis, Nigrograna thailandica, Nigrospora ficuum, Oxydothis chinensis, O. yunnanensis, Petriella thailandica, Phaeoacremonium chinensis, Phialocephala chinensis, Phytophthora debattistii, Polyplosphaeria nigrospora, Pronectria loweniae, Seriascoma acutispora, Setoseptoria bambusae, Stictis anomianthi, Tarzetta tibetensis, Tarzetta urceolata, Tetraploa obpyriformis, Trichoglossum beninense, and Tricoderma pyrrosiae. We provide an emendation for Urnula ailaoshanensis Agaricus duplocingulatoides var. brevisporus introduced as a new variety based on morphology and phylogeny.

Thousand cankers disease (TCD) of walnut is responsible for widespread mortality of black walnut (Juglans nigra L.) in the United States since the mid-1990s (2). The disease is caused by the fungus Geosmithia morbida Kolařik (Ascomycota, Hypocreales), vectored by the walnut twig beetle Pityophthorus juglandis Blackman 1928 (Coleoptera, Scolytinae). In September 2013, TDC was observed in northeastern Italy (Bressanvido, Vicenza, 45°39′ N, 11°38′ E) in black walnuts of different ages: ~80-year-old plants growing in a garden and 17-year-old trees belonging to a nearby walnut plantation for timber production. Main symptoms were yellowing, wilting, twig and branch dieback, and a high number of small bark cankers (3). Longitudinal and radial sections collected through the cankers revealed gray to brown discoloration of both phloem and outer bark, and the presence of bark beetle galleries radiating from the mating chamber and developing horizontally (across the wood grain), and vertical (along the grain) larval galleries. Occasionally, discoloration involved the outward xylematic tissues. Fungal fruiting bodies were not found on or near the cankers. Whitish mycelium, sometimes producing verticillate conidiophores, was frequently detected inside galleries. A number of 1- to 3-cm diameter twigs showing cankers up to 2 cm long surrounding bark beetle penetration holes were randomly collected. From samples, emerging beetles were identified as P. juglandis both morphologically (4) and genetically. DNA extraction was carried following a standard salting out protocol. The barcode region of the mitochondrial gene cytochrome oxydase I was then amplified using universal primers (1) and sequenced, obtaining 627 bp. BLAST analysis showed 100% identity to P. juglandis. Sequences were finally deposited in the BoldSystem database (GenBank Accession No. KF725084). From the necrotic margin of six cankers previously surface-sterilized with 3% sodium hypochlorite, two 3-mm-wide chips per canker were placed on potato dextrose agar and incubated at 23 ± 1°C in the dark. Among a variety of microorganisms, slow growing lobate, plane, yellowish-ochre colonies with hyaline mycelium appeared in 6 days. After subculturing to the same medium, growing features, mycelium, conidiophores, and conidia with morphological characteristics matching Kolařik's description of G. morbida (2) were observed. Same result was obtained culturing the mycelium growing inside the galleries. The ITS region of rDNA was amplified using ITS1F and ITS4 primers and sequenced, obtaining 597 bp. BLAST analysis showed 100% identity to G. morbida strain U173 (HF546283.1) for 558 bp. To our knowledge, this is the first record of TCD and P. juglandis to Europe, where walnut species (mainly J. regia, J. nigra, and their hybrids) are intensively cultivated for timber production. This finding is therefore of particular importance. An intensive survey of the disease is suggested, both to assess fungus/beetle presence and to verify possible pathways of introduction, likely associated to importation of infested/infected timber from native Nearctic regions. Voucher specimens are stored in the TeSAF herbarium (fungus) and in the DAFNAE insect collection. References: (1) O. Folmer et al. Mol. Marine Biol. Biotechnol. 3:294, 1994. (2) M. Kolařik et al. Mycologia 103:325, 2011. (3) C. Nischwitz and M. Murray, Utah Pests Fact Sheet, PRP-015pr, 2011. (4) S. L. Wood. Great Basin Naturalist Memoirs 6:1123, 1982.

Extensive decline and mortality events of alder trees have recently been observed in several riparian ecosystems in Italy. Since there is little information about the aetiology of this disease and given the high ecological relevance of riparian ecosystems, an in-depth study was conducted in three sites spanning from the Mediterranean to Alpine regions. From spring 2019 to spring 2020, 261 samples of bleeding cankers, rhizosphere soil and leaves used as baits along waterways were collected and used for Phytophthora isolation. Based on morphology, colony appearance and DNA sequence data, 10 species belonging to 6 clades were identified. These included P. plurivora (84 isolates), P. pseudocryptogea (50), P. hydropathica (18), P. gonapodyides (14), P. bilorbang (13), P. pseudosyringae (12), P. lacustris (11), P. acerina (7), P. cactorum (1) and one isolate of the hybrid Phytophthora ×serendipita. In addition, two new Phytophthora species, one of which is described here as Phytophthora alpina sp. nov., were isolated. The pathogenicity of P. alpina and other species obtained from samples collected in the green alder stand was assessed on 3-year-old seedlings. All species proved to be pathogenic on green alder causing symptoms congruent with field observations. Results obtained have allowed us to expand knowledge about alder decline aetiology. The diversity of pathogenicity of Phytophthora species associated with symptomatic alder trees suggested that no single agent is responsible for the disease, but that it is the result of multiple infections of different Phytophthora species, variable in assemblages among sites.

The black-banded oak borer, Coraebus florentinus, is an emerging pest of oak trees in the western Mediterranean region. Larvae of the insect are xylophagous and progressively excavate an annular gallery that interrupts sap flow, resulting in the death of the attacked branches. Until now, limited information has been available regarding the ecological interactions between C. florentinus and the main plant pathogenic fungi involved in the etiology of oak decline. Knowledge of these interactions is important in understanding their impact in natural ecosystems and developing appropriate management strategies. Therefore, in this study, we characterized the fungal communities occurring in the exoskeleton of adults and larvae of C. florentinus and associated with the necrotic wood tissues surrounding the branch galleries of declining oak trees. A total of 29 fungal species were identified based on DNA sequence data and morphological features, of which 14 were from symptomatic woody tissues, six from insect exoskeleton, and nine from both insects and symptomatic wood tissues. The most frequent fungal species, Cryphonectria naterciae (15.9% of isolates), Dothiorella iberica (11.3%), and Diplodia corticola (9.9%), were isolated from both insect and gallery systems. All three species are well-known oak pathogens and are reported here, for the first time, to be associated with C. florentinus. At the same time, 89.6% of the fungal taxa were isolated from one or two sites, highlighting the site-dependence of fungal community assemblages.