Danny Haelewaters's research while affiliated with University of Colorado Boulder and other places

Molecular studies of fungi within the order Laboulbeniales (Ascomycota, Pezizomycotina) have been hampered for years because of their minute size, inability to grow in axenic culture, and lack of reliable and cost-efficient DNA extraction protocols. In particular, the genus Laboulbenia is notorious for low success with DNA extraction and polymerase chain reaction (PCR) amplification. This is attributed to the presence of melanin, a molecule known to inhibit PCR, in the cells. We evaluated the efficacy of a standard single cell-based DNA extraction protocol by halving the recommended amount of reagents to reduce the cost per extraction and adding bovine serum albumin (BSA) during the multiple displacement amplification step to reverse the effect of melanin. A total of 196 extractions were made, 111 of which were successful. We found that halving the reagents used in the single cell-based extraction kit did not significantly affect the probability of successful DNA extraction. Using the halved protocol reduces cost and resource consumption. Moreover, there was no significant difference in the probability of successfully extracting DNA based on whether BSA was added or not, suggesting that the amount of melanin present in cells of the thallus has no major inhibitory effect on PCR. We generated 277 sequences from five loci, but amplification of the internal transcribed spacer region, the mitochondrial small subunit rDNA, and protein-coding genes remains challenging. The probability of successfully extracting DNA from Laboulbeniales was also impacted by specimen storage methods, with material preserved in > 95% ethanol yielding higher success rates compared to material stored in 70% ethanol and dried material. We emphasize the importance of proper preservation of material and propose the design of Laboulbeniales-specific primers to overcome the problems of primer mismatches and contaminants. Our new insights apply not only to the genus Laboulbenia; Laboulbeniales generally are understudied, and the vast majority of species remain unsequenced. New and approachable molecular developments will benefit the study of Laboulbeniales, helping to elucidate the true diversity and evolutionary relationships of these peculiar microfungi.

Fungal conservation is gaining momentum globally, but many challenges remain. To advance further, more data are needed on fungal diversity across space and time. Fundamental information regarding population sizes, trends, and geographic ranges is also critical to accurately assess the extinction risk of individual species. However, obtaining these data is particularly difficult for fungi due to their immense diversity, complex and problematic taxonomy, and cryptic nature. This paper explores how citizen science (CS) projects can be leveraged to advance fungal conservation efforts. We present several examples of past and ongoing CS‐based projects to record and monitor fungal diversity. These include projects that are part of broad collecting schemes, those that provide participants with targeted sampling methods, and those whereby participants collect environmental samples from which fungi can be obtained. We also examine challenges and solutions for how such projects can capture fungal diversity, estimate species absences, broaden participation, improve data curation, and translate resulting data into actionable conservation measures. Finally, we close the paper with a call for professional mycologists to engage with amateurs and local communities, presenting a framework to determine whether a given project would likely benefit from participation by citizen scientists.

Fungi are among the least known organisms on earth, with an estimated number of species between 1.5 and 10 million. This number is expected to be refined, especially with increasing knowledge about microfungi in undersampled habitats and increasing amounts of data derived from environmental DNA sequencing. A significant proportion of newly generated sequences fail to match with already named species, and thus represent what has been referred to as fungal “dark taxa”. Due to the challenges associated with observing, identifying, and preserving sporophores, many macro- and microfungal species are only known from a single collection, specimen, isolate, and/or sequence—a singleton. Mycologists are consequently used to working with “rare” sequences and specimens. However, rarity and singleton phenomena lack consideration and valorization in fungal studies. In particular, the practice of publishing new fungal species names based on a single specimen remains a cause of debate. Here, we provide some elements of reflection on this issue in the light of the specificities of the fungal kingdom and global change context. If multiple independent sources of data support the existence of a new taxon, we encourage mycologists to proceed with formal description, irrespective of the number of specimens at hand. Although the description of singleton-based species may not be considered best practice, it does represent responsible science in the light of closing the Linnean biodiversity shortfall.

Scientists ought to apply universally accepted definitions to technical terms to enable precise communication and discussion. Throughout history, many definitions have shifted, such as those of important terms in evolutionary biology, modes of life, and the nature of interactions. Conversely, throughout history, important terms have been used without proper definition. Two such terms are parasites and pathogens. An extensive body of literature considers parasites and pathogens to be categorically negative, which has resulted in definitions that lack objectivity and limit a full understanding of the biology of these organisms. Different interpretations have resulted in shifting definitions, in turn causing confusion. Here, we present the remarkable history of both definitions, an overview of alternative definitions put forward throughout history, and a working definition for both terms. We find that the line between what is a parasite or a pathogen is often blurry, and is additionally complicated due to the multi-modal nature of interactions.

A new saprotrophic species was discovered during our fungal inventory at the Boston Harbor Islands National Recreation Area (Massachusetts), which consists of 34 islands and peninsulas. Simocybe ramosa sp. nov. (Agaricales, Crepidotaceae) is described based on morphology and molecular phylogenetic data. The holotype collection was found in a Quercus (oak)–Carya (hickory) forest under bark of a dead oak tree on World’s End peninsula, the largest land mass of the archipelago. Phylogenetic reconstruction of a dataset of the internal transcribed spacer region (ITS) resolved S. ramosa and S. rhabarbarina as sister species. Simocybe rhabarbarina is here redescribed based on the holotype and newly reported material from the Netherlands, and its presence on the island of Jersey, off the coast of northern France, is confirmed based on an ITS sequence. Finally, we compare morphological features of S. ramosa with S. rhabarbarina and the 20 species in the genus that have thus far been recorded in Canada, the US, and Mexico.

Citizen science is an increasingly powerful tool to gather large quantities of biological data and to engage the public. The number of citizen science initiatives has rapidly increased in the last 15 years. Invasive alien species such as the harlequin ladybird, Harmonia axyridis (Coleoptera, Coccinellidae), provide a particularly good opportunity for broad-scale use of such initiatives. Harmonia axyridis is parasitized by a fungus, Hesperomyces harmoniae (Ascomycota, Laboulbeniales), that can be found throughout the range of its host. Here we present Beetlehangers.org, a website and data repository where we combine observations of He. harmoniae from literature, online databases, and citizen science initiatives, including new records of both Ha. axyridis and He. harmoniae. Whereas Ha. axyridis is now present in 86 countries across six continents (including seven new country records), the distribution of its parasite He. harmoniae comprises 33 countries in five continents (including two new country records since its description in 2022). We explore spatiotemporal trends of He. harmoniae in light of these records. Finally, we discuss challenges and new opportunities for citizen science in relation to species interactions such as these and provide future perspectives for the website as a home for future Laboulbeniales research and outreach.

Between 2016 and 2022, the ladybird (Coleoptera: Coccinellidae) fauna was surveyed on seven main islands of the Canary Islands archipelago. Adult specimens were collected and screened for thalli of Laboulbeniales (Ascomycota: Laboulbeniomycetes). Altogether, 9,807 ladybird specimens belonging to 39 species were screened, of which 103, representing 10 species, were infected by Laboulbeniales of the genus Hesperomyces. Morphological and molecular examination allowed to distinguish at least seven host-specific Hesperomyces species belonging to three groups: He. virescens species complex (associated with Adalia decempunctata, Harmonia axyridis, Hyperaspis vinciguerrae, Novius cruentatus, Parexochomus nigripennis, and P. quadriplagiatus), He. coccinelloides species complex (Scymnus nubilus, Sc. subvillosus durantae, and Stethorus tenerifensis), and a species (on Nephus flavopictus) that cannot be assigned to either of the above species complexes or the currently described species in the genus. The most widespread and abundant species was Hesperomyces ex St. tenerifensis; it was recorded on all seven islands with prevalence rates ranging between 0.04 and 0.19.

The Global Consortium for the Classification of Fungi and fungus-like taxa is an international initiative of more than 550 mycologists to develop an electronic structure for the classification of these organisms. The members of the Consortium originate from 55 countries/regions worldwide, from a wide range of disciplines, and include senior, mid-career and early-career mycologists and plant pathologists. The Consortium will publish a biannual update of the Outline of Fungi and funguslike taxa, to act as an international scheme for other scientists. Notes on all newly published taxa at or above the level of species will be prepared and published online on the Outline of Fungi website (https://www.outlineoffungi.org/), and these will be finally published in the biannual edition of the Outline of Fungi and fungus-like taxa. Comments on recent important taxonomic opinions on controversial topics will be included in the biannual outline. For example, ‘to promote a more stable taxonomy in Fusarium given the divergences over its generic delimitation’, or ‘are there too many genera in the Boletales?’ and even more importantly, ‘what should be done with the tremendously diverse ‘dark fungal taxa?’ There are undeniable differences in mycologists’ perceptions and opinions regarding species classification as well as the establishment of new species. Given the pluralistic nature of fungal taxonomy and its implications for species concepts and the nature of species, this consortium aims to provide a platform to better refine and stabilize fungal classification, taking into consideration views from different parties. In the future, a confidential voting system will be set up to gauge the opinions of all mycologists in the Consortium on important topics. The results of such surveys will be presented to the International Commission on the Taxonomy of Fungi (ICTF) and the Nomenclature Committee for Fungi (NCF) with opinions and percentages of votes for and against. Criticisms based on scientific evidence with regards to nomenclature, classifications, and taxonomic concepts will be welcomed, and any recommendations on specific taxonomic issues will also be encouraged; however, we will encourage professionally and ethically responsible criticisms of others’ work. This biannual ongoing project will provide an outlet for advances in various topics of fungal classification, nomenclature, and taxonomic concepts and lead to a community-agreed classification scheme for the fungi and fungus-like taxa. Interested parties should contact the lead author if they would like to be involved in future outlines.

Laboulbeniales ( Ascomycota ) are an order of understudied, biotrophic microfungi uniquely associated with arthropods. More than 2300 species are described but only a fraction of those have been sequenced. Molecular studies have shown that cryptic diversity and phenotypic plasticity are present within the Laboulbeniales . Thus far, all of the 146 genera described in Laboulbeniales have been based on morphological characteristics; features commonly used to delineate genera are the organization of receptacle cells and the number of perithecial outer wall cells. The genus Botryandromyces was erected to accommodate two species, B. heteroceri and B. ornatus (type), which share similar morphological characteristics and are different from other genera in their number of perithecial outer wall cells. Here, we generated sequences of multiple loci (18S, ITS, and 28S) of B. heteroceri and several Laboulbenia species. Our phylogenetic analyses retrieved Botryandromyces within Laboulbenia with high support. The two Botryandromyces species are similar to related Laboulbenia species in their upper receptacle (i.e., cells IV and V). We propose to transfer Botryandromyces ornatus and B. heteroceri to Laboulbenia as L. heteroceri and L. mairei nom. nov., respectively, due to a complicated taxonomic history. These results advocate the use of molecular data and the necessity of an integrative taxonomy approach in the study of Laboulbeniales not only to delineate species, but also to investigate relationships among species, genera, and higher taxa as well as to understand the evolution of morphology in this group of fungi.