Our lab group does research in the area of fungal biology in which we study taxonomy, life histories, and systematics – particularly of fungi in the Pezizomycetes, the Orbiliomycetes and recently in the Laboulbeniomycetes.
Pfister, D. (Photographer). (2008) Fistulina after harvest [photograph]. Punta Arenas, Chile.
Haelwaters, D. (Photographer). (2013). Laetiporus sulphureus – Chicken of the woods. [photograph]. Hingham, MA: Worlds End.
Arthropod–fungus interactions involving the Laboulbeniomycetes have been pondered for several hundred years. Early studies of Laboulbeniomycetes faced several uncertainties. Were they parasitic worms, red algal relatives, or fungi? If they were fungi, to which group did they belong? What was the nature of their interactions with their arthropod hosts? The historical misperceptions resulted from the extraordinary morphological features of these oddly constructed ectoparasitic fungi. More recently, molecular phylogenetic studies, in combination with a better understanding of life histories, have clearly placed these fungi among filamentous Ascomycota (subphylum Pezizomycotina). Species discovery and research on the classification of the group continue today as arthropods, and especially insects, are routinely collected and examined for the presence of Laboulbeniomycetes. Newly armed with molecular methods, mycologists are poised to use Laboulbeniomycetes–insect associations as models for the study of a variety of basic evolutionary and ecological questions involving host–parasite relationships, modes of nutrient intake, population biology, host specificity, biological control, and invasion biology. Collaboration between mycologists and entomologists is essential to successfully advance knowledge of Laboulbeniomycetes and their intimate association with their hosts.
Harmonia axyridis is an invasive alien ladybird in North America and Europe. Studies show that multiple natural enemies are using Ha. axyridis as a new host. However, thus far, no research has been undertaken to study the effects of simultaneous infection by multiple natural enemies on Ha. axyridis. We hypothesized that high thallus densities of the ectoparasitic fungus Hesperomyces virescens on a ladybird weaken the host’s defenses, thereby making it more susceptible to infection by other natural enemies. We examined mortality of the North American-native Olla v-nigrum and Ha. axyridis co-infected with He. virescens and an entomopathogenic fungus—either Beauveria bassiana or Metarhizium brunneum. Laboratory assays revealed that He. virescens-infected O. v-nigrum individuals are more susceptible to entomopathogenic fungi, but Ha. axyridis does not suffer the same effects. This is in line with the enemy release hypothesis, which predicts that invasive alien species in new geographic areas experience reduced regulatory effects from natural enemies compared to native species. Considering our results, we can ask how He. virescens affects survival when confronted by other pathogens that previously had little impact on Ha. axyridis. View Infographic here
During fungal surveys between 2012 and 2014 in pine-dominated forests of the western Himalayas in Pakistan, several collections of Pseudosperma (Agaricales, Inocybaceae) were made. These were documented, based on morphological and molecular data. During this work, three new species came to light, which are here formally described as Pseudosperma brunneoumbonatum, P. pinophilum and P. triacicularis. These species belong in the genus Pseudosperma fide Matheny et al (2019) = Pseudosperma clade fide Matheny (2005) = Inocybe sect. Rimosae s.s. fide Larsson et al. (2009). Macro- and micro-morphological descriptions, illustrations and molecular phylogenetic reconstructions of the studied taxa are provided. The new species are differentiated from their close relatives by basidiospore size and colouration of basidiomata. Molecular phylogenetic relationships are inferred using ITS (ITS1–5.8S–ITS2), nrLSU and mtSSU sequence data. All three newly-described taxa likely share an ectomycorrhizal association with trees in the genus Pinus. In addition, five names are recombined in Inosperma, Mallocybe and Pseudosperma. These are Inosperma vinaceobrunneum, Mallocybe erratum, Pseudosperma alboflavellum, Pseudosperma friabile and Pseudosperma neglectum.
Orbilia jesu-laurae is a new species of nematode-trapping fungus found on decorticated angiosperm wood in a tropical rainforest in Puerto Rico. The single specimen was studied from fresh apothecia and cultures. Morphology was studied and phylogenetic analysis (rDNA: ITS and LSU) was conducted using both sexual and asexual morphs. Nematodes were added to cultures to verify the formation and morphology of the trapping structures. Our results show that the species is in the Arthrobotrys clade, the phylogenetically closest relative being a possibly Mexican genotype with unknown morphology, erroneously referred to as Arthrobotrys musiformis in GenBank. Macro- and micromorphological, ecological and biogeographic data are provided along with a discussion of closely related species.