Laboulbeniomycetes (Fungi, Ascomycota) of Denmark Author Santamaria, Sergi Unitat de Botànica, Departament de Biologia Animal, de Biologia Vegetal i d’Ecologia, Facultat de Biociències, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès (Barcelona), Spain. sergi.santamaria@uab.cat Author Pedersen, Jan Natural History Museum of Denmark (Zoological Museum), University of Copenhagen, Universitetsparken 15, 2100 København Ø, Denmark. japedersen@snm.ku.dk text European Journal of Taxonomy 2021 2021-11-26 781 1 425 http://dx.doi.org/10.5852/ejt.2021.781.1583 journal article 10.5852/ejt.2021.781.1583 2118-9773 5828924 Genus Hesperomyces Thaxt. MB#2310 Proceedings of the American Academy of Arts and Sciences 25: 264 ( Thaxter 1891 ) . – Type species: H. virescens Thaxt. Brief description Monoecious. Receptacle three-celled. Cells I and II separated by an oblique septum. Cell III in contact with cell I and to a certain extent with cell VI. Primary appendage free, consisting of several superposed cells, each (except for the basal cell) giving rise to 1–2 lateral antheridia, where the uppermost bears a dorsal spinous process (the original spore apex, sx). Perithecium with four cells in each vertical row of outer wall cells; the perithecial tip bears a complex of subapical and apical lobes. Trichogyne two-celled, consisting of a basal cell bearing one apically papillate cell. Remarks The genus consists of ten species ( Das et al. 2018 ), of which three in Europe, two in Denmark . The most recently described species is H. halyziae ( Haelewaters & De Kesel 2020 ) . This is perhaps one of the most studied and recorded genera in the laboulbenialean literature, especially concerning the mostly frequent species, Hesperomyces virescens Thaxt. , well-studied both under SEM and light microscopy ( Weir & Beakes 1996 ), one of the first Laboulbeniales to be sequenced ( Weir & Blackwell 2001 ), and intensively reported and studied because of its presence on the invasive coccinellid beetle, the harlequin ladybird Harmonia axyridis ( Garces & Williams 2004 ) . Key to the Danish species (partially following Santamaria – 2003–) 1. Perithecial tip with four lobes reaching approximately the same height. Lower lobes larger than upper lobes. On Col. Coccinellidae of the subfamily Scymninae ........... H. coccinelloides (Thaxt.) Thaxt. – Upper lobes much longer and larger than minute lower lobes. On several genera of Col. Coccinellidae ....................................................................................................... H. virescens Thaxt.