Hesperomyces Thaxt.

Santamaria, Sergi & Pedersen, Jan, 2021, Laboulbeniomycetes (Fungi, Ascomycota) of Denmark, European Journal of Taxonomy 781, pp. 1-425 : 238-239

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.