Dimorphomyces myrmedoniae Thaxt.

Santamaria, Sergi & Pedersen, Jan, 2021, Laboulbeniomycetes (Fungi, Ascomycota) of Denmark, European Journal of Taxonomy 781, pp. 1-425 : 304-305

Dimorphomyces myrmedoniae Thaxt.

MB#215212

Fig. 73A–F

Proceedings of the American Academy of Arts and Sciences 36: 409 ( Thaxter 1900). –

Type: “ On MYrmedonia flavicornis Fauv. , British Museum (Biologia Coll.), No. 766 , Guatemala ”; FH.

Diagnostic features

Male thalli consisting of a three-celled receptacle supporting a two-celled primary appendage, and a lateral flask-shaped compound antheridium. Female thalli consisting of an underlying cell I subtending a row of 6–14 cells; the first cell of the series (cell II) supports a three-celled primary appendage, where the two basal cells are inflated and separated by constricted and somewhat blackened septa, the distal cell narrower, longer, paler and often disintegrating. Perithecium with a ± perceptible tooth-like outgrowth near the apex ( Fig. 73B, E , arrows). [Detailed descriptions: Thaxter 1908; Majewski 1994b; Santamaria 2003]

Distribution and hosts

On members of the genera Zyras Stephens, 1835 , Myrmedonia Erichson, 1837 , Tachyusa Erichson, 1837 (in part as Ischnopoda Stephens, 1835 ), Gnypeta Thomson, 1858 , Atheta Thomson, 1858 , and Dilacra Thomson, 1858 (Col. Staphylinidae Aleocharinae ). Type host is probably Zyras according to Majewski (1994b). It has been reported from Poland, Spain and Guatemala ( Santamaria et al. 1991), USA ( Seymour 1967, on Myrmedonia ?), United Kingdom (Weir 1996), Italy, Greece ( Castaldo et al. 2004), Bulgaria, Switzerland ( Rossi et al. 2019a), and Belgium ( De Kesel et al. 2020).

Collections examined from Denmark

On Dilacra vilis (Erichson, 1837) (Col. Staphylinidae Aleocharinae ) DENMARK – Lolland, Falster, Møn (LFM) • Lysemose ved Maribo ; 54°46.971′ N, 11°28.959′ E; PF57; 4 Jun. 2018; JP 1133; JP det.; ZMUC C-F-123656 , C-F-123657 .

Other material examined

Type of Dimorphomyces myrmedoniae

GUATEMALA • “ Dimorphomyces myrmedoniae , 2 slides from FH, #569, barcode 00313726, and #570, barcode 00313727, type, all over MYrmedonia flavicornis Fauv. , from Guatemala, ex British Museum coll. no. 766”; FH[00313726] [slide #569 apparently does not include thalli; slide #570 includes seven mature female thalli and two mature male thalli, in very poor condition ( Fig. 73F )]

Remarks

First record from Denmark. Thalli collected on Dilacra vilis from Denmark show a ± conspicuous protuberance near the perithecial apex, on the opposite side of where ostiole is found ( Fig. 73E , arrow). This feature is neither mentioned nor illustrated in any other previous records of D. myrmedoniae . We have reviewed the Spanish material kept in BCB, and all the thalli show this same character, which was overlooked in our previous observations ( Santamaria 2003). Figures and description by Thaxter (1908) do not show or mention this characteristic. To clarify if the American samples may perhaps correspond to a different species from those in Europe we have borrowed the type from FH (see above under other material examined). Unfortunately, the type slide is in very poor condition ( Fig. 73F ) and gives no additional information of interest. Given this situation, for the time being we should keep the European samples as they were classified.

Figures

Fig. 73. Dimorphomyces spp. A–F. D. myrmedoniae Thaxt. A–B. Mature female thalli, showing perithecial outgrowth (arrow). C–D. Male thalli. E. Mature perithecium in detail showing perithecial outgrowth (arrow). F. Mature female thallus from type slide kept in FH. – G–I. D. phloeoporae Thaxt. G, I. Mature female thalli. H. Male thallus. Scale bars: A–B, F–I = 25 µm; C–E = 20 µm. Photographs from slides ZMUC C-F-123656 (A, C–D), ZMUC C-F-123657 (B, E), FH 00313727 (F) (type), ZMUC C-F-124218 (G–I).