Rhachomyces furcatus (Thaxt.) Thaxt.

Santamaria, Sergi & Pedersen, Jan, 2021, Laboulbeniomycetes (Fungi, Ascomycota) of Denmark, European Journal of Taxonomy 781, pp. 1-425 : 86-89

Rhachomyces furcatus (Thaxt.) Thaxt.

MB#186405

Figs 17C–D , 102A

Proceedings of the American Academy of Arts and Sciences 30: 467 ( Thaxter 1895). – Basionym: Acanthomyces furcatus Thaxt., Proceedings of the American Academy of Arts and Sciences 28: 177 ( Thaxter 1893) [MB#581133]. –

Type: “ On abdomen of Othius fulvipennis Fab. , Germany ”; FH.

Diagnostic features

Thallus variably bent to flexuous. Main receptacle axis continuing into a rather conspicuous lateral branch above the perithecium, even exceeding in length its apex.Appendages type “a” and “b” inseparable, long and very abundant, deeply darkened. Appendages of type “c” consisting of a supporting cell and one antheridium, only visible on the upper lateral branch in mature thalli ( Fig. 17D , *). [Detailed descriptions: Thaxter 1896; Santamaria 1989; Majewski 1994b; De Kesel 2002]

Distribution and hosts

Occurs on species belonging to the genus Othius (Col. Staphylinidae Staphylininae ). Known from Europe ( Finland, France, Germany, Hungary, Italy, Poland, Romania, Spain, Sweden, United Kingdom, Russia, former Yugoslavia), Africa ( Algeria, Uganda), and Asia ( Turkey) ( Santamaria et al. 1991). More recently it has been recorded from Belgium ( De Kesel & Haghebaert 1991), Czech Republic ( Rossi & Máca 2006), Denmark ( Rostrup 1935), Slovakia ( Rossi et al. 2010), the Netherlands ( Haelewaters et al. 2012), Armenia, Switzerland, and Bulgaria ( Rossi et al. 2019a).

Collections examined from Denmark

On Othius angustus Stephens, 1833 (Col. Staphylinidae Staphylininae )

DENMARK – Nordøstsjaelland (NEZ) • Lille Lyngby Mose ; 55°40.831′ N, 12°29.094′ E; UC20; 28 Jan. 2018; J. Søgaard Hansen 999; J. Søgaard Hansen det.; ZMUC C-F-123506 .

On Othius punctulatus (Goeze, 1777) (Col. Staphylinidae Staphylininae )

DENMARK – Østjylland (EJ) • Hald Ege ; 56°24.287′ N, 9°20.550′ E; NH25; 19 Oct. 2013; JP 795; JP det.; ZMUC C-F-123290 • Hestehave ved Rønde ; 56°17.015′ N, 10°28.162′ E; NH93; 19 May 1994; N. Scharff 391; JP det.; ZMUC C-F-122874 • Kjellerup ; 56°17.589′ N, 9°26.117′ E; NH23; 21 Oct. 2017; JP 580; JP det.; ZMUC C-F-123066 • Stidsmølle i Mattrup Skov ; 55°55.455′ N, 9°33.811′ E; NG39; 19 Nov. 2017; JP 807; JP det.; ZMUC C-F-123302 . – Lolland, Falster, Møn (LFM) • Nyord ; 55°2.885′ N, 12°12.380′ E; UB20; 27 Apr. 2013; JP 841; JP det.; ZMUC C-F-123336 • Siesø i Klinteskoven ; 54°57.830′ N, 12°32.494′ E; UA49; 15 May 2017; Mo. Hansen DrY0146; Mo. Hansen det.; ZMUC C-F-124214 . – Nordøstsjaelland (NEZ) • Gribskov, Faendriksvang ; 56°1.005′ N, 12°21.245′ E; UC30; 1–31 May 2014; J. Heilmann-Clausen et al. 49; P. Jørum det.; ZMUC C-F-122524 • ibid.; J. Heilmann-Clausen et al. 163; P. Jørum; ZMUC C-F-122642 • ibid.; 1–30 Jun. 2014; J. Heilmann-Clausen et al. 50; P. Jørum; ZMUC C-F-122525 • Gribskov, Kageruphus ; 55°59.428′ N, 12°16.478′ E; UC30; 1–31 May 2014; J. Heilmann-Clausen et al. 47; P. Jørum det.; ZMUC C-F-122522 • ibid.; 55°59.358′ N, 12°16.566′ E; UC30; 1–31 May 2014; J. Heilmann-Clausen et al. 164; P. Jørum det.; ZMUC C-F-122643 • Gribskov, Kalvehave ; 56°0.359′ N, 12°20.339′ E; UC30; 1–31 May 2014; J. Heilmann-Clausen et al. 48; P. Jørum det.; ZMUC C-F-122523 • ibid.; J. Heilmann-Clausen et al. 165; P. Jørum det.; ZMUC C-F-122644 • ibid.; 56°0.419′ N, 12°20.564′ E; UC30; 1–31 May 2014; J. Heilmann-Clausen et al. 166; P. Jørum det.; ZMUC C-F-122645 • Gribskov, Kistrupvang ; 56°1.612′ N, 12°19.959′ E; UC31; 1–31 May 2014; J. Heilmann-Clausen et al. 167; P. Jørum; ZMUC C-F-122646 • ibid.; 56°1.602′ N, 12°20.048′ E; UC31; 1–31 May 2014; J. Heilmann-Clausen et al. 168; P. Jørum det.; ZMUC C-F-122647 • Gribskov, Nederste Koppel ; 56°2.865′ N, 12°19.999′ E; UC31; 1–31 May 2014; J. Heilmann-Clausen et al. 46; P. Jørum det.; ZMUC C-F-122521 • Naerum ; 55°49.077′ N, 12°32.686′ E; UB48; 29 Apr. 2017; JP 402; JP det.; ZMUC C-F-122885 • Stampeskov ved Rådvad ; 55°48.332′ N, 12°33.138′ E; UB48; 14 Apr. 2013; JP 783; JP det.; ZMUC C-F-123278 . – Nordvestsjaelland (NWZ) • Eriksminde syd for Korshage ; 55°57.744′ N, 11°46.504′ E ; PH70; 27 Oct. 2019; JP 1537; JP det.; ZMUC C-F-124297 . – Sydjylland (SJ) • Draved Skov ; 55°0.964′ N, 8°58.395′ E; MF99; 1 Jun. 2013; JP 305; JP det.; ZMUC C-F-122784 • Kollund Skov ; 54°50.219′ N, 9°25.411′ E; NF27; 8 May 2004; H. Liljehult 79; H. Liljehult det.; ZMUC C-F-122554 . – Sydsjaelland (SZ) • Sorø, Kristiansminde ; 55°25.115′ N, 11°35.209′ E; PG64; 1–15 Aug. 2013; JP 525; JP det.; ZMUC C-F-123009 .

On Othius subuliformis Stephens, 1833 (Col. Staphylinidae Staphylininae )

DENMARK – Østjylland (EJ) • Grejsdal syd for Hornstrup ; 55°44.791′ N, 9°33.051′ E; NG37; 8 Mar. 2014; JP 749; JP det.; ZMUC C-F-123243 • Hald Ege ; 56°24.287′ N, 9°20.550′ E; NH25; 19 Oct. 2013; JP 796; JP det.; ZMUC C-F-123291 • Hampen Sø ; 56°1.082′ N, 9°23.149′ E; NH20; 21 Mar. 2014; JP 438; JP det.; ZMUC C-F-122923 • Kjellerup ; 56°17.589′ N, 9°26.117′ E; NH23; 21 Oct. 2017; JP 581; JP det.; ZMUC C-F-123067 • Stidsmølle i Mattrup Skov ; 55°55.455′ N, 9°33.811′ E; NG39; 19 Nov. 2017; JP 808; JP det.; ZMUC C-F-123303 • Tange å vest for Kjellerup ; 56°17.959′ N, 9°23.462′ E; NH23; 17 Feb. 2018; JP 988; JP det.; ZMUC C-F-123495 • Vingsted ; 55°40.512′ N, 9°23.500′ E; NG27; 6 Oct. 2019; JP 1532; JP det.; ZMUC C-F-124291 . – Lolland, Falster, Møn (LFM) • Naesby Strand ; 54°44.625′ N, 11°4.539′ E; PF36; 23 Feb. 2014; JP 552; JP det.; ZMUC C-F-123038 . – Nordøstjylland (NEJ) • Bøgebakken i Tofte Skov ; 56°50.540′ N, 10°11.850′ E; NJ70; 17 May 2013; H. Liljehult 198; JP det.; ZMUC C-F-122677 • Bønderskoven i Tofte Skov ; 56°49.955′ N, 10°14.981′ E; NH79; 19 May 2013; JP 314; JP det.; ZMUC C-F-122793 • ibid.; 8–22 Aug. 2013; I. Aggerholm 932; JP det.; ZMUC C-F-123432 . – Nordøstsjaelland (NEZ) • Bognaes Storskov ; 55°41.242′ N, 12°1.678′ E; UB17; 1 Aug. 2013; JP 362; JP det.; ZMUC C-F-122845 • Gurre Vang ; 56°1.470′ N, 12°29.486′ E; UC41; 14 Apr. 2017; JP 270; JP det.; ZMUC C-F-122749 • Stampeskov ved Rådvad ; 55°48.332′ N, 12°33.138′ E; UB48; 14 Apr. 2013; JP 784; JP det.; ZMUC C-F-123279 . – Nordvestsjaelland (NWZ) • Bognaes Skov på Tuse Naes ; 55°44.966′ N, 11°45.817′ E; PG78; 10 Dec. 2013; JP 889; JP det.; ZMUC C-F-123387 • Nordbredden af Skarresø ; 55°39.425′ N, 11°22.998′ E; PG47; 19 Feb. 2017; H. Liljehult 366; JP det.; ZMUC C-F-122849 • Sonnerup Skov ; 55°56.525′ N, 11°33.988′ E; PH60; 1 Apr. 2017; JP 256; JP det.; ZMUC C-F-122736 . – Sydjylland (SJ) • Nord for Vråby Plantage; 55°6.640′ N, 8°30.239′ E; MG60; 21 Apr. 2000; H. Liljehult 199; JP det.; ZMUC C-F-122678 . – Sydsjaelland (SZ) • Krobaek i Sjolte Skov; 55°10.772′ N, 12°0.863′ E; UB11; 28 Feb. 2015; JP 444; JP det.; ZMUC C-F-122929 .

Remarks

Perhaps one of the most common species of Laboulbeniales in Denmark, where it is infrequent to find specimens of Othius free of this fungus. Also remarkable is the observation of severely infected hosts.

Figures

Fig. 17. Rhachomyces spp. A–B. R. canariensis Thaxt. Mature thalli from Trechus obtusus (A) and Epaphius secalis(B). Appendages type “c” are labelled in A (*). – C–D. R. furcatus (Thaxt.) Thaxt. Mature thalli with appendages of type “c” labelled in D (*). – E–F. R. lasiophorus (Thaxt.) Thaxt. Mature thalli. F. Short form from tarsi. Scale bars: 50 µm. Photographs from slides ZMUC C-F-122765 (A), ZMUC C-F-123438 (B), ZMUC C-F-122521 (C–D), ZMUC C-F-122906 (E–F).

Fig. 102. Habitus of hosts with fungi. Some thalli are zoomed in, and others are encircled. A. Othius punctulatus with thalli of Rhachomyces furcatus. B. Philonthus fumarius with thalli of Rhachomyces philonthinus on the ventral side of the last 4 abdominal segments and a few on the left hind leg. C. Catops tristis heavily infested with Asaphomyces cholevae all over the body, even on the ventral side this specimen has just as many thalli. Scale bars: 1 mm. (Photos: Aslak Kappel Hansen).