Rhachomyces spinosus Santam. & Cuesta-Segura

MB#834607

Fig. 18E–F

Nova Hedwigia 110(3–4): 362 (Santamaria et al. 2020a). –

Type: “ Spain, León, Redipuertas, Valdelugueros, Riopinos valley, 43°01′30″ N, 5°26′26″ W, 1346 m a.s.l., 22.V.2016, A.D. Cuesta-Segura, on Syntomus foveatus (Geoffroy) ( Coleoptera Carabidae), det. A.D. Cuesta-Segura, slide BCB–SS2743n (HOLOTYPE)”; BCB.

Diagnostic features

Thallus small, up to 220 µm. Primary appendage three-celled. Primary septum constricted and darkened, with the dark brown pigmentation extending to the lower quarter of the basal cell of the primary appendage (Fig. 18E, a). Second cell of the primary appendage bearing a stout spinous process on the margin (Fig. 18E, sx). Apical cell of the primary appendage rounded distally, as long as the two lower cells together. Secondary axis three-celled, bearing five antheridial appendages.

Distribution and hosts

On Syntomus (Col. Carabidae). Only known from Spain (original description) and Belgium (Haelewaters & De Kesel 2020: pl. 71, as Rhachomyces sciakyi W.Rossi).

Collections examined from Denmark

On Syntomus foveatus (Geoffroy, 1785) (Col. Carabidae)

DENMARK – Fyn (F) • Flyvesandet ved Agernaes; 55°37.294′ N, 10°18.251′ E; NG86; 19 Apr. 2018; JP 1043; JP det.; ZMUC C-F-123559. – Lolland, Falster, Møn (LFM) • Ulvshale; 55°2.301′ N, 12°16.244′ E; UB20; 25 Sep. 2016; JP 144; JP det.; ZMUC C-F-122623. – Nordøstjylland (NEJ) • Sandmilen; 57°41.793′ N, 10°31.717′ E; NJ99; 21 Nov. 2017; JP 801; JP det.; ZMUC C-F-123296. – Nordøstsjaelland (NEZ) • Asserbo Plantage; 56°1.794′ N, 12°1.589′ E; UC11; 15 Oct. 2017; JP 576; JP det.; ZMUC C-F-123062 • Liseleje; 56°1.048′ N, 11°58.454′ E; PH81; 30 Oct. 2016; JP 132; JP det.; ZMUC C-F-122608. – Nordvestsjaelland (NWZ) • Sandflugtsplantage ved Rørvig; 55°57.126′ N, 11°43.060′ E; PH60; 4 Nov. 2017; JP 712; JP det.; ZMUC C-F-123203 .

Remarks

First record from Denmark, third record after the original description. This species is related to R. sciakyi W.Rossi and R. lavagnei (F.Picard) W.Rossi but may be readily separated from them by the spinous process seen on the second cell of the primary appendage (Santamaria et al. 2020a).