Stigmatomyces hydrelliae Thaxt.

MB#193297

Fig. 59G–J

Proceedings of the American Academy of Arts and Sciences 36: 404 (Thaxter 1901a). –

Type: “ On the superior surface of the abdomen, sometimes on the legs of Hydrellia sp. Kittery Point, Maine ”; FH. [USA]

Diagnostic features

Basal cell of appendage supporting a series of three ± isodiametric cells, each bearing solitary antheridia on the inner or outer side, except the upper cell which gives rise to two antheridia, the distal of which is spinose (Fig. 59I, sx). Perithecium with an oval venter and a well-distinguished short neck, which tapers distally into an asymmetrical and rounded, constricted near the tip, showing a lip which extends into a pointed projection (Fig. 59J, arrow). Perithecial outer wall cells arranged helically, forming conspicuous ribs and protuberances on the distal region of the venter (Fig. 59I). [Detailed descriptions: Thaxter 1908; Dainat 1971; Majewski 1994b; Weir & Rossi 1995]

Distribution and hosts

This is a common species reported from Europe: Portugal, Spain, France, United Kingdom, Italy, Denmark, Poland, Finland and Russia, as well as from the USA and New Zealand (Majewski 2008). The thalli from New Zealand (Hughes et al. 2004) may belong to a separate species. Recently reported from the Netherlands (Haelewaters & De Kesel 2020). On species of the genus Hydrellia ( Diptera Ephydridae).

Collections examined from Denmark

On Hydrellia griseola (Fallén, 1813) ( Diptera Ephydridae) DENMARK – Bornholm (B) • Almindingen; 55°7.448′ N, 14°56.114′ E; VB90; H.J. Hansen Dry0015; ZMUC C-F-124029 • Snogebaek; 55°1.512′ N, 15°6.887′ E; WA09; 18 Jun. 1964; L. Lyneborg et al. Dry0013; T. Zatwarnicki det.; ZMUC C-F-124027 • Sose; 55°2.801′ N, 14°50.531′ E; VB90; 20 Jun. 1965; O. Martin et al. Dry0014; T. Zatwarnicki det.; ZMUC C-F-124028 . – Nordøstjylland (NEJ) • Klitplantagen, Laesø; 57°17.795′ N, 11°2.022′ E; PJ25; 12 Jul. 1969; Zool. Mus. Exp. Dry0019; ZMUC C-F-124033 • Nordmarken, Laesø; 57°18.919′ N, 11°4.819′ E; PJ25; 16 Jul. 1969; Zool. Mus. Exp. DrY0016; ZMUC C-F-124030 • ibid.; 24 Jul. 1969; Zool. Mus. Exp. Dry0017; ZMUC C-F-124031 • ibid.; 27 Jul. 1969; Zool. Mus. Exp. Dry0018; ZMUC C-F-124032 . – Nordøstsjaelland (NEZ) • København; 55°41.332′ N, 12°33.762′ E; UB47; 23 Sep. 1905; W. Lundbeck Dry0020; ZMUC C-F-124034 . – Sydsjaelland (SZ) • Knudsskov; 55°3.534′ N, 11°44.251′ E; PG70; 14 Oct. 2013; JP 1197; W. Gritsch det.; ZMUC C-F-123721 .

Remarks

Majewski (2008) reported the presence of this species from Denmark on Hydrellia griseola and H. maura Meigen, 1838 (see Table 1).