Stigmatomyces purpureus Thaxt.

Stigmatomyces purpureus Thaxt.

MB#191132

Fig. 61A–B

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

Type: [Not designated] [Ind. loc.] “On all parts of Scatella stagnalis Fallen. Kittery Point, Maine, and vicinity of Cambridge, Mass., September”; FH. [USA]

Stigmatomyces scatellae S.W.T.Batra. (Batra 1963: 986) [MB#339711]

Diagnostic features

Thallus hyaline. Basal cell of appendage supporting a series of three cells, each bearing solitary antheridia on the inner side, except for the uppermost cell which gives rise two antheridia, where the distal one bears a dorsal spinous process. Perithecium with an oval venter, and a well-distinguished, short neck, which tapers distally into an asymmetrical tip, showing two distinct projections (Fig. 61A, arrows). Perithecial outer wall cells arranged spirally and forming conspicuous ridges and corrugations.[Detailed descriptions: Thaxter 1908; Majewski 1994b; Weir & Rossi 1995, 1997]

Distribution and hosts

Found on five continents: Europe (Spain, France, United Kingdom, Italy, Poland and Finland), America (USA), Asia (India), Africa (Algeria) and Oceania (New Zealand) (Majewski 2008). Recently reported also from Canada, Portugal (Rossi et al. 2013) and Turkey (Rossi 2016). It is common on flies of the genus Scatella (Diptera Ephydridae).

Collections examined from Denmark

On Scatella stagnalis (Fallen, 1813) (Diptera; Ephydridae) DENMARK – Østjylland (EJ) • Gjerlev; 56°35.242′ N, 10°7.898′ E; NH67; Jul. 1882; H.J. Hansen Dry0012; V. Michelsen det.; ZMUC C-F-124025, C-F-124026.

Remarks

First record from Denmark. Although the Danish material is in rather poor condition, it is perfectly identifiable by the two projections from the perithecial apex and the spiral ridges on the venter of the perithecium.