Cantharomyces italicus Speg.

MB#159942

Fig. 76C–F

Anales del Museo Nacional de Historia Natural de Buenos Aires 27: 42 (Spegazzini 1915b). –

Type: “Sobre el margen superior posterior del abdomen de Dryops (Parnus) algiricus, cazados en el torrente Monticano, Conegliano, Oct. 1913 ”; LPS. [Italy]

Diagnostic features

Thallus slender. Cell II pale, without blackening, sometimes slightly darker than cell I. Septum separating cells I and II not constricted. Cell VI strongly constricted at the middle (Fig. 76D).Antheridium occupying the side of the appendage basal cell (Fig. 76D, an). Primary appendage unbranched. [Detailed descriptions: Majewski 1994b; Santamaria 2003; De Kesel & Haelewaters 2014b]

Distribution and hosts

Occurs on Dryops (Col. Dryopidae). Widespread in Europe: Italy (type), United Kingdom (Thaxter 1931), Poland (Siemaszko & Siemaszko 1933), Finland, Russia (Huldén 1983), Hungary (Bánhegyi et al. 1985), Spain (Santamaria 1992a), Sweden (Huggert 2010), and Belgium (De Kesel & Haelewaters 2014b).

Collections examined from Denmark

On Dryops anglicanus Edwards, 1909 (Col. Dryopidae) DENMARK – Sydsjaelland (SZ) • Holmegårds Mose; 55°17.685′ N, 11°47.928′ E; PG73; 26 Apr. 2020; JP 1606; JP det.; ZMUC C-F-124361 .

On Dryops luridus (Erichson, 1847) (Col. Dryopidae) DENMARK – Lolland, Falster, Møn (LFM) • Røgbølle Sø ved Sørup; 54°42.497′ N, 11°34.760′ E; PF66; 3 Sep. 2019; JP 1511; JP det.; ZMUC C-F-124263, C-F-124264, C-F-124265 .

On Dryops similaris Bollow, 1936 (Col. Dryopidae) DENMARK – Nordøstsjaelland (NEZ) • Amager Faelled; 55°38.631′ N, 12°34.729′ E; UB47; 15 Apr. 2018; JP 1035; JP det.; ZMUC C-F-123549 .

Remarks

First record from Denmark.This species often coexists with C. denigratus on the same host. Cantharomyces italicus was described on thalli from the upper surface of last abdominal tergites, and this seems to be its primary growing location, but heavily infected hosts may have thalli spreading to almost any part of the body. Thalli show rather interesting morphological differences depending on the host growth position, especially slenderer thalli growing on pronotum (on Dryops luridus, ZMUC C-F-124263, C-F-124264 and 124265) which have the cell VI with a corrugated and deeply brown pigmented lower dorsal surface (Fig. 76E, *) similar to thalli drawn from Belgium by De Kesel et al. (2020: fig. 4k), also collected from the pronotum. Further studies are needed to determine if these forms could be different species.