Chitonomyces bidessarius (Thaxt.) Thaxt.

Santamaria, Sergi & Pedersen, Jan, 2021, Laboulbeniomycetes (Fungi, Ascomycota) of Denmark, European Journal of Taxonomy 781, pp. 1-425 : 100-101

Chitonomyces bidessarius (Thaxt.) Thaxt.

MB#166754

Fig. 20C–D

Memoirs of the American Academy of Arts and Sciences 12: 292 ( Thaxter 1896). – Basionym: Heimatomyces bidessarius Thaxt., Proceedings of the American Academy of Arts and Sciences 28: 185 ( Thaxter 1893) [MB#147264]. –

Type: “ On elytra of Bidessus granarius Aube , Kittery , Maine ”; FH. [ USA]

Diagnostic features

Thallus slender, hyaline to yellowish-brow, with cell Ia flattened, subtending parallel cells II and IIa; cells III and IIIa overlapping, nearly parallel, separated by a strongly oblique to nearly vertical septum ( Fig. 20C ). [Detailed descriptions: Scheloske 1969; Sugiyama 1973; Majewski 1994b]

Distribution and hosts

On Col. Dytiscidae of the genera Bidessus Sharp, 1882 , Hygrotus , Guignotus Houlbert, 1934 , Hyphydrus Illiger, 1802 , Laccophilus , Uvarus Guignot, 1939 , Hydrovatus Motschulsky, 1853 , Liodessus Guignot, 1939 , and Hydroglyphus Motschulsky, 1853 from Europe ( France, Poland, Germany, Finland, Hungary and Sweden), USA (type), Asia ( China and Japan) and Oceania ( Fiji) ( Majewski 2008; Huggert 2010). Recently reported from the Netherlands ( Haelewaters & De Kesel 2020).

Collections examined from Denmark

On Hygrotus inaequalis (Fabricius, 1777) (Col. Dytiscidae )

DENMARK – Nordøstjylland (NEJ) • Knarmod i Tofte Skov ; 56°51.824′ N, 10°15.470′ E; NJ70; 8 Aug. 2013; JP 337; JP det.; ZMUC C-F-122816 . – Nordøstsjaelland (NEZ) • Heatherhill ; 56°5.240′ N, 12°8.611′ E; UC21; 22 May 2016; JP 96; JP det.; ZMUC C-F-122571 . – Vestjylland (WJ) • Simmelmose ; 55°46.299′ N, 9°3.519′ E; NG08; 2 Jun. 2019; JP 1477; JP det.; ZMUC C-F-124057 .

Remarks

First record from Denmark. The finding of this species in Denmark is not surprising given its presence in several neighbouring countries.

Figures

Fig. 20. Chitonomyces spp. A–B. C. aculeifer Speg. Mature thalli with labelling of cells and other parts of the thallus, i.e., cells I, Ia, II, IIa, III, IIIa, VI, antheridium (an), primary appendage (pa) and perithecial outgrowth (arrow). A. From Graptodytes. B. From Haliplus. –C–D. C. bidessarius (Thaxt.) Thaxt. Mature thalli with labelling of cells of the thallus, i.e., cells I, Ia, II, IIa, III, and IIIa. – E–F. C. elongatus Speg. E. Thallus from a female host. F. Thallus from a male host. – G. C. ensifer Speg. Mature thallus showing prominent cell VI and perithecial outgrowth (arrow). Scale bars: 50 µm. Photographs from slides ZMUC C-F-123553 (A), ZMUC C-F-124083 (B), ZMUC C-F-122816 (C–D), ZMUC C-F-124060 (E), ZMUC C-F-124061 (F), ZMUC C-F-123670 (G).