Autoicomyces aquatilis (F.Picard) I.I.Tav.

MB#105077

Fig. 2D

Mycologia Memoirs 9: 148 (Tavares 1985). – Basionym: Ceratomyces aquatilis F.Picard, Bulletin de la Société Mycologique de France 29: 560 (Picard 1913) [MB#225059]. –

Type: [Type lost!] “Sur les segments ventraux de l’abdomen d’ Hydrochus carinatus Germ., Trappes (Seine-et-Oise), dans les canaux attenants à l’étang de St-Quentin”. [France]

Autoicomyces melanocerus Speg. (Spegazzini 1915b: 41) [MB#173533]. – Ceratomyces melanocerus (Speg.) Thaxt. (Thaxter 1931: 350) [MB#270804]

Diagnostic features

Thallus variably darkened. Receptacle three-celled. The uppermost wall cell of the anterior row develops a subapical horn-like, unicellular, variably curved, almost blackish brown outgrowth (Fig. 2D, arrow). [Detailed descriptions: Scheloske 1969; Majewski 1994b; Santamaria 2003]

Distribution and hosts

On Hydrochus Leach, 1817 (Col. Hydrochidae) from Europe: France, Germany, Hungary, Italy (as A. melanocerus), Poland, Spain (Majewski 2008) and Sweden (Huggert 2010); also in Cuba and USA (Thaxter 1931).

Collections examined from Denmark

On Hydrochus crenatus (Fabricius, 1792) (Col. Hydrochidae)

DENMARK – Nordøstsjaelland (NEZ) • Heatherhill; 56°5.240′ N, 12°8.611′ E; UC21; 22 May 2016; JP 91; JP det.; ZMUC C-F-122567 .

Remarks

First record from Denmark. Its presence in Denmark was expected given the presence of the species in neighbouring countries, such as Sweden and Germany.