Laboulbenia rougetii Mont. & C.P.Robin

Santamaria, Sergi & Pedersen, Jan, 2021, Laboulbeniomycetes (Fungi, Ascomycota) of Denmark, European Journal of Taxonomy 781, pp. 1-425 : 201

Laboulbenia rougetii Mont. & C.P.Robin

MB#245803

Fig. 43A–B

Histoire naturelle des végétaux parasites qui croissent sur l’homme et sur les animaux vivants: 622 ( Robin 1853). – Type: [Not designated] [Ind. loc.] [Type lost?!] “In antennis, thorace, pedibus et elytris Brachini crepitantis L., B. explodentis Duftschmidt , et B. sclopetae Fabricius ”.

Laboulbenia europaea Thaxt. ( Thaxter 1893: 167) [MB#186192]

Diagnostic features

Thallus reddish-brown. Cell V oval or obtriangular, half the length of cell IV, not connected with cell III. Outer appendage with the dorsal margin of lower part variably darkened, once branched above the suprabasal cell. Inner appendage of immature thalli consisting of a basal cell and a suprabasal cell which supports two simple branches bearing each a pair of antheridia which as the thallus matures will be replaced with sterile and fertile elongate branches bearing lateral solitary or paired darkened antheridia ( Fig. 43B , an). Basal cell of inner appendage half as long than basal cell of outer appendage. [Detailed descriptions: Thaxter 1896; Sugiyama & Yamamoto 1982; Majewski 1994b; Santamaria 1998]

Distribution and hosts

Occurs mostly on Brachinus , Anchomenus , Aptinus Bonelli, 1810 , Chlaenius and other genera. Common and widespread in Europe (including Denmark, by Rostrup 1935), Africa, Asia as well as in Oceania ( New Zealand) ( Santamaria et al. 1991; Majewski 2008). Records from America probably belong to L. flagellata because it is broadly accepted that L. rougetii does not exist in America. Recent new records are from Sweden ( Huggert 2010), Turkey ( Rossi 2016), Bulgaria ( Rossi et al. 2019a), Slovakia ( Rossi et al. 2019b), Cambodia, and Kenya ( Kong et al. 2020).

Collections examined from Denmark

On Brachinus crepitans (Linnaeus, 1758) (Col. Carabidae ) DENMARK – Bornholm (B) • Sose ; 55°2.801′ N, 14°50.722′ E; VB90; 4 Aug. 2008; Mo. Hansen Dry0051; Mo. Hansen det.; ZMUC C-F-124117 .

Remarks

Laboulbenia rougetii is the type of the genus and the first species of Laboulbeniales to be described. Does not differ greatly from L. flagellata and seems to have been confused with it by some authors, at least those records of L. rougetii on carabids like e.g., Agonum spp. Indeed, the differences between both species are few, and without knowing the identity of the hosts they are not easily distinguished. Laboulbenia rougetii shows thalli with reddish shades whereas L. flagellata lacks this colour. The ecological niche that L. rougetii occupies on Brachinus in most of the world is replaced by L. texana Thaxt. in America.

Figures

Fig. 43. Laboulbenia spp. A–B. L. rougetii Mont. & C.P.Robin. A. Mature thallus. B. Two young thalli showing antheridia (an). – C–D. L. slackensis Cépède & F.Picard. In D, the black and constricted septum separating the basal cell of outer appendage from outermost branch is labelled (arrow). – E–F. L. sphaerii Santam. E. A pair of two immature thalli. F. Mature thallus from holotype. Both images with undivided cells III and IV being labelled. Scale bars: 50 µm. Photographs from slides ZMUC C-F-124117 (A–B), ZMUC C-F-124219 (C), ZMUC C-F-122634 (D), ZMUC C-F-124098 (E), BCB SS1047b (holotype) (F).