Laboulbenia inopinata W. Rossi, J.A. Torres et Bernardi, 2015

Rossi, Walter, Torres, Juan A. & Bernardi, Matteo, 2015, New Laboulbeniales parasitic on weevils from the Amazon rainforest, Phytotaxa 231 (2), pp. 187-192 : 190

Laboulbenia inopinata W. Rossi, J.A. Torres et Bernardi sp. nov. Fig. 1D

MycoBank MB 814454

Etymology: —From Latin = unexpected; remarking that the presence of four new Laboulbeniales on weevils was totally unexpected.

Original description: —Basal and suprabasal cells of the receptacle yellowish; the rest of the thallus is grayish brown, with the perithecial tip distinctly paler. Basal cell of the receptacle elongate, very slightly tapering downwards, almost twice longer than the suprabasal, from which it is separated by a distinctly oblique septum and further distinguished by a marked constriction. Cells III, IV and V replaced by a single subconical cell about trice longer than its maximum width, separated from the cell below by a very oblique septum. Insertion cell blackish, small and oblique. Appendage consisting of a flattened cell bearing on the inner side two divergent, elongate and relatively large antheridia, and externally a third antheridium subtended by a subquadrate cell. Stalk-cell of the perithecium small and almost isodiametric. Perithecium at lest two thirds free above the insertion of the appendage, broadly elliptical, the transverse limits of the wall-cells indicated externally by pronounced elevations, the tip rather abruptly distinguished, distinctly bent inwards, tapering to a almost rounded and slightly enlarged apex subtended by a blackish shade. Total length 275–440 μm. Perithecium 55–62 × 163–195 μm. Ascospores about 62 μm.

Type: — ECUADOR. Orellana: P. N. Yasuní, Estación de Biodiversidad Tiputini, 220–250 m, by fogging in tropical rain forest, 31 January 2002, Terry Erwin & al., at the apex of the abdomen of a specimen of Lechriops sp. ( Conoderinae, Lechriopini ), slide no. 3911a (FI). (holotype FI3911a! isotypes QCNE3911b! & FI3911c!).

Additional specimens examined: — Same data as the type, 01 February 2001, on the tip of the elytra of Macrocopturus sp. ( Conoderinae, Zygopini ) (FI3864!); same data as the type, 02 February 2002, on the hind right femur of Macrocopturus sp. (different from the previous) (FI3912!); Zamora Chinchipe: Estación Cientifica San Francisco, about 1900 m, 3°58’17.19”S, 79°04’44.06”W, 10–14 August 2014, M. Bernardi, W. Rossi & J. Torres, on the hind right femur of Lechriops sp. (different from the host of the holotype) (FI3923!). A total of one immature and 23 mature thalli were examined.

Comments:— Laboulbenia inopinata is very different from all the other species parasitic on Curculionidae in having a single undivided cell replacing cells III, IV and V, and also by having appendages lacking sterile branches. These characteristics are only found in a small group of species parasitic on Chrysomelidae , among which it is more similar to L. chaetochnemae (Thaxt.) Thaxt. than to any other. The new species differs from the latter for the perithecium free on the dorsal side for at least 2/3 of its length and with the ventral margin of the same distinctly “wavy”; in L. chaetochnemae the perithecium is free for only one half of its length and its ventral margin is regularly convex. Moreover, in L. inopinata the perithecial tip is more or less bent dorsally and cell III+IV+V is tapered, while the perithecial tip is erect or slightly bent ventrally and cell III+IV+V is cylindrical in L. chaetochnemae ( Thaxter 1914; Rossi 1994: 15, fig.8). The presence on Curculionidae of a species of Laboulbenia displaying the characteristics of parasites usually found on Chrysomelidae is likely due to the phenomenon recently described in the Laboulbeniales as “host switch” ( Rossi 2011).

Among the four species described in the present paper L. inopinata is the only one collected both in the tropical rainforest (Estación de Biodiversidad Tiputini) and in the mountain cloud forest (Estación Cientifica San Francisco).

Figures

FIGURE 1.A. Laboulbenia elephantina (from the type slide). B. Laboulbenia dichroma (from the type slide). C. Laboulbenia microcarpa (from the type slide). D. Laboulbenia inopinata from Macrocopturus sp. (from the paratype FI3864). Bars = 50 μm.