Ochicanthon tristoides (Paulian)

Latha, Mathews, Cuccodoro, Giulio & Sabu, Thomas K., 2011, Taxonomy of the dung beetle genus Ochicanthon Vaz-de-Mello (Coleoptera: Scarabaeidae: Scarabaeinae) of the Indian subcontinent, with notes on distribution patterns and flightlessness, Zootaxa 2745, pp. 1-29 : 21-22

Ochicanthon tristoides (Paulian)

( Figs. 56–60 )

Phacosoma tristoides Paulian, 1983: 616 .

Description. Body ( Fig. 56 ) predominantly black. Annular punctation on head separated by interval of less than their diameter. Pronotum in lateral view weakly convex, outline at base almost in line with that of elytral suture; laterobasal paramarginal ridge well marked, extended on slightly more than one third of pronotal length. Pronotal punctation ( Fig. 57 ) consisting of annular setiferous punctures separated by interval of less than their diameter; setae almost indistinct, straight and recumbent. Elytra in lateral view moderately convex; suture not raised; striae shallow, wide, consisting of chains of confluent discoidal depressions ( Fig. 57 ); interstriae weakly convex, uneven, finely and irregularly punctate; background microsculpture smooth; setae fine, straight and recumbent; lateral ridge posteriorly extended nearly to level of apex of second stria. Mesosternum irregularly punctate towards the base; meso-metasternal line subangulate; metasternal shield with coarse punctation except in the centre which is with fine punctures ( Fig. 58 ). Pygidium covered with shallow setiferous punctures becoming finer ventrally. Protrochanter with outer margin arcuate. Hind wings present.

Male lacking obvious secondary sexual characters. Aedeagus as in Figs. 59–60 .

Measurements (mm; n = 3): TL = 4.0–4.3; BW = 2.1–2.2; PL = 1.2–1.3; PW = 2.2–2.4; EL = 2.5–2.8.

Material examined (3 specimens, MHNG). Holotype (male): “ India, West Bengal, Darjeeling dist., Teesta- Rangpo, [11 km of Teesta] 350m, 12.x.1978, leg. Besuchet & Löbl, #11b” [under bark].

Paratypes (2): Same data as holotype, 1 female; “ India, West Bengal, Darjeeling dist., Sukha, 200m, 7.x.1978, #2b” [sifting in forest], 1 female.

Additional material (6)“ India Meghalaya, West Garo Hills dist, Tura, 700–900m, 01.xi.1978, leg. Besuchet & Löbl, #37b” [sifting in forest of Tura Peak], 2 males and 3 females; “ India Meghalaya, West Garo Hills dist, Mt Nokrek National Park <25°30’02’’ N; 90°14’54’’ E>, 1200m, leg. Carlton, Cuccodoro, Erne & Leschen, #5a” [sifting forest litter], 1 female, in MHNG.

Distribution and natural history. Northeast India (Teesta river valley, in Lower gangetic plains moist deciduous forests ecoregion; Tura and Mount Nokrek National Park in the Meghalaya subtropical forest ecoregion).

Diagnosis. See discussion under O. besucheti . Two males from Garo Hills have the aedeagus very similar to the holotype from Darjeeling, except for a more sinuate dorsal outline of the parameres. Both sexes from Garo Hills have the punctation on metasternum and mesosternum slightly less marked. These specimens from the Garo Hills may represent new species closely related to O. tristoides . However, in the absence of sufficient material of O. tristoides from the type locality in Darjeeling district, notably males, to adequately assess the taxonomic significance of these subtle differences, we treat the specimens from Garo Hills as putative O. tristoides .

Figures

FIGURES 56 – 60. Ochicanthon tristoides (holotype). Dorsal habitus (56); base of pronotum and elytra (57); mesosternum and metasternum (58); aedeagus, ventral view (59); aedeagus, lateral left view (60). Scale bars = 1 mm.