Ochicanthon laetus (Arrow)

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 : 13

Ochicanthon laetus (Arrow)

( Figs. 26–30 )

Phacosoma laetum Arrow, 1931: 356 .

Description. Body ( Fig. 26 ) predominantly black with distinct orange-yellow humeral spot on each elytron. Punctation on dorsal surface of head annular separated by intervals of nearly 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. 27 ) consisting of annular setiferous punctures separated by interval of approximately their diameter, becoming finer anteromedially; setae almost indistinct, straight and recumbent. Elytra in lateral view weakly convex; suture not raised; striae shallow, wide, consisting of chains of fairly confluent discoidal depressions ( Fig. 27 ); interstriae weakly convex, uneven, finely punctate, irregularly; background microsculpture smooth; setae fine, recumbent and straight; lateral ridge posteriorly extended nearly to level of apex of third stria. Mesosternum punctate along the base; mesometasternal line subangulate in middle; metasternum coarsely punctate except the centre which is almost smooth ( Fig. 28 ). Pygidium covered with annular setiferous punctures becoming finer ventrally. Protrochanter with outer margin arcuate. Hind wings present.

Male lacking obvious secondary sexual characters. Aedeagus as in Figs. 29–30 .

Measurements (mm, n=4): TL = 4.1–4.5; BW = 2.5–2.8; PL = 1.1–1.2; PW =2.2– 2.4; EL = 2.1–2.3.

Material examined. Holotype (female, BMNH): “Nilgiri Hills, H.L. Andrews [printed] / Andrewes Bequest B.M.1922-331 [printed] / Phacosoma laetum type arr. [handwritten by Arrow] / Phaccosoma laetum Arrow [handwritten by Bacchus] M.E. Bacchus det 1975”.

Paratypes (3, BMNH) “Nilgiri Hills H.L. Andrews [printed] / Andrewes Bequest B.M.1922-331 [printed] / Phacosoma laetum Arrow [handwritten by Bacchus] M.E. Bacchus det 1975”, 1 male; “Nilgiri Hills H.L. Andrews [printed] / H.L. Andrews Nilgiri Hills [printed] / 363 [handwritten] / Andrewes Bequest B.M.1922-331 [printed] / Phacosoma laetum co-type Arr. [handwritten by Arrow] / Phacosoma laetum Arrow [handwritten by Bacchus] M.E. Bacchus det 1975”, 1 male; “Nilgiri Hills H.L. Andrews [printed] / H.L. Andrews Nilgiri Hills [printed] / Andrewes Bequest B.M.1922-331 [printed] / Phacosoma laetum co-type Arr. [handwritten by Arrow] / Phacosoma laetum Arrow [handwritten by Bacchus] M.E. Bacchus det 1975” 1 female.

Additionnal material (1 male, MHNG): “ India, Kerala, Palghat Hills, [10 km N of] Malampuzha Dam, 150 m, 27.xi.1972, leg. Besuchet, Löbl & Mussard, #54” [sifting in Hevea plantation].

Distribution and natural history. South India (Nilgiri Hills in the South Western Ghats montane evergreen forests ecoregions; Malampuzha, in the South Western Ghats moist deciduous forests ecoregion). The occurrence of this species in northeast India (Balthasar 1963: Bihar, Chota Nagpur) is very doubtful.

Diagnosis. Ochicanthon laetus is the only member of the genus to possess spotted elytra bearing elytral striae consisting of chains of fairly confluent discoidal depressions. It can be easily distinguished from O. mussardi and O. nitidus by its basally punctate mesosternum. See discussion under O. mussardi .

Figures

FIGURES 26 – 30. Ochicanthon laetus. Dorsal habitus (26); base of pronotum and elytra (27); mesosternum and metasternum (28); aedeagus, ventral view (29); aedeagus, lateral left view (30). Scale bars = 1 mm.