Operclipygus distinctus (Hinton 1935)

Caterino, Michael S. & Tishechkin, Alexey K., 2013, A systematic revision of Operclipygus Marseul (Coleoptera, Histeridae, Exosternini), ZooKeys 271, pp. 1-401 : 181-182

Operclipygus distinctus (Hinton 1935) Figs 48L49 A–BMap 17

Phelister distinctus Hinton, 1935a: 589; Operclipygus distinctus : Wenzel 1976: 257.

Type locality.

BRAZIL: Pará: Santarém [2°26'S, 54°42'W].

Type material.

Lectotype, here designated: "H.H. Smith" / "Santarem" / " Phelister distinctus Hntn." / "LECTOTYPE Phelister distinctus Hinton M.S.Caterino & A.K.Tishechkin des. 2010" (BMNH). This species was described from an unspecified number of specimens, and the lectotype designation fixes primary type status on the only known original specimen.

Other material.

BRAZIL: Pará: 1:IPEAN, Utinga, Belém, 1°27'S, 48°26'W, v.1985, FIT (CHND), 1: viii.1985, FIT (CHND), 1: xi.1984, FIT (FMNH); 1: Barcarena, 1°30'S, 48°37'W, 13-25.vi.1991, FIT (MSCC); 1: Tucuruí, 3°45'S, 49°40'W, 23. vi– 7.vii.1986, FIT (AKTC). ECUADOR: Orellana: 1: Yasuní Res. Stn., 00°40'28"S, 76°38'50"W, 215m, 5-10.ix.1999, FIT, primary forest, E.G. Riley (TAMU). FRENCH GUIANA: 1: Rés. Trésor, route de Kaw Pk18, 4°36.63'N, 52°16.74'W, 225m, 6.xi.2009, FIT, SEAG (MNHN); 1: Mont. Tabulaire, Itoupé, 3°1.32'N, 53°5.05'W, 800m, 17.iii.2010, FIT, SEAG (CHND); 1: Réserve des Nouragues, Régina, 4°2.27'N, 52°40.35'W, 3.xi.2009, FIT, SEAG (CHND). PERU: Madre de Dios: 1: Tambopata, 24.x.1982, rotten palm flowers, L. Watrous & G. Mazurek (FMNH).

Diagnostic description.

Length: 1.87-2.22 mm, width: 1.56-1.90 mm; body rufobrunneus to rufopiceous, elongate oval, moderately strongly convex; frons depressed, finely punctate, frontal portion of frontal stria detached from lateral; supraorbital stria complete, but narrowly detached from sides of frontal; epistoma slightly emarginate; labrum rectangular, about twice as wide as long; pronotum curved downward in anterior corners, nearly vertical on either side; pronotal disk lacking prescutellar impression, but strongly depressed across base; ground punctation of pronotal disk very fine and sparse, with ~15 shallowly impressed coarser punctures near sides; marginal pronotal stria obsolete for width of head; lateral submarginal stria complete, continuous with anterior submarginal stria; pronotal gland openings close together behind eye, between end of marginal stria and submarginal stria; elytra strongly swollen in subhumeral interval, with single complete epipleural stria, outer subhumeral stria complete, inner subhumeral stria present in apical half to three-fourths, frequently fragmented basally, rarely absent, striae 1-3 complete, 4th stria present in apical half, 5th stria present in apical third, sutural stria present in apical two-thirds, the sutural stria widening anteriorly; prosternal keel very weakly emarginate at base, carinal striae enclosing triangular area which is finely microsculptured, meeting anteriorly; mesoventrite faintly projecting, with complete marginal stria; mesometaventral arch nearly reaches mesoventral stria, sinuate near mesocoxae, continued by lateral metaventral stria posterolaterally toward middle of metacoxa, slightly curved outward at apex; central portion of metaventral disk weakly depressed on either side; 1st abdominal ventrite with single lateral stria; propygidium with large, elongate punctures separated by about their diameters; pygidial disk strongly convex, with dense, fine ground punctation and numerous conspicuous coarser punctures interspersed; marginal pygidial sulcus distinct, complete, crenulate, with distinct series of punctures within. Male genitalia largely indistinguishable from trhose of Operclipygus farctus (see Figs 48 A–D), except that S8 has its sides more strongly convergent, halves ventrally more strongly divergent along ventral midline, and apical guides narrower; tegmen curved ventrad in apical third(Fig. 48L), but not strongly bent as in Operclipygus farctus .

Remarks.

This species is the only previously described member of a small subgroup of four very similar species (including the following three), all of which have their pronotal gland openings very close together along the anterior margin. All are more or less piceous, and relatively strongly convex, with conspicuously dual punctation on the pygidium (Fig. 49B). Operclipygus distinctus has the most convex pygidium of the four, with the largest secondary punctures. It also lacks an outer lateral stria on the 1st abdominal ventrite, which the last two species in this subgroup have.