Operclipygus impressicollis, Caterino, Michael S. & Tishechkin, Alexey K., 2013

Caterino, Michael S. & Tishechkin, Alexey K., 2013, A systematic revision of Operclipygus Marseul (Coleoptera, Histeridae, Exosternini), ZooKeys 271, pp. 1-401 : 221-222

Operclipygus impressicollis sp. n. Fig. 59AMap 21

Type locality.

COSTA RICA: Puntarenas: Las Cruces Biological Station [8°47'N, 82°57'W].

Type material.

Holotype male: "COSTA RICA: Puntarenas, San Vito, Las Cruces, F.I.T. 1,200m. 1-30 July 1982 B.D.Gill leg."/ "Caterino/Tishechkin Exosternini Voucher EXO-00549" (CNCI). Paratypes (10): same data as type, except as noted: 5: 17. vii– 12.ix.1982 (BDGC, FMNH, MSCC, AKTC), 1: 7-14.viii.1982 (CHSM); COSTA RICA: Puntarenas: 1: Las Alturas Biol. Sta., 08°56.17'N, 82°50.01'W, 1660m, 31. v– 3.vi.2004, FIT, J.S. Ashe, Z. Falin, I. Hinojosa (SEMC); Alajuela, 2: Peñas Blancas, 800m, 19.v.1989, FIT, J. Ashe, R. Brooks, R. Leschen (SEMC); 1: La Selva Biol. Stn., 10°26'N, 84°01'W, 21.vi.1998, FIT, C.E. Carlton & A.K. Tishechkin (LSAM).

Other material.

COSTA RICA: Puntarenas: 3: Est. Biol. Las Cruces, San Vito, 1200m, 1-30.vii.1982, FIT, B.D. Gill; 1: Las Alturas Biol. Sta., 08°56.17'N, 82°50.01'W, 1660m, 31. v– 3.vi.2004, FIT, J.S. Ashe, Z. Falin, I. Hinojosa (SEMC); Alajuela: 1: Peñas Blancas, 800m, 19.v.1989, FIT, J. Ashe, R. Brooks, R. Leschen (SEMC); 1: Reserva Biol. San Ramon, 27km. N. & 8km. W. San Ramon, 10°13'4"N, 84°35'46"W, 810m, 8.vii.2000, FIT, J. Ashe, R. Brooks, Z. Falin (SEMC); Heredia: 1: 16km SSE La Virgen, 10°16'N, 84°05'W, 1050-1150m, 9-14.iii.2001, FIT, primary forest, E.G. Riley (TAMU); 1: La Selva Biol. Stn., 10°26'N, 84°01'W, 21.vi.1998, FIT, C.E. Carlton & A.K. Tishechkin (LSAM), 1: 27.vi.1998 (LSAM), 1: 29.vi.1998 (LSAM), 1: 5.ii.1992, FIT, W. Bell (SEMC), 1: 11.iii.1992 (SEMC).

Diagnostic description.

Length: 2.00-2.03 mm, width: 1.62-1.72 mm; body rufescent, elongate oval, not strongly convex; frons and epistoma strongly depressed at middle, antennal bases prominent, frontal disk with moderately dense, conspicuous ground punctation; frontal stria rounded at sides, sinuate over antennae, weakened and variably interrupted at front; antennal club elongate, twice as long as wide, and twice as long as funicle; labrum about twice as wide as long, weakly emarginate apically; pronotal disk with very fine punctiform or narrowly linear prescutellar impression, fine, sparse ground punctation, and ~10 coarser lateral punctures; marginal pronotal stria not descending to hypomeron, often effaced in anterior half; submarginal pronotal stria continuous along anterior margin, reaching middle of pronotal side, usually obsolete in basal half; male pronotum with shallow, well-defined depression along and behind anterolateral portion of submarginal pronotal stria, the depression delimited posteriorly by a very finely crenulate stria parallel to submarginal stria which converges to submarginal stria at middle of pronotal side; female pronotum faintly or not at all depressed; elytra with two complete epipleural striae, outer subhumeral stria present in apical third, inner subhumeral stria absent, striae 1-4 complete, 5th stria present in posterior on-third or slightly more, sutural slightly longer; most of venter with microsculpture, only faint to lacking along metaventral midline; prosternal keel weakly emarginate at base, broad, with carinal striae well separated, depressed, prosternal lobe apex appearing slightly reflexed; mesoventrite very weakly projecting at middle, with marginal stria broadly interrupted; mesometaventral stria strongly arched forward to near mesoventral margin; metaventrite markedly convex in middle of basal half (in both sexes); lateral metaventral stria extending toward outer corner of metacoxa, but generally abbreviated just behind middle; lateral striae of 1st abdominal ventrite variable, never complete; propygidium and pygidium both with dense microsculpture; propygidium with moderately large punctures mainly in basal half; pygidium with fine sparse ground punctation, and few slightly larger punctures inconspicuously intermingled; marginal pygidial stria fine, obsolete in basal half or more. Male genitalia essentially indistinguishable from those of Operclipygus rufescens (see Figs 57 A–D, L).

Remarks.

This species is difficult to characterize due to a sexual dimorphism. The males are easy to recognize by a narrow, discrete depression along the anterior half of the lateral submarginal stria, where the depression is delimited by a secondary stria, which abruptly converges to the margin at the middle (Fig. 59B). The depression continues behind the anterior portion of the submarginal stria, but is not as clearly delimited. In the females there is a narrower and vague impression, but this is not very distinct from one present in a couple related species (e.g. Fig. 58A). In both sexes the anterior and lateral portions of the submarginal pronotal stria are continuous, the lateral part ending near the pronotal midpoint. They are also among the most microsculptured species, with strong microsculpture on the pygidium and propygidium, as well as most of the venter, just effaced close to the metaventral midline. Due to slight uncertainty in association, we limit the type series to male specimens.

Etymology.

The name of this species refers to the depression behind the submarginal pronotal stria, which is especially noteworthy in males.