Operclipygus bulbistoma, 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 : 168-169

Operclipygus bulbistoma sp. n. Figs 45 F–GMap 16

Type locality.

MEXICO: Oaxaca: 26 km E Valle Nacional [18°2'N, 96°2'W].

Type material.

Holotype female: "MEX: Oax; 1220m, 26km E Valle Nacional, 25. VI– 2.VIII.83,km71, S&J.Peck, FIT, mont. trop. forest"/ “♀” / "Caterino/ Tishechkin Exosternini Voucher EXO-01296" (CMNC).

Diagnostic description.

Length: 1.78 mm, width: 1.12 mm; body rufobrunneus, very elongate, parallel-sided, subdepressed; frons flat, with sides of frontal stria more or less parallel between eyes, central part complete, arching dorsad at middle; supraorbital stria weak, fragmented at middle, detached from frontal stria; epistoma strongly convex, with conspicuous longitudinal waves of microsculpture on the sides; labrum rounded at sides, narrowing to apex, apex appearing narrowly emarginate, with an apical concavity encircled by a sharp carina; left mandible with prominent bifid tooth; right mandible with smaller but similar bifid tooth; pronotal disk with short, narrow, distinct prescutellar impression, but with longer vague depression extending forward in posterior half of disk; ground punctation fine, but relatively conspicuous, with ~15 coarser punctures at sides; lateral submarginal stria absent from sides, only present as short fragments in anterior corners that meet the anterior submarginal stria at a narrow angle; anterior marginal stria weak at front, interrupted behind head; anterior submarginal stria strongly recurved straight posterad reaching behind middle of pronotum; median pronotal gland openings beyond ends of anterior stria, about two-thirds pronotal length from anterior margin; elytra with one complete epipleural stria; outer subhumeral stria complete, inner subhumeral stria absent, striae 1-4 complete to base, striae 1-2 barely obsolete at apex, 5th stria present in apical third, sutural stria present in apical four-fifths, the 2nd-5th striae weakly expanded at apices; prosternal keel weakly produced at base, with very shallow median emargination, carinal striae faint, present in basal half only, not connected anteriorly or posteriorly; prosternal lobe lacking marginal stria; mesoventrite shallowly, broadly emarginate, with marginal stria mostly absent, only weakly present at sides; mesometaventral stria arched forward to near mesoventral margin, continued by lateral metaventral stria extending posterad to inner third of metacoxa; 1st abdominal ventrite with inner lateral stria complete, outer abbreviated and divergent posteriorly; profemur strongly produced along midanterior margin, the protibia correspondingly bent at middle; propygidium with moderately large, shallow ocellate punctures separated by about their widths; pygidium with fine, sparse ground punctation, coarser punctures ocellate, sparse, separated by slightly more than their diameters; marginal pygidial sulcus absent, although vague fragments of a marginal depression can be seen near apex. Male not known.

Remarks.

This species can be very easily recognized by its elongate body form (Fig. 45F), long recurved anterior submarginal stria, and by the strongly convex epistoma (Fig. 45G). Its relationships are obscure, and it is placed in the Operclipygus hospes species group only tentatively. Some superficial characters (mainly pronotal striae and general body form) might also suggest placement in the Operclipygus dubius group, and the position of the openings of the median pronotal glands and the near absence of prosternal striae would be highly apomorphic in either group. Discovery of a male would help to clarify this question.

Etymology.

The name of this species refers to its prominently convex epistoma.