Operclipygus baylessae, 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 : 309-311

Operclipygus baylessae sp. n. Figs 82 E–F83A–EMap 30

Type locality.

ECUADOR: Orellana: Yasuní Research Station [0°40.5'S, 76°24'W].

Type material.

Holotype male: "Ecuador: Napo, mid.Rio Tiputini, Yasuní Res. Stn. 0°40.5'S, 76°24'W, FIT#M2 20-29 Jun 1999. CEC#030 C.Carlton & V.Moseley" / "LSAM 0013234" / “LSAM0045734” (FMNH).

Diagnostic description.

Length: 1.93 mm, width: 1.62 mm; body rufobrunneus, elongate oval, subdepressed, generally smooth, but with conspicuous pronotal ground punctation; frons weakly depressed at middle, with conspicuous ground punctation and very faint granulate microsculpture; frontal stria rounded at sides, slightly sinuate across front; epistoma mostly flat, weakly emarginate at apex; labrum about twice as wide as long, rounded at sides, weakly emarginate apically; left mandible with weak, blunt basal tooth, right mandible concealed in type; pronotum lacking discrete prescutellar impression, but with ground punctation coarser and denser toward prescutellar region; pronotal disk lacking coarse lateral punctures, but with faint granulate microsculpture throughout; marginal pronotal stria broadly interrupted behind head; lateral submarginal pronotal stria complete along side, close to margin, weakly carinate, barely curved inward in front; anterior submarginal pronotal stria absent; median pronotal gland openings behind eye on each side, about 8 puncture widths behind anterior pronotal margin; elytron with single epipleural stria, outer subhumeral stria complete, subcarinate, forming weak lateral elytral margin, inner subhumeral stria absent, dorsal striae 1-5 complete, sutural stria complete and distinctly widened toward base; elytral interstriae with very faint granulate microsculpture; prosternal keel weakly produced at base, carinal striae divergent posteriorly, slightly shortened in front, meeting in narrow anterior arch; prosternal lobe rounded, marginal stria complete; anterior margin of mesoventrite broadly emarginate, marginal stria complete; mesometaventral stria narrowly arched forward to about mesoventral midpoint, angulate near mesocoxa, continued by lateral metaventral stria to near metacoxal midpoint; 1st abdominal ventrite with two complete lateral striae; propygidium and pygidium with fine ground punctation, propygidium with very sparse, small secondary punctures, pygidium lacking secondary punctures; marginal pygidial sulcus fine, complete. Male genitalia (Fig. 83 A–E): accessory sclerites present; T8 with sides evenly convergent to apex, apical emargination narrow, basal emargination subtriangular, not reaching basal membrane attachment line, ventrolateral apodemes most strongly developed basally, narrowed to apex, nearly meeting at midline; S8 elongate, sides subparallel, apical guides evenly developed throughout length, ventral halves separate, weakly divergent to apex; T9 with sides subparallel in basal half, weakly convergent to apex, apices narrow, abruptly inturned; T10 with halves separate; S9 broad, sides subparallel in basal half, base rounded, apex lacking median emargination, apical flange continuous though weakly narrowed medially, basolateral corners weakly prolonged; tegmen narrow, with sides rounded, widest near midpoint, ventromedial projection weak, ‘U’ -shaped, barely projecting beneath about one-third from base; median lobe about one-third tegmen length, proximal apodemes not obviously differentiated; basal piece almost one-half tegmen length.

Remarks.

The placement of this species in the Operclipygus marginellus group follows from the phylogenetic results, and several characters support it. However, it is unusual in numerous characters too, and deserves further investigation. It may be easily recognized by the presence of a complete, fine pygidial sulcus (Fig. 82H), the complete elytral striae (Fig. 82E; minus inner subhumeral), especially the characteristically basally widened sutural stria, and by the increased density of pronotal punctures in the prescutellar region.

Etymology.

We name this species in honor of Victoria Moseley Bayless, curator of the Lousiana State Arthropod Museum and co-collector of the unique type of this species.