Operclipygus cavisternus, 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 : 352-353

Operclipygus cavisternus sp. n. Figs 97 A–E98A–CMap 33

Type locality.

GUYANA: Region 8: 1 km W Kurupukari, Iwokrama Field Station [4°40.32'N, 58°41.07'W].

Type material.

Holotype male: "GUYANA: Region 8, Iwokrama Forest, 1 km W Kurupukari, Iwokrama Forest Field Stn., 60 m, 4°40'19"N, 58°41'4"W, 20-25 MAY 2001 R. Brooks,Z.Falin GUY1BF01 034 ex: flight intercept trap"/ "SM0565892 KUNHM-ENT" (SEMC). Paratypes (3): GUYANA: Region 8: 1: Iwokrama Field Stn., Iwokrama Forest, 1km W Kurupukari, 4°40'19"N, 58°41'4"W, 60m, 20-25.v.2001, FIT, R. Brooks & Z. Falin (SEMC). SURINAME: Sipaliwini: 1: CI-RAP Surv. Camp 3: Wehepai SE Kwamala, 2°21.776'N, 56°41.861'W, 237m, 3-7.ix.2010, FIT, T. Larsen & A.E.Z. Short (SEMC); 1: upper Palumeu, 225m, 2.47700°N, 55.62941°W, CI-RAP Survey camp 1, FIT, 10-16.iii.2012, A.E.Z. Short (MSCC).

Other material.

BRAZIL: Pará: 3: IPEAN, Belém, Utinga, 1°27'S, 48°26'W, viii.1985, FIT (CHND, MNHN, AKTC); 1: Tucuruí, 3°45'S, 49°40'W, 24.iii-11.iv.1985, FIT (CHND). COLOMBIA: Vaupés: 1: Parque Nac. Mosiro-Itajura ( Caparú), Centro Ambiental, 1°04'S, 69°31'W, 60m, 20-30.i.2003, FIT, D. Arias & M. Sharkey (IAVH).

Diagnostic description.

Length: 1.78-1.84 mm, width: 1.50-1.53 mm; body rufo-brunneus, broadly oval, widest near elytral midpoint; frons only very weakly depressed at middle, frontal stria rounded at sides, weakly sinuate over antennal bases, weakly arcuate across front; epistoma convex anteriorly; labrum about twice as wide as long, shallowly emarginate along apical margin; pronotal disk with small, shallow, elongate prescutellar impression, fine sparse ground punctation medially, and moderately numerous (~12) coarser, shallow punctures toward sides; marginal pronotal stria interrupted behind head; lateral submarginal stria complete, curved inward at front, nearly reaching weakly recurved ends of anterior submarginal stria; lateral marginal bead of pronotum convex; median pronotal gland openings situated just beyond recurved ends of anterior stria, about 6-8 puncture widths from margin; elytron with one complete epipleural stria, sinuate at middle and crenulate throughout its length, outer subhumeral stria interrupted at middle, rarely with short basal fragment, inner subhumeral stria complete, striae 1-3 complete, 4th stria present in apical half, 5th stria present in apical third, sutural stria present in apical three-fourths; prosternal keel rather broad, flat, very weakly produced at base, carinal striae complete, weakly converging, connected in anterior arch; pronotal lobe with marginal stria complete; anterior mesoventral margin shallowly emarginate at middle, marginal stria complete; mesometaventral stria weakly arched forward, reaching to about basal third of mesoventral disk, continued at sides by lateral metaventral stria posterolaterad toward rear corner of metepisternum; metaventral disk impunctate, with paired, broad, shallow depressions near posterior margin; 1st abdominal ventrite with two complete lateral striae; propygidium with fine, sparse ground punctation, uniformly covered with larger punctures separated by slightly less than their diameters; pygidium with coarse, fine ground punctation and larger punctures fairly coarsely interspersed; marginal pygidial sulcus complete, even, fine but moderately deep. Male genitalia (Figs 97 A–E): accessory sclerites present, somewhat reduced in size; T8 with sides evenly convergent to near apex, apices broadly rounded, basal apodemes rounded, basal emargination broad, deep, nearly reaching basal membrane attachment line, ventrolateral apodemes most strongly developed near base, diverging to apex, not meeting at midline; S8 elongate, with sides subparallel, apical guides narrow, even throughout length, apices narrowly rounded, halves separate, weakly divergent to apex; T9 with apices weakly enlarged near tip, inturned, subacute; T10 with halves separate; S9 stem narrow, barely widened to narrowly rounded base, apex with narrow median emargination, apical flanges low, separate; tegmen widest at middle, sides rather straight, converging to base and apex, apices narrowly rounded, weakly curved ventrad in apical half, medioventral process narrow, ‘V’ -shaped, projecting beneath about one-fourth from base; basal piece about one-third tegmen length; median lobe nearly one-half tegmen length, proximal apodemes separate.

Remarks.

The shallow depressions of the metaventrite of this species (Fig. 98B), although shallow and not very conspicuous, are unusual and distinctive (and not limited to either sex, as such depressions may sometimes be in Exosternini ). This character, in combination with small size, complete, fine, deep pygidial sulcus (Fig. 98C), and complete inner subhumeral stria will distinguish the species. We limit the type series to specimens from the Guianas, which all have a complete frontal stria. Slight variation in specimens from other areas should be investigated more fully.

Etymology.

This species’ name refers to the distinctive impressions on either side near the posterior margin of the metaventrite.