Operclipygus subsphaericus, 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 : 331-332

Operclipygus subsphaericus sp. n. Figs 91 C–DMap 31

Type locality.

BRAZIL: São Paulo: São Miguel [24°01'S, 48°00'W].

Type material.

Holotype female: “BRASIL:São Paulo, São Miguel, Elev.800m. Turvo-River.XII-1963, 24°01 ’[S]-48°00’ [W], F. Plaumann leg."/ "FMNH-INS 0000069135" / “♀” / "Caterino/Tishechkin Exosternini Voucher EXO-01341" (FMNH). Paratype (1, probably a male, but genitalia missing): BRAZIL: Rio de Janeiro: Represa do Rio Grande, Guanabara, iii.1972, F.M. Oliveira (UFPR).

Diagnostic description.

Length: 1.50-1.53 mm, width: 1.31-1.37 mm; body small, rounded, nearly circular, generally impunctate, faintly bicolored, head, pronotum, venter and pygidia rufescent, elytra piceous; head vertical when retracted; frons flat, relatively narrow, sides rounded, central portion of frontal stria outwardly arcuate, sinuate over antennal bases, complete or narrowly interrupted at sides; epistoma flat; labrum about twice as wide as long, apical margin straight; pronotum wide, sides evenly rounded to anterior corners; pronotal disk with basal plicae present in front of 3rd elytral stria, short; small, irregular but distinct prescutellar impression present, disk otherwise with fine, sparse ground punctation, no coarser punctures present; lateral marginal stria interrupted behind head; lateral submarginal pronotal stria complete, close to margin, curved inward anteriorly nearly to anterior submarginal stria, which is crenulate, narrowly recurved posterad at sides; median pronotal gland openings situated between free ends of submarginal striae, about 6 puncture widths from anterior margin; elytron with single complete epipleural stria, outer subhumeral stria present in apical half, laterad humeral swelling, inner subhumeral absent, dorsal striae 1-3 complete, 4th stria present in apical two-thirds, 5th stria present in apical half, sutural stria present in apical two-thirds; prosternal keel weakly emarginate at base, carinal striae converging to front, connected anteriorly but not basally; mesoventrite projecting at middle, marginal stria complete; mesometaventral stria arched forward at middle, sinuate near mesocoxae, continued by lateral metaventral stria, which curves posterolaterad toward middle of metepimeron; metaventral disk impunctate at middle, with few coarse lateral punctures; 1st abdominal ventrite with single arcuate inner lateral stria, and weak series of small punctures along posterior margin; propygidium with ground punctation very sparse, coarser shallow, round punctures in basal two-thirds, denser and larger toward base, apical third impunctate; pygidium with very small, sparse punctures separated by 4' their diameters or more, diminishing to apex; apical marginal stria fine, present on apical half, obsolete at base. Male: genitalia not known.

Remarks.

The small size and strongly convex body of this species (Fig. 91C) is practically diagnostic among Operclipygus . In addition the faint bicoloration, propygidium with coarse punctures restricted largely to the basal half (Fig. 91D), and the fine, incomplete marginal pygidial sulcus will help identify it. The paratype specimen is probably a male (genitalia were dissociated while in bulk sample, evidently), exhibiting a depressed metaventral disk, a fairly common sexual dimorphism. This specimen differs in a few other minor characters, most noteably lacking any indication of darker elytra, and also having the marginal mesoventral stria interrupted at the middle. With single specimens from each of two localities, it is impossible to interpret the significance of these characters.

Etymology.

This species’ name refers to its unusually rounded and convex body form, quite distinctive within Operclipygus .