Osoriellus parcus ( SHARP, 1887 ) Irmler, 2014

Irmler, Ulrich, 2014, The Neotropical species of the genus Osoriellus FAGEL, 1959 (Coleoptera: Staphylinidae: Osoriinae), Beiträge Zur Entomologie = Contributions to Entomology 64 (2), pp. 231-354 : 281-282

Osoriellus parcus ( SHARP, 1887) new combination

( Figs 80 A-C, 99E)

Osorius parcus SHARP, 1887: 680

Type material examined: Guatemala: Panzos (89°37'W, 15°24'N), 3 specimens, leg. Champion (syntypes in BMNH) .

Further material examined: Mexico: Mexico City (99°07'W, 19°25'N), Desiertos de los Leones D.F. side Rio Mala , 1 specimen, 23.04.1946, leg. J. Pallister ( AMNH) ; San Antonio (92°46'W, 16°16'N), Volcan Tacaná, leaf litter beside Rio Mala , 9 specimens, 20.12.1976, leg. H. Frania ( AMNH, UIC) ; Union Juarez , NW slope Vulc. Tacaná (92°06'43"W, 15°07'58"N), Barranca Providencia , 1540 m elevation, 4 specimens, 25.12.1976, leaf litter flat area nr. stream, montane trop. forest, 1 specimen, 17.12.1975, Sumidero San Antonio, under moss and large rock, montane trop. forest, 1760 m elevation, 1 specimen, 20.12.1975, Pico Gallo, leaf litter, seepage area, montane trop. forest, 1700 m elevation, leg. H. Frania ( AMNH) ; Tamaulipas (98°55'50"W, 21°09'56"N), 6 mi NW Gomez Farias, Ranch del Cielo , human dung traps, 1230 m elevation, 1 specimen, 4.7.1969, leg. J. Peck ( AMNH) ; Palenque (91°58'W, 17°29'N), Ruines , stump litter, 1 specimen, 6.4.1974, leg. C. Alteri ( AMNH) ; Chiapas, Volcan Tacaná, sumidero San Antonio, leaf litter beside Rio Mala , 1760 m elevation, male, 20.12.1976, leg. H. Frania ( AMNH) ; Tamaulipas, shaded sand gravel banks of Nacimento Rio Frio , 4.5 mi SSE Gomez Farias, male, 4.01.1972, leg. H. Frania ( AMNH) ; Chiapas, 2 mi NE Tenejapa, 30 mi ENE Tuxtla Gutierrez , in debris filled cracks of large rocks (92°22' W, 16°50'N), 2300 m elevation, male 30.12.1972, leg. H. Frania ( AMNH) ; Union Juarez (92°04'W, 15°03N), 4 km N, lower slopes, cloud forest litter, 1950 m elevation, 16 specimens, 18.9.1992, leg. R. Anderson ( KNHM, UIC) ; San Luis Potosi, Tlamaya (nr. Xilitla ), 1 specimen, 01.09.1991, leg. D. Yanega ( KNHM) ; Motozintla (92°14'W, 15°21'N), 7.4 km SSW, cloud forest litter, 4 specimens, 17.09.1992, leg. R. Anderson ( KNHM) ; Jalapa , 2.3 km S, deep litter in rock cracks, 1320 m elevation, 1 specimen, 18.07.1992, leg. J.S. Ashe ( KNHM) ; Bazóm, Chiapas, Mpio., Huixtán , mixed magnolia/oak forest litter, 1 specimen, 09.07.2003, leg. R. Anderson ( KNHM) ; Guatemala: Quezaltenango , 14.4 km SW Zunil, 1340 m elevation, 1 specimen, 18.06.1993, leg. J.S. Ashe ( KNHM) ; Panzos , 2 specimens without further data, leg. G.C. Champion ( AMNH) .

Diagnosis: O. parcus is similarly sized as O. sexpunctatus and O. majusculus . In O. sexpunctatus the pronotum is more convergent from anterior angles to posterior angles than in O. parcus . Furthermore, the setiferous punctation of the pronotum is denser than in O. sexpunctatus , and the protibia is strongly digitate at outer edge. Compared to the similar O. rougemonti , O. parcus is larger and the pronotal punctation is denser and the punctures smaller.

Description: Length: 7.2 mm. Colouration: Black; legs and antennae reddish.

Head: 1.00 mm long, 1.50 mm wide; eyes not prominent; angles of clypeus produced to short granules; anterior edge slightly emarginate; setiferous and granulate punctures irregularly dense; moderately wide midline and area at base of antennae impunctate; on average, interstices between punctures as wide as or slightly wider than diameter of punctures; supraocular punctures coriaceous; dense netlike microsculpture distinct; surface slightly shiny.

Antennae with first antennomere slightly shorter than four following antennomeres; second antennomere oblong; longer than wide and nearly as long as conical third; following three antennomeres increasing in width, but decreasing in length; sixth antennomere quadrate; following four antennomeres slightly wider than sixth antennomere; approximately quadrate; last antennomere smaller than penultimate antennomere.

Pronotum: 1.30 mm long, 1.40 mm wide; widest at anterior angles; anterior angles slightly produced to short teeth; evenly convergent to posterior angles; more distinctly convergent in posterior third; lateral margin fine; setiferous punctures distinctly larger than on head and not granulate; along impunctate midline in irregular rows; adjacent to midline punctures partly coriaceous; laterally sparser; on average, interstices between punctures shorter than or as wide as diameter of punctures; fine microsculpture netlike; sparse micro-punctation present. Elytra: 1.50 mm long, 1.50 mm wide; coriaceous groundsculpture; punctures deep, in irregular rows.

Abdomen with dense setiferous punctation and narrow impunctate midline; weak isodiametric microsculpture; surface shiny.

Protibia: 0.79 mm long, 0.35 mm wide; 10 spines on outer edge; apical 4 spines on short digits; WLR: 1.40; in posterior aspect; comb at inner emargination visible throughout its total length; posterior face with moderately dense setation.

Aedeagus with slender apical lobe widely curved to acute apex; at inner edge of apical lobe slightly sinuate at base.

Figures

Fig. 79-83: Osoriellus-s. str.-group: Osoriellus debilis (79), O. parcus (80), O. schwarzi (81), O. trapezoides (82), O. opacus (83); antenna (A), protibia (B), aedeagus in lateral aspect (C); scale bar: 0.1 mm.