Plochionocerus humeralis Sharp 1885
Creators: name: Asiain, Julieta
name: Márquez, Juan
name: Morrone, Juan J.
Publisher: name: Zenodo
Year: 2007
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Plochionocerus
Plochionocerus humeralis

description: Plochionocerus humeralis (Sharp, 1885)
Sterculia humeralis Sharp, 1885: 469; Fauvel, 1891: 106 (Sterculia); Herman, 2001: 3745 (Plochionocerus). Sterculia kayseri Bernhauer, 1927: 163; Herman, 2001: 3745 (Plochionocerus), syn. nov.
Type material (11 specimens). Lectotype of Sterculia humeralis by present designation, male: “ Sterculia humeralis, Type, D.S., V. Chiriqui, 3–4000 ft., Champion (specimen on card) / Type / V. Chiriqui, 3–4000 ft., Champion / B. C. A. I. 2. Sterculia humeralis, Sharp / Sharp Coll. 1905–313 / Syntype / Lectotype Sterculia humeralis Asiain, Márquez & Morrone des. 2007” (BMNH). Paralectotypes of Sterculia humeralis: “ Sterculia humeralis, D.S., V. Chiriqui, 3–4000 ft., Champion, V. Chiriqui, 3–4000 ft., Champion (specimen on card) / B. C. A. I. 2. Sterculia humeralis, Sharp / Sharp Coll. 1905–313 / Syntype / Paralectotype Sterculia humeralis Asiain, Márquez & Morrone des. 2007” (BMNH, Ψ); “V. de Chiriqui, 3–4000 ft., Champion / B. C. A. CoI. I. 2. Sterculia humerali s, Sharp / Paralectotype Sterculia humeralis Asiain, Márquez & Morrone des. 2007” (BMNH, ɗ); “ Sterculia humeralis, D.S., V. Chiriqui, 25–4000 ft., Champion (specimen on card) / Sp. figured / V. Chiriqui, 25–4000 ft., Champion / B. C. A. I. 2. Sterculia humeralis, Sharp / Sharp Coll. 1905–313 / Syntype / Paralectotype Sterculia humeralis Asiain, Márquez & Morrone des. 2007” (BMNH, ɗ); “ Sterculia humeralis, D.S., V. Chiriqui, 25–4000 ft., Champion (specimen on card) / V. Chiriqui, 25–4000 ft., Champion / B. C. A. I. 2. Sterculia humeralis, Sharp / Sharp Coll. 1905–313 / Syntype / Paralectotype Sterculia humeralis Asiain, Márquez & Morrone des. 2007” (BMNH, Ψ, ɗ); “V. Chiriqui, 25–4000 ft., Champion / B. C. A. I. 2. Sterculia humeralis, Sharp / Syntype / Paralectotype Sterculia humeralis Asiain, Márquez & Morrone des. 2007” (BMNH, 2ɗɗ); “Medellin, Colombia (specimen on card) / B. C. A. Col. I. 2. Sterculia humeralis Sharp / Sharp Coll. 1905–303 / Syntype / Paralectotype Sterculia humeralis Asiain, Márquez & Morrone des. 2007” (BMNH, ɗ). Lectotype of Sterculia kayseri by present designation, male: “ Venezuela / kayseri Brnh. Cotypus. Mus. Ger. / Chicago NH Mus M. Bernhauer Collection / Lectotype Sterculia kayseri Asiain, Márquez & Morrone des. 2007” (FMNH); Paralectotype, male: “Venezuel / kayseri / Sterculia kayseri Brnh. Cotypus. Mus. Ger. / Chicago NH Mus M. Bernhauer Collection / Paralectotype Sterculia kayseri Asiain, Márquez & Morrone des. 2007” (FMNH).
Additional material (106 specimens). BRAZIL: Jabatinga, 18.X.1904, Ducke (FMNH, ɗ). COLOM- BIA: no locality data (IRSNB, Ψ). COSTA RICA: Prov. Puntarenas, Fca. Cafrosa, Est. Las Mellizas, P. N. Amistad, LS 316100 596100, 1300 m, V.1990, M. Ramírez & G. Mora (INBC, Ψ, 4ɗɗ); idem, except: V.1991, M. Ramírez (INBC, 3ɗɗ); idem, except: VI.1991 (INBC, Ψ); Prov. Guanacaste, Est. Pitilla, 9 km S Santa Cecilia, 330200, 380200, 700 m, VII.1988, GNP Biodiversity Survey (INBC, Ψ); Heredia, San Rafael, centro, 10.VI.1984, E. Carvajal (INBC, ɗ); Prov. Limón, Res. Biol. Hitoy Cerere, Est. Hitoy Cerere, send Bobócara, LN 184250 641800, 300 m, 16.IV.2000, W. Arana, Intersección (INBC, Ψ); no locality data (FMNH, Ψ); San José, San Antonio de Escazu, 9°39’16”N, 84°9’16”W, 1300 m, 1–30.IX.1998, W. Eberthard & P. Hanson (SEMC, Ψ); Puntarenas, Las Alturas Field Station, 20 km N San Vito de Hava, 1400 m, 1–5.VII.1991, DeVries, malaise trap (AMNH, Ψ); idem, except: 20–24.V.1991 (AMNH, ɗ). ECUADOR: Napo, Rio Hollin, 1100 m, 3–5.XII.1994, N. Oleas (QCAZ, 2ɗɗ); Napo, Cotococha, 860 m, 15.IV.1995, X. Cisneros (QCAZ, ɗ); Napo, Archidona, 500 m, 10.IV.1993, C. Segovia (QCAZ, ɗ); Napo, Coca, VII.1986, E. Martínez (QCAZ, ɗ); Napo, Jatun Sacha, 400 m, 6.XII.1994, I. Benitez (QCAZ, ɗ); Pichincha, Sto. Domingo, IV.1973, N. Venedicto (QCAZ, 1?); Dos Rios, 9.IV.1963, L. Peña (FMNH, 3ɗɗ); Tena, 16.III.1923, F. X. Williams (FMNH, 1?, ɗ); Pompeya, V.1965, L. Peña (FMNH, ɗ; CC-UAEH, ɗ); Quito (FMNH, ɗ); Macas, Buckley (FMNH, ɗ); West-Ecuador, Ejanus, Rolle (FMNH, ɗ, Ψ); Pastaza, Cushueme, Rio Cushueme, 150 km SE Puyo, 1– 2.VII, B. Malkin (FMNH, Ψ); Jatun Yacu, 700 m, III.1937 (BMNH, ɗ); Jatun Yacu, Rio Nabo, Watershed, 700 m, I.1937 (BMNH, ɗ); Quito (BMNH, ɗ); Guilca, Nr. Macas, L. Gomez, Colcófn (BMNH, ɗ); Prov. Loja, Zamora, C. Carrión (BMNH, Ψ); Loja, 1.III.1889 (BMNH, ɗ); no locality data, Buckley, 1879 (BMNH, 3ΨΨ, 9ɗɗ); no locality data (BMNH, ɗ); no locality data, L. Gomez (BMNH, ɗ, Ψ); El Partidero, 16.XI.1935, W. Macintyre (AMNH, ɗ); Morona, Santiago, Puyo-Macas Rd., 950 m, 13.2 km SW Pastaza R. (logging road), 26.IX.1995, D. Brzoska (SEMC, ɗ); Pastaza, Pto. Sta. Ana, Rio Pastaza, 01°39.7’S, 77°57.9’W, 23.X.1998, D. Brzoska (SEMC, ɗ); Zamora-Chinchipe, Rio Bombuscaro, 4°7’0”S, 78°59’0”W, 26.VI–4.VII.1996, P. Hibbs, ex: flight intercept trap (SEMC, Ψ); no locality data, Baron (IRSNB, 1?); Laja (IRSNB, 1?). GUATEMALA: no locality data (IRSNB, Ψ). PANAMA: V. de Chiriqui, 3000–4000 ft., Champion (FMNH, ɗ); V. de Chiriqui, 4000–6000 ft., Champion (FMNH, ɗ); Chiriqui?, Bang. Haas (FMNH, Ψ); no locality data, Eing, 1925 (FMNH, Ψ). Chiriqui (FMNH, Ψ; IRSNB, Ψ, ɗ); Chiriqui, 20 km N Gualaca, Finca La Suiza, 1350 m, 08°39’N, 82°12’W, 24.V.–9.VI.1995, J. Ashe & R. Brooks, ex: flight intercept trap (SEMC, Ψ). PERU: Middle Rio Ucayali, 14.XII.1923 (AMNH, 2ɗɗ, Ψ); Rio Santiago, 21.XI.1928 (AMNH, 3ɗɗ); idem, except: 13.VIII.1930 (AMNH, 1?); Middle Rio Maranon, IX.1929 (AMNH, ɗ); Iquitos (AMNH, 2ɗɗ, 2?); no locality data (BMNH, ɗ); Archid., Bowring (BMNH, 1?); no locality data (FMNH, Ψ); no locality data (BMNH, 1?); Archidona (BMNH, ɗ); no locality data (BMNH, ɗ). USA: California (BMNH, ɗ). VENEZUELA: Lara Sanaré, 17.4 km SE Yacambú N. P., 1510 m, 9°42’26”N, 69°34’34”W, 18.V.– 1.VI.1998, J. Ashe, R. Brooks & R. Hanley, ex: flight intercep trap (SEMC, 2ɗɗ, Ψ); no locality data (BMNH, 3ɗɗ; FMNH, 2ɗɗ); Caracas, Waterhouse (BMNH, 1?); no locality data, Buq Varcas (BMNH, Ψ); Caracas (BMNH, Ψ; IRSNB, Ψ, 2?); Orénoque (IRSNB, 1?); Merida (FMNH, ɗ; CC-UAEH, ɗ). TOBAGO: Roxborough (10 km NE), Gilpin Trail, 400–500 m, montane rain forest, 26–31.VI.1993, flight intercept trap, S. & J. Peck (FMNH, ɗ); no locality data, Nova Granada (FMNH, ɗ).
Diagnosis. Total length 19.8–26.0 mm; metallic violet-blue, green or a combination of both; head rectangular, 1.31–1.41 times as long as wide, moderately wider than pronotum (1.05–1.16 times), dorsal and ventral surface of head flat (Fig. 13), ventrally with dense, expanded, umbilicate punctures (20–29 in each half of head), arranged in “v” (similar to Fig. 50); antennomere 9 shorter than antennomere 10 in males (0.81–0.90 times), apical antennomere in males conspicuously longer than wide (1.66–2.00 times), as long as antennomeres 9+10 combined (0.96–1.15 times; Fig. 25); mandibles with basal external channel (Fig. 63); pronotum 1.47–1.58 times as long as wide, shorter than elytra (0.77–0.83 times their length), with two clearly visible depressed areas in posterior third (Fig. 56); prosternum moderately transverse (length/width: 0.83–0.95); and aedeagus pear-shaped, length 4.30–5.86 mm, parameres moderately long (0.30–0.32 times as long as median lobe), apical areas of median lobe 0.25–0.29 times as long as the total length of median lobe, and internal sac moderately visible (Fig. 81).
Variation. Most of the specimens are entirely metallic blue, but in a few individuals the head, pronotum and elytra are metallic blue, and the abdomen metallic green or has violet reflections. More than 50% of the specimens examined have a well-developed external mandibular channel and the remainder has it reduced. A few specimens have less than 20 expanded, umbilicate punctures in each half of the head.
Comparative notes. Based on the revision of the types, P. kayseri (Bernhauer, 1927) is a junior synonym of P. h u m e r a l i s (Sharp, 1885). The species can be confused with P. fulgens. For both species the head is rectangular and conspicuously oblong, the apical antennomere in males is almost as long as antennomeres 9+10 combined, and the aedeagus is pear-shaped. They can be distinguished because in P. h u m e r a l i s the head is flat dorsally and ventrally, the ventral surface has dense, expanded, umbilicate punctures (20–29 in each half of the head), antennomere 9 in males is shorter than antennomere 10, and the internal sac of the aedeagus is moderately conspicuous. It is separated easily from other species with a rectangular or subquadrate, dorsally and ventrally flat head (as P. impressipennis, P. janthinus and P. puncticeps) because the apical antennomere in males of these species is shorter than antennomeres 9+10 combined.
Geographical distribution. Costa Rica, Brazil, Tobago, Ecuador, and Peru (first national records), USA and Guatemala (first national records with doubt, possibly due to erroneous labels, to be confirmed from BMNH and IRSNB, respectively), Panama, Colombia, and Venezuela (Herman 2001).
description: Published as part of Asiain, Julieta, Márquez, Juan & Morrone, Juan J., 2007, Phylogenetic systematics of the genera Plochionocerus Dejean and Agrodes Nordmann (Coleoptera: Staphylinidae: Xantholinini), pp. 1-53 in Zootaxa 1584 on pages 17-19, DOI: 10.5281/zenodo.178410