Plochionocerus janthinus Erichson 1847
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 janthinus

description: Plochionocerus janthinus (Erichson, 1847)
Agrodes janthinus Erichson, 1847: 88; Bernhauer & Schubert, 1914: 315 (Sterculia); Herman, 2001: 3745 (Plochionocerus).
Sterculia peruviana Bernhauer, 1907: 284; Herman, 2001: 3746 (Plochionocerus), syn. nov.
Type material (2 specimens). Lectotype of Agrodes janthinus by present designation, female: “5796 / Peru mont. Phil / janthina / Hist. Coll. (Coleoptera) Nr. 5796 Sterculia janthina N. Peru mont., Phil. Zool. Mus. Berlin / Syntypus Agrodes janthinus Erichson, 1847 labelled by MNHUB 2006 / janthina Er */ Lectotype Agrodes janthinus Asiain, Márquez & Morrone des. 2007” (ZMHB). Holotype of Sterculia peruviana, male: “Callanga, Perú / occidua Fvl. Det. Fauvel. Bang-Hass determ. M. Bernh. / peruviana Brh. Typus / Chicago NHMus M. Bernhauer Collection” (FMNH).
Additional material (23 specimens). BOLIVIA: Coroico, 1800 m, X–XII.1906, Gerlopp, Fassl (BMNH, Ψ; FMNH, Ψ); Rio Bongo, 750 m, Fassel (FMNH, Ψ); Cochabamba, 109 km E Yungas (Cochabamba-Villa Tunari Rd), 1480 m, 17°8’59”S, 65°42’29”W, 8–12.II.1999, R. Anderson, ex: transition montane forest cloud litter (SEMC, ɗ); Cochabamba, 117 km E, Yungas, Lagunitas, 1000 m, 17°6’22”S, 65°40’57”W, 1–6.II.1999, F. Genier, ex: flight intercept trap (SEMC, ɗ); San Antonio (BMNH, ɗ); Songo (BMNH, ɗ); Yungas (IRSNB, 3ΨΨ). PERU: Chanchamayo, 1500 m, Hogne (FMNH, Ψ); Chanchamayo, Rolle (AMNH, Ψ); Chanchamayo (FMNH, Ψ); Poguzo, Rolle (CC-UAEH, ɗ); no locality data (BMNH, ɗ; FMNH, Ψ; IRSNB, Ψ); Chanchamayo, 1899, E. Viale, D. Batian (FMNH, Ψ); Depto. Cuzco, km 165 on Cosnipata Hwy., 1200 m, Cosnipata Vly., 13.X–25.XI.1981, tropical forest, J. Fitzpatrick & D. Willard (FMNH, ɗ); Upper Rio Huallaga, 3.X.1929 (AMNH, ɗ); Rio Santiago, 21.XI.1924 (AMNH, Ψ); Huanuco, Piedras Grandes, 2500–3600 m, 22.XI.1937, F. Woytkowski (SEMC, ɗ); Callanga (IRSNB, ɗ).
Diagnosis. Total length 22.5–27.2 mm; metallic violet-blue with green or violet-blue reflections and green abdomen; head rectangular, 1.31–1.49 times as long as wide, moderately wider than pronotum (1.15– 1.29 times), dorsally and ventrally flat (similar to Fig. 13), ventral surface with moderately dense, expanded, umbilicate punctures (10–19 in each half of head), arranged in “v” (similar to Fig. 50); apical antennomere in males moderately longer than wide (1.33–1.70 times) and shorter than antennomeres 9+10 combined (0.88– 0.93 times their length); mandibles with basal external channel (Fig. 63). Pronotum long (length/width: 1.50– 1.64); shorter than elytra (0.79–0.85 times their length); with two slightly visible, depressed areas in posterior third; prosternum moderately transverse (length/width: 0.82–0.91); aedeagus ovate, with basal half curved, length 3.2–3.9 mm, with parameres moderately long (0.33–0.41 times as long as the median lobe), apical area of median lobe 0.30–0.35 times as long as the total length of median lob, and internal sac moderately visible (Fig. 84).
Variation. Usually the head is narrowed from the posterior angles toward the neck; and that the umbilicate punctures on the dorsal area of the head constitute deep cells, like a honeycomb. Some punctures on the pronotum are wider than the remaining fine punctures.
Comparative notes. Based on the revision of the holotypes, P. peruvianus (Bernhauer, 1907) is a junior synonym of P. janthinus (Erichson, 1847). The species can be confused with other species, such as some specimens of P. impressipennis, with a rectangular, dorsally and ventrally flattened head. The apical antennomere in males of both species is shorter than antennomeres 9+10 combined, the length/width proportions of the head and pronotum are similar, and both have moderately dense, expanded, umbilicate punctures on the ventral surface of head. They can be distinguished because in P. janthinus the head is moderately wider than the pronotum, some punctures are wider on the pronotum and the aedeagus is moderately longer, with its base curved and with a moderately visible internal sac.
Geographical distribution. Peru and Bolivia (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 22-23, DOI: 10.5281/zenodo.178410