A review of Paraxenopygus Bernhauer (Insecta: Coleoptera: Staphylinidae), with description of two new species Author Chatzimanolis, Stylianos Department of Biology, Geology and Environmental Science, University of Tennessee at Chattanooga, Chattanooga, TN, USA; Author Brunke, Adam J. Canadian National Collection of Insects, Arachnids and Nematodes, Agriculture and Agri-Food Canada, Ottawa, ON, Canada; Author Navarrete-Heredia, José L. Centro de Estudios en Zoología, CUCBA, Universidad de Guadalajara, Zapopan, México text Journal of Natural History 2024 2024-08-30 58 37 - 40 1509 1528 http://dx.doi.org/10.1080/00222933.2024.2391450 journal article 303343 10.1080/00222933.2024.2391450 5b6cb74e-6d97-4cfc-b291-0156356aa0c1 1464-5262 13758597 53764B33-1DC2-4103-97E6-4AA07C6EB12D Paraxenopygus peruvianus Bernhauer, 1915 ( Figures 1C , 2C , 3C , 4C , 5G–I , 6) Paraxenopygus peruvianus Bernhauer, 1915 , p. 298 . Type material Lectotype , here designated, male with labels: ‘ Chanchamayo , Peru [ Peru : Junín : Chanchamayo, −11.00°, −75.25°] Heyne [leg.] Berlin-Wilm’ /‘ ♀ ’/ ‘ peruvianus Bernh Typus’ / ‘ Chicago NHMus M. Bernhauer Collection’ /‘FMNHINS4518387 ’/‘ Lectotype Paraxenopygus peruvianus Bernhauer des. Chatzimanolis, Brunke and Navarrete-Heredia’. In the collection of FMNH . Additional materials COLOMBIA : Antioquia : Rionegro [6.15°, −75.37°], Bernhauer coll . ( 1 female FMNH ) ; ECUADOR : Orellana : [ Puerto Francisco de Orellana ] Coca [−0.46°, −76.98°], v .1965, Peña coll . FMNHINS4518388 ( 1 male [lacking barcode], 1 female FMNH ) ; PERU : Cuzco : Quispicanchi , Marcapata [−13.59°, −70.98°], Fauvel coll . ( 1 female HNHM ; 2 male , 2 female RISBN ) ; Huánuco : Monzon Valley , Tinga María [−9.29°, −75.99°], 27 .x .1954, E .I . Schlinger and E .S. Ross leg . ( 1 male , 1 female CAS ); Yurao , 67.5 mi . E. of Tingo María [−9.29°, −75.04°], 16 .xi .1954, E .I . Schlinger and E .S. Ross leg . ( 1 female CAS ) ; Junín : Chanchamayo [−11.00°, −75.25°], Sharp coll . ( 1 male NHMUK ); same locality, 800 m , 1 .ii .1939, in nest with Atta cephalotes , Scheerpeltz coll. ( 1 female NMW ) ; Pasco : Villa Rica Rd . [−10.79°, −75.32°], 1475 m , 15–18 .x .1999 , FIT , R . Brooks, D. Brzoska leg ., SM0149866 ( 1 female SEMC ) ; Madre de Dios : CICRA Field Station , airfield, −12.558°, −70.106°, 290 m , 11 .vii .2010, hand collected, DJ Bennett leg ., SEMC0985413 ( 1 male SEMC ); CICRA Field Station , trail 6, research plot, −12.552°, −70.109°, 295 m , 7–9 .vi .2011, FIT , Chaboo team leg ., SEMC1014435 ( 1 male SEMC ); CICRA Field Station , garden, −12.569°, −70.101°, 260 m , 12–19 .vii .2010, malaise, M .J . Endara leg ., SEMC1095993 ( 1 male SEMC ); same locality and collector, 9–16 .ix .2010, SEMC1097837 , SEMC1097839 ( 2 male SEMC ); same locality and collector, 23 .ix .–2.x .2010, SEMC1062346 ( 1 female SEMC ); same locality and collector, 26 . viii .–2.ix .2010, SEMC1061639 ( 1 female SEMC ); Pakitza Biol . Station Castanal Trail , Reserved Zone , Manu NP [−11.945°, −71.283°], 317 m , 15–16 .x .2000, FIT , R . Brooks leg ., SM0210549 ( 1 female SEMC ); Pantiacolla Lodge 2–7 km NW El Mirador trail, Alto Madre de Dios River [−12.653°, −71.258°], 450–700 m , 23–26 .x .2000, FIT , R . Brooks leg ., SM0210968 ( 1 female SEMC ); same locality and date, 8 km NW El Mirador Trail , 800 m , [−12.642°, −71.278°], SM0210921 ( 1 male SEMC ); unknown state : unknown locality, Bang-Haas [leg.] ( 1 female AMNH ); unknown locality ( 1 female NHMUK ; 1 female MFNB ) . Diagnosis Among species of Paraxenopygus with metallic green head and pronotum, P. peruvianus can be distinguished from P. newtoni by having a pronotum with dense setose punctures in confused rows, nearly evenly distributed ( Figure 2C ); tergite 7 with dark median band ( Figure 1C ); apex of median lobe in ventral view converging to narrow rounded tip ( Figure 5G ); and median lobe in lateral view with subapical tooth ( Figure 5I ). Description Forebody length 6.1–8.5 mm . Colour of head and pronotum shining metallic green; mesoscutellum, elytra, antennae and legs orange-brown. Abdomen orange-brown (but see Remarks below) except tergite 7 and sternite 7 with broad dark brown to black area medially ( Figure 4C ). Epicranium ( Figure 2C ) with small to medium punctures, distance between punctures as wide as 1–1.5 punctures. Antennomere 1–4 without tomentose pubescence. Mandibles straight, except apically. Neck with dense, small punctures. Pronotum width/length ratio = 0.96–1.00; pronotum with medium-sized punctures; pronotum with rows of punctures confused and nearly becoming evenly distributed ( Figure 2C ); superior marginal line of pronotal hypomeron joins inferior marginal line before neck. Elytra length/pronotal length ratio = 1.06–1.15; elytra with small punctures and few wrinkled irregularities between punctures. Metacoxal shield slightly elongate and wide ( Figure 3C ), but length of shield variable (see Discussion); abdominal tergites 3–4 without faint curved line posterior to anterior transverse basal line. Sternite 7 in males with small circular porose structure ( Figure 4C ); sternite 8 with U-shaped emargination ( Figure 4C ). Aedeagus as in Figure 5G–I ; in ventral view paramere wide, converging to rounded apex; paramere shorter and narrower than median lobe; in lateral view paramere concave, with narrower rounded apex; paramere with peg setae in two short rows as in Figure 5H . Median lobe in ventral view wide, converging to narrow rounded tip; in lateral view median lobe becoming much narrower near apex; median lobe with subapical tooth. Endophallus in ventral view wide, converging to pointed apex, in lateral view converging to narrow rounded apex. Distribution Known from the department of Antioquia in Colombia , the province of Orellana in Ecuador , and the departments of Cuzco , Huánuco , Junín , Pasco and Madre de Dios in Peru ( Figure 6 ). There is a female specimen of Paraxenopygus in FMNH from Tobago ( 10 km NE Roxborough , Gilpin Trail , 400–500 m , Montane Rain Forest , 26–31.vi.1993 , FIT , S. and J. Peck leg.) that is similar to P . peruvianus but the punctation pattern of the pronotum is a bit more sparse. This specimen may be P . peruvianus or a new species, but unfortunately we are unable to make a determination. Habitat Collected in low- and mid-elevation tropical rainforests. There is one record indicating a host association with Atta cephalotes (Linnaeus) . Remarks In a couple of specimens, the abdomen was much darker, almost brown, but no differences in the aedeagi were found.