A review of the Neotropical genus Diochus ERICHSON, 1840 (Coleoptera: Staphylinidae: Staphylininae) Author Irmler, Ulrich text Beiträge Zur Entomologie = Contributions to Entomology 2017 2017-06-30 67 1 1 62 journal article 10.21248/contrib.entomol.67.1.001-062 0005-805X 5212522 6526DDDB-7F27-41AC-8575-AF3C28A4177C Diochus vicinus SHARP, 1876 Figs 10A–C , 39D , 43C Diochus vicinus SHARP, 1876: 185 Diochus flavicans SHARP, 1876: 185 new synonymy Type material examined : 1 female , Brazil : Pará , Tapajos ( BMNH ) ; 2 female syntypes of D. flavicans , Brazil : Pará , Tapajos ( BMNH ) . Further material examined : Colombia : Vichada , PNN El Tuparro , Cerro Tomás ( 67°51'W , 5°21'N ), 140 m elev., Malaise trap , male, 22.5.– 3.6.2001 , leg. I. Gill ( KNHM ) ; Brazil : Amazonas , Ilha de Marchanteria ( 59°58'W , 3°15'S ), Varzéa , floating meadow, 3 males , 16.2.1982 , 22.1.1982 , leg. J. Adis ( UIC ) ; Ilha Muratú ( 60°21'W , 3°34'S ), 2 females , 25.2.1975 , leg. U. Irmler ( UIC ) ; Roraima , mouth of Rio Branco , Lago Adauaú ( 61°51'W , 1°19'S ), male, 22.8.1971 , leg. U. Irmler ( UIC ) ; Pará , 5 km E Belém , soil litter layer, in primary terra firme forest, male, 30.5.1973 , leg. R.T. Schuh ( AMNH ) ; IPEAN, from litter in “ Mocambo ”, male, 3.7.1973 , leg. R.T. Schuh ( AMNH ) ; Mato Grosso , Barra de Tapirapé , at light, 4 males , 1 female , 15.12.1960 , leg. B. Malkin ( FMNH ) ; male, same location, same collector, but 1.– 11.1.1963 ( FMNH ) ; Peru : Loreto , Lake Yarinachocha , 10 km NW Pucallpa , 150 m elev., collected at light, male, 27.12.1971 , leg. R.T. Schuh ( AMNH ) ; Madre de Dios , Tambopata , male, 26.10.1982 , leg. L.E. Watrous , G. Mazurek ( FMNH ) . Diagnosis : In size, colouration and length of antennae, D. vicinus resembles D. inornatus and D. hanagarthi . The EL: HL is 0.24, slightly shorter than in D. hanagarthi , separates both species from D. inornatus with longer temples (EL: HL = 0.21). Moreover, the antennae are slightly longer than in D. hanagarthi and D. inornatus . The species can be easily separated from the other Diochus species by the elongate hooked apical process of the paramere. Unfortunately, the two syntypes of D. flavicans are females. As I found no significant differences to D. vicinus , D. flavicans is synonymised to D. vicinus . Description : Length: 4.3 mm . Colouration: head and pronotum totally yellow-brown; elytra light brown with dark transverse spot in anterior half on each side of suture; abdomen darker than fore-body, but posterior margin of segments as light elytra; legs yellow; antennomeres 1, 2, and 11 yellow; antennomeres 4–10 darker, brown. Head: 0.46 mm long, 0.40 mm wide; eyes slightly prominent; moderately large; temples 2.5 times as long as eyes; EL: HL = 0.24; temples slightly divergent posteriad; PW: EW 1.14; posterior angles nearly rectangular; sharply rounded; clypeus widely rounded; neck one third as wide as head; inter-ocular space and clypeus densely and deeply punctate; wide midline impunctate; on average, interstice between punctures as wide as or slightly shorter than diameter of setiferous punctures; on average, setae distinctly longer than interstices; on vertex sparsely punctate; large area without punctures; laterad densely punctate; surface without microsculpture; shiny. Antennae slightly longer than head and half of pronotum combined; first to third antennomere distinctly longer than following antennomeres; nearly twice as long as wide; fourth to eleventh antennomeres approximately quadrate; first antennomere with long thick setae; fourth to eleventh antennomere pubescent;. Pronotum: 0.54 mm long, 0.49 mm wide; widest close to posterior margin; slightly narrowed to anterior margin, but nearly parallel; posterior and anterior angles widely rounded; sides finely margined; in dorsal aspect, margin covered in anterior half; setiferous punctures large, but sparse; on average, interstices between punctures twice as wide as diameter of punctures; on each side of impunctate midline with 3–4 setiferous punctures in longitudinal line; without microsculpture, but indistinct extremely weak ground sculpture; surface shiny. Elytra: 0.67 mm long, 0.67 mm wide; sides divergent to posterior margin; posterior angles and shoulders widely rounded; shoulders obtuse; setiferous punctures in longitudinal lines; setae pointing posteriad; interstices between punctures of lines and between lines at least two to three times as wide as diameter of punctures; surface with indistinct weak ground sculpture; shiny. Abdomen densely pubescent and matt in contrast to fore-body. Aedeagus with seminal vesical slightly longer than half of total length of central lobe; basal inner duct looped; apical inner duct with large coil; paramere narrow at base; slightly widened to apex; not projecting apex of central lobe; with long asymmetric acute process at apex with short apical hook. Spermatheca 0.47 mm long, 0.21 mm wide; bursa copulatrix in central position of coiled oval duct; coiled duct widest in anterior half; narrowed at middle and slightly widened in posterior half.