A review of the Neotropical genus Diochus ERICHSON, 1840 (Coleoptera: Staphylinidae: Staphylininae) Irmler, Ulrich Beiträge Zur Entomologie = Contributions to Entomology 2017 2017-06-30 67 1 1 62 369Z6 ERICHSON, 1839 ERiCHsON 1839 [869,1192,1875,1902] Insecta Staphylinidae Diochus Animalia Coleoptera 34 35 Arthropoda species nanus   Figs 35A–C, 40I, 45D   Type material examined: female, Lectotype: Columbia, without more data, coll. Moritz( ZMHB).   Paralectotype: female, with same data as lectotype ( ZMHB).   Fig. 1: Head of  Diochus maculicollisshowing measurements to indicate relative length of eyes and posterior divergence of head ( A); Male copulatory organs of  D. perplexus( B); inner organs of aedeagus of  D. longicornis( C); ejected aedeagus of  D. perplexuswithout funnel-like widening of basal duct ( D); aedeagus of  D. newtoniwith funnel-like widening of basal duct ( E); female copulatory organs of  D. longicornis( F).  Additional material examined:  Costa Rica: Heredia, 3 km S. Puerto Viejo, OTS-La Selva( 84°01'W, 10°26'N),  100 melevation, 2 females,  Sept. 1992, leg. P. Hanson( KNHM);  Rd. Barrigones( Osa),> Chacarita(83°15'- 26'W, 8°36'-48'N),  0–250 melevation, pastures, plantages, devastated forest, car net, 1 male, 3 females,  11.12.2012, leg. Schülke& Grünberg(1 MSC, 3 UIC);  S Rincon de la Vieja, Rd. Hacienda Guachipilin> Santa Maria(85°20.15'-22.45'W, 10°42.43'-45.10'N),  520–700 melevation, car net, farmland & dry forest, 1 male, 2 females,  4.12.2012, leg. Schülke& Grünberg( UIC);  Osa Peninsula, Rd. Bahia Drake> Rincon de Osa(83°29'-40'W, 8°41'-42'N),  0–400 melevation, car net, devastated forest & plantations, 1 male, 2 female,  9.12.2012, leg. Schülke& Grünberg( MSC);  Alajuela Prov., Rd. Colonia  Puntarenas> Rio Negro(84°46'-57'W, 10°50'-53'N),  40–90 melevation, fincas, meadows, forest remnants, car net, 1 female,  18.12.2013, leg. Schülke Grünberg( MSC);  Guanacaste Prov., Nicoya Peninsula, PN Diria, Area Conservacion Tempisce( 85°35.44'W, 10°09.43'N), river bank and old car track, 2 females,  15.12.2013, L.M. Schülke(1 MSC, 1 UIC);  Sardinal, 2 females,  23.2.1941, leg. A. Bierig( FMNH);  Pearl Island, San Miguel, 2 females, leg. Champion( FMNH);  Panama: Colon Prov., Maria Chiquita, composted grasses at beach, 1 male, 5 females,  3.1.1981, leg. W. Suter( FMNH);  Colombia: Magdalena, Cañaveral( 73°56'W, 11°19'N),  200 melevation, leaf litter, male,  11.8.1985, leg. J. Longino#708 ( KNHM);  Suriname: Marienburg, sweep from grass, female,  19.5.1916, leg. C.B. Williams( BMNH);  Saint Thomas: 3 males, 6 females, without additional data, coll. Kraatz( SDEI); without further data, coll. Eppelsheim, 3 males, 9 females(3 FMNH, 9 NMW); same location, 7 females, but leg. v. Eggers( NMW).   Diagnosis:  D. nanuscan be separated from the other species of the group by the less widened paramere. The eyes are as large as in  D. perplexusand  D. parvulus. It can be distinguished from  D. parvulusby the unicoloured elytra and from  D. perplexusby the deeper microsculpture of the head and the striate microsculpture at the anterior angles of the pronotum.   Description: Length: 2.8 mm. Colouration: light brown to yellowish; abdomen slightly darker brown with posterior margin of abdominal segment lighter; legs and antennae yellow.   Figs 2–5: Diochuslongicornis-group:  Diochus longicornis( 2),  D. tarsalis( 3),  D. adisi( 4),  D. guianensis( 5); aedeagus ( A), paramere ( B) and antenna ( C); scale bar: A, B: 0.1 mm, C: 0.2 mm. Head: 0.40 mmlong, 0.37 mmwide; eyes slightly prominent; large; temples twice as long as eyes; EL: HL = 0.28; temples slightly divergent posteriad; PW: EW = 1.13; posterior angles widely rounded; posterior margin approximately straight; setiferous punctation moderately deep and dense; wide midline impunctate; adjacent to midline irregular row of three to four punctures; between medial row and eyes two further rows of punctures; postocular area more densely punctate; netlike microsculpture more distinct on clypeus and interocular area; weaker on posterior vertex; surface moderately shiny. Antennae slightly longer than head; first antennomere longer and thicker than following antennomeres; second antennomere two third as long as first; twice as long as wide; third antennomere conical; only slightly longer than wide; following antennomeres rectangular; wider than long; fourth slightly wider than long; eighth and ninth nearly twice as wide as long; all antennomeres pubescent and with apical setae. Pronotum: 0.52 mmlong, 0.43 mmwide; sides approximately parallel; posterior angles widely rounded; posterior and anterior margins nearly semi-circular; lateral margin fine; in dorsal aspect visible in posterior half; setiferous punctation moderately deep and sparse; adjacent to wide impunctate midline with row of three punctures; interstice between anterior pair of punctures one third wider than between posterior pairs of punctures; between inner row and lateral margin few sparse punctures; along lateral margin several punctures; with weak microsculpture in anterior half, surface shiny. Elytra: 0.52 mmlong, 0.55 mmwide; shoulders shortly rounded; sides divergent to posterior angles; posterior margin emarginate; setiferous punctures in irregular rows of six to seven punctures; between suture and lateral margin four rows of punctures; ground-sculpture weak; surface moderately shiny. Abdomen densely pubescent. Aedeagus elongate; seminal vesical two third as long as central lobe; basal inner duct looped; ending in complex sclerotised forceps; paramere slender; apex obtusely angulate; not projecting central lobe; widened shortly in front of bifurcate apex; each process obtusely rounded; outer process with one short seta; inner process with two short setae; shaft with numerous sensillae. Spermatheca 0.25 mmlong, 0.15 mmwide; bursa copulartix in lateral position to coiled duct; coiled duct with irregular approximately oval coils. ZMHB Columbia & Moritz 34 35 1 lectotype ZMHB Columbia & Moritz 34 35 1 paralectotype 1992-09 KNHM S. Puerto Viejo & P. Hanson Costa Rica 100 10.433333 Selva 1298 -84.01667 36 37 2 2 Heredia 2012-11-12 MSC, UIC Schulke & Grunberg Costa Rica Rd. Barrigones 125 Chacarita Osa 36 37 4 3 1 Heredia 2012-04-12 UIC S Rincon de la Vieja & Schulke & Grunberg Costa Rica 610 Santa Maria Rd. Hacienda Guachipilin 36 37 3 2 1 Heredia 2012-09-12 MSC Schulke & Grunberg Costa Rica Osa Peninsula 200 Rincon de Osa Rd. Bahia Drake 36 37 3 2 1 Heredia [384,669,681,705] Costa Rica Rd. Colonia 36 37 1 Alajuela 2013-12-18 MSC Schulke Grunberg Costa Rica 65 Rio Negro 36 37 1 1 Puntarenas 2013-12-15 MSC, UIC PN Diria & L. M. Schulke Costa Rica 10.1571665 Area Conservacion Tempisce 13 -85.59067 Nicoya Peninsula 36 37 2 2 Guanacaste [189,733,905,929] 1941-02-23 FMNH A. Bierig Costa Rica Sardinal 36 37 2 2 Guanacaste Prov. FMNH Champion Costa Rica San Miguel Pearl Island 36 37 2 2 Guanacaste Prov. 1981-01-03 FMNH W. Suter Panama Maria Chiquita 36 37 6 5 1 Colon 1985-11-08 KNHM J. Longino Colombia 200 11.316667 Canaveral 1295 -73.933334 36 37 1 Magdalena 1916-05-19 BMNH C. B. Williams Suriname Marienburg 36 37 1 Magdalena SDEI Kraatz Virgin Islands Saint Thomas 36 37 9 6 3 Magdalena FMNH, NMW Eppelsheim Saint Thomas 36 37 12 9 3 Magdalena NMW v. Eggers Saint Thomas 36 37 7 7 Magdalena