Diochus longicornis SHARP, 1876

Irmler, Ulrich, 2017, A review of the Neotropical genus Diochus ERICHSON, 1840 (Coleoptera: Staphylinidae: Staphylininae), Beiträge Zur Entomologie = Contributions to Entomology 67 (1), pp. 1-62 : 6-7

Diochus longicornis SHARP, 1876

Figs 2A–C , 38A , 41A

Diochus longicornis SHARP, 1876: 184

Type material examined: male, Syntype, Brazil: Pará ,

Tapajos, ( BMNH).

Further material examined: Mexico: San Luis Potosi, Sierra de la Abra, Sotano de la Tinaja, flood debris on mud slope, 1500 ft. from entrance; 1 male, 1 female, 18.2.1970, leg. J.A.L. Cooke ( AMNH) ; same location, 11 km NE Ciudad Valles, cave, debris, Berlese , 2 males, 4 females, 4.7.1970, leg. J. Cooke, 1 male, 2 females, 20.2.1973, leg. S. Willey (7 AMNH, 2 UIC) ; same location, La Cueva de la Tinaja, 10.5 km NE Cd. Valles , cave, female, 20.2.1973, leg. T.R. Mollhagen ( AMNH) ; Belize: Orange Walk Distr., Rio Bravo Conserv. Area, rd. to Archaelogical site (17°50.56'N, 89°02.34'W), flight intercept trap #2, female, 25.4.– 5.5.1996, leg. C. Carlton #102 ( KNHM) ; Costa Rica: Vara Blanca , zwischen Barba & Poas, 2000 m elev., female, leg. H. Schmidt ( FMNH) ; Finca Castilla , male, 6.1938, leg. A. Bierig ( FMNH) ; Cuba: Aspiro , 1 male, 6.8.1933, leg. A. Bierig ( FMNH) ; Rangel , 3 females, 6.4.1930, leg. A. Bierig ( FMNH) ; Panama: Colon, 15 km N jct. Escobal & Piña Rds. Ca. 30 m elevation, collected by flight intercept trap, male, 2.–11. Jun.1996, leg. J. Ashe & R. Brooks, #PAN1AB96 121 ( KNHM) ; Bocas del Toro Prov., Almirante , forest floor litter, female, 1.4.1959, leg. H.S. Dybas ( FMNH) ; French Guiana: Caussade (52°57'W, 5°10'N), car net, 1 male, 3 females, 7.11.2011, leg. T. Struyve (2 TSC, 2 UIC) ; Coralie (52°21'W, 4°30'N), car net, 2 females, 7.11.2011, leg. T. Struyve ( TSC) ; Colombia: Putumayo, PNN La Playa Rio Vega (74°56'W, 0°07'S), 320 m elevation, Malaise trap, 1 female, 15.– 30.10.2001, leg. R. Cobete #2437 ( KNHM) ; Putumayo, PNN La Playa, Cabaña Viviano Concha (74°56'W, 0°07'S), 320 m elevation, Malaise trap, 1 male, 15.– 30.10.2001, leg. R. Cobete #M2438 ( UIC) ; Vichada, PNN El Tuparro Cerro Tomás (67°51'W, 5°21'N), 140 m elevation, Malaise trap, 1 female, 22.5.– 3.6.2001, leg. I. Gil #1789 ( KNHM) ; Venezuela: Zulia Distrito, Municipio Perija Libertad , El Tarra, 100 km S of, at light, female, 7.1982, leg. V. Linares ( FMNH) ; same region, 15 km W of Machiques , at light, 1 male, 1 female, 6.1982, leg. V. Linares ( FMNH) ; same region, Hacienda Aponcito , 35 km W Manchiques, at light, male, 7.1982, leg. V. Linares ( FMNH) ; same region, El Amparo , at light, female, 6.1982, leg. V. Linares ( FMNH) ; same region, Rancho Calvario, NW Manchiques , at light, 1 male, 1 female, 7.1982, leg. V. Linares ( FMNH) ; Ecuador: Sucumbios, Sacha Lodge (76°5'W, 0°5'S), 270 m elevation, Malaise trap, 1 male, 4.– 14.3.1994, 1 male, 1 female, 14.– 24.3.1994, leg. Hibbs (2 KNHM, 1 UIC) ; Peru: Madre de Dios Dept., Tambopata , 3 males, 5 females, litter at swamp edge, 2 males, 3 females, rotten figs, 28.10.1982, leg. L.E. Watrous & G. Matzurek ( FMNH, UIC) ; Bolivia: El Beni, Beni Stn. Palm Camp , NE of San Borja, collected at lights, BIOLAT-SI/MAB, 1 male, 1.8.1988, leg. W. Brooks ( KNHM) ; Beni, Ilha Flores, Rio Iténez , 1 male, 2 females, 7.8.1964, leg. J.K. Bouseman & L. Lussenhop ( AMNH) ; Beni Prov., Chacobo Indian village, on Rio Benicito (66°0'W, 12°20'S), male, 26.7.– 4.8.1960, leg. B. Malkin ( FMNH) ; Dept. Beni, Prov. Vac Diez , 2 km NW Tumichucua, leaf litter in sunken aera, 2 females, 12.8.1990, leg. P. Parillo ( FMNH) ; same region, Isla Motacu , forest leaf litter, female, 16.8.1990, leg. P. Parillo & P. Bettella ( FMNH) ; Brazil: Amazonas without further data, male, Sharp coll. ( FMNH, excgange with BMNH) ; Amazonas, PNN Amacayacu Matamata (70°15'W, 3°41'S), 150 m elevation, Malaise trap, 1 female, 8.– 14.8.2000, leg. A. Parente #M689 ( KNHM) ; Choco, PNN Los Katios, Centro Adiministrativo Sautatá , Dentro del Bosque (77°8'W, 7°51'N), 30 m elevation, Malaise trap, 1 male, 13.– 29.6.2003, leg. P. López #3764 ( KNHM) ; Norte de Santander, ANU Los Estoraques Qda., La Media (8°13'N, 73°14'W), 1480 m elevation, collected by Malaise trap, female, 15.9.– 1.10.2003, leg. J. Vegas #M4046 ( KNM) ; Santa Catarina, Linha Facão , 1 female, May. 1954, leg. F. Plaumann ( KNHM) ; Nova Teutonia (52°23'W, 27°11'S), 300–500 m elev., female, 3.1954, 2 females, 10.–12.1952, leg. F. Plaumann ( FMNH) ; same location, 3 females, coll. A. Bierig ( FMNH) ; Gioas , Sta. Isabel, R. Araguaia , Isla Bananal , at light, male, 27.10.– 4.11.1960, leg. B. Malkin ( FMNH) ; Mato Grosso, Barra do Tapirapé , at light, 1 male, 3 females, 15.12.1960, leg. B. Malkin ( FMNH) ; Mato Grosso do Sul, Corumba , 1 male, 1 female ( FMNH) .

Diagnosis: Within the species group, D. longicornis resembles D. tarsalis in size and long antennae. Antennae are slightly longer than in D. tarsalis . The main difference is the shorter seminal vesical and the larger coils of the apical filament duct of the endophallus. The paramere is more slender without the apical process of D. tarsalis .

Description: Length: 4.9 mm. Colouration: head dark brown; pronotum and elytra light brown; abdomen brown; only slightly darker than elytra and pronotum; antennae light brown with three basal antennomeres slightly lighter than following antennomeres; legs yellowish brown.

Head: 0.65 mm long, 0.51 mm wide; eyes not prominent; approximately half as long as temples; EL: HL = 0.28; temples slightly divergent to posterior angles; PW: EW = 1.14; posterior angles widely rounded to narrow neck; neck approximately one fourth as wide as head; setiferous punctation moderately deep and dense; on average, interstices between punctures 2.5 times as wide as diameter of punctures; with wide impunctate midline; without microsculpture; surface shiny.

Antennae as long as head and pronotum combined; conical first antennomere at apex slightly thicker than following antennomeres; 1.5 times as long as wide; second antennomere as long as first, but more or less parallel; third antennomere slightly longer than second; following antennomeres decreasing in length; fourth antennomere distinctly shorter than third; penultimate antennomere only half as long as third, but still one third longer than wide; last antennomere again slightly longer than penultimate antennomere; all antennomeres with few long apical setae and sparsely pubescent.

Pronotum: 0.74 mm long, 0.62 mm wide; widest at middle; slightly narrowed to anterior and posterior angles in smooth curve; anterior and posterior angles widely rounded without distinct angles; lateral margin fine; in dorsal aspect, covered in anterior half; posterior and anterior margin as fine as lateral margin; setiferous punctation sparse and weak; two pairs of punctures at central midline; large areas in front of anterior pair of punctures and laterad to pairs of punctures impunctate; on average, interstices between punctures on lateral disc at least three times as wide as diameter of punctures; without microsculpture; surface shiny.

Elytra: 0.79 mm long, 0.83 mm wide; widest at posterior angles; slightly narrowed to shoulders; shoulders obtusely rounded, but distinct; lateral punctures with long black setae; on disc, setiferous punctation in irregular longitudinal rows; fist row directly adjacent to suture line; three further lines laterally; surface with indistinct weak ground sculpture; shiny.

Abdomen densely pubescent.

Aedeagus with seminal vesical slightly shorter than half of total length of central lobe; apical inner duct with several coils; paramere exceeding central lobe; narrow; only slightly widened to apex; at obtuse apex with four long setae; no sensillae at shaft.

Spermatheca 0.46 mm long, 0.27 mm wide; bursa copulatrix in central position to coiled duct; coiled duct asymmetrically oval; at one end smaller than at other.

Figures

Figs 41: Fore-bodies of Diochus longicornis (A), D. tarsalis (B), D. adisi (C), D. ashei (D), D. guianensis (E), D. unicolor (F), D. inornatus (G), D. hanagarthi (H); scale bar: 0.5 mm.

Figs 2–5: Diochus longicornis-group: Diochus longicornis (2), D. tarsalis (3), D. adisi (4), D. guianensis (5); aedeagus (A),

Fig. 38: Spermathecae of Diochus longicornis-group: D. longicornis (A), D. tarsalis (B), D. ashei (C), D. guianensis (D), D. unicolor (E); Diochus inornatus-group: D. inornatus (F), D. hanagarthi (G), D. antennalis (lateral aspect H), D. hermani (I), D. hibbsi (J), D. newtoni (K), D. novus (L); scale bar: 0.1 mm.