Diochus curtipennis, Irmler, 2017

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 : 29-30

Diochus curtipennis spec. nov.

urn:lsid:zoobank.org:act:9F36420A-6AD4-4940-AAB0-A0535101A319

Figs 31A–C , 40C , 44G

Type material: male, Holotype: Brazil: Santa Catarina, Linha Facão , May 1954, leg. F. Plaumann ( KNHM).

Paratypes: 1 male with same data as holotype ( KNHM) ; Nova Teutonia, Santa Catarina , female, 12.1953, leg. F. Plaumann ( FMNH) ; Argentina: Jujuy, Termas de Reyes , male, 27.12.1971, leg. L. Herman #829 ( AMNH) ; San Luis Prov. Irideus, Quebrada del Tala (32°39.01'S, 64°57.23'W), litter in moist narrow quebrada, 1100 m elev., male, 8.12.2000, leg. L. Herman ( UIC) ; Aguas Buenas (32°35.05'S, 64°57.01'W), litter near stream, 1070 m elev., male, 9.12.2000, leg. L. Herman ( AMNH) ; Cerro El Mago , cuesta norte (32°43.01'S, 66°09.40'W), under rocks, 1660 m elev., female, 5.12.2000, leg. L. Herman ( AMNH) ; Tucuman, Villa Nugués , female, 13.12.1971, leg. L. Herman #781 ( AMNH) ; 7 km W San Pedro de Colalao , female, 15.12.1971, leg. L. Herman #786 ( AMNH) ; Tucuman, Parque Aconguija , 800 m elev. leaf litter , 1 male, 1 female, 30.3.1953, leg. Wygodzinsky ( FMNH) ; Choromora , Quebrada de la Higuera, 800 m elev., forest floor debris , 3 females, 15.3.1953, leg. Wygodzinsky ( FMNH) .

Diagnosis: Within the species group, the species is easily to distinguish by the short elytra that are distinctly wider than long. The paramere resembles that of D. brunneus in shape, but the apical plate is broader and with slightly sinuate upper margin. Species with similarly short elytra are found in the D. brooksi-group, i.e. D. mexicanus and D. panamensis from Central America. The eyes are slightly larger in D. curtipennis (EL: HL = 0.25) compared to those two species (maximum EL: HL = 0.20) and the head less divergent to posterior angles.

Description: Length: 3.2 mm. Colouration: dark brown; pronotum and clypeus lighter brown; legs and antennae still lighter brown, except antennomeres four to eleven dark brown.

Head: 0.49 mm long, 0.42 mm wide; eyes slightly prominent; moderately large; temples 2.5 times as long as eyes; EL: HL = 0.25; temples moderately divergent posteriad; PW: EW = 1.19; posterior angles widely rounded to approximately straight posterior margin; setiferous punctation moderately deep and dense; vertex with impunctate midline; adjacent to impunctate midline with row of five punctures; on supraocular area, laterad to medial row with dense setiferous punctation; postocular area with several punctures; distinct microsculpture deeper on clypeus than on vertex; on clypeus, microsculpture closely netlike; on vertex with transverse, elongate meshes; surface slightly shiny.

Antennae short; slightly longer than head; first elongate antennomere thicker than following antennomeres; nearly twice as long as apical width; second and third antennomeres conical; slightly shorter than twice as long as its apical width; following antennomeres wider than long; tenth antennomere 1.3 times as wide as long; all antennomeres pubescent and with long apical setae.

Pronotum: 0.67 mm long, 0.52 mm wide; sides approximately parallel; in anterior half continuously rounded; anterior third semi-circular; posterior angles shortly rounded to slightly convex posterior margin; lateral margin fine; in dorsal aspect, visible in posterior half; setiferous punctures moderately deep and sparse; adjacent to impunctate midline three pairs of setiferous punctures; interstice between anterior pair 2.6 times as wide as interstices between posterior pairs; laterally with curved row of four to five punctures; along lateral margin several setiferous punctures; without microsculpture; surface polished.

Elytra: 0.52 mm long, 0.60 mm wide; sides distinctly divergent to posterior angles; shoulders nearly absent; at posterior angles 1.3 times as wide as at shoulders; posterior angles shortly rounded to deeply emarginate posterior margin; setiferous punctation in irregular rows of six punctures; first row adjacent to suture line; laterally with two additional rows of three to four punctures; interstice between suture row and next lateral row wider than between two rows on disc; ground sculpture weakly coriaceous; surface slightly shiny.

Abdomen densely pubescent.

Aedeagus thick; seminal vesical of endophallus long and moderately thick; three fourth as long as total length of central lobe; basal inner duct looped with apical appendices; paramere shorter than central lobe; in apical third widened to oval plate with three long setae at upper margin; upper margin slightly sinuate close to outer angle; slender shaft with four sensillae.

Spermatheca 0.27 mm long, 0.18 mm wide; bursa copulatrix in lateral position to coiled duct; coiled duct with several irregular coils.

Etymology: The specific name is a combination of the Latin words curtus for short and pennis for elytra. It refers to the short elytra of the species.

Figures

Figs 44: Fore-bodies of Diochus pumilio (A), D. panamaensis (B), D. angustiformis (C), D. brunneus (D), D. schaumii (E), D. argen-

Figs 30–33: Diochus schaumii-group: D. brunneus (30), D. curtipennis (31), and Diochus verhaaghi-group: D. verhaaghi (32), D. santacatarinae (33); aedeagus (A), paramere (B) and antenna (C); scale bar: A, B: 0.1 mm, C: 0.2 mm.

Fig. 40: Spermatheca of Diochus schaumii-group: Diochus argentinae (A), D. brunneus (B), D. curtipennis (C), D. schaumii (D), D. verhaaghi-group: D. verhaaghi (E), D. santacatarinae (F), D. nanus-group: D. perplexus (G), D. parvulus (H), D. nanus (I), D. apicipennis (J), D. formicetorum (K); scale bar: 0.1 mm.