Diochus santacatarinae, 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 : 34-35

Diochus santacatarinae spec. nov.

urn:lsid:zoobank.org:act:99209529-EE6A-43A3-BE1F-413C5DF5CA1C

Figs 33A–C , 40F , 45A

Type material: male, Holotype: Brazil: Santa Catarina (plate with Korge’s determination: Diochus tarsalis ) ( SDEI) . Paratypes: Brazil: Santa Catarina, 21 males, 15 females, leg. Klimsch (6 FMNH, 2 AMNH, 27 NMW) ; Nova Teutonia , female, leg. Plauman ( FMNH) ; same location, but 27°11'S, 52°23'W, female, 3.1954, leg. F. Plaumann ( FMNH) ; French Guiana: Coralie (52°21'W, 4°30'N), car net, 1 male, 2 females, 15.11.2011, leg. T. Struyve ( UIC) ; Barrage de Petit Saude (53°02'W, 5°03'N), car net, male, female, 15.11.2011, leg. T. Struyve ( TSC) ; Ecuador: Napo Prov., 25 km W Tena, Tena-Talag Grande road, litter nr. steam, 2000 ft. elev., male, 23.5.1993, leg. L. Herman #2739 ( AMNH) ; Peru: Cuzco Dept., Consuelo, Manu rd. km 165, leaf litter, 2 males, 6.10.1982, leg. L.E. Watrous & G. Mazurek ( FMNH) ; same location, but litter under crown of felled tree, female, 2.10.1982, leg. L.E. Watrous & G. Mazurek ( FMNH) ; same location, but leaf litter, 1 male, 3 females, 7.10.1982, leg. L.E. Watrous & G. Mazurek ( FMNH) ; same location, but litter along stream, 1 male, 1 female, 5.10.1982, leg. L.E. Watrous & G. Mazurek ( FMNH) .

Diagnosis: The aedeagus of the species closely resembles that of D. verhaaghi , in particular, regarding the triangular apical process of the parameres. In D. santacatarinae , the apical setae are much longer than in D. verhaaghi , the apex of the apical process is more acute and the number of sensillae is smaller and they are locate closer to the base of the shaft. D. santacatarinae is distinctly larger than D. verhaaghi . In this respect it is similar to many other species of the D. inornatus- or D. schaumii-group of the same size.

Description: Length: 3.6 mm. Colouration: dark brown; pronotum slightly lighter brown; legs and antennae as light brown as pronotum with antennomeres four to ten dark brown.

Head: 0.56 mm long, 0.43 mm wide; eyes slightly prominent; temples 1.9 times as long as eyes; EL: HL = 0.22; temples slightly divergent posteriad, PW: EW = 1.15, posterior angles widely rounded; posterior margin convex; setiferous punctation deep and dense; clypeus densely punctate; partly coriaceous; vertex with small impunctate midline; convergent row of four punctures from anterior edge of eyes to middle of vertex; another curved row of setiferous punctures on supraocular area laterad to medial row; on postocular area and at posterior marginal area several more setiferous punctures; between setiferous punctures with sparse micro-punctures; without microsculpture; surface polished.

Antennae as long as head and half of pronotum combined; first antennomere thicker and longer than remaining antennomeres; more than twice as long as wide; second and third antennomere conical; twice as long as its apical width; third slightly shorter and narrower than second; following antennomeres distinctly shorter than basic three antennomeres; fourth antennomere slightly longer than wide; tenth antennomere 1.5 times wider than long; all antennomeres pubescent and with apical setae.

Pronotum: 0.63 mm long, 0.54 mm wide; sides nearly parallel; anterior angles widely rounded; in anterior third, strongly convergent; posterior angles shortly rounded; lateral margin fine; in dorsal aspect, visible in posterior half; posterior margin slightly convex; setiferous punctation sparse and deep; along impunctate midline three pairs of punctures; interstice between anterior pair twice as wide as interstices between posterior pairs; laterad, two to three additional punctures; several setiferous punctures along lateral margin; between large setiferous punctures with sparse micropunctation; surface polished.

Elytra: 0.67 mm long, 0.75 mm wide; sides divergent to posterior margin; shoulders obtuse; posterior angles approximately rectangular; posterior margin slightly emarginate; setiferous punctures in irregular rows; first row of five punctures adjacent to suture line; two additional rows laterad; interstice between two rows on disc much closer than between row at suture and first row on disc; ground sculpture weakly coriaceous; surface less shiny than pronotum or head.

Abdomen densely pubescent.

Aedeagus broad; seminal vesical of endophallus diagonal; slender; 0.6 times as long as central lobe; basal inner duct shortly looped; with complex sclerotised apical forceps; central lobe with two long hooks at apex; paramere slender; at apex widened to slender triangular process; four long setae at apical edge; shortly in front of widening with smoothly rounded lateral process; three sensillae at basal shaft.

Spermatheca 0.27 mm long, 0.16 mm wide; bursa copulatrix outside coiled duct; coiled duct with only very few approximately circular coils.

Etymology: The name of the species derived from the Brazilian State Santa Catarina, where the holotype was found.

Figures

Figs 45: Fore-bodies of Diochus santacatarinae (A), D. perplexus (B), D. parvulus (C), D. nanus (D), D. apicipennis (E), D. formicetorum (F); scale bar: 0.5 mm.

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.