Diochus guianensis, 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 : 5-6

Diochus guianensis spec. nov.

urn:lsid:zoobank.org:act:BDD3E1B7-96A0-4ACE-BC32-4D24ADA1D2DB

Figs 5A–C , 38D , 41E

Type material: male Holotype: French Guiana, Saül , 7 km N, 3 km NW Les Eaux Claire, Mt. La Fumée (3°39.46'N, 53°13.19'W), collected by flight intercept trap, 1.– 8.6.1997, leg. J. Ashe, R. Brooks #FG1AB97 162 ( KNHM).

Paratypes: 1 male, 1 female with same data as holotype (1 KNHM, 1 UIC); Roura, 39.4 km SSE (4°32.43'N, 52°8.26'W), 270 m elevation, collected by flight intercept trap , 3 males, 3 females, 29.5.– 10.6.1997, leg. J. Ashe, R. Brooks #FG1AB97 172 ( KNHM) ; same location and collectors , 3 females, 25.– 29.5.1997, #FG1AB97 076 (2 KHNM, 1 UIC) .

Diagnosis: Regarding the size, D. guianensis resembles D. longicornis and D. tarsalis of this group. The male can be easily separated by the short nearly globular seminal vesical. In contrast to D. guianensis , the seminal vesicals are elongate in D. longicornis and D. tarsalis . Moreover, the antennae are much shorter in D. guianensis than in those species.

Description: Length: 4.4 mm. Colouration: dark brown to black; at anterior half of pronotum indistinctly lighter brown; legs and antennae light brown.

Head: 0.59 mm long, 0.49 mm wide; eyes not prominent; EL: HL = 0.25; temples 2.5 times as long as eyes; temples slightly divergent to posterior angles; PW: EW = 1.19; posterior angles widely rounded to convex posterior margin; setiferous punctation sparse and moderately deep; wide midline impunctate; on vertex, adjacent to midline three pairs of punctures; interstice between anterior pair slightly shorter than between posterior pairs; additional supraocular row of three to five punctures; postocular area with several punctures; very weak transversely striate microsculpture on clypeus and anterior vertex; surface shiny.

Antennae slightly longer than head and half of pronotum combined; first antennomere thicker and longer than following antennomeres; 2.5 times as long as wide; second and third antennomere conical; twice as long as apical width; following antennomeres decreasing in length; fourth antennomere one third longer than wide; tenth antennomere one third wider than long; all antennomeres pubescent and with several apical setae.

Pronotum 0.72 mm long, 0.55 mm wide; sides nearly parallel; anterior angles widely rounded to evenly convex anterior margin; posterior angles shortly rounded to convex posterior margin; lateral margin fine; in dorsal aspect, visible in posterior half; setiferous punctation sparse and moderately deep; adjacent to wide impunctate midline with three pairs of punctures; interstice between anterior pair 2.5 times as wide as between posterior pairs; few setiferous punctures laterad; several setiferous punctures along lateral margin; without microsculpture; with sparse micro-punctation; surface polished.

Elytra: 0.69 mm long, 0.72 mm wide; sides slightly divergent to posterior angles; shoulders obtuse; posterior angles nearly rectangular; posterior margin slightly concave; setiferous punctation in irregular rows of five to six punctures; ground sculpture weakly coriaceous; surface less shiny than that of head and pronotum.

Abdomen densely pubescent.

Aedeagus narrow in dorsal aspect; in lateral aspect broad; seminal vesical thick; oval; 0.45 times as long as total length of central lobe; basal inner duct looped; apical duct flagellate with three wide coils; paramere slender; curved in apical third to acute apex; at outer angle with three setae; in basal part of shaft with several sensillae.

Spermatheca 0.47 mm long, 0.21 mm wide; bursa copulatrix in central position of shoe-like shaped coiled duct.

Etymology: The species name derived from the country, where the holotype was collected by J. Ashe and R. Brooks.

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.