Cylindroxystus janualis Ramírez & Asenjo, 2017

Ramírez, José & Asenjo, Angélico, 2017, First record and a new species of Cylindroxystus Bierig (Coleoptera, Staphylinidae, Paederinae) in Colombia, Zootaxa 4341 (3), pp. 437-440 : 438

Cylindroxystus janualis Ramírez & Asenjo , sp. nov.

( Figs. 1–9 )

Type material (6 ♂). Holotype: COLOMBIA: ♂, labeled: “Colombia, / Chocó, / Acandí, / Capurganá, / Camino a los rios, / Bosque, / 250m [meters of altitude above sea level], / Pitfall trap / 14. x [October]. 2008 / C. Becerra, M. Betancur, A. López, J. Ruíz collectors”; “HOLOTYPE [red label]/ Cylindroxystus / janualis Ramírez & Asenjo / Desig. Ramírez & Asenjo, 2017” (MPUJ).

Paratypes: COLOMBIA: 5♂. Labeled: “Colombia, / Chocó, / Acandí, / Capurganá, / Los Girasoles, / 300m [meters of altitude above sea level], / Bosque, / Pitfall trap / 11. x [October]. 2008 / A. Quintero collector”; “PARATYPE [yellow label]/ Cylindroxystus / janualis Ramírez & Asenjo / Desig. Ramírez & Asenjo, 2017” (4 MPUJ, 1 CEMT).

Diagnosis. Cylindroxystus janualis sp. nov. resembles C. messus Herman but differs as follows: elytral length is greater than the pronotum length; foramen is larger occupying the basal third, two transverse carinae at the lateral part of the aedeagal operculum ( Figs. 8–9 ).

Description. Holotype male, BL: 3.76.

Body reddish-brown ( Fig. 1 ). Antennae, legs and palps paler.

Head: Vertex with setigerous punctation confined to edges of the frontal region. Postocular margin of head converging gradually rounded to basal margin of head. Eye length longer than postocular length of head. Gena with setigerous punctation surrounding the eye. Gular sutures widely separated. Labrum edentate and deeply and broadly emarginate at anterior margin. Mandible long, slender, falcate and edentate. Galea and lacinia of maxilla moderately long, forming a bulb with a set of bristles in apical third. Maxillary palpus moderately long, second segment shorter than third and gradually expanded apically, third segment strongly expanded from base to near middle then slightly narrowed towards apex ( Fig. 3 ); Labial palpus with first segment shorter than second and second longer than third; first and second segments of similar thickness and third more slender. Antenna with segments 4–10 each with short, stout, spine-like setae around apex ( Fig. 2 ), segment 10 approximately as long as 9. Thorax: Pronotum longer than wide (PL: 0.43; PW: 0.32) with parallel lateral margins. Disk shinning, with a pair of paramedial longitudinal rows of setigerous punctation and with a few scattered punctures either side of the row. Prosternum with median carina present but short and moderately developed. Hypomeron polished and without punctures or sculpturing. Elytra longer than pronotum (EL: 0.64; EW: 0.5), surface with two discal longitudinal rows of setigerous punctures. Epipleural elytral present. Abdomen: Abdominal segments VII and VIII with tergum and sternum separated ( Fig. 1, 6, 7 ). Abdominal segments III to VI with longitudinal depression at base near lateral margin ( Fig. 5 ). Sterna II and III with medial longitudinal carina ( Fig. 5 ). Tergum III with three internal canals at base ( Fig. 4 ). Sternum VII with broad, shallow, median emargination at posterior margin. Tergum VIII with two lateral and two median internal canals at base and with broad, apically acute, triangular lobe on apical margin ( Fig. 6 ). Sternum VIII with two lateral and two median internal canals at base and with moderately deep and broad median emargination on apical margin ( Fig. 7 ).

Aedeagus: with median orifice covered by operculum ( Fig. 8 ). Operculum with median lobe in basal margin, with a shallow depression in both lateral sides ( Fig. 9 ).

Female. Unknown.

Habitat. The specimens were collected in rainforest leaf litter.

Etymology. The specific epithet name is an eponym based on the name of the brother of the first author, Frank Janual Ramírez.

Distribution. Northwest Colombia: Chocó; Acandí.

Comments. The new species belongs to the genus Cylindroxystus based on the characters used by Herman (1991), and that are in the new species: presence of one pair of paratergites on segment III (fig. 4) and their absence from segments IV to VII ( Fig. 1 ), and by the cupulate third antennal segment (fig. 2). Tergum and sternum IV to VI are fused to form a cylinder ( Fig. 1 ), the fourth segment of the maxillary palpus is nipple-shaped (fig. 3), and the mesothoracic peritreme is small.

Figures

FIGURES 1 – 9. Cylindroxystus janualis sp. nov., holotype male. 1, habitus, dorsal view; 2, Right antenna, ss spinelike setae, ts thrid segment cupulate; 3, Right maxilla, la lacinia, g galea, fs fourth segment nipple-shaped; 4, Tergum III, pt paratergites, bc three internal canals at base; 5, Sternite II and III, mlc medial longitudinal carina, ldl lateral longitudinal depression; 6, Tergum VIII; 7, Sternum VIII; 8, aedeagus in ventral view; 9, aedeagus in dorsal view, op operculum. Scale bars: 1, 1 mm; 6 – 7, 0.5 mm; 8, 0.05 mm.