Belonuchus pulcher, Márquez & Asiain, 2022

Márquez, Juan & Asiain, Julieta, 2022, Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae), Zootaxa 5152 (1), pp. 1-129 : 42

Belonuchus pulcher sp. nov.

http://zoobank.org/NomenclaturalActs/df66e884-2f52-4c9b-bbb8-92dedd3ddea7

Figs. 3d , 17–l, 18–l, 22c, 28b

Total body length 12.8 mm. Body almost completely black, except elytra and legs which are reddish (excluding coxae that are black). On some parts of antennae, mandibles, maxillary and labial palpi, coxae, scutellum and abdominal segments, the black color appears as dark-brown or reddish-brown. Elytra with setiferous punctures somewhat dark color. Abdominal sternites darker in basal half and reddish-brown in apical half.

Head: transverse, ratio length/width 0.68, slightly convex dorsally and at posterior corners. Dorsal surface with sulcate longitudinal midline visible in anterior half of head; front with a circular foveate area between antennal insertions. Eyes slightly less than 0.5 times the cephalic lateral length, not protruding laterally. Antennomere 4 slen- der and elongate, 5–7 elongate, 8–10 transverse. Mandibles 1.42 times longer than head; with two well separated teeth (basal and middle), basal tooth bigger than a middle tooth; mandibular channel well developed, external and internal margins well separated at base, the latter being carinate at base and extending like impressed line slightly beyond level of middle tooth. Apical palpomere of maxillary and labial palpi near 1.25 times longer than preapical palpomere. Ventral surface convex, with a depressed stripe parallel to anterior margin below mouth parts and with some sparse fine punctures. Head 1.3 times wider than pronotum. Neck with wrinkled microsculpture ventrally.

Thorax: pronotum with five punctures in each dorsal row; slightly longer than wide (ratio 1.1), almost as wide at anterior corners as at posterior corners (ratio 1.05). Scutellum with punctures denser than on elytra; elytra with setiferous punctures moderately dense. Prosternum with anterior margin depressed, followed by an elevated zone which ends like small arc. Intercoxal process of mesoventrite shield-shaped, transverse discal ridge diffusely visible, slightly rounded. Metaventrite very glossy, longitudinal midline not visible, with sparse setae in center and toward sides. Procoxae dark in external half and reddish in internal half; profemur with external row of spines initiating in basal third and reaching near 3/4 of its length, basal spines smaller and more spaced than spines at middle part and near the apex; internal margin with few spines near apex. Metatrochanter modified like a big, elongate hook, as long as, or slightly longer than 1/2 length of metafemur, its apex strongly curved and directed toward internal part of body; metafemur not flattened or curved at level of overlap with hook; metatibia slightly curved in anterior third. Tarsomeres flattened dorsally.

Abdomen: first three visible tergites with posterior basal transverse carina well developed, adjacent area weakly depressed, covered with sparse punctures, which are slightly wider than punctures on remaining tergites and all sternites, where punctures are fine and sparse. Male pregenital sternite with posterior margin with small U-shaped emargination, and slightly convex at each side of it (Fig. 17–l). Male genital sternite short (2.44 times longer than wide), slightly asymmetrical, anterior portion occupying 52% and posterior portion 48% of its length, apical emargination very deep ( Fig. 18–1 ). Abdominal styli very slender.

Aedeagus: length 2.2 mm; oval-elongate shape; apex somewhat acute, spine-shaped; base rounded; in ventral view, basal half moderately wider than apical half, most notable in lateral view; internal sac visible in anterior half ( Fig. 22c ).

Variability. The female has mandibles, head and pronotum black, shiny; abdomen and sterna irregularly dark brown to black; legs reddish-brown, with coxae dark-brown. The transverse discal ridge of the mesoventrite is better developed and is a little acute, projecting posteriad. Metaventrite with dense setae. Abdomen with fine, sparse punctures. Total body length 13.2 mm; ratio length/width of head 0.81; ratio mandibular length/cephalic length 1.18; ratio cephalic width/pronotal width 1.23; ratio length/width of pronotum 1.11; ratio anterior width/posterior width of pronotum 1.03. One studied male specimen from Guatemala (El Progreso) with a total body length 14.9 mm; ratio length/width of head 0.65; ratio mandibular length/cephalic length 1.7; ratio cephalic width/pronotal width 1.41; ratio length/width of pronotum 1.07; ratio anterior width/posterior width of pronotum 1.07. Antennomeres 1–9 almost black and 10–11 reddish-brown; procoxae clearly bicolored; mesoventrite with transverse discal ridge slightly visible; abdominal styli elongate and slightly widened at apex.

Taxonomic comment. This species is very similar to B. julietitae . See taxonomic comments for that species on how to distinguish them.

Etymology. The name refers to the beauty that this species possesses, with its lustrous reddish legs and elytra that are contrasting with the black color of the rest of the body.

Type material (two males, one female): Holotype (male, CC-UAEH): “ Guatemala: El Progreso, Sierra de Las Minas, Pinalón , N15.0754°, W89.94717°, 2236 m, bosque nuboso, en hojarasca cernida, 29-V-2014, M. Barrios col.” . Paratypes: México: Chiapas: “ 9 km W San Cristóbal, hwy 190, (2390 m), oak-pine forest, 29 June 1979 / FMHD #79-305 ex leaf litter, J. S. Ashe (m 1, FMNH)”. “ San Cristóbal de las Casas (4 mi W), 7900 ft., 16°43’N, 92°42’ W, 30-VIII-1973, pine-oak-madroño forest / mushroom trap (rotting), A. Newton 544F, FMHD #73-1122, Field Museum N. H.” (f 1, FMNH) .

Figures

FIGURE 3. Dorsal view of males of: a) Belonuchus magnistylus (paratype), b) B. metafemoralis (paratype), c) B. oxyporimimus (paratype), d) B. pulcher (paratype), e) B. oxyporinus (holotype, NHM©), f) B. oxyporinus, g) B. rufisternus (holotype), h) B. singularis (holotype). Scale bars = 2.5 mm.

FIGURE 18. Male genital sternite of: a) Belonuchus altenans, b) B. apiciventris, c) B. cariniventris, d) B. colon, e) B. confusus, f) B. julietitae, g) B. magnistylus, h) B. linuzensis, i) B. metafemoralis, j) B. oxyporimimus, k) B. oxyporinus, l) B. pulcher, m) B. rufisternus, n) B. singularis, o) B. tenuistylus. Scale bars = 0.5 mm.

FIGURE 22. Ventral (left) and lateral (right) view of the aedeagus of: a) Belonuchus oxyporimimus, b) B. oxyporinus, c) B. pulcher, d) B. rufisternus, e) B. singularis, f) B. tenuistylus, g) B. tepoztecus (at center detail of the paramere), h) B. trochanterinus, i) B. zunilensis. Scale bar = 0.5 mm (all figures).