Belonuchus cyanipennis, Márquez & Asiain, 2022

Márquez, Juan & Asiain, Julieta, 2022, Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae), Zootaxa 5152 (1), pp. 1-129 : 90-91

Belonuchus cyanipennis sp. nov.

http://zoobank.org/NomenclaturalActs/4ff36336-a7af-4f6e-b4a5-60ad1b256c6a

Figs. 9b, k , 12c , 15g , 20n , 25f , 29b

Total body length 7.6 mm. Body black, shiny, except elytra that are metallic blue, legs dark-brown and genital segment reddish.

Head: oval ( Fig. 10h ); ratio length/width 1.03. Dorsal surface with sulcate longitudinal midline visible in anterior half of head; punctures slightly sparser than in majority of species; front moderately foveate between antennal insertions. Eyes slightly more than 0.5 times the cephalic lateral length, notably protruding at sides. First antennomere shorter than 2–3 combined (0.75 times), antennomere 2 slightly shorter than 3 (0.8 times), antennomere 3 the smallest and oblong, 4 as long as wide, 5–10 transverse; antennomeres 4–10 of characteristic shape, like pieces of a rosary ( Fig. 9k ). Mandibles shorter than head (ratio 0.78); narrow at base, each with a small middle tooth, no basal tooth discernible; mandibular channel slightly developed, with external margin not carinate and internal margin like impressed line extending forward slightly beyond level of middle tooth. Apical palpomere of maxillary palpi 1.8 times longer than preapical palpomere; apical palpomere of labial palpi almost as long as preapical palpomere. Head almost as wide as pronotum (ratio 1.03).

Thorax: each dorsal row of pronotum with five punctures; pronotum slightly longer than wide (ratio 1.1) and almost as wide at anterior corners as at posterior corners (ratio 1.03). Scutellum very large, nearly 1/4 of elytral length measured at center, with punctures wider and denser than on elytra, latter with fine and sparse punctation. Prosternum with a narrow transverse area near anterior margin delimited backwards by slightly visible impressed line. Intercoxal process of mesoventrite ( Fig. 12c ) triangularly scutellum-shaped, but with its apex not as acute; transverse discal ridge well developed like curved wave, laterally reaching very close to margin of intercoxal process. Legs long and slender, with few setae and spines, particularly hind legs. Profemur without row of spines at external margin, internal margin visible only near apex of femur where having three to four small spines. Metafemur without modifications or spines. Tarsomeres very slender and not flattened dorsally.

Abdomen: punctures and setae at medial part of each tergite very sparse, majority of setae large and placed at all margins of each tergite, so dorsal part of abdomen looks very glossy. Visible tergites 1–3 with fine posterior basal transverse carina, adjacent area weakly depressed, on tergite 3 practically not visible. Visible sternites 1–3 with entire surface covered with dense, wide-superficial punctures, combined with fine punctures, its density decreasing from anterior to posterior margin and from first visible to fifth visible sternite, on sixth visible sternite only with fine punctures. Male pregenital sternite not emarginate at posterior margin ( Fig. 15g ). Genital segment yellowish. Male genital sternite very elongate (3.14 times longer than wide), moderately asymmetrical, anterior portion occupying 36% and posterior portion 64% of its length, apical emargination very deep ( Fig. 20n ). Abdominal styli slender.

Aedeagus: length 1.0 mm; oval in basal half and subparallel in apical half; apex subacute; basal half wider than apical half; internal sac weakly developed ( Fig. 25f ).

Variability. Total body length in males 7.35 mm (range 6.3–8.1 mm), in females 7.41 mm (range 6.6–8.2 mm); ratio length/width of head in males 0.93 (range 0.90–0.95), in females 0.94 (range 0.91–0.95); ratio mandibular length/cephalic length in males 0.73 (range 0.60–0.85), in females 0.72 (range 0.70–0.75); ratio cephalic width/pronotal width in males 1.12 (range 1.07–1.16), in females 1.10 (range 1.05–1.16); ratio length/width of pronotum in males 1.13 (range 1.09–1.17), in females 1.15 (range 1.10–1.21); ratio anterior width/posterior width of pronotum in males 1.05 (range 1.03–1.08), in females 1.04 (range 1.00–1.08). Furthermore, the dorsal surface of head is more convex in some specimens; the metallic hue of elytra is mainly bluish, but may be slightly greenish or more rarely purplish violet; anterior portion of prosternum may not show the impressed line that separates it from the rest of prosternum; wide-superficial punctures can be dense on first visible sternite, less dense on second sternite, sparse on third sternite and very sparse on fourth sternite.

Taxonomic comments. The main differences to distinguish B. cyanipennis from B. godmani are the same as those included in the key and since there are only two species in this group, it is not considered necessary to repeat them.

Etymology. The name of this species is a combination of the words “cyaneus” and “pennis”, which denotes the dark blue metallic coloration of its elytra, while the rest of the body is glossy black.

Type material (15 males, nine females): Holotype (male, CC-UAEH) : “ México: Hidalgo, Tlanchinol, cerca de La Cabaña , N21°01.328´, W98°38.770´, bosque mesófilo de montaña, 1450 m, en hongo de repisa de tronco, 16-IV-2003, J. Márquez y J. Asiain cols.” . Paratypes: Mexico: Hidalgo: “ Tenango de Doria, camino a La Viejita , N20°19´37.9”, W98°14´39.7”, bosque mesófilo de montaña, 1647 m, NTP-80 (calamar) # 5, 29-III a 12-IV-2011, J. Márquez col.” (1, CC-UAEH) . “ Tlanchinol, cerca de La Cabaña , N21°01.328´, W98°38.770´, bosque mesófilo de montaña, 1450 m, en hongo de repisa de tronco, 16-IV-2003, J. Márquez y J. Asiain cols.” (9, CC-UAEH) . Same data, except: “en tronco caído, 8-XII-1997, J. Márquez col.” (1, MAAS) . “ Zacualtipán, camino a Santo Domingo , N20°37´44.9”, W98°34´51.06”, en troncos, 6 a 7-X-2006, J. Márquez y J. Asiain cols.” (3, CC-UAEH) . “ Zacualtipán, camino a Tizapán , N20°39.076´, W98°36.055´, bosque mesófilo de montaña, 1690 m, trampa de intercepción de vuelo # 1, 14-IV a 28-IV-2011, J. Márquez col.” (1, CC-UAEH) . Same data, except: “trampa de intercepción de vuelo # 3, 20-IX a 4-X-2011 ” (1, CC-UAEH) . Puebla: “ Zacapoaxtla, Ex-hacienda Apulco, cascada La Gloria , N19°54´12”, W97° 37´00”, 1,508 m, dentro de cañada bosque mesófilo de montaña rodeado por pinos, trampa de intercepción de vuelo, 18 a 28-V-2021, familia Márquez-Asiain cols.” (3, MAAS) . Veracruz: “ Córdoba, camino a Plan de Ayala , N18°57´15.2”, W96°58´41”, bosque mesófilo de montaña, 1352 m, en troncos caídos con hongos, 19-V-1999, J. Asiain, Q. Santiago y J. Márquez cols.” (4, MAAS) .

Figures

FIGURE 9. Dorsal view of males of: a) Belonuchus sp. Q, b) B. cyanipennis (holotype), c) B. godmani. Head of B. dichrous showing the temporal carina (red arrow): d) lateral view (male), e) dorsal view (male). Dorsal view of the mandibles of males of: f) B. platypterus, g) B. viridipennis. Mandibles of Belonuchus sp. Q (male): h) dorsal view, i) ventral view. Antennae of males of: j) B. godmani, k) B. cyanipennis. Scale bars = 2.5 mm.

FIGURE 10. Dorsal view of the head of males of: a) Belonuchus julietitae, b) B. singularis, c) B. connexus, d) B. platypterus, e) B. bidens, f) B. nigerrimus, g) B. optatus, h) B. cyanipennis, i) B. godmani. Dorsal view of the head and pronotum of the holotype female of: j) B. optatus.

FIGURE 12. Mesoventrite of males of: a) Belonuchus viridipennis, b) Belonuchus sp. Q, c) B. cyanipennis. Ventral view of the left femur of male anterior leg of: d) B. apiciventris, e) B. oxyporimimus, f) B. oxyporinus, g) B. tepoztecus, h) B. bidens, i) B. viridipennis. Ventral view of the left posterior leg of males of: j) B. julietitae, k) B. linuzensis (small specimen), l) B. linuzensis (large specimen), m) B. metafemoralis, n) B. oxyporimimus, o) B. oxyporinus. Red arrow: intercoxal process of the mesoventrite, blue arrow: transverse discal ridge.

FIGURE 15. Male pregenital sternite of: a) Belonuchus alternans, b) B. oxyporinus, c) B. tepoztecus, d) B. jalappensis, e) B. iridescens, f) B. platypterus, g) B. cyanipennis, h) B. apiciventris, i) B. linuzensis, j) B. metafemoralis, k) B. rufisternus, l) B. tenuistylus, m) B. bidens, n) B. pollens, o) B. longitarsus.

FIGURE 20. Male genital sternite of: a) Belonuchus cifuentesi, b) B. dichrous, c) B. flavipennis, d) B. aenigmaticus, e) B. iridescens, f) B. nigerrimus, g) B. optatus, h) B. platypterus, i) B. juanmorronei, j) B. abnormalis, k) B. pectinipes, l) B. viridipennis, m) Belonuchus sp. Q, n) B. cyanipennis, o) B. godmani. Scale bars = 0.5 mm.

FIGURE 25. Ventral (left) and lateral (right) view of the aedeagus of: a) Belonuchus juanmorronei, b) B. abnormalis, c) B. pectinipes, d) B. viridipennis, e) Belonuchus sp. Q, f) B. cyanipennis, g) B. godmani. Scale bar = 0.5 mm (all figures).

FIGURE 29. Geographical distribution in Mexico of: a) B. linuzensis and Belonuchus sp. Q; b) B. cyanipennis, B. flavipennis and B. tepoztecus.