Belonuchus platypterus ( Sharp, 1885 )

Márquez, Juan & Asiain, Julieta, 2022, Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae), Zootaxa 5152 (1), pp. 1-129 : 83-84

Belonuchus platypterus ( Sharp, 1885)

Figs. 8d , 9f , 10d , 11k , 15f , 20h , 24–l , 30a

Philonthus platypterus Sharp, 1885: 412 . Belonuchus platypterus comb. nov. ex Philonthus ( Chani-Posse et al. 2018b) .

Total body length in males 8.66 mm (range 7.8–9.4 mm), in females 8.75 mm (range 8.4–9.1 mm). Body black, except fifth and sixth visible abdominal segments, genital segment and abdominal styli, which are reddish or yellowish.

Head ( Fig. 10d ): subquadrate shape, slightly convex dorsally; ratio length/width in males 0.90 (range 0.86– 0.93), in females 0.90 (range 0.88–0.91). Dorsal surface with sulcate longitudinal midline visible only in anterior half of head; front slightly foveate between antennal insertions. Eyes slightly shorter than 0.5 times the cephalic lateral length, weakly protruding laterally. First antennomere as long as antennomeres 2–3 combined, antennomere 3 slightly longer than antennomere 2, 3–5 elongate, 6–10 transverse. Mandibles ( Fig. 10d ) shorter than head (ratio in males 0.855, range 0.81–0.92, in females 0.78, range 0.76–0.80); left mandible with two small teeth, very close to each other, interspace C-shaped; right mandible with a large middle tooth; basal tooth in both mandibles barely visible; mandibular channel weakly developed, external margin not carinate and internal margin like impressed line extending slightly beyond level of middle tooth, where it is extended slightly toward inside. Apical palpomere of maxillary and labial palpi nearly 1.5 times longer than preapical palpomere. Ventral surface with two setiferous punctures placed in external anterior quarter. Head wider than pronotum (ratio in males 1.22, range 1.15–1.28, in females 1.11, range 1.10–1.12).

Thorax: each dorsal row of pronotum with five punctures; pronotum slightly longer than wide (ratio in males 1.12, range 1.08–1.15, in females 1.11, range 1.08–1.14) and slightly wider at anterior corners than at posterior corners (ratio in males and females 1.09, range in males 1.05–1.14, in females 1.07–1.11). Scutellum with very dense punctures, as on elytra, but wider than on elytra. Prosternum without modifications. Intercoxal process of mesoventrite triangularly scutellum-shaped, distinctly extended posteriad; transverse discal ridge faintly impressed, broadly U-shaped, finely crenulate, reaching very close to margin of intercoxal process laterally ( Fig. 11k ). Profemur of both sexes without rows of spines, except for two to three small spines near to apex of internal side. Rest of legs (except tarsomeres) without modifications. Tarsomeres flattened and slightly excavated dorsally.

Abdomen: first three visible tergites with posterior basal transverse carina well developed; adjacent area moderately depressed and moderately wide; visible tergites 1–2 with wide-superficial punctures combined with fine punctures on almost entire surface, becoming less dense toward posterior margin; visible tergites 3–4 with widesuperficial punctures denser at anterior half than in posterior half; visible tergites 5–6 only with fine punctures. First visible sternite with posterior basal transverse carina completely developed, sternites 2–3 with incomplete posterior basal transverse carina, only visible at center; visible sternite 4 without posterior basal transverse carina; sternites with punctures as on tergites, but slightly denser; with coarse, meshed microsculpture near anterior margin of each sternite, at sides is extended backward, remaining of surface of each sternite with finer microsculpture of wavy lines. Male pregenital sternite not emarginate at posterior margin ( Fig. 15f ). Male genital sternite moderately elongate (2.6 times longer than wide), slightly asymmetrical, anterior portion occupying 25% and posterior portion 75% of its length; apical emargination moderately deep and rather broad ( Fig. 20h ). Abdominal styli slender, with external margin slightly curved.

Aedeagus: length 1.0 mm; oval-elongate shape; apex subacute; basal half moderately wider than apical half, occupying slightly more than 1/2 of aedeagus length, so apical portion appears short; internal sac clearly visible ( Fig. 24–l ).

Variability. In addition to measurements and ratios included in the description, the apical antennomere, and sometimes also the subapical one, may be paler than previous ones (reddish). Tarsomeres can be reddish brown instead of black; even all legs can be reddish brown. The reddish coloration of fifth visible abdominal segment is darker than that of sixth visible segment, while genital segment is almost yellow. The fine punctures of sixth visible abdominal segment are widely dispersed compared to that of fifth segment.

Taxonomic comments. This species is distinguished from the rest of species in this group by being almost completely black, except for the last two visible abdominal segments that are reddish, the left mandible with two middle teeth very close to each other, the tarsomeres markedly flattened dorsally, the male pregenital sternite not emarginate at posterior margin ( Fig. 15f ), the male genital sternite moderately elongate (2.6 times longer than wide) ( Fig. 20h ) and aedeagus oval-elongate, with slightly acute apex and basal half moderately wider than apical half ( Fig. 24–l ). Although the type material of this species was studied, the redescription was based on non-type specimens because the types were returned to the collection of origin earlier.

Type material examined (one male, one female): Lectotype (male, NHM): “ Philonthus platypterus Type D.S. Cerro Zunil. 4–5000 ft. (On the plaque with the specimen) / Type/ Cerro Zunil. Guatemala. Champion/ B. C. A. Col. I. 2. Philonthus platypterus, Sharp / Sharp Coll. 1905.-313/ Lectotype Philonthus platypterus Sharp, 1885 des. Chani Posee et al. 2018” . Paralectotype: same data as lectotype, except: “ Paralectotype Philonthus platypterus Sharp, 1885 , des. Chani Posse et al. 2018” (f 1, NHM) . Additional material examined (seven males, three females): Mexico: Hidalgo: “ Juárez , bosque mesófilo perturbado, 1970 m, N20°47’9.6”, W98°49’5.2”, trampa de intercepción de vuelo #2, 7 al 14-III-2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols.” (1, CC-UAEH) . “ Tenango de Doria , camino a La Viejita, bosque mesófilo de montaña, 1647 m, N20°19.0’ 37.9”, W98°14.0’ 39.7”, trampa de intercepción de vuelo #3, 5 a 10-V-2013, N. Gutiérrez col.” (2, CC-UAEH) . “ Tepehuacán de Guerrero, Chilijapa , bosque mesófilo de montaña, 1401 m, N21°01.2’ 5.1”, W98°51.8’ 2.1”, trampa de intercepción de vuelo #2, 27-VIII al 10-IX-2011, J. Márquez col.” (1, CC-UAEH) . “ Tlanchinol, camino a Apantlazol, El Pozo , bosque mesófilo de montaña, 1391 m, N20°59’6.73”, W98°37’ 39.86”, trampa de intercepción de vuelo #1, 22-IV al 10-V-2011, J. Márquez e I. Martínez cols.” (1, CC-UAEH) . Same data, except: “1 al 22-X-2011 ” (1, CC-UAEH) . “ Zacualtipán, camino a Tizapán , bosque mesófilo de montaña, 1690 m, N20°39.076’ W98° 36.055’, trampa de intercepción de vuelo #2, 14 al 28-IV-2011, J. Márquez col.” (2, 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.” (1, MAAS) Veracruz: “ Córdoba, camino a Plan de Ayala , bosque mesófilo de montaña, 1352 m, N18°57’15.2”, W 96°58’41”, NTP-80 (calamar), 20-III al 17-IV-1999, J. Asiain, Q. Santiago y J. Márquez cols.” (1, MAAS) .

Group 7: viridipennis

Included species: B. abnormalis (Shap, 1885) , B. pectinipes Bernhauer, 1910 , B. viridipennis Baudi di Selve, 1848 , and Belonuchus sp. Q.

Diagnosis of the viridipennis group: without any of the male sexual structures indicated in the previous groups; head without temporal carina; mandibles almost as long as head (ratio mandibular length/cephalic length 0.82-1.09; Fig. 9a ), right mandible with two medial teeth, one of them (usually the longest one) in ventral position and the other in dorsal position ( Figs. 9g –i ); body color mainly black (sometimes with the sixth or fifth and sixth abdominal segments reddish); specimens of small size (body length 6.6-11.9 mm); tarsomeres somewhat flattened dorsally; aedeagus with reduced paramere ( Figs. 25b–e ).

Key to Mexican species of Belonuchus of the viridipennis group

1 Last two visible abdominal segments mainly reddish, remaining body black ( Figs. 8f , 9a )............................ 2

- Body entirely black or reddish-brown ( Figs. 8g, h )........................................................... 3

2(1) Head oval ( Fig. 8f ); each dorsal row of pronotum with three punctures, which are widely separated from each other; male pregenital sternite with a narrow and moderately deep emargination at posterior margin, V-shaped (Fig. 17a); male genital sternite almost symmetrical, apical emargination less deep ( Fig. 20j ); aedeagus as in Fig. 25b..................... B . abnormalis

- Head subquadrate ( Fig. 9a ); each dorsal row of pronotum with five almost equidistant punctures; male pregenital sternite with distinct, deep and broad V-shaped emargination at posterior margin (Fig. 17e); male genital sternite very asymmetrical, apical emargination deep ( Fig. 20m ); aedeagus as in Fig. 25e ........................................... Belonuchus sp. Q

3(1) Body black, elytra with a faint iridescent reflection ( Fig. 8h ); head subquadrate; left mandible with only one middle tooth of peculiar shape ( Fig. 9g ), right mandible with two teeth, ventral tooth longer than dorsal tooth, without basal tooth; pronotum distinctly wider at anterior corners than at posterior corners (ratio 1.23–1.53); metafemora with two rows of spines in both sexes ( Fig. 13j ); male with metacoxae and metatrochanters without spines; aedeagus as in Fig. 25d.............. B . viridipennis

- Body reddish-brown ( Fig. 8g ); head oval; left mandible with a basal tooth and two middle teeth, the longer in dorsal position and the smaller in ventral position, right mandible with a basal tooth and three middle teeth, the longer in ventral position and higher than small dorsal teeth; pronotum slightly wider at anterior corners than at posterior corners (ratio 1.13); metafemora without row of spines; coxae and trochanters of posterior legs of males with large, black spines irregularly distributed; aedeagus as in Fig. 25c................................................................................ B . pectinipes

Figures

FIGURE 8. Dorsal view of males of: a) Belonuchus aenigmaticus (paratype), b) B. nigerrimus, c) B. optatus, d) B. platypterus, e) B. juanmorronei, f) B. abnormalis, g) B. pectinipes (paralectotype), h) B. viridipennis. Scale bars = 2.5 mm.

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 11. Mesoventrite of males of: a) Belonuchus cariniventris, b) B. oxyporinus, c) B. rufisternus, d) B. tepoztecus, e) B. bidens, f) B. jalappensis, g) B. longitarsus, h) B. ephippiatus, i) B. dichrous, j) B. flavipennis, k) B. platypterus, l) B. juanmorronei, m) B. iridescens. Red arrow: intercoxal process of the mesoventrite, blue arrow: transverse discal ridge, green arrow: longitudinal carina in anterior half.

FIGURE 13. Ventral view of the left posterior leg of males of: a) B. trochanterinus, b) B. tenuistylus, c) B. zunilensis, d) B. rufipennis, e) B. mixtecus, f) B. pollens, g) B. ephippiatus, h) B. aenigmaticus, i) B. iridescens, j) B. viridipennis. Tarsomeres of posterior leg of males of: k) B. colon, l) B. ephippiatus. Yellow ovals: median longitudinal groove.

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 24. Ventral (left) and lateral (right) view (except e) of the aedeagus of: a) Belonuchus rufiventris, b) B. xanthomelas (at center, detail of the apex of the median lobe), c) B. ephippiatus, d) B. moroni, e) B. cifuentesi (left: detail of paramere, right: ventral view; from Rodríguez and Navarrete-Heredia, 2016), f) B. dichrous, g) B. flavipennis, h) B. aenigmaticus, i) B. iridescens, j) B. nigerrimus, k) B. optatus, l) B. platypterus. Scale bar = 0.5 mm (all figures, except e).

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 30. Geographical distribution in Mexico and Guatemala of: a) Belonuchus abnormalis, B. bidens and B. platypterus; b) B. basiventris and B. jalappensis.