Belonuchus pollens Sharp, 1885

Márquez, Juan & Asiain, Julieta, 2022, Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae), Zootaxa 5152 (1), pp. 1-129 : 57-58

Belonuchus pollens Sharp, 1885

Figs. 5b, c , 13f , 15n , 19h , 23e , 31a

Belonuchus pollens Sharp, 1885: 431 .

Total body length in males 11.22 mm (range 10.2–13.3 mm), in females 10.02 mm (range 8.1–12.6 mm). Black on head, mandibles, pronotum, scutellum, prosternum, mesoventrite, anterior and middle coxae, basal 3/4 of fifth and entire sixth visible abdominal segment, and abdominal styli. Reddish on maxillary and labial palpi, elytra, metaventrite, legs (except anterior and middle coxae), visible abdominal segments 1–4 and anterior quarter of fifth visible segment.

Head: transverse, ratio length/width in males 0.78 (range 0.74–0.84), in females 0.86 (range 0.80–0.91). Dorsal surface with sulcate longitudinal midline visible in anterior half of head or slightly backward; front slightly foveate at space between antennal insertions. Eyes nearly 0.5 times the cephalic lateral length, not protruding laterally. Antennomeres 4–5 elongate, 6–10 transverse. Males with mandibles 1.14 times longer than head (range 0.85–1.42), in females 0.83 (range 0.77–1.00); each with two small, moderately separated teeth (basal and middle); mandibular channel slightly developed, external margin not carinate and internal margin like impressed line extending forward, far exceeding level of middle tooth. Apical palpomere of maxillary and labial palpi slightly longer than preapical palpomere. Males with head 1.13 times wider than pronotum (range 1.03–1.20), in females almost equally wide (ratio 0.99, range 0.92–1.12).

Thorax: each dorsal row of pronotum with by five punctures; pronotum slightly longer than wide (ratio in males 1.11, range 1.06–1.15, in females 1.15, range 1.1–1.2), as wide at anterior corners as at posterior corners (ratio in males 1.07, range 1.03–1.13, in females 1.05, range 1.02–1.12). Scutellum with punctures slightly denser than on elytra, where are moderately dense. Prosternum with area next to anterior margin slightly elevated. Intercoxal process of mesoventrite shield-shaped; transverse discal ridge well developed, broadly V-shaped, not meeting with margin of intercoxal process laterally. Profemur of males with external row of small, darker spines extending from base to apical third, near level where internal apical spines initiate, which are longer and slenderer than external spines; profemur not widened at apex as in B. bidens . Metafemur of males with spines at ventral surface not clearly arranged in two rows, with large, black and disordered external spines near base; internal spines near base smaller and paler than external spines, arranged in a row reaching nearly 1/2 of length of femur ( Fig. 13f ). Tarsomeres flattened dorsally.

Abdomen: first three visible abdominal tergites with posterior basal transverse carina well developed; adjacent zone slightly or not depressed, with sparse, wide-superficial punctures combined with fine punctures that also cover remaining surface of tergites 1–3; fourth visible tergite with punctures as in previous tergites; tergites 5–6 only with fine punctures. Visible sternites 1–4 with wide-superficial punctures denser than on tergites, covering main part of their surface and combined with fine punctures; sternites 5–6 only with fine punctures. Male pregenital sternite with broad V-shaped emargination at posterior margin ( Fig. 15n ). Male genital sternite moderately large (2.53 times longer than wide), moderately symmetrical, anterior portion occupying 39% and posterior portion 61% of its length, apical emargination deep ( Fig. 19h ). Abdominal styli slender.

Aedeagus: length 1.55 mm; cone shape; apex moderately acute; apical half notably narrower than basal half; internal sac visible ( Fig. 23e ).

Variability. In some specimens the apical half of antennae is reddish-brown, the apical antennomere reddish, and antennomere 4 varies in size relative to size of specimen; in two large males, a small ridge or carina was noted near base of first antennomere, on the side facing forward or towards mandibles, which is not observed in females or in small specimens. The basal tooth of each mandible is very small to undiscernible in small specimens. In one specimen, the prosternum is reddish in anterior half and black in posterior half. The metaventrite may be irregularly black with reddish brown; the proportion of black and reddish color of the fifth visible abdominal segment is a little variable, but the black color never reaches the anterior margin or less than half of the segment, and tergite and genital sternite can be black or pale gray. Pregenital sternite of males can be less deeply emarginate at posterior margin.

Taxonomic comments. Belonuchus pollens is very similar to B. erichsoni , B. mixtecus and B. rufipennis . In taxonomic comments of the first two species, it has been pointed out how to distinguish them. It is distinguished from B. rufipennis by the black procoxae and mesocoxae, spines of posterior femora of males large, unaligned and not exceeding the basal half, and by the shape and size of aedeagus and genital sternite; B. rufipennis has all coxae reddish, males have two rows of small spines along almost entire internal margin of the metafemur, and the aedeagus and genital sternite are of different size and shape. The syntypes of this species were not studied, but we analized some photos of these specimens ( Fig. 5b ; NHM, shared by M. Chani Posse), which together with the information of the original description ( Sharp 1885) allowed us to identify this species.

Material examined (nine males, 10 females): Mexico: Hidalgo: “ La Misión, camino al río Moctezuma , N21°8’30.6”, W99°5’49.1”, bosque tropical subcaducifolio, trampa de intercepción de vuelo, 23-VI a 5-VII-2017, J. Márquez y A. Lora cols.” (1, CC-UAEH). “Pacula, camino Jacala-Pacula, 15.3 km hacia Pacula, selva baja caducifolia, 808 m, N21°02’20.3”, W99°16’32”, NTP-80 (calamar), 7 al 17-VI-2008, J. Márquez col.” (2, CC-UAEH) .

Morelos: “ Tlayacapan , San José de los Laureles, NTP-80, localidad 3, bosque mesófilo de montaña perturbado, IV-1996, J. Márquez col.” (1, MAAS). “ Tlayacapan, selva baja caducifolia, zona 4, NTP-80, IV-1996, J. Márquez y K. Villavicencio cols.” (1, MAAS). Same data, except: “ X-1995 ” (1, MAAS) . Oaxaca: “carretera Oaxaca-Tehuantepec , km 93.6 (delante de Totolapan), matorral xerófilo, 1212 m, N16°40’667” W96° 13’676”, en nopal podrido, 18-XI-1999, J. Márquez col.” (1, MAAS). “ San Mateo Peñasco, en jardín, 1788 m, N17°09’7”, W97°3’38”, en nopal podrido, 6-VIII-2001, S. Bautista, J. Asiain y J. Márquez ” (1, MAAS). “km 2 carretera El Camarón-San Carlos Yautepec, 850 m, trampa de intercepción de vuelo, 21 a 22-agosto-2003, Q. Santiago y L. Delgado cols.” (2, IEXA). Puebla: “km 4 carretera Tepexco – Izúcar de Matamoros , N18°39´22”, W98°39´53.2”, 1350 m, trampa de intercepción de vuelo #2, 18-VII-2015, A. y L. Delgado col.” (1, IEXA). Tamaulipas: “ Adolfo López Mateos, El Chamalito , trampa de intercepción de vuelo diurna, 15-IX-2003, L. Cervantes y Q. Santiago cols.” (1, IEXA). Veracruz: “ Xalapa, San Antonio Paso del Toro , trampa de intercepción de vuelo #2, 25-VII-2015, K . Cortes y Q. Santiago cols.” (5, IEXA). Same data, except: “ 19-IX-2015 ” (1, IEXA). Same data, except: “ 17-X-2015 ” (1, IEXA) .

Figures

FIGURE 5. Dorsal view of males (except figure g) of: a) B. mixtecus (holotype), b) B. pollens (syntype, NHM©), c) B. pollens, d) B. rufipennis, e) B. basiventris (syntype, NHM©), f) B. basiventris, g) B. connexus (female holotype of B. xanthopus, synonym of B. connexus, shared by A. Kovalev©), h) B. connexus. Scale bars = 2.5 mm.

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 19. Male genital sternite of: a) Belonuchus tepoztecus, b) B. trochanterinus, c) B. zunilensis, d) B. bidens, e) B. erichsoni, f) B. jalappensis, g) B. mixtecus, h) B. pollens, i) B. rufipennis, j) B. basiventris, k) B. connexus, l) B. longitarsus, m) B. rufiventris, n) B. xanthomelas, o) B. ephippiatus, p) B. moroni. Scale bars = 0.5 mm.

FIGURE 23. Ventral (left) and lateral (right) view of the aedeagus of: a) Belonuchus bidens, b) B. erichsoni, c) B. jalappensis, d) B. mixtecus, e) B. pollens, f) B. rufipennis, g) B. basiventris, h) B. connexus (at center, detail of the apex of the median lobe), i) B. longitarsus (at center, detail of the apex of the median lobe). Scale bar = 0.5 mm (all figures).

FIGURE 31. Geographical distribution in Mexico and Guatemala of: a) Belonuchus pollens; b) B. rufipennis.