Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae) Author Márquez, Juan 0000-0001-5423-3545 marquezorum@gmail.com Author Asiain, Julieta 0000-0002-7958-4779 asiainae@yahoo.com text Zootaxa 2022 2022-06-10 5152 1 1 129 http://zoobank.org/92e9dd85-6cc6-4602-bd7c-c51f49ceef47 journal article 10.11646/zootaxa.5152.1.1 1175-5326 6630873 92E9DD85-6CC6-4602-BD7C-C51F49CEEF47 Belonuchus tepoztecus sp. nov. http://zoobank.org/NomenclaturalActs/4790a935-2ad7-4ef0-bd6f-bad5e420780d Figs. 4b , 11d , 12g , 14b , 15c , 19a , 22g , 29b Total body length 11.6 mm . Black on head, antennae, mandibles (except apex and internal margins), pronotum, scutellum, posterior half of prosternum, sixth visible abdominal segment (except anterior border) and abdominal styli. Reddish on elytra, legs, sterna (except posterior half of prosternum and anterior half of mesoventrite), visible abdominal segments 1–5 and anterior border of sixth. Brown at apex and internal margins of mandibles, maxillary and labial palpi, anterior half of mesoventrite and genital segment. Head : transverse, ratio length/width 0.69. Dorsal surface with sulcate longitudinal midline visible from anterior margin to almost posterior margin of head, but less notable in posterior half; front clearly foveate between antennal insertions. Eyes slightly longer than 0.5 times the cephalic lateral length, not protruding laterally.Antennomeres 4–5 elongate, 6–7 as long as wide, 8–10 transverse. Mandibles 1.58 times longer than head; each with two well separated teeth (basal and middle); mandibular channel well developed, with external and internal margins moderately separated at base, internal margin carinate, extending forward to level of middle tooth. Apical palpomere of maxillary and labial palpi nearly 1.25 times longer than preapical palpomere. Head 1.3 times wider than pronotum. Thorax : each dorsal row of pronotum with five punctures; pronotum almost as long as wide (ratio 1.06) and almost as wide at anterior corners as at posterior corners (ratio 1.06). Scutellum with punctures denser than on elytra, latter with sparse punctation, with fine, pale setae. Prosternum with an elevated area next to anterior margin and a transverse line near the place where black color initiates. Intercoxal process of mesoventrite shield-shaped; transverse discal ridge well developed, broadly U-shaped, reaching close to margin of intercoxal process, but not touching it ( Fig. 11d ). Profemur with external row of spines initiating near basal third and reaching the apex or very close to it, the most apical spines are placed at same level as spines of internal apex that are less numerous and shorter; external spines increasing in size from base to apex, where being conspicuous ( Fig. 12g ). Metatrochanter modified like a hook that is as long as or longer than 1/2 length of metafemur, hook elongate, slender, with apex strongly curved and acute; metafemur with internal margin curved at level of overlap with hook; metatibia clearly curved at internal margin near basal third. Tarsomeres moderately flattened dorsally. Abdomen : first three visible tergites with posterior basal transverse carina well developed, adjacent zone slightly depressed and narrow ( Fig. 14b ); tergite one with sparse, wide-superficial punctures in depression, becoming denser toward remaining surface; depression on visible tergites 2–3 with wide-superficial punctures denser than on remaining surface; all tergites also with fine punctures that are denser on last three visible tergites. All sternites ( Fig. 14b ) with wide-superficial punctures denser than on tergites, but on sternites 5–6 less dense than on remaining sternites, also all sternites with fine punctures as on tergites. Male pregenital sternite without emargination at posterior margin ( Fig. 15c ). Genital sternite short (2.31 times longer than wide), moderately asymmetrical, anterior portion occupying 40% and posterior portion 60% of its length; apical sinuation deep ( Fig. 19a ). Abdominal styli very slender. Aedeagus : length 1.8 mm ; oval-elongate shape, apex wide and slightly convex; sides with slight constriction before apex, widened toward base; basal half moderately wider than apical half, most notable in lateral view; paramere with irregular anterior margin (or a little jagged); internal sac visible ( Fig. 22g ). Variability . Total body length in males 10.8 mm (range 9.9–12.0 mm), in females 9.8 mm (range 8.8–10.6 mm ); ratio length/width of head in males 0.69 (range 0.67–0.74), in females 0.84 (range 0.82–0.87); ratio mandibular length/cephalic length in males 1.56 (range 1.33–1.70), in females 0.90 (range 0.82–0.96); ratio cephalic width/ pronotal width in males 1.30 (range 1.21–1.36), in females 1.08 (range 1.00–1.15); ratio length/width of pronotum in males 1.06 (range 1.02–1.10), in females 1.14 (range 1.10–1.18); ratio anterior width/posterior width of pronotum in males 1.1 (range 1.07–1.18), in females 1.03 (range 1.00–1.04). Sulcate longitudinal midline of head may be less visible than in the holotype . In some specimens the entire prosternum is black. Posterior margin of male pregenital sternite can be weakly emarginate or without emargination, with the latter state being the most frequent. Taxonomic comments . This species is very similar to B. apiciventris and B. rufisternus , both in the color pattern as well as in the total length and other characters. In the description of B. apiciventris the main differences with this species are pointed out. Belonuchus tepoztecus is distinguished from B. rufisternus by having the anterior half of the mesoventrite black (or at least dark) and the posterior half reddish, five punctures in each dorsal row of pronotum, male pregenital sternite with emarginate posterior margin and different male genital sternite and aedeagus. Belonuchus rufisternus has the entire mesoventrite reddish, six punctures in each dorsal row of pronotum, male pregenital sternite moderately emarginate in posterior margin, and a different male genital sternite and aedeagus. Etymology . The name of this species is derived from the geographical place of origin of the specimens, which is known as “Sierra del Tepozteco” in the state of Morelos . Type material ( 63 males ): Holotype (male, CC-UAEH ) : “ México : Morelos , Tlayacapan , San José de los Laureles , camino a Amatlán , bosque mesófilo de montaña, 1783 m , N18°58.7’ , W99°01’ , NTP-80 (calamar), 1 a 30-VII-1995 , J. Márquez col.” . Paratypes (all specimen males): same data as holotype (16, CC-UAEH ) . Same data, except: “ 1 a 30-VIII-1996 ” (6, MAAS ) . Same data, except: “ 1 a 30-IX-1995 ” (5, MAAS ) . Mexico : Morelos : “ Tlayacapan , camino a Santa Catarina , N18°57´13” , W99°00´15” , 1550 m , Loc-4, selva tropical caducifolia, 1-30- VII-1995 , K. Villavicencio y J. Márquez cols.” (3, MAAS ) . Same data, except: “ 1 a 30-VIII-1995 ” (1, MAAS ) . Same data, except: “ 1 a 30-IX-1995 ” (10, MAAS ) . Same data, except: “ 1 a 30-X-1995 ” (10, MAAS ) . Same data, except: “ 1 a 30-XI-1995 ” (2, MAAS ) . Same data, except: “ 1 a 30-XII-1995 ” (2, CC-UAEH ). “ Tlayacapan , San José de los Laureles , Loc-1, N18°58’33” , W99°00’47” , 2000 m , bosque de pino-encino, NTP-80 (calamar, 1-30- IX-1995 , J. Márquez col.” (1, MAAS ). Same data, except: “ 1 a 30-XI-1995 ” (1, MAAS ). “ Tlayacapan , San José de los Laureles , bosque mesófilo de montaña, Loc. 3, 1803 m , NTP-80 (pulpo), 28-X a 19-XI-1989 , G. Quiroz y J. L. Navarrete cols.” (1, MAAS ) . Same data, except: Loc. 5, 1751 m , 21-VII a 24-VIII-1991 ” (1, MAAS ). Same data, except: “bosque de pino-encino, Loc. 1, 1830 m , 8 a 29-IX-1990 ” (1, MAAS ) . Same data, except: “ 3 a 30-VI-1990 ” (1, MAAS ) . “ Ocuituco , Jumiltepec , trampa de fruta, 22-VI-1998 , A. C. Deloya col.” (1, MAAS ) .