Belonuchus connexus ( Say, 1830 )

Márquez, Juan & Asiain, Julieta, 2022, Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae), Zootaxa 5152 (1), pp. 1-129 : 63-65

Belonuchus connexus ( Say, 1830)

Figs. 5g, h , 10c , 16–l , 19k , 23h , 32a

Staphylinus connexus Say, 1830: 35 , also 1834: 448. Belonuchus connexus comb. nov. ex Staphylinus ( Erichson 1840: 927) .

Belonuchus xanthopus Solsky, 1868: 139 , new synonymy.

Philonthus celatus Sharp, 1885: 420 , new synonymy. Belonuchus celatus comb. nov. ex Philonthus ( Chani-Posse et al. 2018b) .

Total body length in males 9.70 mm (range 8.8–10.3 mm), in females 9.67 (range 8.5–10.3 mm). Body black, except elytra and, in some specimens, legs reddish (see variability). In legs, sterna and abdomen the color can be brown.

Head: transverse, ratio length/width in males 0.78 (range 0.73–0.82), in females 0.88 (range 0.85–0.92). Dorsal surface with sulcate longitudinal midline visible in anterior half of head; front weakly foveate between antennal insertions. Eyes somewhat small, less than 0.5 times the cephalic lateral length, slightly protruding laterally. Antennomere 4 as long as wide, antennomeres 5–10 transverse. Males with mandibles 1.15 times longer than head (range 1.08–1.27), in females shorter than head (ratio 0.84, range 0.77–0.88); males with mandibles notably expanded at base, each with two clearly separated teeth (basal and middle) of almost equal size; mandibular channel well developed, external margin carinate and internal margin like conspicuous carinate line, extending forward beyond level of middle tooth. Apical palpomere of maxillary and labial palpi nearly 1.25 times longer than preapical palpomere. Male with head 1.22 times wider than pronotum (range 1.15–1.29), in females almost equally wide (ratio 1.05, range 1.00–1.08).

Thorax: each dorsal row of pronotum with five punctures; pronotum slightly longer than wide (ratio in males 1.13, range 1.11–1.16, in females 1.18, range 1.11–1.23); in males, slightly wider at anterior corners than at posterior corners (ratio 1.10, range 1.06–1.12), in females almost equally wide (ratio 1.04, range 1.02–1.08). Scutellum with punctures denser than elytra, elytral punctation moderately dense. Prosternum with area adjacent to anterior margin slightly elevated transversally and delimited backward by an impressed line. Intercoxal process of mesoventrite shield-shaped; transverse discal ridge well developed, broadly U-shaped, meeting margin of intercoxal process laterally. Profemur of males with internal margin only discernible near apex, there with five to six aligned spines of moderate size; external margin with row of spines only in anterior third, not reaching apex, spines in middle part of row larger than spines at sides, even larger than apical spines of internal margin. Posterior legs of males and females without modifications. Tarsomeres flattened dorsally.

Abdomen: first three visible tergites with posterior basal transverse carina well developed, which is curved at sides of tergites 1–2 and straight in tergite 3; depressed adjacent area slightly deeper and narrower than in B. xanthomelas , but with punctures on tergites and sternites as has been described for B. xanthomelas ; anterior half of sternites and near margins of tergites with wrinkled microsculpture. Male pregenital sternite slightly emarginate at posterior margin ( Fig. 16–l ). Male genital sternite moderately elongate (2.76 times longer than wide), very asymmetrical, anterior portion occupying 34% and posterior portion 66% of its length, apical emargination deep ( Fig. 19k ). Abdominal styli slender.

Aedeagus: length 1.1 mm; cone-shaped, sides abruptly narrowed subapically toward sharply point tip; basal half moderately wider than apical half, although in lateral view, basal half is notably widened; internal sac visible ( Fig. 23h ).

Variability. The color of legs ranges from reddish in specimens from central and northern Mexico, to almost black in specimens from southern and southwestern states. In some specimens, the entire ventral portion of the body and abdomen are dark brown rather than black. The anterior borders of first three or four visible abdominal segments may be lighter (brown or reddish) than the rest of the segment and in other specimens the posterior border may be lighter. In small males, the emargination of the pregenital sternite is less noticeable than in large males. The rest of the variation is included in the description, in addition to the general variation related to the sex and size of the specimens.

Taxonomic comments. Belonuchus connexus is rarely confused with any other species in this group because of the black body, with only the elytra and (usually) legs reddish, which may also be almost black.

Say (1830: 35, 1834: 448) described B. connexus (as Staphylinus ) and commented that it is very similar to B. ephippiatus (as Staphylinus ), which he described a paragraph earlier. He mentions that the main differences between both species is that B. connexus is smaller (just over 9 mm), has cinnamon red legs like the color of the elytra, and a black abdomen, without an iridescent dark blue reflection. On the other hand, B. ephippiatus is larger (more than 15 mm), the legs are black and the abdomen has a dark blue iridescent shine. The collection records that we have of these two species indicate that they are sympatric, frequently coexisting in decomposing cacti in semiarid sites, so we assume that the original description of these two species followed by one another may be due to being collected together. The Say type material is known to be destroyed ( Smetana 1995), so it was not possible to review the type specimen(s) of B. connexus . Despite this, the characters included in the original description, as well as the sympatric distribution that it presents with B. ephippiatus , allow us to propose that B. xanthopus as described by Solsky (1868) is the same species as B. connexus since Solsky mentions similar characteristics.

Although a photo of the holotype of B. xanthopus was available, its usefulness was limited because few diagnostic characters are visible as it is a possibly teneral female; however, the information in the original description, along with the photo, is sufficient for the proposed synonym. Sharp (1885), when referring to the differences between B. xanthopus and B. celatus , the latter of which is also proposed here as a synonym of B. connexus , stated the following: “This species is distinguished from P. xanthopus always only because of the dark color of the legs. The sexual characteristics are the same in these species as they are in P. xanthomelas and P. basiventris ” ( Sharp 1885: 420) . The revised specimens from Morelos and Oaxaca have darker legs than those from other states, but all the other characters, including the aedeagus, body length, pregenital and genital sternites, etc., are the same. Therefore, the dark or reddish legs can be considered as (possibly geographic) variation.

The following are some relevant characters coincident in the original descriptions of B. connexus ( Say, 1830) , B. xanthopus Solsky, 1868 , and B. celatus ( Sharp, 1885) , which support the synonymies here proposed: total body length 7–11 mm; body black shiny, elytra and legs red, mandibles, antennae and abdominal segments piceous-red, scutellum piceous-black; male mandibles expanded; each dorsal row of pronotum formed by five punctures; femora of anterior legs with long spines along the margin; abdomen with sparse punctures; and sixth ventral segment emarginate.

Type material. The holotype or syntypes of B. connexus are considered destroyed ( Smetana 1995), so it is not possible to study them. Two photographs (ventral view and dorsal view) of the female holotype of B. xanthopus , probably teneral, provided by A. Kovalev (Zoological Institute of the Russian Academy of Sciences) were reviewed. The type material of B. celatus was not studied, although a photograph of the lectotype designated by Chani-Posse et al. (2018b) was analyzed. Additional material examined (94 males, 87 females): Mexico: Aguascalientes: “San José de Gracia, Estación Biológica Agua Zarca, bosque de encino y matorral espinoso, 2200 m, N22°5’30”, W102°34’45”, en cactácea descompuesta, 23-VII-2015, J.A. Escoto-Moreno, J. Escoto-Rocha y J. Márquez cols. (2, CC-UAEH). Hidalgo: “Acatlán, Loma Larga, El Llano, cultivos de encinos y matorral xerófilo, 2097 m, N20°16’13”, W98°28’18”, en nopales podridos, 13-VII-2010, J. Asiain, D. López y J. Márquez cols.” (5, CC- UAEH). Same data, except: “NTP-80 (calamar) 13 al 20-VII-2010, J. Márquez y J. Asiain cols.” (11, CC-UAEH). “Actopan, camino a La Magdalena, matorral xerófilo perturbado, 2236 m, N20°17’39.1”, W98°53’13.6”, en nopal podrido, 31-X-2007, J. Márquez, J. Asiain, Z. Huerta y C. Pedraza cols.” (2, CC-UAEH). “Atotonilco el Grande, 3 km NE de Montecillos, bosque Juniperus-Quercus, N20°18’9”, W98°36’17”, trampa de intercepción de vuelo, 12 al 19-VII-2010, J. Márquez y J. Asiain cols.” (1, CC-UAEH). “Atitalaquia, Texas, UTM 14Q0481484-2214345, 2,210 m, matorral xerófilo con cultivo de maíz y alfalfa, en NTP-80, 25-VIII a 10-IX-2009, J. Islas col.” (5, CC-UAEH). “Cardonal, Grutas de Tolantongo, cultivo de aguacate, en fruto podrido, 17-VII-1994, J. Márquez col.” (1, MAAS). “Huasca de Ocampo, Sta. María Regla alrededores del rio cultivos y Juniperus , en nopales podridos, 27-VIII-2014, J. Márquez col.” (1, CC-UAEH). “Ixmiquilpan, La Flor, N20°25.419´, W99°8.315´, 1839 m, matorral xerófilo, NTP-80 (calamar), 27-VIII a 8-IX-2009, J. Islas col.” (2, CC-UAEH). “Barranca de Metzquitlitlan, matorral xerófilo, en biznaga podrida, 14-II-1992, J. Márquez col.” (5, MAAS). “Barranca de Meztquititlán, matorral xerófilo, en biznaga podrida, 14-II- 1992, J. Márquez col.” (4, MAAS). “Mineral de la Reforma, Colonia Carboneras, matorral xerófilo y cultivos, en composta, 7-VII-2003, L. Garduño col.” (1, CC-UAEH). “Mineral de la Reforma, cerca de Pachuquilla camino a la Mina, matorral xerófilo, en nopales podridos, 28-V-2009, J. Bueno y J. Márquez cols.” (2, CC-UAEH). “Mineral de la Reforma, Colinas de Plata, N20°4´43.4”, W98°43´46.4”, en composta de jardín, 4-IX-2016, J. Asiain col.” (3, MAAS). “Tasquillo, delante de Motho, matorral xerófilo, 1652 m, N20°32’13.1”, W 99°16’43.2”, cascara de nuez, 3-IX-2005, J. Márquez, F. Ramírez y J. Asiain cols.” (1, CC-UAEH). “Tetepango, UTM 14Q0484780-2221394, 2,152 m, matorral xerófilo, NTP-80 (cal.), 25-VIII a 10-IX-2009, J. Islas col.” (4, CC-UAEH). “Pachuca, en composta, 1320 m, IX-2003, L. Garduño col.” (2, CC-UAEH). “Pacula, Puerto Grande, bosque de encino, 2109 m, N20°53.850’, W99°19.562’, NTP- 80 #3, 28-III al 04-IV-2009, J. Márquez, M. Rivero, M. Torres, M. Vargas y J. Sánchez cols.” (2, CC-UAEH). Same data, except: “NTP-80 #1 (calamar)” (1, CC-UAEH). Same data, except: “NTP-80 #2 (calamar)” (3, CC-UAEH). “Santiago de Anaya, El Encinal, N20°26’56.0”, W98° 55’20.5”, matorral xerófilo y encinos, trampa cebada con nopales fermentados, 24-VI a 1-VII-2018, F.M. Gómez e I.S. Hernández cols.” (1, CC-UAEH). Same data, except: “ 18 a 25-VII-2018 ” (2, CC-UAEH). “Singuilucan, Matías Rodríguez, N20°3.734’, W98°33.136’, bosque de pino-encino, 2740 m, en troncos con hongos, 8-IV-2007, J. Márquez y J. Asiain cols.” (1, CC-UAEH). “Tepatitlán, Presa Endho, Pedro Ma. Anaya, N20°9.621´, W99°21.874´, 2025 m, matorral xerófilo y cultivo de maíz, NTP-80 (calamar), 26-VIII a 10-IX-2009, J. Islas col.” (1, CC-UAEH). “Zempoala, La Trinidad, matorral xerófilo, 2452 m, N19°57.697’, W98°43.936’, NTP-80 (carne de cerdo) 4 al 25- VIII-2004, G. Pajas y J. Márquez col.” (1, CC-UAEH) “Zempoala, Mina San Juan Tepemazalco, matorral xerófilo, 2200 msnm, N19°54’29.3”, W98°43’47.5”, semana 4, 4 al 30-IV-2007, NTP-80 (carne de cerdo), T2, Z. Huerta y J. Márquez cols”. (1, CC-UAEH). “Zempoala, Sierra de Pitos, cerca de Mina San Juan Tepemazalco, matorral xerófilo, 2550 m, N19°54’, W 98°43’, en nopales podridos, 10-IX-2002, J. Asiain y J. Márquez cols.” (3, CC-UAEH). “Zempoala, La Trinidad, matorral xerófilo, 2452 msnm, N19°57.697’, W98° 43.936’, NTP-80 (carne de cerdo) 4 al 25-VIII-2004, G. Pajas y J. Márquez col.” (2, CC-UAEH). “Zempoala, La Trinidad, matorral xerófilo, 2459 msnm, N19°57’605”, W98°43’055”, NTP-80 (carne de cerdo) 4 al 11-VIII-2004, T6, G. Pajas y J. Márquez cols.” (1, CC- UAEH). “Zimapán, P. N. Los Mármoles, Trancas, bosque de pino-encino, 2444 m, N20°48’12.222”, W99°14’41”, en nopal podrido, 18-IX-2007, J. Márquez, J. Asiain y S. Sierra cols.” (2, CC-UAEH). Same data, except: “NTP-80 (calamar), 10-X al 13-XI-2007 ” (1, CC-UAEH). “P. N. Los Mármoles, Zimapán, Minas Viejas, bosque de encino, 1897 m, N20°55’23.7”, W99°12’28”, en excremento, 20-X-2006, J. Márquez y J. Asiain cols.” (3, CC-UAEH). Morelos: “Tlayacapan, San José de los Laureles, localidad 5, cultivos de temporal, NTP-80, X-1995, K. Villavicencio y J. Márquez cols.” (3, MAAS). Same data, except: “localidad 3, bosque mesófilo de montaña perturbado, IV-1996, J. Márquez col.” (1, MAAS). “Tlayacapan y Tlalnepantla camino a San José de los Laureles, cultivo temporal, en nopales podridos, 15-VIII-1998, R. Toledo y J. Márquez cols.” (1, MAAS). “Tlayacapan, selva baja caducifolia, zona 4, NTP-80, VII-1996, J. Márquez y K. Villavicencio cols.” (1, MAAS). Same data, except: “ III- 1996 ” (1, MAAS). Oaxaca: “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 cols.” (4, MAAS). “San Juan Chicomesuchitl, Rio Grande, 16-IX- 1999, en nopal y mandarina podridos, J. Márquez col.” (m 1, MAAS). “Zaachila, 21-VIII-37, Mex, 4500 ft / A. R. Mead collector” (m 2, f 1, FMNH). Querétaro: “Ezequiel Montes, Bernal, El Descanso, matorral xerófilo, 2100 m, 5-III-1999, en nopales podridos, S. Arenas y J. Márquez col.” (8, MAAS; 5, CC-UAEH). Same data, except: “ 3-III- 1999, J. Márquez col.” (57, MAAS). Same data, except: “El Puerto, 5-III-1999, NTP-80 (pescado), A. Romero y J. Márquez col.” (10, MAAS). “Ezequiel Montes, Peña de Bernal, 2100 m, matorral xerófilo, en nopal, 3-III-1999, E. García col.” (13, MAAS). “Ezequiel Montes, km 44 de carretera Bernal-Tolimán, 2067 m, matorral xerófilo, en nopal podrido, 2-III-1999, K. Robles y J. Márquez cols.” (2, MAAS).

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 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 16. Male pregenital sternite of: a) Belonuchus moroni, b) B. dichrous, c) B. flavipennis, d) B. aenigmaticus, e) B. nigerrimus, f) B. juanmorronei, g) B. godmani, h) B. magnistylus, i) B. trochanterinus, j) B. rufipennis, k) B. basiventris, l) B. connexus, m) B. xanthomelas, n) B. ephippiatus, o) B. optatus.

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 32. Geographical distribution in Mexico and Guatemala of: a) Belonuchus cifuentesi, B. connexus and B. pectinipes; b) B. dichrous, B. iridescens and B. xanthomelas.