Belonuchus iridescens Solsky, 1868

Márquez, Juan & Asiain, Julieta, 2022, Taxonomy of the Mexican species of Belonuchus Nordmann (Coleoptera: Staphylinidae), Zootaxa 5152 (1), pp. 1-129 : 78-79

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Belonuchus iridescens Solsky, 1868


Belonuchus iridescens Solsky, 1868

Figs. 7f, g View FIGURE 7 , 11m View FIGURE 11 , 13i View FIGURE 13 , 15e View FIGURE 15 , 20e View FIGURE 20 , 24i View FIGURE 24 , 32b View FIGURE 32

Belonuchus iridescens Solsky, 1868: 140 .

Philonthus latecinctus Sharp, 1885: 415 , new synonymy. Belonuchus latecinctus comb. nov. ex Philonthus ( Chani-Posse et al. 2018b) .

Total body length 7.3 mm. Body reddish, except for head (excluding antennae and mouthparts), major part of third visible abdominal segment (except its anterior border), entire fourth and anterior 2/3 of fifth. Rest of body black. Antennomeres 4–10 dark, almost black.

Head: subquadrate, ratio length/width 0.91. Sulcate longitudinal midline slightly visible in less than anterior half of head; front weakly foveate. Eyes small, 0.41 times the cephalic lateral length, slightly protruding laterally. First antennomere almost as long as antennomeres 2–3 combined, 2 slightly shorter than 3, 4 slightly elongate, 5 as long as wide, 6–10 transverse. Mandibles shorter than head (ratio 0.76), left mandible with two middle teeth very close to each other and right mandible with one middle tooth, without basal tooth; mandibular channel slightly developed, external margin slightly defined, internal margin like very fine carinate line extending forwards beyond level of most apical tooth. Apical palpomere of maxillary and labial palpi slightly more than 1.5 times longer than preapical palpomere. Head 1.27 times wider than pronotum. Ventral surface with very fine and sparse punctures.

Thorax: pronotum with five punctures in each dorsal row; 1.1 times longer than wide; 1.1 times wider at anterior corners than at posterior corners. Scutellum with punctures slightly wider than, and almost as dense as on elytra, where punctures are fine and moderately dense. Prosternum without any evident elevation near anterior margin. Intercoxal process of mesoventrite scutellum-shaped, somewhat projected downwards; transverse discal ridge crenulate, not meeting margin of intercoxal process laterally ( Fig. 11m View FIGURE 11 ). Protibia without aligned spines at external margin, only with two to four moderately large spines near apex. Tibiae of all legs with black spines contrasting with the reddish color of legs. Posterior legs without modifications ( Fig. 13i View FIGURE 13 ). Tarsomeres flattened dorsally.

Abdomen: visible tergites 1–3 with posterior basal transverse carina well developed; adjacent area weakly depressed (tergites 1–2) to almost flat (tergite 3), narrow, with sparse wide-superficial punctures combined with fine punctures that are moderately dense; outside depressions and remaining tergites only with dense, fine punctures; visible tergites 3–5 with anterior part (1/3 to 1/4) with mesh-like microsculpture, which is different than microsculpure like wavy lines on their remaining surface. Visible sternites 1–3 with posterior basal transverse carina, which is not visible in sternites 4–6; all sternites covered with dense, fine punctures; microsculpture as on tergites. Male pregenital sternite only slightly emarginate medio-apically ( Fig. 15e View FIGURE 15 ). Male genital sternite very elongate (3.41 times longer than wide), weakly asymmetrical, anterior portion occupying 56% and posterior portion 44% of its length, apical emargination deep ( Fig. 20e View FIGURE 20 ). Abdominal styli slender.

Aedeagus: small, length 0.85 mm; elongate shape, apex very narrow and slightly curved backward; basal half slightly wider than apical half; internal sac slightly visible ( Fig. 24i View FIGURE 24 ).

Variability. Unknown, only one male specimen was studied.

Taxonomic comments. Belonuchus iridescens is easily distinguished from the rest of species of the platypterus group by its coloration pattern (first three antennomeres, pronotum, first two visible abdominal segments, sixth and genital segment reddish to yellowish), its small size (close to 7 mm) and the black spines of tibiae that contrast with the reddish color of legs ( Fig. 7g View FIGURE 7 ), characteristics that do not appear in any other species of this group.

Information from the original description of B. iridescens and B. latecintus was compared, a photo of the holotype of the first species (provided by A. Kovalev, Zoological Institute of the Russian Academy of Sciences) and a photo of lectotype of the second species ( Chani-Posse et al. 2018b) were analyzed, as well as the study of a specimen recently collected in Oaxaca (IEXA), and it was concluded that they are the same species, so the name Philonthus latecinctus Sharp, 1885 is proposed as junior synonym of B. iridescens Solsky, 1868 .

The following are some relevant characters coincident in the original descriptions of B. iridescens Solsky (1868) and Philontus latecinctus Sharp (1885) , which support the synonymy here proposed: total body length 5.5–7.0 mm; body bright reddish, head shiny, metallic-iridescent black, mandibles red, antennal apex and ante-apical segments of abdomen black, first three antennomeres red, last dark brown, pronotum shiny metallic-iridescent red, elytra testaceous-reddish, abdomen testaceous red, except segments 3–4 and margin of 5 that are black, prosternum red, legs red-testaceous; head quadrate; series of five dorsal punctures on the pronotum, in addition, with five punctures on margins of both sides; elytra with fine punctures, pubescence yellow (golden), dense and sub-opaque; abdomen with numerous punctures; without evident sexual dimorphism.

Type material. The female holotype of B. iridescens Solsky was not studied, but the dorsal and ventral view were analyzed in a photograph provided by A. Kovalev (Zoological Institute of the Russian Academy of Sciences). Type material of B. latecinctus Sharp was not studied, but a photograph of the lectotype designated by Chani-Posse et al. (2018b) was analyzed. Additional material examined (one male): Mexico: Oaxaca: “Uluapan, 4 km NE Ayautla, N18.05956°, W96.64558°, +- 10 a 420 m, 9 a 16-VI-2016, M. García et al., cols. / Lowland rainforest, Malaise trap” (m 1, IEXA).














Belonuchus iridescens Solsky, 1868

Márquez, Juan & Asiain, Julieta 2022

Philonthus latecinctus

Sharp, D. 1885: 415

Belonuchus iridescens

Solsky, S. 1868: 140