Callirhinus nandu Ramírez-Ponce & Zaragoza, sp.nov.

(Figs 8D, 9D, 12)

ZooBank: urn:lsid:zoobank.org:act: FABBBCA8-D3F0-4132- 8A6D-419BA7FC2E17

Type material: Holotype (male, IEXA): (a) ‘ MEXICO: Hidalgo / Apan 4-IX-62 / R. MacGregor, col’., (b) ‘ Callirhinus nandu Ramírez-Ponce & Zaragoza, 2022 HOLOTYPE ♂’ (red label).

Diagnosis: Pronotum with lateral margins subparallel; surface finely punctate (punctures separated by 2.5–3.0 point diameters); mesometaventral projection wide; protibia with apical denticles not elongate; parameres clearly wider than long.

Description: Holotype (male, IEXA): length 9.95 mm; width 4.96 mm. Colour (Figs. 8D, 12A, B): head, disc of pronotum, and scutellar shield shiny metallic green; lateral margins of pronotum and elytra yellow; elytral suture, epipleura, venter, and legs reddish brown. Head (Fig. 12C, D): frons densely areolate-rugose transverse to punctate toward occipital area; spaces wide and deep. Clypeus with apex slightly curved, reflexed, lateral borders straight, broad-based, short; densely areolate-rugose, spaces rugulose-transverse. Interocular width equals six transverse eye diameters. Antennal club subequal to scape, pedicel and funicle together. Pronotum (Fig. 12E): lateral margins slightly divergent (distal half); surface moderately dense and uniformly punctate (separated by a 2.0–3.0 puncture diameter), punctures small, shallow, rounded (Fig. 12F). Elytra: surface with 12 punctate striae subparallel; punctures moderate in size and shallow, irregularly contiguous even close to each other (on proximal half); 7 striae on disc, 5 laterad of humerus; dorsal striae 8 very irregularly impressed, incomplete; all striae not mixed; interstriae not raised, sutural striae very slightly raised towards apex, subbasal sinuation weak. Pygidium (Fig. 12G): surface imbricate, with moderately long and moderately thick setae, longer and very slender on apex; concavity pronounced in apical third (lateral view). Venter (Fig. 12A, B): mesometaventral projection wide, surpassing the mid-mesocoxa, apex rounded and scarcely protruding (lateral view); abdominal ventrites with transverse, regular rows of moderately long, yellowish setae, mesial area almost glabrous. Legs (Fig. 12 H-L): protibia very wide; upper teeth very short, curved and pointed; protarsomere 5 enlarged, slightly longer than the length of the previous ones combined, internobasal protuberance keel-shaped; protarsomeres 1–4 progressively shorter and widened; protarsomere 4 with interno-mesial lobe not notably increased; protarsomere 1 subequal to 2. Lower ramus of inner claw 3.6 times the width of upper one. Mesotibia widest at middle, weakly expanded at apex; external margin with separate, thick and relatively long spines at base; incomplete oblique carina in basal third (composed of 6–7 relatively long and slender spines), and continuous oblique carina in subapical two-thirds (composed of 10–11 short spines); apex with 8 relatively long spines; apical spurs rounded; internal spine exceeding the middle of mesotarsomere 2, external spur exceeding mesotarsomere 1. Metatibia widest at middle, weakly expanded at apex; external margin with incomplete oblique carina at basal third (composed of 3–4 short spines), and continuous oblique carina in subapical two-thirds (composed of 9–10 spines); apex with 14–15 short spines; internal spine produced near to the half of mesotarsomere 2, external spur subequal to mesotarsomere 1. Metatarsomere 5 subequal to the length of the previous ones combined; internal mesoapical patch of setae present in metatarsomere 4; internal spines on metatarsomere 1 and external ones in metatarsomere 4 thick. Parameres (Fig. 9D): wider than long; external margins slightly curved, preapical notch present; apices rounded.

Etymology: From the Otomí denomination ‘ñandú’ (variant of the Mezquital Valley), due to the preponderance of this ethnic group in the state of Hidalgo, Mexico (SEP-INALI 2014).

Distribution: The holotype was collected in Apan, in the state of Hidalgo, Mexico (Fig. 15).

Phenology: September (1).

Natural history: This is the species with the highest distribution recorded in a locality with vegetation of pine, oak, pine-oak forests, and crasicaule scrub around 2500 m a.s.l.

Taxonomic remarks: Callirhinus nandu bears the closest resemblance to C. metallescens both in size and in the form of diagnostic characters such as the pronotum and protibia; however, it has a more abundant vestiture on the venter and the most distinct parameres of all species, which are notably shorter.