Oxytrechus juani, Delgado & Ruiz-Tapiador, 2019

Delgado, Pedro & Ruiz-Tapiador, Ildefonso, 2019, Two new species of Oxytrechus Jeannel, 1927 (Coleoptera, Carabidae, Trechini) from Peru, Zootaxa 4565 (1) : -

Oxytrechus juani n. sp.

( Fig 1 and 2 )

Type locality. Perú, Puno, Cordillera Carabaya, Pucacancha , 4646 m, 13°59’43’’ S 70°30’45’’ W .

Type series. Holotype ♂, Peru, Puno, Cordillera Carabaya, Pucacancha , 4646 m, 13°59’43’’ S 70°30’45’’ W, 26.IV.2017, leg. P. Delgado (MNCNM).

Paratypes: 12 ♂ 3 ♀, same data as the holotype (8 ♂ y 2 ♀ ( CPD), 3 ♂ and 1 ♀ ( CIRT) and 1 ♂ ( MNCNM)) .

Description. Total length (ABL): 2.11–2.20 mm ♂, 2.19–2.23 mm ♀. Micropterous, body dark brown with paler, testaceous appendages. Smooth and shiny integument, glabrous, with visible microsculpture.

Elongated head (HW /HL = 0.78–0.82), totally covered by microreticulation, especially intense close to the supraorbital sulci; temples of same length as the eyes, prominent and narrow in the neck; frontal sulci deep and complete; eyes not very large, flat and approximately of the same length as the genae; two supraorbital setae at each side. Antennal length (TLA) between 0.83–0.85 mm., the apical antennomere clearly exceeding the base of the elytra. Antennomeres markedly pubescent, with the exception of the scape where pilosity is scarcer.

Pronotum transverse (PW / PL = 1.48–1.56), convex, with maximum width at the anterior third of the length. Lateral margins arched through their length, sinuate before the posterior angles, which are obtuse and prominent; anterior angles not projected forwards; basal peduncle prominent; median sulcus and basal impressions weakly marked. Two lateral setae at each side, the anterior one just before the widest point, the posterior one before the posterior angle. Microsculpture is more noticeable near the lateral margins and is progressively less marked toward the disc region.

Elytra ovoid and convex (EW / EL = 0.75-0.77), fully covered by microreticulation; lateral groove wide and flattened. Shoulder region regularly round, not angular. Internal striae of elytra weakly marked, absent in the apical region; external striae not visible; no trace of basal striola. Apex of elytra ends in a marked curve. Scutellar pore clearly marked. Two discal pores present, the first one located in the basal fifth of the total length and the second, just behind the half of the elytra. The umbilicate series is regular and corresponds to the usual model for the genus. External pore of the apical group absent. Humeral group with pores 1° to 4° equidistant, 1° and 2° slightly closer; apical group with the anterior pore at the same level than the 8° pore of the umbilicate series.

Legs short and slim; testaceous, with femora slightly darker proximally. Protibial sulcus superficial, straight metatibiae. Two first male protarsomeres asymmetrically dilated.

Aedeagus (fig 2) strongly bent, with a robust basal bulb, lacking of sagittal carina. Apex of median lobe slightly arched downwards, very obtuse. Endophallus with a scaly laminar piece, clearly visible. Parameres with four setae at their distal ends.

Differential diagnosis. O. juani n. sp. clearly differs from the other three species previously described from Perú in the structure of the aedeagus. In O. cyathiderus the general structure of aedeagus is characterized by a short base and the rest of the median lobe longer, versus the more “proportioned” look of the base and rest of lobe in O. juani n. sp. The other two species, O. gitzeni and O. paredesi , show a general shape of aedeagus more akin to that of O. juani n. sp., but are notoriously different in the shape of the apex of aedeagus, in both cases slightly hooked and pointing downwards.

The aedeagus of O. juani n. sp. shows certain morphological affinities with other species of the genus ( Jeannel, 1927; Mateu, 1991), as O. lallemandi Jeannel, 1927 from Ecuador and O. caucaensis Mateu, 1991 from Colombia, both species with a geographic distribution range far away from the Peruvian plateau.

Etymology. The species is dedicated to Juan Ruiz-Tapiador in appreciation for his patience and understanding.

Figures

FIGURE 1. Oxytrechus juani n. sp. Habitus, male (holotype). Scale bar: 0.5 mm.

FIGURE 2. Male genitalia of O. juani n. sp., lateral view. Scale bar: 0.1 mm.