Oxytrechus belloi, Giachino, Pier Mauro, Allegro, Gianni & Baviera, Cosimo, 2014

Giachino, Pier Mauro, Allegro, Gianni & Baviera, Cosimo, 2014, Two new species of Oxytrechus Jeannel, 1927 from Ecuador (Coleoptera, Carabidae), Zootaxa 3895 (1), pp. 144-150 : 148-150

Oxytrechus belloi n. sp.

( Figs. 3–4 )

Type locality. Ecuador, Pichincha, c/o Paso de la Virgen, m 3515, S 0°18.468 W 78°14.881

Diagnosis. An Oxytrechus species 2.70–3.06 mm long, dark testaceous, shiny, with antennae and legs testaceous (fig. 3). O. belloi n. sp. is well differentiated, as far as the morphology of aedeagus is concerned, respect to the congeneric species living in Ecuador and, in particular, to the sympatric species spread in the Páramo of Papallacta (figs. 4, 5–7).

Type series. HT ♂, Ecuador, Pichincha, c/o Paso de la Virgen, m 3515, S 0°18’ 468’’ W 78°14’ 881’’, vaglio paramo, 2.VIII.2008, Ecuador 2008, legg. Baviera, Bellò, Osella & Pogliano (CGi). PTT: 5 ♂♂, same data as the holotype (CAl, CBa, CGi, QCAZ).

Description. Total length (from apical margin of labrum to tip of elytra): mm 2.70–3.06 ♂♂. Micropterous; dark testaceous, with legs, mandibles, palpi and antennae testaceous. Teguments smooth, shiny, glabrous, with microsculpture hardly visible on disk of pronotum and elytra, consisting of very thin transversal meshes.

Head small and elongated; temples long (shorter than the eyes), prominent and narrowing on neck; frontal furrows deep and complete; eyes not very large and flat, markedly longer than genae; two supraorbital setae on each side and on lines not converging backwards. Antennae narrow and short, hardly exceeding the elytral base, with the apical segment longer than penultimate.

Pronotum transverse (PW/PL = 1.17–1.27 ♂♂), convex, largest at the anterior third. Sides long arcuate, sinuate before the hind angles, which are right and prominent; front angles not projecting forwards; basal peduncle prominent and laterally bisinuate, not bordered at the posterior edge; lateral keel relatively wide; median furrow superficial; basal impressions small, adjoining the terminal part of the lateral keel. Two lateral setae on each side, the anterior one at the anterior fourth, the posterior markedly advanced with respect to basal angle.

Elytra largely oval, short, convex; lateral keel broad, flattened, with salient and almost reflex borders; shoulders regularly rounded, not angulate, not prominent; external elytral striae completely obsolete, striae 1–3 hardly visible in the basal part, completely obsolete in the apical one; sutural stria hardly visible. Basal striole absent, recurrent stria and apical carina scarcely evident. Chaetotaxy: juxtascutellar pore present, two discal pores relatively small, the first one at basal fifth, the second one just after the middle; umbilicate series regular, humeral group with the pores 2nd to 4th almost equidistant,1st and 2nd slightly closer; the apical group with the anterior pore moved backwards, definitely beyond the 8th pore of the umbilicate series; the exterior pore of the apical group absent.

Legs short and slender; protibial furrow complete but very superficial; metatibiae straight; in ♂ two first protarsomeres asymmetrically dilated.

Aedeagus (fig. 4) robust, elongate. Median lobe, in lateral view, markedly and sharply curved at base, subrectilinear in the central part, gently curved upwards in the apical one; apex like shoe-shaped. Basal bulb long, sagittal carina long, evident, but not extended to the dorsal part. Inner sac provided with a large, sclerified and benttile shaped copulatory piece. Styles long, reaching the apical third of the median lobe, each provided with 4 long distal setae.

Female unknown.

Etymology. It is a pleasure for us to dedicate this new species to one of its collectors, our friend and colleague Cesare Bellò, a specialist of Coleoptera Curculionoidea , as a token of our esteem for his valuable contribution to the WBA expeditions in South-America.

Distribution and ecology. At present O. belloi n. sp. is only known from the type locality, Paso de la Virgen ( Ecuador, Pichincha province), where it was collected by sifting soil collected under stones and tree branches on soil at the edges of a forest fragment (fig. 9). Three other Oxytrechus species living in sympatry with O. belloi n. sp. are recorded from the Páramo of Papallacta: they are O. pichinchanus Mateu, 1988 , O. moreti Mateu, 1988 and O. ecuatorianus Mateu, 1988 , which are syntopic and belong to the same species-group.

Comparative notes. We have compared type material of O. belloi n. sp. with specimens of the other sympatric Oxytrechus in the area of Papallacta Páramo, namely Oxytrechus moreti Mateu, 1988 (HT ♂, 1 PT ♀ from Ecuador, Prov. Napo, Pichincha, Col de Papallacta, antennas 4370 m, 5.IV.86, Pierre Moret leg. [CMa]); Oxytrechus pichinchanus Mateu, 1988 (HT ♂, 1 PT ♀ from Ecuador, Prov. Napo, Pichincha, Col de Papallacta, 4050–4150 m, 6.XII.84, Pierre Moret leg. [CMa]); and Oxytrechus ecuatorianus Mateu, 1988 (HT ♂, 1 PT ♀ from Ecuador, Prov. Napo, Pichincha, Col de Papallacta, antennas 4370 m, 5.IV.86, Pierre Moret leg. [Cma]) (figs. 4, 5–7).

O. belloi n. sp. is probably related to O. pichinchanus Mateu, 1988 , O. moreti Mateu, 1988 and O. ecuatorianus Mateu, 1988 with regard to the slender shape of the median lobe of aedeagus, the apex more or less curved and / or like shoe-shaped; it differs from all these in the presence of a well defined copulatory piece (fig. 4), which is wanting in the other sympatric species (figs. 5–7). O. belloi n. sp. also differs from O. pichinchanus for the apex of the median lobe slightly turned upwards and more evidently shoe-shaped, as well as the pronotum less transverse; from O. moreti also for the apex of the median lobe shoe-shaped and the elytra more globose, less elongated; from O. ecuatorianus for the apex of the median lobe slightly turned upwards and the pronotum less transverse.

The complete revision of this homogeneous group of Oxytrechus will be the object of a more detailed contribution concerning all the Ecuadorian species, which is currently at an advanced stage of drafting (Giachino, Allegro, Moret, in prep.).

Figures

FIGURES 1 – 4. Habitus (1, 3) and aedeagus (2, 4) of: O. osellai n. sp. HT ♂ (1, 2) and O. belloi n. sp. HT ♂ (3, 4).