Trechisibus recuayi, Allegro, Gianni & Giachino, Pier Mauro, 2016

Allegro, Gianni & Giachino, Pier Mauro, 2016, Nine new Trechisibus species from Peru and Argentina (Coleoptera: Carabidae: Trechinae), Zootaxa 4193 (1), pp. 49-72 : 54-56

Trechisibus recuayi n. sp.

( Figs. 3 , 4 a, 4b, 4c, 4d, 14)

Type locality. Peru, Dip. Ancash, Punta Olímpica 4,550 m, laguna.

Diagnosis. A Trechisibus species 2.98–3.24 mm long, dark brown, moderately shiny; elytra with apex, marginal border and sutural interval lighter brown; legs, antennae and mouth parts reddish-brown. Hind angles of pronotum nearly right or scarcely obtuse. Elytra oval, not depressed on disc, with one setigerous puncture on 3rd stria at about 1/3 from base. Due to the peculiar median lobe of aedeagus with hook shaped apex, T. recuayi n. sp. may be confused with two other species living in Cordillera Blanca ( Trechisibus lamasi Etonti & Mateu, 1992 and Trechisibus decensii Allegro, Giachino & Sciaky, 2008 ), which also share a very similar external morphology, but it the can be easily distinguished by the smaller size and by a shorter and more stumpy median lobe of aedeagus, with differently shaped copulatory piece ( Fig. 5 ).

Type Series. HT ♂, Peru, Dip . Ancash, Punta Olímpica , m 4,550, 5.VII.2008, legit G. Allegro (CAl). PTT: 1 ♀, same data as the holotype (CGi) ; 1 ♀, Peru, Dip. Ancash, Punta Olímpica , m 4,550, 6.XII.2005, legit G. Allegro (CAl).

Description. Habitus as in Fig. 4 a. Overall length of the HT ♂ (from labrum to apex of elytra) 3.24 mm (PTT ♀♀ 2.98–3.17 mm). Body dark brown, obovate, moderately shiny. Microsculpture in transverse meshes superficially impressed on elytra and on disc of pronotum, more visible near base and apex of pronotum and on head. Antennae, tibiae, clypeus and labrum reddish, femora a little darker; palpi yellowish. Brachypterous.

Head moderately large, eyes small and scarcely convex; temples oblique and delicately pubescent, as long as eyes. Microsculpture markedly impressed over all surface but even stronger (almost wrinkled) near clypeus and towards eyes, laterally to frontal impressions, which are arcuate and deep. Clypeus with two apical setae on each side, the inner one shorter and thinner; labrum transverse, 6-setose, excavate at apex. Frons between eyes convex. Antennae slender, reaching the basal fifth of elytra.

Pronotum moderately convex on disc, transverse (width/length = 1.38), with base wider than anterior margin ( Fig. 14 ). Disc shiny with very superficial microsculpture, which is distinct only near base and near front margin. Sides rounded in the fore half and subrectilinear in the basal half, shortly sinuate before base; basal margin excavate at middle and oblique near hind angles. Front angles scarcely prominent; hind angles marked, right or nearly obtuse. Mid longitudinal line distinctly impressed between the submarginal sulci. Lateral margins wide and broadened towards base; anterior and posterior margins bordered only at sides. Two lateral setae on each side, one at hind angles and one about 3/4 from base.

Elytra oval (length/width=1.40), fairly convex and not depressed on disc. Microsculpture in transverse meshes, superficial in both sexes. Shoulders scarcely angulate with humeral angle distinct. The basal margin is interrupted in correspondence with the 6th interval. Scutellar stria absent. A juxtascutellar pore is present near base, in correspondence with the 2nd stria. Sides moderately rounded; lateral border narrow. One setigerous puncture on the 3rd stria at about 1/3 from base; preapical pore at about middle of the recurrent striole. Umbilicate series of 4+2+2 punctures, with the groups widely distanced from each other. 1st–5th striae very superficial and hardly visible, the others obliterated. Intervals flat. Elytral apex broad and rounded. The recurrent striola short and subrectilinear, without a remarkable apical carina.

Legs slender. Protibiae nearly straight and externally superficially furrowed. Tarsi pubescent on the upper side. The 1st and 2nd male protarsomeres asymmetrically dilated.

Median lobe of aedeagus short and stout ( Fig. 4 b), in lateral view the inferior edge delicately bent downward before apex, which is short and, in dorsal view, sinuate at sides and blunt ( Fig. 4 c). The internal armature is made by a robust copulatory piece with a dense cover of sclerotized teeth ( Fig. 4 b). Parameres narrow and long, almost equally long and longer than half of the median lobe, each provided with 3 apical setae ( Fig. 4 b).

Etymology. Species name derived from the noun, in the genitive case, of the pre-columbian culture Recuay, that flourished in the Andean area of Cordillera Blanca from 200 BC to 600 AC.

Distribution and habitat. At present Trechisibus recuayi n. sp. is only recorded from the type locality. The three specimens of the type series were collected under stones laying on humid soil near a lake (about 4,550 meters a.s.l.) below the Punta Olímpica Pass, in a glacial area characterized by coarse detritic sediments ( Fig. 3 ). It lives in syntopy with Trechisibus huascarani n. sp. and Blennidus (Agraphoderus) huascarani Allegro, 2010 , which are recorded from the same type locality.

Relationships. Trechisibus recuayi n. sp. is probably a close relative of Trechisibus lamasi Etonti & Mateu, 1992 and Trechisibus decensii Allegro, Giachino & Sciaky, 2008 , according to similarities in external morphology and in male genitalia (in particular all them have a hooked apex of the median lobe of aedeagus) ( Fig. 5 ). These species live in Cordillera Blanca, all inhabiting humid soils. Due to the marked similarities in male genitalia, they can be included in the ‘ T. lamasi ’ species group.

Figures

FIGURE 3. Peru, Dept. Ancash, Cordillera Blanca. The lagoon below the Punta Olímpica Pass (4,550 m a. s. l.) type locality of Trechisibus huascarani n. sp., as well as of Trechisibus recuayi n. sp. and Blennidus (Agraphoderus) huascarani Allegro, 2008.

FIGURE 4. Trechisibus recuayi n. sp. HT: habitus (a); median lobe of aedeagus in lateral view (b); median lobe of aedeagus in dorsal view (c).

FIGURE 5. Median lobe of aedeagus of the ‘ Trechisibus lamasi group’ species: T. lamasi Etonti & Mateu, 1992 (a); T. recuayi n. sp. HT (b); T. decensii Allegro, Giachino & Sciaky, 2008 HT (c).

FIGURES 13 – 16. Pronotum of Trechisibus: huascarani n. sp. HT (13); recuayi n. sp. HT (14); curtii n. sp. HT (15); lemairei n. sp. HT (16).