Perigona (s. str.) liboloensis Serrano & Capela, 2017

Serrano, Artur R. M., Capela, Rúben A. & Santos, Carmen Van-Dúnem Neto, 2017, Biodiversity and notes on carabid beetles from Angola with description of new taxa (Coleoptera: Carabidae), Zootaxa 4353 (2), pp. 201-256 : 228-232

Perigona (s. str.) liboloensis Serrano & Capela sp. n.

( Figs 1a , 2 , 3 )

Type series. Holotype, ♂; Angola (Kwanza Sul), Alto Ventura-Col ( Calulo ) (9° 59´42´´ S, 14° 50´32´´ E, 1116 m alt., 128), 4.XII.2015, DO, A. Serrano & R. Capela leg., ASC . Allotype, 1♀, same locality and date as holotype, ASC. Derivatio nominis. This species is named after Libolo (noun in apposition), a municipality of the Kwanza Sul Province where the specimens were found and home of one of the most remarkable Angolan Sports Club : the Sports Club Recreativo do Libolo .

Diagnosis. Body elongate, sub-parallel, slightly convex and reddish-brown ( Fig. 1a ); integument with microreticulation, shiny; surface with sparse micropunctures visible at high magnification. Elytral color as Perigona pallida Castelnau, 1835 . Internal sac of median lobe of aedeagus ( Fig. 2 ) with a conspicuous twisted sclerite closer to the apex and a posterior bone shaped cut half sclerite (lateral view).

Description. Length of Holotype: 3.36 mm. Length of allotype: 3.16 mm.

Head. Slightly wider than long [length: 0.59 mm (holotype), 0.64 mm (allotype), width: 0.72 mm (holotype), 0.75 mm (allotype)], darker (black-brownish) than pronotum and elytra, clypeus, labrum, mouth parts and antennae piceous; surface with sparce fine punctuation, microreticulation distinct, isodiametric, rather glossy; eyes large, moderately protruding, labrum moderately notched; clypeal-frontal furrows distinct, oblique, extended to level of anterior supraorbital seta; frons and occiput slightly convex; antenna short just attaining base of pronotum, scape two times longer than wide, 3rd to 9th antennomeres as long as wide, slightly globulose, last antennomere 1.6‒1.8 times longer than wide. Cephalic chaetotaxy (large setae): Labrum with three pairs of setae gradually shorter from exterior to inner sides, one pair on sides of clypeus and two pairs of supraocular setae present over each eye.

Thorax. Pronotum ( Fig. 1a ) 1.27‒1.29 times wider than long [length: 0.66 mm (holotype), 0.74 mm (allotype), width: 0.85 mm (holotype), 0.94 mm (allotype)], reddish-brown dark, wider than head, barely subcordiform, widest at first third; surface sparcely micropunctate, with microreticulation distinct, consisting of isodiametric meshes in diskal area and transverse meshes and lines laterally, shiny; apical margin not margined, lateral margins with complete and distinct margination continuing in the two thirds of the basal margin after the posterior angle; apical margin arcuate, apical angles roundly acute, protruded; lateral margin slightly curved at first two thirds, followed by a slight sinuosity and ending straight obliquely before the roundly obtuse basal angles, posterior margin distinctly emarginated; median line distinct, not reaching anterior or posterior margins, anterior transverse sulcus indistinct, posterior transverse sulcus slightly conspicuous; anterior marginal setae situated close to the widest width, posterior marginal seta situated at basal angle, none short setae at disk or sides.

Elytra ( Fig. 1a ) 1.61‒1.62 times longer than wide [length: 1.90 mm (Holotype), 1.97 mm (allotype), width: 1.17 mm (holotype), 1.22 mm (allotype)], reddish-brown lighter than pronotum, sutural stripe slightly darker; surface glossy, with sparse very fine punctuation and superficial microreticulation of fine transverse meshes; narrow and elongate, sub-parallel, dorsally moderately convex, very slightly depressed on disk, widest at middle; humeral angles distinct but broadly rounded; mediam marginal punctures arranged in a straight line; marginal channel towards apex widened, depressed, first half scarsely pilose, second half densely pilose; only inner three striae recognizable at two thirds by inconspicuous sulci not marked by punctures, anterior setiferous puncture situated at 3rd striae and at basal quarter, median setiferous puncture situated in 3rd interval close to 2nd striae slightly behind middle, apical setiferous puncture (long setae) situated at 3rd striae just above sub-apical border.

Abdominal segments brown-yellowish, covered with dense dressed short hairs; last segment with 3 pairs (male) or 5 pairs (female) of setae near the posterior margin; terminal abdominal sternite in both sexes with fringe of short hairs. Legs brown-testaceous.

Aedeagus ( Figs 2 a, b, c ) with median lobe short and stout, ventral margin slightly curved, apex downwards (lateral view); internal sac with a conspicuous twisted sclerite and a bone shaped cut in half sclerite at right and left sides, respectively; genital ring ( Fig. 2 d ) rather asymmetric, with wide, obliquely rounded apex, rather parallel, base evenly rounded.

Female genitalia ( Fig. 3 ) with the ordinary pattern shape of the genus. Stylomere 1 with two ventral large setae on subapical margin. Stylomere 2 with two medium sized ensiform ventro-lateral setae, one quite large ensiform dorso-median seta located about in middle of stylomere, and a single nematiform ventro-seta originating from a groove in apical third of stylomere. Some sensillae (probably chemoreceptors) are dispersed over ventral lateroapical margins of stylomere 1, and other sensillae over basal, medial and sub-apical areas of ventral, lateral and dorsal sides of stylomere 2.

Remarks. The new species belongs to the subgenus Perigona s.str. based on the arrangement of the three lateral marginal elytral pores in a straight line and by the presence of distinct clypeo-orbital sulci. Until now there are six species known for continental Africa belonging to this subgenus ( Basilewsky 1989, Baehr 2004 and Serrano 2008). Perigona liboloensis sp. n. is easily segregate from P. parallela Chaudoir, 1878 , P. nigrociliata Basiewsky, 1953 , P. mediornata Basilewsky, 1989 , P. wachteli Baehr, 2004 and P. principensis Serrano, 2008 , among other characters, by the quite dissimilar aedeagi of all these species. Certainly the new species is next related to P. pallida Laporte de Castelnau, 1835 with which it shares the general color, the elongate, almost parallel body shape and male median lobe general shape, though differs in its general body length (3.16‒3.36 mm vs. 2.30‒2.70 mm), pronotum conformation (slightly sinuouse before the posterior angles vs. not sinuouse before the posterior angles), elytral index (1.61‒1.62 vs. 1.47‒1.55), and in the shape of the sclerotized plates in the internal sac of the median lobe of aedeagus (cf. Figs 2a, b vs. Fig. 5b in Basilewsky 1989). Moreover, P. pallida presents the pronotal widest situated in the middle while in the new species is in the first third. In the former species the elytral striae are conspicuous with punctuation well marked while in the latter the elytral striae are almost indistinct and without marked punctuation. By the Perigona pallida previous records (e.g. Basilewsky 1989) and the new species known locality, the two taxa seem to be sister species with vicariant (allopatric) distribution, a fact referred already for tiger beetle and ant nest beetle species of Angola also (Serrano et al. 2015, Serrano & Capela 2015a).

Ecological notes. A species known until now only from Angola. Adults were found under the bark of a fallen tree within an abandoned coffee plantation ( Fig. 9a ) with Catascopus beauvoisi Laporte de Castelnau, 1835 and Coptodera (Coptoderina) congolensis Burgeon, 1937 . Further adults of Dermaptera [ Apachyus depressus (Palisot de Beauvois, 1805 and Echinosoma afrum (Palisot de Beauvois, 1805) ] and Coleoptera Endomychidae , Trogossitidae , Tenebrionidae (several species) were found together (syntopic) with the new species.

Figures

FIGURE 1. Facies of:a) Perigona liboloensis sp. n. male holotype, b) Lasiocera schuelei sp. n. male holotype.

FIGURE 2. Perigona liboloensis sp. n.: a) Aedeagus, median lobe and parameres (left lateral view), b) apex of median lobe (dorsal view), c) median lobe (right lateral view) and, d) genital ring.

FIGURE 3. Perigona liboloensis sp. n., female genitalia: stylomeres 1 and 2 (ventral view).

FIGURE 5. Lasiocera schuelei sp. n., Aedeagus: a) Median lobe and parameres (left lateral view), b) apex of median lobe (dorsal view).

FIGURE 9. Habitats of: a) Perigona liboloensis sp. n., Alto Ventura, Kwanza Sul, b) Lasiocera schuelei sp. n., Cambamba, Malanje, c) Galerita procera capelai ssp. n, Calulo-Cabuta, Kwanza Sul, d) Habrodera nilotica and Lophyra neglecta intermediola destroyed by sand removal (arrow) before Cambambe dan, Kwanza Sul, e) and f) Dromica fredericoi and Trichotaeniapepetela inNovember 2014 and 2015, well perserved and destroyed by fire, respectively, Catota, Bié.