Typhlocharis acutangula, Pérez-González, Sergio, Zaballos, Juan P. & Ghannem, Samir, 2013

Pérez-González, Sergio, Zaballos, Juan P. & Ghannem, Samir, 2013, Intraspecific variation in Typhlocharis Dieck, 1869 (Coleoptera, Carabidae, Anillini): the case of two new species of the baetica group, Zootaxa 3710 (1) : -

Typhlocharis acutangula n. sp.

Figs 2 , 3

Type series. Holotype, ♂, SPAIN, Huelva, San Silvestre de Guzmán (0.7 km N), 21- 11-2012, 175 m (37º 23’ N, 07º 21’ W), J.P. Zaballos, S. Pérez & S. Ghannem leg. (Coll. J.P. Zaballos, UCM). Paratypes: 18♂♂, 13 ♀♀ same data as holotype (Coll. J.P. Zaballos and Coll. S. Pérez-González, UCM). 1♂, 1 ♀ same data as holotype (MNCN, Madrid, Catalogue number: 9999).

Diagnosis. Small endogean beetle, anophthalmous, with narrow and subrectangular body covered by microreticulate integument and scattered pubescence. Vertex with pars stridens. Elytra well serrated in lateral margins and apical margin with four to six pairs of small denticles. Umbilicate series with six setae (4 + 2). Metatibiae with a distinct dentiform projection at the anterodistal end. Abdomen without ventral foveae. Aedeagus as in Fig. 3 , ‘stick-shaped’ endophallic sclerite. Female genitalia as in Fig. 3 , with ovoid spermatheca.

Description. Length 1.14–1.35 mm (males), 1.17–1.35 mm (females) ( Fig. 2 ). Head: wider (0.25–0.30 mm) than long (0.24–0.27 mm), with subhexagonal microsculpture and stridulatory organ (pars stridens) in vertex region, in both sexes. Posterolateral semilunar notch in both sides of cephalic capsule. Subrectangular labrum, with rounded edges and triangular area with middle button of thicker cuticle. Clypeus with straight anterior margin. Moniliform antennae with 11 antennomeres progressively more quadrate in lateral view (morph 1 sensu Pérez- González & Zaballos 2013b), last one pyriform. Pedicel of third antennomere not elongate. Sensilla coeloconica of last antennomere distributed in a three anterodorsal and one posterodorsal pattern. Ventral sensilla coeloconica in antennomeres 5º and 6º. Right mandible with a low, rounded terebral tooth on inner margin. Left mandible without teeth. Labium without special characters, the middle tooth is slightly rounded. Ligula with moderately prominent middle lobe and long paraglossae. Wide gula approximately twice as long as wide. Cephalic chaetotaxy: six pairs of labral setae (s-s-l-m-s-m / m-s-m-l-s-s), two pairs of clypeal setae (l-s / s-l), one pair of frontal setae, two pairs of supraocular setae (anterior and posterior), one pair of supraantennal setae, three pairs of occipital setae and two pairs of genal setae, as well as scattered pubescence. Labium with a pair of setae near base of the middle tooth, a pair of long setae near base of epilobes, a pair of very short setae near apex of epilobes and one or two pairs of very short setae near posterior suture. Prebasilar with a pair of lateral long setae near anterior margin, a pair of very short lateral setae in mid-region and two pairs of setae (lateral pair much longer) in posterior region, with some degree of individual variation over this basic pattern.

Pronotum: subquadrate, longer (0.31–0.38 mm) than wide (0.30–0.35 mm). Anterior and posterior margins smoothly sinuate. Anterior margin slightly crenulate, with medial hiatus (approximately as wide as two adjacent intersetae spaces). Lateral margins with two or three denticles near posterior angles, blunt and irregular. Surface covered by subhexagonal microreticulation. Disc flattened, with medial line and pair of faint lateral sulci. Chaetotaxy: one pair of long setae in first third of lateral margins, one pair of long setae near posterior angles, a row of five to six pairs of setae [l-(l)-l-l-l-l / l-l-l-l-(l)-l] parallel to anterior margin, two, rarely three pairs of setae parallel to posterior margin [(s)-l-l / l-l-(s)], row of small, thin setae regularly placed in anterior (bulb shaped) and posterior (filiform) margins, row of short setae in lateral margins, and four or five pairs of longitudinal rows of short pubescence in disc. Proepisternal suture marked. Prosternal apophysis rounded. Anterior margin of prosternum with a row of long, thin setae and six to eight pairs of short setae parallel to it. Prosternum covered in scattered pubescence, absent in proepisternum.

Elytra: approximately two times longer (0.60–0.72 mm) than wide (0.33–0.39 mm), subparallel. Lateral margins with 19–21 very strong denticles, “hooked” in the first third progressively less marked toward posterior, but reaching the apical region to the beginning of the apical denticles. Apical margin smoothly rounded, with four to six pairs of small denticles (affected by individual variation, five pairs in average). Disc flattened, with longitudinal lateral carinae associated to seventh stria but not reaching the apical margin. Surface with irregular subhexagonal microreticulation. Faint elytral pores, scattered along seventh stria, scutellar region and disc. Transverse scutellar organ with straight margin, and pair of ‘buttonholes’ present near base of elytra. Chaetotaxy: umbilicate series composed by anterior group of four setae and posterior group of two setae ( Fig. 2 ). One pair of scutellar setae. No discal setae. Discal pubescence arranged in five or six pairs of longitudinal rows. Apical row of short pubescent setae. Lateral margins with a short seta for every denticle, forming a row.

Legs: similar in both sexes. Intermetacoxal space not widened. Metacoxae with smoothly rounded “flap” (a flat extension of the margin of metacoxae, overlapping over the base of metatrochanters, Fig. 2 ). Rounded metatrochanters, slightly angular metafemora and metatibiae with dilated anterodistal region, ending in a prominent dentiform projection. Inner side of meso- and metafemora covered by small scaly protuberances. Clearly pentamerous tarsi in all the legs.

Abdomen: covered by irregular microreticulation, last segment with ‘belt’ of scaly microsculpture, every scale with finely serrated edge in both sexes. Ventral foveae absent. Last ventrite without lateral teeth, pattern of five to six pairs of setae in posterior margin, sexually dimorphic: l-s-s-l-s / m-s-l-s-s-l ( Fig. 2 ). Aedeagus: sickle-shaped median lobe (length: 0.18 mm) and subtriangular, smoothly rounded apex, bent to right (anatomically oriented) in dorsal view ( Fig. 3 A, B). Endophallus with large and complex “branched, stick-shaped” sclerites ( Fig. 3 B), with lateral projection smoothly curved upwards. Parameres subtriangular, with two medium-sized apical setae ( Fig. 3 B). Female genitalia as described by Vigna-Taglianti (1972). Long tubular gonocoxites, with double apical setae. Lateral setae absent, but lateral pores in the gonocoxites. Short gonoduct with two regions: a thinner proximal (diameter 0.0017 mm) and thicker distal region (diameter 0.0045 mm). Irregularly ovoid spermatheca (length: 0.014 mm). Conical spermathecal gland (length: 0.016 mm), sclerotized in distal region ( Fig. 3 C).

Etymology. The name “ acutangula ” is referred to the characteristic diagnostic feature of the species, the prominent dentiform projection that gives the “acute angled” shape to the anterodistal region of metatibiae.

Habitat. The type locality ( Fig. 1 ) is found in open holm oak ( Quercus ilex L.) environment, with abundant laudanum shrubs ( Cistus ladanifer L.) and scarce asphodels ( Asphodelus L.) and thistles. Reddish soil, with high clay content and high humidity at the moment of sampling, filled with various-sized boulders of breakable shales (Upper Carboniferous). The sample was taken under big boulders next to young holm-oak trees and laudanum shrubs.

Variability. The range of variability observed in Typhlocharis acutangula n. sp. (34 specimens) is similar to that described for other species of baetica group (Pérez-González & Zaballos 2013a).

It mainly affects to the shape and number of posterolateral denticles of pronotum (two or three, irregularly marked); the degree of pronunciation of the lateral denticles of elytra (two specimens have blunt, worn lateral denticles, other two have denticles less marked than average, not hooked on the first third), the shape of transverse scutellar organ (from straight to subtriangular, rarely irregular), the shape of median lobe of ligula (very low in some specimens) and the apodemal ring of male genitalia.

Variation in the apical denticles of elytra is very common, with individuals having four, five or six pairs. Asymmetries in the number of denticle pairs in each elytron are abundant and the observed combinations includes 4/6, 5/4, 4/5, 6/5 and 5/7. Bifid or double denticles appear in two specimens. The most common combinations are 5/4 (17% of the series) and 5/5 (32% of the series) denticles.

Chaetotaxy of labium, prebasilar and last ventrite shows subtle variations. There are asymmetric alterations of the pattern of sensilla coeloconica in 11th antennomere in two specimens.

Affinities. Typhlocharis acutangula n. sp. is included in the baetica group by the presence of four to six pairs of apical denticles in elytra (Zaballos & Banda 2001; Pérez-González & Zaballos 2013a). Within the group, it shares an umbilicate series of 4+2 with T. pacensis Zaballos & Jeanne, 1987 ; T. furnayulensis Zaballos & Banda, 2001 and T. secunda Perez-González & Zaballos, 2013 . The latter is the morphologically closest species, both sharing a similar shape of aedeagus, parameres and endophallic sclerites. The presence of protuberances in the inner margin of femora is shared with T. baetica Ehlers, 1883 ; T. tertia Perez-González & Zaballos, 2013 and T. quarta Perez-González & Zaballos, 2013 .

The new species can be immediately distinguished by the presence of the pointy dentiform projection in the anterodistal end of metatibiae, a feature only known in other species of the genus, T. crespoi Serrano & Aguiar, 2008 , of quadridentata group (Pérez-González & Zaballos 2013c). It is worth noting that other rare character, the bulb shaped setae in the anterior margin of pronotum is shared with T. baeturica Perez-González & Zaballos, 2013 , included in quadridentata group.

Figures

FIGURE 1. Map of the distribution range of baetica group: 1, location of Typhlocharis acutangula n. sp.; 2, location of Typhlocharis mixta n. sp. Black circles represent the distribution of the other species of the group. Dashed lines indicate political frontiers.

FIGURE 2. Typhlocharis acutangula n. sp. — habitus: ventral (male: left half; female: right half) and dorsal (male) views (abdomen not drawn in dorsal view).

FIGURE 3. Typhlocharis acutangula n. sp. (A, B) Aedeagus: (A) median lobe (dorsal view); (B) median lobe and parameres (lateral view). (C) Female genitalia (ventral view).