Typhlocharis baeturica Pérez-González & Zaballos, 2013

Pérez-González, Sergio & Zaballos, Juan P., 2013, Tarsal tetramery and extreme size reduction in Anillini (Coleoptera, Carabidae, Trechinae): the case of Typhlocharis Dieck, 1869; description of three new species and definition of a new intra-generic species group, Zootaxa 3682 (2), pp. 249-269 : 251-255

Typhlocharis baeturica Pérez-González & Zaballos new species

( Figs 1–2 )

Type series. Holotype, 3, SPAIN: Huelva, Sanlúcar de Guadiana (1.7 km SE), 11-02-2011, 61 m (N 37º 27’, W 07º 27’), J.P. Zaballos & S. Pérez leg. (Coll. J.P. Zaballos, UCM). Paratypes: 1 Ƥ same data as holotype; 2 3 same locality as holotype, 21-11-2012, J.P. Zaballos, S. Pérez & S. Ghannem leg.; 2 3, 5 ƤƤ SPAIN: Huelva, Sanlúcar de Guadiana (4 km SE), 21- 11-2012, 129 m (N 37º 26’, W 07º 26’), J.P. Zaballos, S. Pérez & S. Ghannem leg. (10 ex. Coll. J.P. Zaballos, UCM).

Diagnosis. Small endogean beetle, anophthalmous, with narrow and subrectangular body covered by microreticulate integument and scattered pubescence. Vertex with pars stridens. Gula partially fused to cephalic capsule. Serration in lateral margins of elytra well developed, hooked in the first third. Apical margin with two pairs of denticles (a sutural pair and a pair associated to 7th stria), pointy and well defined. Umbilicate series with seven setae (4+3). Sternum II with a pair of foveae in females. Tarsal formula: 4-4-4. Aedeagus as in Fig. 2 A, B, with two-pieced, "scissor-shaped", endophallic sclerites. Female genitalia with tubular gonocoxites, as in Fig. 2 C.

Description. Length of holotype: 1.14 mm; length of paratypes: 1.00– 1.14 mm (males), 1.06–1.12 mm (females) ( Fig. 1 ).

Head: wider (0.23–0.26 mm) than long (0.20–0.21 mm), covered by subhexagonal microreticulation. Stridulatory organ (pars stridens) on vertex, present in both sexes. Semilunar notch in posterolateral region of cephalic capsule. Sub-rectangular labrum, with a triangular area and middle button of thicker cuticle. Clypeus with slightly arcuate anterior margin, curved outwards. Moniliform antennae with 11 rounded antennomeres progressively more quadrate (morph 1, as defined in Pérez-González & Zaballos 2013b), except last one, pyriform. The last antennomere has a pattern of three antero-dorsal and one postero-dorsal sensilla coeloconica. Ventral sensilla coeloconica in antennomeres 5th and 6th. Stem of third antennomere not elongate. Mandibles without terebral teeth. Labium with sharp, pointy epilobes, separated by a wide space, and blunt middle tooth. Ligula with convex middle lobe and long paraglossae. Gula partially fused to cephalic capsule (suture only visible in the proximal and distal ends, diffuse in the middle). Cephalic chaetotaxy: five or six pairs of labral setae (s-(s)-lm-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 supra-antennal setae, one pair of vertical 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 middle tooth, a pair of long setae near base of epilobes, a pair of very short setae near apex of epilobes and a pair of very short setae near posterior suture. Prebasilar with two pairs of setae near anterior margin (lateral pair much longer) and two pairs of setae (lateral pair much longer) in posterior region, with some degree of individual variation over this basic pattern.

Pronotum: subquadrate, slightly longer (0.28–0.32 mm) than wide (0.27–0.30 mm), subtly narrowed in posterior region. Anterior margin straight, slightly crenulate, with medial hiatus (approx. as wide as two adjacent intersetae spaces); posterior margin smoothly sinuate. Lateral margins with three-four faint to very faint denticles near posterior angles. Surface covered by subhexagonal microreticulation. Disc flattened, with a strongly developed medial line and a 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 seven to eight pairs of setae [l-(l)-l-l-l-l-l-l / l-l-l-l-ll-(l)-l] parallel to anterior margin, four pairs of setae parallel to posterior margin [m-m-l-m / m-l-m-m], row of small setae, regularly placed in anterior and posterior margins (bulb-shaped setae, thickened at base in anterior margin), row of short setae in lateral margins and approximately four pairs of longitudinal rows of short pubescence in disc, but irregularly distributed. 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, glabrous proepisternum.

Elytra: approximately twice as long (0.52–0.62 mm) as wide (0.27–0.30 mm), subparallel. Lateral margins with 20–22 subtriangular denticles, well developed in all the length, "hook-shaped" in the first third. Apical margin with two pairs of large, pointy denticles (a pair associated to the end of 7th stria and a pair near the suture). Disc flattened, with longitudinal lateral carinae associated to 7th stria. Surface covered by irregular subhexagonal microreticulation. Slight elytral pores along 7th stria; scattered pores also in scutellar and discal region. Transverse scutellar organ (smoothly subtriangular or arquate to irregular) and pair of "buttonholes" present near base of elytra. Chaetotaxy: umbilicate series formed by anterior group of four setae and posterior group of three setae ( Fig. 1 ). One pair of scutellar setae. No discal setae. Discal pubescence arranged in five or six pairs of longitudinal rows, those of the third row alternative long and short. Lateral margins with a short seta for every denticle.

Legs: similar in both sexes. Wide intermetacoxal space. Metacoxae with a pointy triangular, dentiform "flap". Rounded metatrochanters. Inner margin of femora with small scaly prominences. Slightly angular metafemora and metatibiae with dilated distal region. All tarsi with four tarsomeres (tarsal formula: 4-4-4), apparently from fusion of tarsomeres 4th and 5th. Abdomen: covered by irregular microreticulation, the last segment present a belt of scaly microsculpture, scales with finely serrated edge in both sexes. Females have a pair of foveae on first ventrite (sternum II); second ventrite (sternum III) with a slight pair of foveae. Males lack ventral foveae. Last ventrite with a pair of lateral teeth and six to eight pairs of setae in posterior margin, sexually dimorphic: l-(s)-s-s-l-s-s / s-l-s-l-ss-(s)-l ( Fig.1 ).

Aedeagus: sickle-shaped median lobe (length: 0.17 mm) with subtriangular, smoothly rounded apex, bent to right (anatomically oriented) in dorsal view ( Fig. 2 A,B). Endophallus with two pieces, "scissor-shaped" sclerites. Parameres subtriangular, with two medium-sized apical setae ( Fig. 2 A).

Female genitalia: adjusts to the description of Vigna-Taglianti (1972). Tubular, slender, gonocoxites, with one apical setae. Two setae in distal region of the gonocoxite, a longer, ventral one (pointing outwards), and a shorter, dorsal one (pointing inwards). Lateral pores present in the gonocoxites. Acute gonosubcoxites. Moderately long gonoduct, with two regions: thinner, proximal (diameter: 0.002 mm) and thicker, distal (diameter: 0.006 mm). Subsphaeric spermatheca (length: 0.015 mm). Large, conical spermathecal gland (length: 0.029 mm), distally sclerotized ( Fig. 2 C).

Habitat. T. baeturica sp.n. was collected in two localities, separated 2.2 km: 1) stony slope and valley bottom in open holm oak forest ( Quercus ilex L.), with scarce laudanum shrubs ( Cistus ladanifer L.), olives ( Olea europaea L.), almonds ( Prunus dulcis (Mill.) D.A. Webb ), plantains ( Plantago sp. L.) and asphodels ( Asphodelus sp. L.). Clayey soil with abundant and different sized boulders. 2) Top of hill in pasture-like terrain, with a recent holm oak plantation (scarce young trees aligned in rows), ploughed soil, boulders of shale (Upper Carboniferous) and with laudanum shrubs. It coexists in both localities with Typhlocharis lunai Serrano & Aguiar, 2006 and T. elenae Serrano & Aguiar, 2002 .

Etymology. The Roman Baeturia Celticorum was defined by Caius Plinius Secundus (Naturalis historia III: pp. 13–14) as the territory between rivers Baetis –now Guadalquivir- and Anas –now Guadiana- bordering Lusitania, where this species was found.

Variability. There is certain degree of common intraspecific variation affecting some characters, such as chaetotaxy of labium and basilar, number and marking of posterolateral denticles in pronotum (from faintly marked to almost absent), marking of the hook-shaped lateral denticles of elytra, marking of sutural denticles of elytra or chaetotaxy of the last ventrite. The transverse scutellar organ varies between subtriangular and pointed, smoothly and slightly curved and roughly and irregularly curved. It is also common that some individuals show short and long setae irregularly mixed in the anterior row of setae in pronotum. The apodemal ring of male genitalia shows more variation than observed for other species, with an anterior projection ranging from narrow and prominent to more broad and low.

One of the female paratypes lacks the hiatus in the anterior margin of pronotum. One of the male paratypes exhibits a malformed, abnormally narrow, clypeus.

Affinities. The new species have an umbilicate series of 4+3 setae, which places it in the diecki group sensu Zaballos & Ruiz-Tapiador (1997). Nevertheless, the possession of a diffuse gula and four tarsomeres is a rare condition only known, but not described, in other species of the genus: Typhlocharis crespoi Serrano & Aguiar, 2008 . T. quadridentata ( Coiffait, 1969) also possess a diffuse gula, but five tarsomeres. Both species are the morphologically closest to T. baeturica sp.n., sharing a very small body size, shape of elytral apex, construction of aedeagus and parameres and particular shape of the labium (with prominent and pointy epilobes separated by a wide gap with a low medial tooth). However, the new species is well differentiated from both, by the 4+3 umbilicate series instead of 4+2, presence of stridulatory organ (absent in T. quadridentata and T. crespoi ) and slender, tubular gonocoxites, unguiform-like in T. quadridentata and tubular, but short in T. crespoi .

Apart from the diffuse gula, the new species has many features that resembles T. diecki Ehlers, 1883 ; T. outereloi Novoa, 1978 ; T. bivari Serrano & Aguiar, 2006 ; T. navarica Zaballos & Wrase, 1998 ; T. sanstchii Normand, 1915 or T. rochapitei Serrano & Aguiar, 2008 ; such as the presence of a wide intermetacoxal space, shape of antennomeres, pattern of basilar chaetotaxy, presence of stridulatory organ, very faint or absent elytral pores, lateral carinae of elytra associated to apical denticles or morphology and chaetotaxy of last ventrite. Within these, T. bivari also show a similar shaped aedeagus, with two endophallic pieces.

Figures

FIGURE 1. Typhlocharis baeturica sp. n. – habitus: ventral (left half: male, right half: female) and dorsal (male) views. Abdomen not shown in dorsal view for a clearer view of elytral apex.

FIGURE 2. Typhlocharis baeturica sp. n. (A, B) Aedeagus: A) median lobe (dorsal view); B) median lobe and parameres (lateral view). C) Female genitalia (ventral view).