Typhlocharis mixta, 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 mixta n. sp.

Figs 4 , 5

Type series. Holotype, ♂, SPAIN, Badajoz, Puerto de los Reventones (11 km NE Fregenal de la Sierra), 22- 11- 2012, 500 m (38º 15’ N, 06º 34’ W), J. P. Zaballos, S. Pérez & S. Ghannem leg. (Coll. J.P. Zaballos, UCM). Paratypes: 659♂♂, 616 ♀♀ same data as holotype; 1♂ same locality as holotype, 24-04-2012, J. P. Zaballos & S. Pérez leg.; 10♂♂, 11 ♀♀ SPAIN, Badajoz, Valverde de Burguillos (4.4 km NE), 22- 11-2012, 488m (38º 21’ N, 06º 31’ W), J. P. Zaballos, S. Pérez & S. Ghannem leg. (Coll. J.P. Zaballos and Coll. S. Pérez-González, UCM). 4♂♂, 4 ♀♀ same data as holotype (MNCN, Madrid, Catalogue number: 11612).

Diagnosis. Small endogean anophthalmous beetle, with narrow and subrectangular body covered by microreticulate integument and scattered pubescence. Vertex with pars stridens. Clypeus with a distinctive median tooth. Pronotum with a wide medial hiatus. Elytra faintly serrated in lateral margins and apical margin with three to six pairs of small denticles, highly irregular. Umbilicate series with six setae (4 + 2). Abdomen with ventral foveae only in females. Pseudotetramerous tarsi in all the legs. Aedeagus as in Fig. 5 , ‘plough-shaped’ endophallic sclerite and broad parameres. Female genitalia as in Fig. 5 , with subcylindrical spermatheca.

Description. Length 1.21–1.49 mm (males), 1.27–1.60 mm (females) ( Fig. 4 ). Head: wider (0.24–0.34 mm) than long (0.22–0.30 mm), labrum subrectangular to slightly notched, rounded edges and triangular sclerotized area with middle button. Clypeus with a median tooth in the anterior margin. Right mandible with a prominent, pointy, terebral tooth on inner margin. Left mandible without teeth, but inner margin with sharp edge. Ligula with very prominent middle lobe and long paraglossae. Wide gula, approximately twice as long as wide, the lateral sutures may appear fainter. Rest of cephalic characters and cephalic chaetotaxy, including antennae, as described for T. acutangula n. sp.

Pronotum: subrectangular, longer (0.32–0.45 mm) than wide (0.3–0.4 mm), slightly narrowed in posterior region. Proportions of pronotum present a wide range of variation ( Fig. 6 ). Wide medial hiatus (moderately wider than three adjacent intersetae spaces). Lateral margins with denticles near posterior angles highly variable in shape and number, from two or three, irregular and faint to four or five, well marked and serrated. The posterior angles are also variable from pointy and protruding to blunt and low ( Fig. 6 ). Other characters and chaetotaxy are the same as for T. acutangula n. sp., except a pattern of three pairs of setae, parallel to posterior margin [s-l-l / l-l-s], the row of small, thin setae of anterior and posterior margins (filiform) and the short discal pubescence, arranged in four pairs of longitudinal rows. Prosternum as described for T. acutangula n. sp.

Elytra: approximately two times longer (0.64–0.85 mm) than wide (0.32–0.41 mm), subparallel. Lateral margins with 18–21 subtriangular denticles, faint and progressively smoother towards posterior, but still marked in last third. Apical margin smoothly rounded, with three to six pairs of small denticles (showing a notable range of individual variation, but mostly combinations of four and five pairs) ( Fig. 7 A, B). Transverse scutellar organ with straight to slightly subtriangular margin and pair of ‘buttonholes’ present near base of elytra. Chaetotaxy: umbilicate series formed by anterior group with four setae and posterior group with two setae ( Fig. 4 ). One pair of scutellar setae. No apparent discal setae, but the population of Puerto de los Reventones is prone to have one pair of anterior “pseudodiscals” (i.e. pubescent setae longer than the surrounding pubescence). Rest of characters as in T. acutangula n. sp.

Legs: similar in both sexes. Intermetacoxal space not widened. Metacoxae with smoothly rounded “flap”. Rounded metatrochanters, metatibiae with moderately dilated distal region and a short perpendicular seta in the inner side. Inner side of pro- and mesofemora covered with small protuberances, absent in metafemora. Pseudotetramerous tarsi in all the legs, tarsomeres 4º and 5º retain a faint articular membrane, but are partially fused and not capable of a normal articulation.

Abdomen: as described for T. acutangula n. sp., but with deep ventral foveae in the first and second ventrite of females, absent in males. Last ventrite with a sexually dimorphic pattern of five to six pairs of setae in posterior margin: l-s-s-l-s-m / m-(s)-l-s-s-l ( Fig. 4 ). Aedeagus: sickle-shaped median lobe (length: 0.22 mm) and “bottleneck-shaped”, smoothly rounded apex, slightly bent to right (anatomically oriented) in dorsal view ( Fig. 5 A,B). Endophallus with ‘plough-shaped’ sclerites, as drawn in Fig. 5 B. Short and broad parameres, both with two medium-sized apical setae ( Fig. 5 B). Female genitalia adjusts to the description of Vigna-Taglianti (1972). Long tubular gonocoxites, with double apical setae. Lateral setae absent, but lateral pores in the gonocoxites. Short gonoduct with two regions, thinner proximally (diameter 0.003 mm) and thicker distally (diameter 0.008 mm). Spermatheca subcylindrical and short, “barrel-shaped” (length: 0.011 mm). Conical spermathecal gland (length: 0.014 mm), sclerotized in distal region ( Fig. 5 C).

Etymology. The name of the species plays a double meaning, referring to the high intraspecific variation that gives a mixture of body shapes and sizes to the populations. On the other hand, it refers to the presence of certain morphologic traits (such as the tooth in clypeus, the trend to diffuse gula or the pseudotetramery) unexpected for members of baetica group, but known in other species groups, like mixed pieces in different jigsaw puzzles.

Habitat. Typhlocharis mixta n. sp. is found in two localities separated 13 km ( Fig. 1 ): 1) Puerto de los Reventones, in open prairie environment with low hills and valleys crossed by seasonal streams. Vegetation mainly composed by low herbaceous plants, grasses and thistles, with scattered broom bushes (Retam Raf.). Higher grasses and rushes ( Juncus L.) appears near the stream. Dark, brownish soil, with scarce large boulders of gneisses and shales (Proterozoic, Valverde Formation). This location was sampled four times (March, April, June and November), with the best humidity range in the last sampling. 2) Valverde de Burguillos, in a small meadow surrounded by cultures and open holm oak forest. Vegetation is akin to the former locality, with the exception of holm oaks. Brown to reddish soil, rich in clays, with embedded small to medium sized granite boulders (Proterozoic).

Variability. There are not significant differences between the populations of Puerto de los Reventones (1285 specimens) and Valverde de Burguillos (21 specimens), both have the same range of intraspecific variation.

The species is morphologically very diverse in proportions and size, from 1.2 to 1.6 mm in length, but the presence of a tooth in clypeus, umbilicate series 4+2, the perpendicular setae on distal end of metatibiae, pseudotetramerous tarsi, ventral foveae in females, genitalia and the wide hiatus are virtually constant within the population.

The terebral tooth is usually very prominent but in some specimens is blunt, low or almost absent. The tooth of clypeus ranges from blunt to very pointy (but always present). The lateral sutures of the gula are very faint in about 20% of the series, resembling the “difusse gula” morphology observed in quadridentata group (Pérez-González & Zaballos 2013c). There is slight variation in the pronouncement of epilobes. Two specimens have a widened pars stridens, two times wider than the average.

Pronotum and elytra have the higher rates of variability. Pronotum proportions can be certainly different, with three main morphs: subrectangular, smoothly curved lateral margins and 3-4 well marked posterolateral denticles ( Fig 6 : 1,2), the most common; rectangular, straight lateral margins and 4-5 (even 6 in one specimen) well marked denticles ( Fig 6 : 3,4) and subsquare, with 2-3 blunt and irregular denticles ( Fig 6 : 5,6). Asymmetric pronotum are abundant, and they affect the number of denticles or the pronouncement of the posterior angle ( Fig 6 : 7). Five specimens have aberrant pronotums with widened, notched or asymmetric lateral margins ( Fig 6 : 8–10).

Transverse scutellar organ varies from straight to subtriangular and the margins can be irregular or smooth. Lateral denticles of elytra can be more or less marked. Apical denticles of elytra appear in a wide range of combinations and shapes ( Fig. 7 ): the most common are 4/4 (17% of the series), 4/5 (15%), 5/4 (15%), and 5/5 (22%), but they range from 2/3 to 7/7. All the observed combinations and their abundance within the population are expressed in Fig. 7 B.

The inner pair, closer to the elytral suture is especially developed and bigger than the other denticles ( Fig. 7 A: 3) in some specimens, resembling those of Typhlocharis tertia Pérez-González & Zaballos, 2013 . About 14% of the series (145 specimens) have bifid or double denticles and 7 specimens show triple denticles ( Fig. 7 A: 4-6). Asymmetries ( Fig. 7 A: 7–9) and damaged elytra are also common.

Variations in patterns of chaetotaxy occur in labium, prebasilar, last ventrite and sensilla coeloconica of the 11th antennomere. It is remarkable that the ventral sensilla coeloconica in 5º and 6º antennomeres also varies: 7 specimens have only sensilla coeloconica in the 5º antennomere and 3 specimens have them in antennomeres 5º, 6º and 7º. It is the first evidence of variation in this feature within the same species, and the presence of sensilla coeloconica in 5º antennomere but not in 6º has been reported only in Typhlocharis tetramera Pérez-González & Zaballos, 2013 .

Finally, there are several specimens with teratologies, like antennomere fusion (5 specimens, with fused 3º-4º, 5º-6º, 9º-10º and 10º-11º antennomeres respectively), or malformed mesotibiae (1 specimen, associated with a malformed pronotum, possible result of a failed moult).

Affinities. Typhlocharis mixta n. sp. presents the diagnostic characters of baetica group, defined by the presence of several pairs of apical denticles. Affinities with other species of the group are the umbilicate series of 4+2, shared with T. pacensis Zaballos & Jeanne, 1987 ; T. furnayulensis Zaballos & Banda, 2001 ; T. secunda Perez- González & Zaballos, 2013 and T. acutangula n. sp.

The protuberances in femora also appears in T. baetica Ehlers, 1883 ; T. tertia Perez-González & Zaballos, 2013 ; T. quarta Perez-González & Zaballos, 2013 and T. acutangula n. sp.; the high number and serrated aspect of posterolateral denticles of pronotum are also typical of T. baetica and T. quarta , but many specimens have pronotum with few and less defined denticles akin to that of T. tertia and the other species of baetica group. The broad parameres are unusual within the group and strongly resembles those of T. tertia .

T. secunda Perez-González & Zaballos, 2013 is very similar: both species shares the same umbilicate series, size range, overall shape of pronotum posterolateral denticles and presence (not always in T. mixta ) of anterior “pseudodiscal” setae. However, the new species is well differentiated by its diagnostic features.

The tooth of clypeus, subcylindrical spermatheca, metatibial perpendicular short seta and the pseudotetramerous tarsi found in T. mixta n. sp. are unique of this species within baetica group, but appear in other Typhlocharis species. The tooth of clypeus is the definitory trait of the six species of gomezi group (Zaballos & Farinós 1995; Zaballos & Ruiz-Tapiador 1997) which also have a short perpendicular seta in metatibiae.

The trend of diffuse gula in some specimens, the variability of ventral sensilla coeloconica in antennomeres 5º and 6º and the pseudotetramerous tarsi are features previously observed only in species of quadridentata group (Pérez-González & Zaballos 2013c). In both cases the possible homology of these characters remains unclear.

Key to species of baetica group (update of Pérez - González & Zaballos 2013a)

1. Elytra with umbilicate series 4+4...................................... T. quarta Pérez-González & Zaballos, 2013

- Elytra with umbilicate series different to 4+4.............................................................. 2

2. Elytra with umbilicate series 4+3........................................................................ 3

- Elytra with umbilicate series 4+2 or 4+1.................................................................. 6

3. Inner side of femora with protuberances, warty surface. Length> 1.4 mm ....................................... 4

- Inner side of femora without protuberances, smooth surface. Length <1.4 mm .................................... 5

4. Apical margin of elytra with 6–7 pairs of small denticles. Length 1.5......................... T. baetica Ehlers, 1883

- Apical margin of elytra with 3 pairs of large denticles. Length 1.7 mm .......... T. tertia Pérez-González & Zaballos, 2013

5. Elytra with lateral denticles marked in all their length. Very faint or absent ventral foveae. Length 1.1 mm ........................................................................................ T. aguirrei Zaballos & Banda, 2001

- Elytra with lateral denticles marked only in the first third of their length. Ventral foveae well developed in both sexes. Length 1.3 mm T. matiasi Zaballos & Banda, 2001

6. Elytra with umbilicate series 4+2........................................................................ 7

- Elytra with umbilicate series 4+1....................................................................... 11

7. Clypeus with a median tooth. Ventral foveae in females. Length 1.2–1.6 mm ........................... T. mixta n. sp.

- Clypeus with straight margin, without median tooth........................................................... 8

8. Metatibiae with a pointy dentiform projection in the distal end. Ventral foveae absent. Length 1.1–1.3 mm ..................................................................................................... T. acutangula n. sp.

- Metatibiae without dentiform projection.................................................................... 9

9. Elytra with 1 pair of discal setae in the anterior third. Length 1.4 mm .......... T. secunda Pérez-González & Zaballos, 2013

- Elytra without discal setae. Length <1.1 mm .............................................................. 10

10. Apical margin of elytra with 4–5 pairs of small denticles. Diffuse endophallus sclerites. Length 0.9–1 mm ........................................................................................ T. pacensis Zaballos & Jeanne, 1987

- Apical margin of elytra with 5–7 pairs of small apical denticles. “Y-shaped” endophallus sclerites. Length 1.1 mm ............................................................................. T. furnayulensis Zaballos & Banda, 2001

11. Elytra with lateral denticles marked in all their length. Thin, “Y-shaped” endophallus sclerites. Subspheric-irregular spermath- eca. Length 1.1 mm T. millenaria Zaballos & Banda, 2001

- Elytra with lateral denticles marked only in the first third of their length. Thick, stick-shaped endophallus. Reniform spermath- eca. Length 1.1 mm ................................................. T. prima Pérez-González & Zaballos, 2013

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 4. Typhlocharis mixta n. sp. – habitus: ventral (male: left half; female: right half) and dorsal (male) views (abdomen not drawn in dorsal view).

FIGURE 5. Typhlocharis mixta n. sp. (A, B) Aedeagus: (A) median lobe (dorsal view); (B) median lobe and parameres (lateral view). (C) Female genitalia (ventral view).

FIGURE 6. Range of intraspecific variation in pronotum of Typhlocharis mixta n. sp.: 1 – 6 main morphotypes, 7 – 10 asymmetries, malformations and teratologies: 1, 2, subrectangular pronotum with smoothly curved lateral margins and well marked denticles; 3, 4, rectangular pronotum, with straight lateral margins and high number of well marked denticles; 5, 6, subsquare, with smoothly curved lateral margins and low number of blunt denticles; 7, Asymmetric posterior angles, note the different aspect of pointy and blunt angles; 8, symmetrically widened lateral margins; 9, asymmetric malformed margins; 10, symmetrically notched lateral margins.

FIGURE 7. Range of intraspecific variation in elytra of Typhlocharis mixta n. sp.: (A) Elytral apex: 1 – 3 general morphotypes: 1, lower number of denticles; 2, higher number of denticles; 3, enlarged inner pair of denticles; 4 – 6 double or triple denticles: 4, large double denticles; 5, bifid, fused double denticle; 6, fused triple denticle; 7 – 9, strong asymmetries. (B) Graphic showing the abundance of every observed combination of apical denticles, expressed as “ denticles in left elytra / denticles in right elytra ”. Note the majority of the series present combinations of four and five pairs of denticles. “? ” indicates missing data (e. g. damaged elytra). Total number of specimens: 1306.