Typhlocharis scrofa 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 : 255-258

Typhlocharis scrofa Pérez-González & Zaballos new species

( Figs 3–4 )

Type series. Holotype, 3, SPAIN: Huelva, Cumbres de San Bartolomé (3.4 km SW), Arroyo La Dehesa, 21-03- 2012, 358 m (N 38º 04’, W 06º 46’), J.P. Zaballos & S. Pérez leg. (Coll. J.P. Zaballos, UCM). Paratypes: 62 3, 45 ƤƤ same data as holotype; 1 Ƥ SPAIN: Huelva, Cumbres de San Bartolomé (7.4 km SW), Rio Sillo, 21-03- 2012, 275 m (N 38º 03', W 06º 49'), J.P. Zaballos & S. Pérez leg. (106 ex. Coll. J.P. Zaballos, UCM, 2 ex. nº ref. 2375 MNCN, Madrid).

Diagnosis. Very 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. Elytra subtly serrated in lateral margins, almost imperceptible in posterior region. Apical margin with two pairs of denticles (a sutural pair and a pair associated to 7th stria). One pair of anterior discal setae. Umbilicate series with five setae (4+1). Tarsal formula: 4-4-4. Aedeagus as in Fig. 4 A,B, with "parenthesis-shaped" endophallic sclerite. Female genitalia with club-shaped gonocoxites, as in Fig. 4 C.

Description. Length of holotype: 0.86 mm; length of paratypes: 0.86–1.05 mm (males), 0.88–1.07 mm (females) ( Fig. 3 ).

Head: almost as wide (0.19–0.24 mm) as long (0.17–0.23 mm). Clypeus with straight anterior margin. Moniliform antennae with 11 rounded antennomeres progressively more quadrate (morph 1), except last one, pyriform. The last antennomere has a pattern of two antero-dorsal and one postero-dorsal sensilla coeloconica. Ventral sensilla coeloconica in antennomeres 5th and 6th. Stem of third antennomere short. Labium without special characters, but epilobes tend to be pointy. Ligula with prominent middle lobe and short, thick paraglossae. Gula partially fused to cephalic capsule (diffuse suture, only visible in proximal and distal ends) ( Fig. 7 C). Cephalic chaetotaxy and rest of cephalic characters as described for T. baeturica sp.n.

Pronotum: subtrapezoidal, slightly longer (0.23–0.3 mm) than wide (0.21–0.26 mm), narrowed in posterior region. Anterior margin virtually straight, slightly crenulate; medial hiatus approx. as wide as two or three adjacent intersetae spaces. Posterior margin smoothly curved. Denticles of lateral margins near posterior angles absent or barely insinuated; the teeth in posterior angles are also blunt and smooth. Rest of characters and chaetotaxy as described for T. baeturica sp.n., except the row of setae parallel to anterior margin, with five to six pairs of setae [l- (l)-l-l-l-l / l-l-l-l-(l)-l], three pairs of setae parallel to posterior margin [l-l-l / l-l-l], a row of small, filiform and thin setae regularly placed in anterior and posterior margins, and four to five pairs of longitudinal rows of short pubescence in disc. Prosternum as described for T. baeturica sp.n.

Elytra: approximately two times longer (0.44–0.56 mm) than wide (0.22–0.27 mm), subparallel. Lateral margins with 17–20 sub-triangular denticles, very subtly marked and progressively smoother, practically inexistent beyond the first third. Apical margin with two pairs of denticles, a pair associated to the 7th stria and a pair associated to the suture, the latter pointing outwards and defining a characteristic "V-shaped” end of the suture. Small and scarce elytral pores, present along 7th stria, scutellar region and disc. Transverse scutellar organ (straight to irregular) and pair of "buttonholes" present near base of elytra. Chaetotaxy: umbilicate series with anterior group of four setae and posterior group of one seta ( Fig. 3 ). One pair of scutellar setae and one pair of anterior discal setae. Discal pubescence arranged in five pairs of longitudinal rows, progressively longer towards posterior region. Apical pair of pubescent setae present. Lateral margins with a short seta for every denticle. Other characters as described for T. baeturica sp.n.

Legs: similar in both sexes. Intermetacoxal space slightly widened. Metacoxae with blunt triangular "flap". Rounded metatrochanters, slightly angular pro- and metafemora, metatibiae with dilated distal region. Tarsi with four tarsomeres (tarsal formula 4-4-4).

Abdomen: microsculture and belt as in T. baeturica sp.n. Ventral foveae very faint to absent. Last ventrite with lateral teeth, pattern of six to seven pairs of setae in posterior margin, sexually dimorphic: l-s-s-l-s-s / s-l-s-l-s-s-l ( Fig. 3 ). In females, it is characteristic that the second (l) and third (s) innermost setae are practically overlapped.

Aedeagus: sickle-shaped median lobe (length: 0.14 mm) and broad, rounded apex, not bend in dorsal view ( Fig. 4 A,B). Endophallus with short and thin "parenthesis-shaped" sclerites. Parameres subtriangular, with two medium-sized apical setae ( Fig. 4 A).

Female genitalia: club-shaped, robust gonocoxites with two apical setae: one large, one very small ( Fig. 4 C). Two short lateral setae, pointing inwards, and scattered pores. Gonoduct with a thinner proximal region (diameter: 0.002 mm) and thicker distal region (diameter: 0.007 mm). Subsphaeric spermatheca (length: 0.016 mm). Spermathecal gland tubular to conical (length: 0.028 mm), slender and sclerotized in distal region ( Fig. 4 C).

Habitat. T. scrofa sp.n. was found in two localities separated 4 km: 1) Under embedded boulders of shale (Upper Cambrian) in open land with some holm oaks ( Quercus ilex L.), laudanum shrubs ( Cistus ladanifer L.), broom ( Retama sp. Raf.) and asphodels ( Asphodelus sp. L.). Brownish clayey soil. 2) In the slopes of a small river, with the same kind of environment and vegetation.

Etymology. The new species is named after the black Iberian pig (Sus scrofa L.), a common and very important component of the landscapes, culture and economy in the surrounds of the type locality.

Variability. The large series studied (109 specimens) allowed a good perception of intraspecific variability. There are the usual minor alterations: chaetotaxy in labium and basilar; some variability in clypeus, usually straight but slightly arcuate in some specimens; development of pronotum denticles, more pronounced in some males than in the rest; or in the chaetotaxy of the last ventrite. Some individuals have a narrow hiatus. Proportions of pronotum are variable between shorter, almost square, and longer, more rectangular shapes. General body proportions vary, especially within males, from more robust to more slender individuals.

Three specimens show asymmetric alteration in the pattern of sensilla coeloconica in last antennomere. Some individuals have longer paraglossae than usual.

One male paratype shows asymmetry in the sutural denticles of elytra (lacking one of the denticles). These are also slightly variable within the series, with some specimens lacking the characteristic "V-shaped" apex.

There is some variation in the marking of the "flap" of metacoxae, but never reaching the degree observed in T. baeturica sp.n. In contrast with the observed in T. baeturica sp.n., the shape of apodemal ring is virtually constant in all the males.

One of the male paratypes presents an abnormal three-setae paramere. The apex of the elytra is damaged in one female paratype.

Affinities. T. scrofa sp.n. is the fourth species known to have a diffuse gula along with T. quadridentata ( Coiffait, 1969) , T. crespoi Serrano & Aguiar, 2008 and T. baeturica sp.n., and the third with four tarsomere condition. It is also the smallest species known to date, with individuals of 0.86 mm, even more than the minute T. quadridentata . It is very similar to T. baeturica sp.n. but immediately recognizable from it by the 4+1 umbilicate series (which would include it in the outereloi group sensu Zaballos & Ruiz-Tapiador, 1997), instead of 4+3; the extremely faint lateral denticles of elytra, the presence of anterior discal setae (also present in T. crespoi ) the shape of teeth of elytral apex, and the genitalia, among other details.

Female genitalia is quite unique, and resembles an intermediate between the unguiform-like condition present in T. quadridentata ( Pérez-González & Zaballos 2012) and the short tubular gonocoxites present in T. crespoi ( Serrano & Aguiar 2008) . Affinities with other species are the same as commented for T. baeturica sp.n., except the intermetacoxal space is narrower in T. scrofa sp.n. and the aedeagus mostly closely resembles the broad apex present in T. outereloi and T. diecki .

Figures

FIGURE 3. Typhlocharis scrofa 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 4. Typhlocharis scrofa sp. n. (A, B) Aedeagus: A) median lobe (dorsal view); B) median lobe and parameres (lateral view). C) Female genitalia (ventral view).

FIGURE 7. Different types of gula in the genus Typhlocharis. Light microscopy photographs and schematic diagrams of: A) T. pacensis Zaballos & Jeanne, 1987; wide gula, approx. twice as long as wide, lateral sutures clearly visible. B) T. elenae Serrano & Aguiar, 2002; narrow gula, approx. four of five times as long as wide, lateral sutures clearly visible, subparallel. C) T. scrofa sp. n.; diffuse gula, same proportions as wide gula, but lateral sutures only visible in the proximal and distal ends, partially fused to the cephalic capsule.