Pseudoxycheila tucumana Perger & Guerra

Perger, Robert & Guerra, Fernando, 2012, Two new tiger beetle (Coleoptera, Carabidae, Cicindelitae) species from the Tucuman-Bolivian forest in the National Tariquia Reserve, Bolivia, Zootaxa 3434, pp. 49-58 : 55-57

Pseudoxycheila tucumana Perger & Guerra n.sp.

( Figs. 1 H; 3C, D; 4B, C)

Type material. Bolivia, Tarija, O`Connor province, Tariquia: 1 male, holotype, CBF, 1.4 km south west of Salinas, 0.66 km east of Salinas River, S21°49' 23, W64°14' 35, 1093 m a.s.l., Tucuman-Bolivian subhumid forest, bank of small mountain river, November 2011, F. Guerra and R. Perger; 1 female, allotype, same data; 4 males, 4 females, paratypes, same data; 2 males 3 females, paratypes, CBF, 3.2 km east of Salinas River, 2.5 km east of road to Salinas, S21°49' 19, W64°14' 20, 1200 m a.s.l., Tucuman-Bolivian subhumid forest, humid bank of a temporarily dry small mountain stream, December 2011, F. Guerra and B. Bernal; Bolivia, Santa Cruz, Valle Grande province: 5 specimens, paratypes, MHN-NKM, Alto Seco, 16–17. March 2006, Ivan Garcia; Bolivia, Santa Cruz, Cordillera province: 1 male, paratype, MHN-NKM, Incahuasi, 16. March 2008, Tito Vidaurre.

Derivation of specific epithet. The epithet “ tucumana ” refers to the ecoregion Tucuman-Bolivian forest in which we collected the species. The species is most likely endemic to Tucuman-Bolivian forest.

Diagnosis. P. tucumana n.sp. is geographically and morphologically closest to P. andina Cassola, 1997 . Both are distinguished from other congeners by relatively short elytra, pronotum with velvet-like blue reflections and the male aedeagus with a nearly straight tip. Specific for Pseudoxycheila tucumana n.sp. is a significantly larger orange spot on each elytron, 1/3 as long as the elytron (about 1/ 4 in P. andina ) and obviously longer than the elytral width (shorter in P. andina ) (Tab. 2). In P. tucumana n.sp., the aedeagus is angled less than in P. andina and ends in a fingertip like apex.

Character P. t u c um a na n.sp. (n=20) P. andina (n=20) t-test Ratio Length Elytra/Spot 2.96+/-0.12 4.24+/-0.37 0.0001 Ratio Length Spot/Width Elytra 0.92+/-0.03 1.3+/-0.13 0.00012

Description. General. Body length 14–16.3 mm. Head and pronotum dorsally shiny velvety-like blue, body ventrally black with green-blue reflections, head large, laterally convex behind eyes, pronotal disk dorsally and laterally convex, elytra short and narrow with large orange spots.

Head proportionally large, laterally (when seen in dorsal view) convex between eye and circular line, and concave between circular line and postoccipital ridge, width behind eye at same level with outer eye margin; completely glabrous except two sensory setae near eyes, two pits close to antennal sockets. Finely rugose behind eyes, frons and vertex relatively smooth. Labrum, mouthparts and antennae shining black. First two proximal segments of labial palp densely setose. Antennal scape and antennomeres except pedicellus with 1 erect subapical seta, antennomeres 5–11 finely pubescent.

Pronotum relatively smooth, trapezoid, wider than long, widest in the middle, anterior margin obviously wider than posterior, both margins with deep transverse sulci, pronotal disk convex dorsally and anterior-laterally, at same level as lateral pronotal margin when seen from dorsal view, with deep longitudinal median groove. Scutellum small, triangular.

Elytra short and narrow, outline oval, widest in middle, anterior fifth nearly parallel, forming a continuous transition with the posterior elytral margin, humerus obtuse; elytra basally coarsely punctured, dark blue, median with black velvety-like area, surrounding orange spots, spots large, elongated, longer than wide, 1/3 as long as elytra length and obviously longer than elytra width, laterally extending over the margin of the black velvety spots, posterior on both sides slightly impressed, area posterior of black velvety-like patches and elytral apex (depending angle of view) shiny light blue-turquoise, apex laterally rounded, spineless, with edge part of the suture.

Abdominal segments 3 and 4 with a pair of erect subapical seta distal, margin of abdominal segment 6 lined with long seta.

Legs black, longitudinally lined with short, stout, erect, setae. Mesotibia in distal half with fine, brownishyellow hairs. in males dense, in females sparse; coxae and trochanters black. Metacoxa and apex of pro- and mesotrochanters with a single sensory seta.

Male aedeagus long, arc-shaped, slightly angled, ending in a straight, fingertip like rounded apex.

Geographic distribution. P. tucumana n.sp. is known from the northern (Valle Grande, Santa Cruz Department) and southern limit (type location) of Tucuman-Bolivian forest. It replaces P. andina somewhere between Florida and Valle Grande province (Santa Cruz Department). Specimens from near the Argentinean border extend the known distribution range of the genus Pseudoxycheila more than 400 km southwards. We consider P. tucumana n.sp. endemic to Tucuman-Bolivian forest.

Ecology. This species was not observed during the dry season from October to mid November. With increasing rainfall in November and December, we observed single individuals on a shady and moist bank substrate of a stony mountain river and a humid bank of a temporarily dry river in a gully (type locations). The latter was shady as well and bordered with steep sloping, humid walls with growth of mosses and liverworts (1F, H). Co-occurring tiger beetle species were Cylindera (Plectographa) yaguaree n.sp., Pentacomia (Mesachantina) cribrata and Oxycheila germaini . As noted for other species of Pseudoxycheila , disturbed individuals of P. tucumana n.sp. did not fly when disturbed but tried to escape by running, exposing their large orange spots on the elytra.

Specimens of the other two Bolivian congeners, P. andina and P. quechua , have not been reported from river banks, but instead from humid mountain habitats such as areas close to rivers with temporary water and landslides ( Pearson et al. 1999). Our observations suggest that P. t u c u m a n a n.sp. prefers humid habitats as well, which in Tucuman-Bolivian forest might be limited to riverbanks and the bottom of gullies.

Figures

FIGURE 1. A, Relief map Bolivia, subhumid Tucuman-Bolivian forest highlighted green, according to Navarro & Ferreira (2007); (+) most southern records for Pseudoxycheila andina Cassola 1997, (*) Pseudoxycheila tucumana n. sp. (coll. MHN- NKM); B, Subandean region of Tarija department, study areas indicated by solid white line, limit of Tariquia by white line; C, study areas, view from the Andes; D, E, surveyed transects (white lines), collection location of Cylindera (Plectographa) yaguaree n. sp. (red points) and P. tucumana n. sp (red lines), (a) S 21 ° 45 ' 18, W 64 ° 12 ' 32, (b) S 21 ° 49 ' 23, W 64 ° 14 ' 35; F, habitat of C. yaguaree n. sp. and P. tucumana n. sp.; Life habitus and preferred substrate, G, C. (P.) yaguaree n. sp.; H, P. t u c u m a n a n. sp.