Hister lucia, Leivas, Fernando W. T., Moura, Daniel P. & Caterino, Michael S., 2015

Leivas, Fernando W. T., Moura, Daniel P. & Caterino, Michael S., 2015, Brazilian Histerini (Coleoptera, Histeridae, Histerinae): a new species, key to the genera, and checklist of species, Zootaxa 3941 (3), pp. 437-444 : 438-441

Hister lucia sp. nov.

Type locality. Serro Azul (currently Cerro Largo, Rio Grande do Sul, Brazil).

Type material. Holotype: (♂) [“Serro Azul / 9. 40] ( MGAP). Paratype (1). (1 ♀) [“Serro Azul / 9. 40] ( DZUP).

Diagnosis. Frons flat, subtly concave anteriorly; mandibles dorsally and laterally concave and longer than frons and clypeus together; cavity for insertion of antennal club deep, well defined; marginal stria of prosternal lobe complete and laterally represented by three sulci; marginal pronotal stria complete laterally, united with the anterior marginal stria behind the head; elytra with dorsal and subhumeral striae deeply impressed, 1st–4th dorsal striae complete, inner subhumeral united with oblique humeral stria; anterior, middle and hind femora robust, tibiae broad; propygidium coarsely punctuated on the sides; pygidium smooth.

Description. (pronotum+elytra) 10–11 mm, elytral width (humeral region): 8–9 mm. Cuticular color black. Body shape oval, glabrous ( Fig. 1 A–C). Frons flat, subtly concave anteriorly; frontal stria strong and complete; supraorbital stria absent; frontoclypeal suture absent; epistoma slightly concave medially; mandibles concave dorsally and laterally, longer than the frons and epistoma together ( Fig. 1 D); postoccipital stria complete with setae; postgena with a fovea. Antennae with scapus slender at the base; antennal club with distinct apical sensorial area, basal pseudo-suture straight, apical pseudo-suture represented by small sensorial points. Submentum subpentagonal with few setae on the surface. Prothorax, cavity for insertion of antennal club deep, well defined, broadly open beneath; prosternal lobe about 1/3 of the total length of prosternum, anterior margin rounded ( Fig. 1 B), marginal stria complete and laterally represented by three sulci ( Fig. 1 B); lateral marginal prosternal stria complete; prosternal keel without stria and the posterior margin rounded ( Fig. 1 B). Pronotum, anterior margin with a medial pronotal and anterolateral gland openings; marginal stria complete laterally, united with the anterior marginal behind the head; outer lateral stria rounding the anterior corners ending freely; inner lateral stria complete along the sides and front, joined by the marginal, sometimes vanishing on the anterior angles. Elytra, longer than 1.5x the length of pronotum, without depression at the sutural and posterior region ( Fig. 1 A); dorsal and subhumeral striae deeply impressed, except the oblique humeral stria; 1st–4th dorsal striae complete, 5th dorsal and sutural striae present only on posterior half, the last one shorter ( Fig. 1 A); inner subhumeral united with oblique humeral stria; outer subhumeral stria present on anterior half; epipleural region with three striae, the first short and marked on the anterior region, the second and third striae derived from a single branch and ramified in the posterior half of the elytra. Mesoventrite with anterior margin emarginate medially; marginal stria complete; mesometaventral stria absent ( Fig. 1 B). Metaventrite with lateral metaventral stria curved outward extending up to the middle of metasternal-metepisternal suture, postmesocoxal stria present ( Fig. 1 B). Anterior, middle and hind femora and tibiae robust, the middle and hind almost parallel sided. Anterior leg, femora with setae on the anterior surface and a row of setae on the outer margin; apical margin of tibiae truncated, wider than femora, outer margin with three-four teeth adorned with spines or not, inner submarginal and marginal striae complete, the last one adorned with setae, tarsal cavities straight; thickness of the tarsus similar of tibial spurs. Middle and hind tibiae, outer margin with two series of short denticles adorned with spines longer than denticles; inner margin with marginal and submarginal striae; tarsus thicker than the tibial spurs. Stria of 1st visible abdominal sternum marked only laterally. Propygidium coarsely punctuated on the sides. Pygidium smooth ( Fig. 1 E).

FIGURE 2. Hister lucia sp. nov., male. A. 8th sternite; B. 9th and 10th tergite; C. Aedeagus, ventral view; D. Aedeagus, dorsal view (scales: 0.25 mm).

Male terminalia. 8th tergite truncated on posterior margin; 8th sternite, 9th and 10th tergites with two regions more sclerotized (Fig. 2 A, B); 8th sternite with bristles on the posterior region (Fig. 2 A). Aedeagus, dorso-ventrally flat; basal piece longer than parameres, only the basal region fused ventrally; (Fig. 2 C, D); parameres ventrally not fused; medial lobe with proximal apodemes beginning on the posterior third of the basal piece; bridge absent (Fig. 2C, D).

Female terminalia. Coxites with short bristles dorsally; internal margin carinate ( Fig. 3 A, B). Spermatheca, spermathecal gland, bursa copulatrix and common oviduct were not observed.

Remarks. The pronotum in the male has two central foveae and two latero-posterior foveae, not present in the female. The inner subhumeral stria varies slightly, from complete to beginning anteriorly close to the oblique humeral stria. When the anterior tibiae exhibit four spines, the basal-most is very subtle. When compared with other species recorded in Brazil the cavities for insertion of the antennal club are deeper.

Hister lucia sp. nov. appears to be related to Hister alegre Caterino and Hister platanus (Marseul) . The three species all have quite similar male genitalia, with elongate proximal arms of the median lobe (relative to those of other members of the H. coenosus group). The apico-ventral pads of the parameres are shorter and blunter than those of the other two species. Externally all three species share a somewhat elongate, subparallel-sided body form, as well as broad, flattened meso- and metatibiae, the latter being most pronounced in H. lucia sp. nov. Notwithstanding the above characters, Hister lucia sp. nov. is highly distinctive and easily recognized. It is the largest species of Hister in the New World by a substantial margin. In addition to the extremely flattened posterior tibiae, the irregular pronotal striae are also very distinctive.

Distribution and ecological data. This species is known from the northwest part of Rio Grande do Sul, near the city of Cerro Largo ( Brazil, 28.144305 S, 54.719269 W) ( Fig. 4 ), a contact region between Seasonal Semideciduous Tropical Forest (component from the Atlantic Forest biome) and Pampa biome, with an elevation of 211 meters.

It is tempting to speculate on the habits of H. lucia . A few of its near relatives are associated with leafcutting ants ( Attini : Acromyrmex spp., principally), and some morphological characters of H. lucia are reminiscent of those seen in Epiglyptus Lewis , another Attini associate. However, at this point there is no direct evidence of a myrmecophilous association. Some efforts should be made to recollect this species to confirm or refute this idea.

Etymology. We dedicate the new species to Dra. Lucia Massutti de Almeida in recognition of her help in our studies. The specific name “ lucia ” is a noun in apposition, gender feminine.

Figures

FIGURE 1. Hister lucia sp. nov. A. Dorsal view; B. Ventral view; C. Lateral view; D. Frontal view; E. Propygidium and Pygidium (scales: A – C = 2 mm; D – E = 1 mm).

FIGURE 3. Hister lucia sp. nov., female. A. Coxites, ventral view; B. Coxites, dorsal view (scales: 0.25 mm).

FIGURE 4. Known distribution of Hister lucia sp. nov. in South Brazil.