Hydrolutos gransabanensis Derka, Fedor & Svitok 2013

Derka, Tomáš, Fedor, Peter, Svitok, Marek & Trizna, Milan, 2013, Hydrolutos gransabanensis sp. n. (Orthoptera: Anostostomatidae), a new semi-aquatic Lutosini species from Gran Sabana (Venezuela), Zootaxa 3682 (3), pp. 432-440 : 434-439

Hydrolutos gransabanensis Derka, Fedor & Svitok 2013

Description. Male: Body dark brown. Head capsule, including mandibles, dark brown with no bright pattern on vertex, shiny and almost smooth, eyes black. Palpi completely light, distally even lighter. Thorax and abdomen very dark brown dorsally, with light bands on terga (light area on pronotum). Legs brighter than body ( Figure 2 ).

Head. Antennal flagellum about 3.5 times total body length, proximally smooth, in middle and distal section swollen and covered by short fine microsetae. Fastigium as broad as antennal segment S1, slightly flattened, not declinate, with a median carina. Vertex convex, clypeus subtriangular with distinct median carina. Labrum heartshaped, proximally as broad as distally, without indistinct median carina in its apical half. Maxillary palps bright, the last segment swollen and covered by short fine and soft microsetae. Eyes elevated in frontal view ( Figure 3).

Thorax. Pronotum slightly elevated over mesonotum, as long as wide, bordered by a smooth rolled margin, containing both smooth and gently rugose areas. All thoracic sterna with 2 spines, prosternum: 2 indistinct spines posterolaterally elevated, mesosternum: 2 spines posterolaterally elevated, metasternum: 2 distinct spines posterolaterally elevated. Legs long, forecoxa with a moderate lateral spine, femora without spines. Fore tibiae dorsally with 1 spine medially and 2 apically, ventrally with 2 rows of 5 spines (including the apical ones). Middle tibiae dorsally with a row of 4 spines on internal side and a row of 3 spines on external side, ventrally with 2 rows of 5 spines. Hind tibiae with 2 lateral and 1 central combs of short but firm spines, ventrally with 2 moderate subterminal and 2 superior terminal spines. Tympanum ellipsoid, dark brown.

Abdomen. Abdominal apex and genitalia as on Figures 4, 5, 6. Abdominal tergites smooth with fine transverse striae mesally and numerous yellowish maculae. Genitalia pubescent. Supra-anal plate bilobulate, with a V-shape emargination, terminally slightly curved upwards. Cerci cylindrical, rugose, directed gently upwards, with blunt apices and without internal processes. Subgenital plate longer than wide, semicircular posteriorly, very gently divergent laterally, with long styli directed ventrad and a triangular tubercle ventrally.

Measurements. Body length 30 mm (including cerci 34 mm), fastigium width 1.4 mm, interocular space 4.5 mm, first antennal segment width 1.4 mm, pronotum length 9 mm, width 10 mm, hind femur length 28 mm, width 6.5 mm (max.), hind tibia length 27 mm, hind tarsus length 11.0 mm, hind tarsalia length: I 5.3 mm, II 2.9 mm, III 1.0 mm, IV 5.3 mm, abdomen length (without cerci) 17 mm, cerci 6.7 mm, subgenital plate length 4.3 mm, width 3.6 mm.

Female: Body brown, with lighter pronotum and head, terga with light band medially. Head capsule, including mandibles, brown with lighter vertex, shiny and almost smooth, eyes black. Palpi light uniformly. Legs distinctly brighter than body (Figure 7).

Head. Antennal flagellum (despite damaged) proximally smooth, in middle and distal section swollen and covered by short fine microsetae. Fastigium as broad as or more narrow than antennal segment S1, slightly flattened, not declinate, with a median carina ( Figure 8). Vertex convex, clypeus subtriangular with distinct median carina. Labrum heart-shaped, proximally as broad as distally, with indistinct median carina in its apical half. Maxillary palps bright, the last segment swollen and covered by short fine and soft microsetae. Eyes elevated in frontal view.

Thorax. Pronotum slightly elevated over mesonotum, slightly wider than long, bordered by a smooth rolled margin, containing both smooth and gently rugose areas. All thoracic sterna with 2 spines, prosternum: 2 indistinct spines posterolaterally elevated, mesosternum: 2 spines posterolaterally elevated, metasternum: 2 distinct spines posterolaterally elevated. Legs long, forecoxa with a moderate lateral spine, femora without spines. Fore tibiae dorsally with 1 spine medially and 2 apically, ventrally with 2 rows of 5 spines (including the apical ones). Middle tibiae dorsally with a row of 4 spines on internal side and a row of 3 spines on external side, ventrally with 2 rows of 5 spines. Hind tibiae with 2 lateral and 1 central combs of short but firm spines, ventrally with 2 moderate subterminal and 2 superior terminal spines. Tympanum ellipsoid, brown.

Abdomen. Abdominal apex and genitalia as on Figures 9, 10, 11. Abdominal tergites smooth with fine transverse striae mesally and with posterior edges darker. Ovipositor moderate, slightly dorsad curved with smooth dorsal and ventral margins. Cerci conical angustate distally, hirsute. Epiproct triangular acute. Subgenital plate subtriangular with hind margin strongly incised, forming two tiny distinct lobes terminally.

Measurements. Body length 29 mm (including ovipositor 39 mm), fastigium width 1.4 mm, interocular space 5.5 mm, antenna: damaged (appears similar to male), first antennal segment width 1.4 mm, pronotum length 10.2 mm, width 11 mm, hind femur length 24.5, width 7.2 mm (max.), hind tibia length 22.5 mm, hind tarsus length 10.5 mm, hind tarsalia length: I 4 mm, II 2.2 mm, III 0.6 mm, IV 4.3 mm, abdomen length (without ovipositor) 13.5 mm, ovipositor length 15 mm, cerci length 3.5 mm, subgenital plate length 2 mm, width 2 mm.

Type data and depository. Holotype: 1 ♂, Venezuela, Edo. Bolívar, Cueva El Tigre, 1001 m a.s.l., 04°38´59,3´´ N, 61°06´10,8´´ W, 25.XI. 2011. Holotype has been preserved in 70% ethanol.

Paratype. 1 ♀, Venezuela, Edo. Bolívar, Cueva El Tigre, 1001 m a.s.l., 04°38´59,3´´ N, 61°06´10,8´´ W, 25.XI. 2011. Paratype has been preserved in 70% ethanol.

Holotype and paratype will be deposited in Museo del Instituto de Zoología Agrícola ( MIZA), Facultad de Agronomía, Universidad Central de Venezuela, Maracay, Edo. Aragua, Venezuela.

Etymology. The species has been named after La Gran Sabana, Venezuela, the region of its origin.

Diagnosis. The species is easily distinguished on a few characters. Fastigium as broad as antennal segment I (rarely more narrow), but more narrow in H. roraimae and H. aracamuni . Fore tibiae dorsally with 1 spine medially and 2 apically. Posterior margin of epiproct strongly bilobulate, while lightly bilobulate ( H. auyan , H. breweri ), very lightly bilobulate ( H. chimantea ) or oval in H. aracamuni . Male subgenital plate longer than wide, while in H. roraimae , H. chimantea , H. aracamuni and H. breweri as long as wide. Female subgenital plate subtriangular with hind margin strongly incised, forming two tiny distinct lobes terminally.

Figures

FIGURE 2. Male Hydrolutos gransabanensis— a total view.