Scelimena gombakensis Muhammad, Tan & Skejo, 2018

Muhammad, Amira Aqilah, Tan, Ming Kai, Abdullah, Nurul Ashikin, Azirun, Mohammad Sofian, Bhaskar, Dhaneesh & Skejo, Josip, 2018, An annotated catalogue of the pygmy grasshoppers of the tribe Scelimenini Bolívar, 1887 (Orthoptera: Tetrigidae) with two new Scelimena species from the Malay Peninsula and Sumatra, Zootaxa 4485 (1), pp. 1-70 : 6-11

publication ID	https://doi.org/ 10.11646/zootaxa.4485.1.1
publication LSID	lsid:zoobank.org:pub:EDC89718-2F45-494A-80F1-A187DA926CC4
DOI	https://doi.org/10.5281/zenodo.5959386
persistent identifier	https://treatment.plazi.org/id/0636885F-FFB4-7271-FF74-5226FBB6849C
treatment provided by	Plazi
scientific name	Scelimena gombakensis Muhammad, Tan & Skejo
status	sp. nov.

Treatment

Scelimena gombakensis Muhammad, Tan & Skejo View in CoL , sp. nov.

( Figs 1 View FIGURE 1 , 2 View FIGURE 2 )

Material examined. Holotype (male): Peninsular Malaysia, Selangor, Ulu Gombak Field Studies Centre, lowland secondary rainforest, on river rocks, N3.325609, E101.753433, 257m, 24 September 2017, 10:20 a.m. MYT, coll. A.A. Muhammad, Muhammad Hafiz Mohd Amin & Afyza Maisarah Azizan, [AAM.17.79] (deposited in the ZRC).

Paratypes: 4 males, 4 females (deposited in the ZRC, MZUM & FRIM). Same locality and environments as holotype: males (AAM.18.2, AAM.18.3 & AAM.18.4), N3.325410, E101.753047, 256m, 9 March 2018, coll. A. A. Muhammad & N. A. Abdullah; females (AAM.17.68 & AAM.17.277), N3.325609, E101.753433, 257m, 24 September 2017, coll. A.A. Muhammad, Muhammad Hafiz Mohd Amin & Afyza Maisarah Azizan; (AAM.18.1 & AAM.18.5), N3.325410, E101.753047, 256 m, 9 March 2018, coll. A. A. Muhammad & N. A. Abdullah.

Diagnosis. This new species differs from congeners by the following characters: (1) median and lateral carinae substraight and lined with yellow nodules, (2) tegminal (dorsal) sinus less tall than lower sinus, (3) posterior angles of lateral lobes in dorsal view produced into a long, acute spine that curved anteriorly, (4) color pattern.

Comparison with congeners. This new species closely resembles Scelimena discalis ( Hancock, 1915) from Indochina and Scelimena melli Günther, 1938 from southern China (Guangdong, Guangxi, Guizhou).

New species differs from S. discalis by a relatively smaller size: BL (including pronotum) in males 20.1–24.6, females 23.7–28.7 (males 25, females 29.5–30.5 for S. discalis ); PL (from collar) males 19.3–23.5, females 22.8– 27.8 (males 24, females 28.5–29.5 for S. discalis ); PW (with spines) males 5.5–6.8, females 6.1–8.0 (males 7.0– 7.2, females 8.3–8.5 for S. discalis ); HFL males 7.8–9.0, females 7.2–9.9 (males 7.0–7.5, females 9.2–9.5 for S. discalis ); HFW: males 2.0–2.4, females 1.6–2.7 (males 1.8–1.9, females 2.4 for S. discalis ).

New species differs from S. melli by its tegminal (dorsal) sinus excised more deeply (in S. melli shallowly excised); median and lateral carinae substraight and lined with yellow nodules (in S. melli almost straight and smooth, without nodules).

This new species also differs from sympatric Scelimena razalii Mahmood, Idris & Salmah, 2007 by size (in S. razalii relatively smaller), medium carina (obsolete in S. razalii ), texture of pronotum surface (in S. razalii smooth without nodules), anterior margin of pronotum (truncated in S. razalii ), and shape of tegmina (in S. razalii elongated and acuminate) (Mahmood et al., 2017).

Description. Male. Body large sized for Tetrigidae in general ( Figs. 1A, 1C View FIGURE 1 ). Body dark grey with a tint of green.

Antennae. Antennae filiform, 13-segmented; antennal bases below the level of lower margin of eyes; 1 st massive scapus (scutellum width a third (1/3) width of scapus), 2nd stout pedicel, 3rd to 6th elongated basal segments, 7–9th extremely elongated mid segments (about 11.2 times as long as wide), elongated 10–11th subapical segments, 12–13th reduced, small apical segments. Antennal segment dark grey with yellow apex. Face yellow with dark grey patterns ( Fig. 2A View FIGURE 2 ).

Head. In frontal view . Transverse and lateral carinae of the vertex slightly elevated. Frontal costa long, bifurcates below the mid of the compound eyes height, just between the paired lateral ocelli. Scutellum in its widest part as wide as an antennal groove. Scutellum forms shallow concavity, becoming wider ventrally. Upper margin of the antennal grooves visible below (about 0.1 mm) the lower margins of the compound eyes. Lateral ocelli placed near the level of lower margins of eyes ( Fig. 2A View FIGURE 2 ). Compound eyes oblongly ovoid. Generally dark grey with some pale-yellow patterns ( Fig. 2A View FIGURE 2 ). In dorsal view . Fastigium of vertex with deep concavities behind lateral carinae, not produced in front of the eyes, 1.3 times wider than the width of one eye ( Fig. 2B View FIGURE 2 ). Scutellum width one third the width of the scapus. Anterior margin of fastigium truncated, median carina of fastigium strongly produced in front of the anterior margin of fastigium ( Fig. 2B View FIGURE 2 ); lateral carinae elevated; subocular lobes distinct. Compound eyes oval. In lateral view . Compound eyes hemispheric, exerted above vertex. Frontal ridge (or scutellum) distinctively produced to form two broadly rounded lobes; the two lobes are of about equal height ( Fig. 2C View FIGURE 2 ).

Pronotum. Pronotum finely nodulose, very long (macropronotal state), well surpassing abdominal apex, hind femur, and entire hind tibiae ( Figs. 1A, 1B View FIGURE 1 ). In frontal view . ML slightly projected outwards as blunt yellowish tubercle. VL strongly projected outwards as bright spine. In dorsal view . Anterior margin slightly concave; posterior process of pronotum, with truncated apex ( Fig. 2D View FIGURE 2 ). Dorsal plate of pronotum dark grey with tint of green. Nodules along the carinae yellow. Prozonal carinae diverge posteriorly. FM very small, almost unrecognizable, tubercle-shaped; FL1 small sized, tuberculated, yellowish; FL2 large, projected laterally, spinelike with oblique apex, yellowish; FL3 small, angular; PM medium sized tubercle; PML1 and PML2 small tubercles; PL low; MM1 large tubercle, MM2 and MM3 smaller tubercles; MML1 larger than MML2 and MML3, ML strong tubercle directed outward, yellowish, not spine-like; VL strong, produced outwards and forwards. In lateral view . Median carina of pronotum substraight ( Fig. 2C View FIGURE 2 ). Prozonal carinae well defined and lined with yellow nodules. Hind margin of lateral lobes of pronotum bisinuate, tegminal (dorsal) sinus less deep than lower sinus; lower part of lateral lobe directed laterally; posterior angles of lateral lobes in dorsal view produced into a long, acute spine that curved anteriorly ( Fig. 2C, 2D View FIGURE 2 ). Lateral lobes of pronotum, dark grey with posterior and ventral margin yellow ( Fig. 2C View FIGURE 2 ). FM small, almost unrecognizable, tubercle-shaped; FL1 small sized, tuberculated, yellowish; FL2 large, projected laterad, spine-like with oblique apex, yellowish; FL3 small, angular; PM medium sized, slightly elevated above the dorsum; PML1 and PML2 small, tubercle-shaped; PL low; MM1 higher than MM2 and MM3; MML1 the highest of metamediolateral projections; MML2 and MML3 lower than MM1, ML present as strong tubercle, yellowish, not spine-like; VL strong, produced outwards and its apex forwards.

Wings. Tegmenula elongated, oval with apical margin subacute; 3.4 times longer than wide; visible part of tegmen 0.6 times less wide than mid femur ( Fig. 2C View FIGURE 2 ). Hind wings long, not surpassing apex of pronotum.

Legs. Fore and middle legs. Fore and mid femora not compressed laterally; basal half of upper carina of the fore femur finely serrated, apical half smooth ( Figs. 2C, 2D View FIGURE 2 ). The upper and lower carinae of middle femur slightly sinuated and finely serrated. Fore femur 6.2 times, mid femur 6.4 times as long as wide. Fore and mid legs dark grey, with parts of carinae yellow. First segment of fore and mid tarsi dark grey, third segment with dark grey base and yellow ring. Hind legs. Hind femur 3.8 times as long as wide. Upper side of hind tibia with 4 to 5 outer and 0 inner spines; spines can be indistinct with minute denticles between spines. Ventral surface of first tarsal segment with 3 pads. Length of first tarsal segment of hind legs 1.5 times the length of third segment (without claws). Hind femora greenish dark grey with some yellow patterns ( Fig. 1A View FIGURE 1 ). Hind tibiae dark grey, with yellow patterns and nodules. First segment of hind tarsus yellow with ventral grey, second segment grey, third segment grey with yellow band in the middle.

Abdominal apex. Tergite greyish with yellow patterns. Basal sternite yellow, apical sternite incusing subgenital plate dark grey with yellow patterns ( Fig. 2E View FIGURE 2 ). Subgenital plate in ventral view triangular, with apex of plate slightly excised ( Fig. 2F View FIGURE 2 ); in lateral view slender and elongated ( Fig. 2G View FIGURE 2 ). Cerci stout basally with pointed apex ( Fig. 2G View FIGURE 2 ).

Female. Similar to male, but larger. Body, head and legs generally similar colored ( Figs. 1C, 1D View FIGURE 1 ). Mid antennal segments 14.2 times as long as wide. Fastigium of vertex 1.5 times wider than width of one eye from above. Frontal ridge between eyes (scutellum width) a third of scapus' width. Tegmen 3.2 times longer than wide. Fore femur 5.8 times, mid femur 6.6 times as long as wide. Hind femur 3.7 times as long as wide. Upper side of hind tibia with 2 to 5 outer and 2 to 3 inner spines. Length of first tarsal segment of hind legs 1.5 times as long as that of third segment (without claws).

Subgenital plate 1.1 times longer than broad; posterior margin of plate lobed ( Fig. 2H View FIGURE 2 ). Cerci same as male. Valves of ovipositor narrow, dentate. Upper valve of ovipositor 3.4 times longer than its maximum width. Lower valve of ovipositor 3.7 times longer than its maximum width; apical tooth curved downward ( Fig. 2I View FIGURE 2 ). Ovipositor dark grey with yellow pattern, with apices of denticles blackish ( Fig. 2I View FIGURE 2 ).

Measurements. See Table 1.

Etymology. This species is named after the type locality Ulu Gombak, Peninsular Malaysia. The specific epithet is third declension Latin adjective ( gombakensis , -e) in female grammar gender.

Life history. This species was found perching on river rocks in lowland secondary rainforest. Found in cool and high humidity area under canopies.

Remarks. Owing to its morphological similarities with S. discalis barring some size discontinuities, we initially hypothesized that S. gombakensis sp. nov. may represent one of the subspecies of the widely distributed S. discalis (first described from Sivasagar, Upper Assam, India and then recorded in Kanchanaburi province, Thailand [see Storozhenko & Dawwrueng, 2015]). However, without data on its population genetics, we refrain from describing this taxon as a subspecies.

Moreover, because these morphologically similar Scelimena (including S. melli ) are semi-aquatic in behavior and rely on the river they inhabit (Zha et al., 2017), we speculate that these populations are probably restricted to the water catchments that they are found in: S. discalis from India restricted to the Brahmaputra catchment; S. discalis from Thailand restricted to the Mae Khlong (= Mekong) watershed; S. gombakensis sp. nov. restricted to the Sungai Gombak of the Gombak Catchment in Selangor, Malaysia. This lends support that these populations are likely to be evolving independently, thus representing distinct lineages and species.