Discotettix (Mnesarchus) scabridus ( Stål, 1877 )

Skejo, Josip, Pushkar, Taras I., Kasalo, Niko, Pavlović, Marko, Deranja, Maks, Adžić, Karmela, Tan, Ming Kai, Rebrina, Fran, Muhammad, Amira Aqilah, Abdullah, Nurul Ashikin, Japir, Razy, Chung, Arthur Y. C. & Tumbrinck, Josef, 2022, Spiky pygmy devils: revision of the genus Discotettix (Orthoptera: Tetrigidae) and synonymy of Discotettiginae with Scelimeninae, Zootaxa 5217 (1), pp. 1-64 : 49-52

Discotettix (Mnesarchus) scabridus ( Stål, 1877) ( Fig. 33 )

Vernacular name: Filipino Spiky Pygmy Devil

Mnesarchus scabridus Stål, 1877: 55 [original description, type locality: the Philippines]; Casto de Elera 1895: 207.

Discotettix scabrides: Hancock 1907a [lapsus calami].

Discotettix scabridus: Bolivar 1877: 307 [in revision]; Kirby 1910: 2 [listed in the catalog]; Günther 1938: 302 [in revision]; Yin et al. 1996: 866 [listed in the catalog]; Blackith 1992: 46 [listed in the catalog]; Otte 1997: 32 [listed in the catalog].

Discotettix (Mnesarchus) scabridus: Kevan 1966: 380 [new records].

This is the type species of the subgenus Mnesarchus and the only species presently assigned to this subgenus. The species diagnosis and the description may hence be used as subgeneric diagnosis and description of Mnesarchus .

Type locality. The Philippines (without exact locality).

Lectotype designation. The lectotype for this species is designated herewith, that being the female deposited in NHRS, under the inventory number NRM-ORTH 00112879, designated by J. Tumbrinck. The lectotype bears the red label ‘lectotypus’. Lectotype designation is important because of the future analysis of intraspecific differences among D. scabridus populations in Mindanao and other islands that could result in the discovery of new species or subspecies. Since Tetrigidae species are usually morphologically well-defined, the lectotype may provide a basis for the identification of the nominotypical and/or already described taxon.

Material examined.

Type material. LECTOTYPE ( Fig. 33 ): ♀ Ins. Philipp. Collector: Semper, det. C. Stål, inventory number NRM-ORTH 00112879 ( NHRS); labeled Mnesarchus scabridus ; here designated.

Additional museum material. 2♀♀ the Philippines, Mindanao , Zambaonga, date uknown, Collector: W. Schultze, det. K. Günther ( SMTD) ; 1♂ Ins. Philipp. Collector : Semper, det. K. Günther ( MFN) ; 1♀, 1♂ the Philippines, Mindanao , Pt. Bango, det. J. Tumbrinck ( NHRS) ; 1♀ labeled ‘100.4115’ ( MNCN) det. J. Skejo; 1♀ nymph, 2♂♂ the Philippines, Mindanao , Zambonga Del Norte, VIII.2020. Collector: Sandayong, det. J. Tumbrinck ( ZMHU) ; 1♀, 1♂ the Philippines, Luzon , N-Luzon Island, Hueva, Belance, III.2014, det. J. Tumbrinck ( ZMHU) ;

Additional material from eBay. 3♀♀ the Philippines, Mindanao, Zambaonga del Sur, IX.2013. Collector : unknown (not in museum) (found on eBay on 18.VI.2016) det. J. Skejo ; 2♂♂, 2♀♀ the Philippines: Samar Collector : unknown (not in museum) (found on eBay on 21.VII.2016) det. J. Skejo ; 4♀♀ the Philippines: Mindanao: Bukidnon Collector : unknown (not in museum) (found on eBay on 04.VIII.2016) det. J. Skejo ; 1♂ the Philippines: Mindanao: Davao Collector : unknown (not in museum) (found on eBay on 15.VIII.2016) det. J. Skejo ; 3♀♀ the Philippines: Mindanao: Surigao unknown (not in museum) (found on eBay on 01.IX.2016) det. J. Skejo.

Distribution. This species inhabits the Philippines, where it has been reported from the islands of Mindanao, Samar, and Luzon. Numerous records from Mindanao, while few from Luzon might indicate that the species has higher abundance in Mindanao.

Subgeneric diagnosis of Mnesarchus and specific diagnosis of Discotettix scabridus . The species is morphologically very different from other Discotettix members and is thus assigned to its own subgenus, Mnesarchus . It can be easily separated from other species of the genus by the set of the following characters: (I) frontal costa bifurcates on the lower margin of the compound eyes (bifurcation is in the lower third of the compound eyes in D. aruanus sp. n., D. belzebuth , D. doriae , D. kirscheyi sp. n., D. selysi , and D. sumatrensis sp. n.), (II) FM present as a low tubercle (developed and elevated in D. aruanus sp. n., D. belzebuth , D. doriae , D. kirscheyi sp. n., D. selysi , and D. sumatrensis sp. n.), (III) MM laterally compressed and elevated (spine-like in D. belzebuth , triangular protrusions in D. sumatrensis sp. n., D. kirscheyi sp. n., while very low in D. aruanus sp. n., D. doriae and D. selysi ), (IV) MML low and triangular, compressed elevations (spine-like in D. belzebuth , triangular protrusions in D. sumatrensis sp. n., similarly formed in D. selysi ), (V) interscapular area triangular, with large concavity (similarly to D. selysi , and D. sumatrensis sp. n., almost parallel in D. belzebuth ), (VI) lateral and humeral carinae strongly toothed (similar to D. belzebuth , granulated in D. selysi , and D. sumatrensis sp. n.), (VII) weak ML (almost absent in D. scabridus , while well visible in other species), (VIII) VL complex, with a few spines (in other species usually with one main spine, and a saw-like margin) and (IX) tegmen more elongated (TL/TW> 5) than in other species of the genus (TL/TW <3.5).

Redescription ( Fig. 33 ).

General features. Medium-sized flattened species (body 12.3–12.75 mm) (15–17 mm cited in the original description, but in this measurement, pronotum was probably included as well), relatively robust in dorsal view. The entire body finely granulated, rugose; pronotum wrinkled and with numerous small tubercles and medium-sized projections. Macropronotal form.

Coloration. Body color from almost black, dark brown, and ferruginous brown to yellowish-brown. Pronotal protuberances usually colored in different colors (black, reddish, yellow, whitish) and often different in color from the rest of the pronotal surface. Antenna with pale colored joints between the antennomeres; scapus, pedicel, basal and medial segments dark brown, while subapical and apical even darker. Maxillary palpi dark brown, sometimes with even darker distal margins of the last segments. The visible part of the tegmen dark brown, without spots. Tibiae and tarsi with unclear pale colored rings.

Head. In dorsal and frontal view, vertex 2.4–2.65 times as wide as the eye. Lateral carinae of the vertex granulated. Lateral ocelli situated at the level of the lower margin of the compound eye. In frontal view, frontal costa narrow, bifurcating a bit above the lateral ocelli into slightly divergent facial carinae forming a very narrow scutellum.Antennal groove slightly wider than the scutellum, situated just below the lower margin of the compound eye ( Fig. 33C ). Antenna 13-segmented (in male seems 12-segmented, because 13 th segment very small and not visible under an optical microscope, only under SEM): scapus (1 st antennomere) and pedicel (2 nd antennomere) massive; basal segments (3 rd to 6 th) elongated and circular in cross-section; central or subapical segments (7 th and 8 th) widened, weakly pennate, 7 th and 8 th antennal segments almost equal in width (2–2.4 times as long as wide); apical segment 9 th elongated, but much smaller than the subapical and much larger than the rest of the apical segments; apical segments 10 th to 13 th reduced, very small, and borders between them barely visible. Antennomeres 3 rd to 9 th bear weak saw-like margins (weaker than in the other species of the genus), because of the presence of large basiconic sensilla. Antennomeres of D. scabridus are less significantly widened than in other species of the genus and less saw-like in appearance, supposedly because of fewer or smaller basiconic sensilla.

Pronotum. Pronotum wrinkled and granulated, covered in numerous small tubercles, medium-sized and large triangular protuberances. The posterior process of the pronotum slender, surpassing the hind knee for about half the length of the hind femur (macropronotal form). Disc of the pronotum a bit depressed behind the well-developed shoulder, gradually descending backward. Pronotum with 5 unpaired projections of variable size on the medial carina (FM, PM and 3 MMs), three pairs of FLs, two pairs of more or less distinguished PMLs, and two of MMLs; three pairs of lateral and a pair of VL (well visible in profile). Anterior margin of the pronotum truncated, with small FM directed upwards. FM considerably lower than in the other species of the genus. Prozonal carina elevated and decurved caudad in the direction of the median carina, in females projected anteriorly as a small dentiform FL1. Extralateral carinae distinct in males, saw- or fan-like and elevated along the entire length much more than the prozonal carina, surpassing the anterior margin of the pronotum as a dentiform FL2. FL3 weak, but distinct. Prozona of variable length, from subsquare to wider than long, but still very short when compared to other species of the genus. Behind the FM median carina extended along the whole length of pronotum. PM larger than FM, and MM1 larger than PM1. MM2 medium-sized in males or small in females. MM3 lies in the middle of pronotum length, in females as large as PM, while in males smaller. MM4 small and indistinct. PML1 and PML2 very small. MML1 small, situated between the shoulders. MML2 large. MML3 very small, better visible in females than in males. MML4 almost indistinct in both sexes. PL1 and PL2 small and triangular tubercles between the sulci on the line joining the extralateral carinae and the humero-apical carinae. ML reduced, almost absent. The apex of the posterior pronotal process very narrow, and rounded; in females weakly excised. The posterior part of the pronotal process (about a fifth of the pronotum length) directed slightly upwards or in the level of the rest of the pronotum. The lower part of the lateral lobe with serrate margins (2–3 larger teeth on the posterior margin, and numerous smaller teeth on the anterior margin), elongated as strong spine-like VL directed outwards and slightly forwards ( Fig. 33A, B, D, E ).

Wings. The visible part of the tegmen shaped quite elongated oval, lower side slightly curved. The tegmen is not always visible. Based on the photographs, it is hard to say whether tegmina are visible or not, in both sexes they can be noticed only after careful examination under the stereomicroscope. Hind wing present, visible under pronotum, not reaching the apex of the pronotum.

Legs. Femora robust and compressed laterally. Dorsal and ventral margins of the fore and the mid femora roughly serrate, with genicular tooth on knees, and additionally with 1–3 strongly projected teeth on each margin. Teeth of ventral margin projected outwards and downwards. Hind femur with small teeth on the dorsal and ventral margins; one large tooth projected outwards situated on the ventro-external carina. Genicular and antegenicular teeth small, but recognizable. Both sides of the dorsal margins of the hind tibia finely serrated, additionally with 5–8 outer and 2–4 inner bit larger teeth. The first tarsal segment of the hind leg slightly longer than the third segment.

Abdominal apex. Ovipositor elongated.

Measurements. BL ♂ 10.56 mm, ♀♀ 12.31–12.74 mm; PnL ♂ 14.99 mm, ♀♀ 15.48–16.52 mm; PnW ♂ 8.16 mm, ♀♀ 7.99–8.95 mm; AnL ♂ 5.08 mm, ♀♀ 6.89–7.01 mm; TL ♂ 2.49 mm, ♀♀ 2.51–2.7 mm; TW ♂ 0.49 mm, ♀♀ 0.47–0.52 mm; fFL ♂ 3.45 mm, ♀♀ 3.86–4.01 mm; fFW ♂ 0.84 mm, ♀♀ 0.68–0.77 mm; mFL ♂ 3.52 mm, ♀♀ 3.42–3.93 mm; mFW ♂ 0.84 mm, ♀♀ 0.76–1.01 mm; hFL ♂ 6.69 mm, ♀♀ 7.39–7.91 mm; hFW ♂ 2.05 mm, ♀♀ 2.16–2.22 mm; OvL ♀♀ 1.39–1.55 mm; AnL/fFL ♂ 1.48, ♀♀ 1.68–1.72; VW ♂ 0.93 mm, ♀♀ 1.11–1.18 mm; EW ♂ 0.49 mm, ♀♀ 0.42–0.49 mm; VW/EW ♂ 1.9, ♀♀ 2.51–2.65 mm; SW ♂ 0.22 mm, ♀♀ 0.19–0.23 mm; AgW ♂ 0.39 mm, ♀♀ 0.31–0.36 mm; ScW ♂ 0.25 mm, ♀♀ 0.18–0.21 mm; SW/AgW ♂ 0.64, ♀♀ 0.51–0.7; SW/ScW ♂ 1.48, ♀♀ 0.96–1.02; As—L/W ♂ 2.41, ♀♀ 2.06–2.11; PrzW ♂ 3.25 mm, ♀♀ 3.18–3.24 mm; PrzL ♂ 2.41 mm, ♀♀ 1.34–1.74 mm; Prz—W/L ♂ 1.35, ♀♀ 1.84–2.41; TL/TW ♂ 5.08, ♀♀ 4.68–5.71; mFW/TW ♂ 1.75, ♀♀ 0.47– 0.51; fFL/fFW ♂ 4.01, ♀♀ 5.18–5.34; mFL/mFW ♂ 4.09, ♀♀ 3.88–3.91; hFL/hFW ♂ 3.26, ♀♀ 3.49–3.66; T1L/ T3L ♂ 1.14, ♀♀ 1.22–1.31.

Figures

FIGURE 33. Discotettix scabridus (Stål, 1877). A–B, E) lectotype female from the Philippines, in NHRS: A. dorsal view; B. lateral view; C. frontal view (photograph by Josef Tumbrinck); D–E). male from the Philippines in MfN: D. dorsal view; E. lateral view (photograph by Sigfrid Ingrisch, reproduced with the author's permission).