Duolandrevus (Duolandrevus) nobilis Tan & Japir & Chung & Robillard 2022, sp. nov.
Creators: name: Tan, Ming Kai
name: Japir, Razy
name: Chung, Arthur Y. C.
name: Robillard, Tony
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Orthoptera
Gryllidae
Duolandrevus
Duolandrevus nobilis

description: Duolandrevus (Duolandrevus) nobilis sp. nov.
(Figs 3–6)
Material examined. Holotype: EAST MALAYSIA • 1♂; Sabah State, Sabah State, Mount Silam, near Lahad Datu; N4.97667, E118.19135, 428.3± 7.9 m.a.s.l.; 13 May 2022, 21h36; on the ground along the trail; coll. M.K. Tan, T. Robillard & R. Japir; SBH.22.62 (FRC)
Paratypes: • 1♂; Sabah State, Tabin Wildlife Reserve; N5.19438, E118.50294, 93.7±11.0 m.a.s.l.; 15 May 2022, 19h35; calling from a burrow on the clayey bank of a forest stream; coll. M.K. Tan, T. Robillard & R. Japir; SBH.22.84 (ZRC) • 1♂, 1♀; Sabah State, Mount Silam, near Lahad Datu, lowland forest; N4.97589, E118.19060, 341 m.a.s.l.; 13 May 2022, 21h10, video of male calling song (TR00022); male at the base of a large tree under the bark; female on the ground, near the entrance of burrow; coll. T. Robillard, M.K. Tan & R. Japir; TR22-12; (MNHNEO-ENSIF11147, MNHN-EO-ENSIF11148)
Other material examined: EAST MALAYSIA • 1♀ juvenile; Sabah State, Sandakan, Sepilok, Rainforest Discovery Centre; N5.87395, E117.93871 (SAB14), 54 m. a.s.l.; 19 May 2022; coll. T. Robillard & M.K. Tan; TR22-39 (MNHN)
Diagnosis. This new species differs from other species of the nominal subgenus Duolandrevus by the shape of the pseudepiphallus [epiphallus], metanotal gland and FW venation. Its male genitalia are most similar to Duolandrevus (Duolandrevus) kalimantan Gorochov, 2016 from Kalimantan; but the new species differs by FW with a larger harp area and more strongly curved oblique veins (instead of mostly straight), the metanotal gland more transverse; dorsal projection of the pseudepiphallic lophi [posterolateral epiphallic lobe], when viewed laterally, with the apex rounded (instead of subacute). It is also similar to Duolandrevus (Duolandrevus) brachypterus (Haan, 1844) from Java; but differs by the FW without a mirror area, more strongly curved oblique veins and the shapes of pseudepiphallic posteromedial lophi and pseudepiphallic lophi [posteromedial and posterolateral epiphallic lobes, respectively]. From other Bornean species of the subgenus: this new species differs from Duolandrevus (Duolandrevus) kubah Gorochov, 2016 and Duolandrevus (Duolandrevus) sabah Gorochov, 2016 by the absence of mirror on the FW and the dorsal projection of the pseudepiphallic lophi [posterolateral epiphallic lobe] broadly rounded (instead of slender or humped, respectively); from Duolandrevus (Duolandrevus) balikpapan Gorochov, 2016 and Duolandrevus (Duolandrevus) spinicauda Gorochov, 2016 by the pseudepiphallic lophi [posterolateral epiphallic lobe] not elongated and slender; from Duolandrevus (Duolandrevus) matang Gorochov, 2017 by the dorsal projection of the pseudepiphallic lophi [posterolateral epiphallic lobe] broadly rounded (instead of hooked).
Remarks. This new species is placed under the nominal subgenus Duolandrevus according to these characters: the hindwings well surpassing metanotal gland; the male anal plate without a bundle of strong setae directed dorsad; the male genitalia with dorsal denticle at or near base of each pseudepiphallic lophi [posterolateral epiphallic lobe].
Etymology. The species name refers to the rarity of finding landrevine males forming burrows on the clayey bank of a forest stream. Often, landrevines call among cavity and crevices of tree trunk or branches.
Description. Typical of the genus, body dorso-ventrally compressed and not pubescent, dark red-brown in colouration. Head rostrum not pubescent, about 1.7 times as wide as scape, with apex broadly rounded (in dorsal view) (Fig. 4A). Scapes brown (Fig. 4A). Eyes medium-sized, rather rounded (in profile view). Maxillary palpi yellow brown; with apical (fifth) segment yellow, longer than third and subapical (fourth) segments, slightly enlarged apically, with apex obtusely rounded; subapical segment, widens slightly apically, slightly longer than third segment (Fig. 4B). Head in anterior view slightly wider than tall (Fig. 4C). Lateral ocelli posterior of scapes oval; median ocellus between scapes small circular (Fig. 4C). Pronotum transverse, 1.7 times as broad as long; anterior margin as wide as posterior margin; dorsal disc with anterior margin lined with a row of setae and concave, and posterior margin feebly substraight (Fig. 4A). Pronotal lateral lobe about 1.3 times as long as wide; anterior half about 1.6 times as tall as posterior half, with ventral margin straight (Fig. 4B). TI with both tympana open and having oval tympanal membrane, inner one larger than outer one. TIII inner and outer margins with 4–5 stout articulated spurs (also known as movable spines) on each dorsal side; and 3 inner and ca. 9 outer basal spines, much smaller. TaIII with about 4 inner and 5 outer denticles.
Male. FW glossy red-brown, harp area transparent (Figs 4D, 4E). Dorsal field not distinctly longer than lateral field, apical field stout (Fig. 4E). Venation (Figs. 4D, 4E): no distinct mirror present; harp area very large with 6 oblique veins (3 strongly curved long posterior veins and 3 substraight small anterior veins). Lateral field wide, R and M closely-spaced. Sc parallel to R and M, with four longitudinal and parallel branches; third vein (from dorsal) bifurcate in middle. Hind wings well surpassing metanotal gland (Fig. 4F). Metanotal gland with anterior margin with a row of strong setae, anterior lateral ends slightly swollen; two shallowly sunken divided from each other by a narrow longitudinal ridge; posterior margin broadly and faintly concave (Fig. 4F).
Anal plate triangular with truncated apex, with setae along posterior margin but without bundle of strong setae directed dorsad (Fig. 5A). Male pseudepiphallus [epiphallus] (Figs 5B–D) notched in the middle, anterior half not raised. Pseudepiphallic posteromedial lophi [posteromedial epiphallic lobules] triangular, not elongated with obtuse apex; these lobules separated from each other by very shallow and narrow notch, appears fused together with a groove. Pseudepiphallic lophi [posterolateral epiphallic lobes] forming narrow plate-like projection, pointing dorsad at the apex (when viewed laterally); with a shorter and smaller projection pointing posteriorly (when viewed laterally); ventrally folded internally (when viewed dorsally or ventrally), also with a small projection pointing interno-posteriorly. Dorsal and posterior projections with apices bearing a few setae; apex of dorsal projection more broadly rounded, apices of posterior projections narrowly obtuse. Ectophallic fold [rachis] when viewed ventrally faintly surpassing pseudepiphallic posteromedial lophi, but not reaching the posterior end of pseudepiphallic lophi; very slender with acute apex. Each ectophallic apodeme [endparamere] forked posteriorly, and forming a Y-shape structure. Endophallic sclerite [formula] when viewed ventrally fairly stout, narrow anteriorly, widened and truncated at the posterior end. Rami not fused together by the anterior ends.
Measurements (2♂, in mm). PronL = 2.7–2.9 (mean = 2.8); PronW = 4.6–5.3 (5.0); FWL = 7.1; FIIIL = 12.7; TIIIL = 8.9.
Ecology. One of the males was found calling from a burrow on the clayey bank of a forest stream (Fig. 3). Another male was found on the ground along the trail. These suggest that this species is a more ground-dwelling landrevine.
Distribution. Borneo, Sabah State: Mount Silam near Lahad Datu, Tabin Wildlife Reserve.
Type locality. EAST MALAYSIA, Sabah State, Mount Silam near Lahad Datu.
Calling song (1 ♂, in the field, 23.3°C) (Fig. 6). The calling song consists of an echeme made up of 32–48 syllables. The first few syllables are of lower amplitude but the amplitude of subsequent syllables increases to a maximum and remains relatively consistent. Each echeme has an average duration of 0.60±0.07 s (0.46–0.70 s). The interval between consecutive echemes is 5.01±1.84 s (3.19–8.47 s). Each syllable has an average duration of 9.1±0.5 ms (8.5–10.0 ms) and the interval between consecutive syllables is 5.6±0.6 ms (4.4–6.1 ms). The dominant frequency is 3.90±0.03 kHz (3.86–3.95 kHz).
description: Published as part of Tan, Ming Kai, Japir, Razy, Chung, Arthur Y. C. & Robillard, Tony, 2022, New taxa and notes on bark and bush crickets (Orthoptera, Grylloidea, Gryllidae Landrevinae and Podoscirtinae) from Sabah, pp. 201-228 in Zootaxa 5178 (3) on pages 206-210, DOI: 10.11646/zootaxa.5178.3.1, http://zenodo.org/record/7026150