Nisitrus musicus Ingrisch, 1987

Figs 5, 7F, 9B, 10G, 11G, 12G, 13F, 14G, 16F, 17L–M, 26, 28; Tables 1–2, 9

Nisitrus musicus Ingrisch, 1987: 178 .

Nisitrus musicus – Tan et al. 2019: 303. — Cigliano et al. 2020 ( Orthoptera Species File Online).

Diagnosis (revised from Ingrisch, 1987)

Frons whitish with a black stripe between eyes and black mouthparts; femora reddish brown with a black stripe dorsally; male genitalia with pseudepiphallus slenderer than in congeners. This species is most similar to N. danum sp. nov., also from Borneo, from which it differs by mouthparts black (instead of yellow), FIIIs black dorsally and female papilla. While this species is restricted to the highlands in the Kinabalu range, N. danum sp. nov. occurs in the Danum Valley and Tawau Hill areas at the east of Sabah. It is also similar to N. vittatus, N. crucius sp. nov. and N. malaya sp. nov., from which it differs by slightly larger and slenderer habitus, frons whitish with black front head and mouthparts, FIIIs with a black pattern dorsally, and slenderer pseudepiphallus.

Material examined

Holotype

MALAYSIA – Sabah • ♂; Mount Kinabalu; 6°07′16.09″ N, 116°35′46.86″ E; 1000–1800 m a.s.l.; 5–7 Aug. 1984; S. Ingrisch leg.; SMFD.

Paratype

MALAYSIA – Sabah • 1 ♀; same collection data as for holotype; SMFD .

Additional specimens

MALAYSIA – Sabah • 6 ♂♂; Mount Kinabalu Mesilau Trail; 6°02′37.74″ N, 116°35′46.30″ E; 5000 ft a.s.l.; 13–15 Mar. 1964; S. Kueh (Royal Society Expedition) leg.; NHMUK • 1 ♀; Mount Kinabalu Mesilau Trail; 6°02′37.74″ N, 116°35′46.30″ E; 15 Feb. 1964; Royal Society Expedition leg.; NHMUK 012497572 • 3 ♂♂; Mount Kinabalu; 6°02′37.74″ N, 116°35′46.30″ E; 20 Mar. 1964; S. Kueh (Royal Society Expedition) leg.; NHMUK • 1 ♂; west of 3.1 km on Road Tenom Keningau, depleted lowland forest; 5°15′39.17″ N, 115°58′30.22″ E; 240 m a.s.l.; 25 Jun. 1986; J. Huisman leg.; RMNH • 2 ♀♀; Tenompok 30 miles east of Jesselton; 6°00′10.40″ N, 116°31′45.20″ E; 1460 m a.s.l.; 17–21 Oct. 1958; T.C. Maa leg.; BPBM • 2 ♂♂; same collection data as for preceding; BPBM • 2 ♂♂; west coast Residency, Kundasan; 5°57′37.51″ N, 116°33′18.03″ E; 1240 m a.s.l.; 15 Oct. 1958; T.C. Maa leg.; BPBM • 4 ♂♂; southern part of Kinabalu National Park; 5°59′50.78″ N, 116°33′39.77″ E; ~ 1500–2000 m a.s.l.; 26 Apr.– 1 May 2013; A. Gorochov, M. Berezin, V. Gorochova and E. Tkatsheva leg.; PII: N52; ZIN • 3 ♀♀; same collection data as for preceding; ZIN • 5 ♂♂; Mount Trus Madi; 5°33′53.94″ N, 116°30′11.31″ E; ~ 1000 m a.s.l.; 13–25 May 2007; A.V. Gorochov leg.; PIII: N37 Nmu3; ZIN • 2 ♀♀; same collection data as for preceding; ZIN • 2 ♂♂; Mount Kinabalu; 6°07′16.09″ N, 116°35′46.86″ E; J. Zhang leg.; MNHN • 1 ♂; same locality data as for preceding; Dec. 2018; J. Zhang leg.; PII: N48; MNHN-EO- ENSIF11070 • 3 ♀♀; same locality data as for preceding; J. Zhang leg.; MNHN • 2 ♀♀; Tenompok near Kinabalu; 6°00′10.40″ N, 116°31′45.20″ E; 4500 ft a.s.l.; 18 Mar. 1929; H.M. Pendlebury leg.; identified as Nisitra vittata by L. Chopard; MNHN-EO-ENSIF1738, MNHN-EO-ENSIF1743 • 1 ♀; “ Crocker Range National Park not far from Keningau Town, secondary-primary forest ”; 5°28′07.79″ N, 116°04′22.95″ E; 1000–1300 m a.s.l.; 6 May 2013; A. Gorochov, M. Berezin, V. Gorochova and E. Tkatsheva leg.; N29-NboG2; ZIN • 1 ♀; Kinabalu Park, Ranau; 6°0′22.0″ N, 116°32′33.5″ E; 3 Aug. 2018; lhurteau leg.; iNaturalist.org/observations/15440494 • 1 ♀; Ranau, Kinabalu Park World Heritage Site; 6°10′18.9″ N, 116°43′45.9″ E; 10 Mar. 2018; rbeunen leg.; iNaturalist.org/observations/18843361 • 1 ♂; Kinabalu Park, Kota Belud; 6°3′24.8″ N, 116°33′58.7″ E; 1 Aug. 2019; a1virginia leg.; iNaturalist.org/observations/30690023 • 1 ♀; Kota Belud District; 6°0′49.0″ N, 116°30′35.3″ E; 28 Jun. 2019; paulsullivan25 leg.; iNaturalist.org/observations/27783166 • 1 juvenile; Tambunan; 5°45′11.5″ N, 116°30′0.6″ E; 24 Jun. 2019; paulsullivan25 leg.; iNaturalist.org/observations/28232546 • 1 ♂; Crocker Range, 89300 Tambunan; 5°45′0″ N, 116°30′0″ E; 24 Jun. 2019; paulsullivan25 leg.; iNaturalist.org/observations/28232543 • 1 ♀; Tambunan; 5°45′10.9″ N, 116°30′1.9″ E; 24 Jun. 2019; paulsullivan25 leg.; iNaturalist.org/observations/28232551 • 1 juvenile; 89300 Ranau; 6°12′26.5″ N, 116°38′27.2″ E; 2 Aug. 2019; a1virginia leg.; iNaturalist.org/observations/30808860 • 1 ♀; Kinabalu Park, Ranau; 6°0′19.4″ N, 116°32′36.4″ E; 25 Oct. 2019; twan3253 leg.; iNaturalist.org/observations/35365957 • 1 juvenile; Tambunan; 5°45′58.3″ N, 116°20′32.9″ E; 31 Dec. 2019; F. Jarvis leg.; iNaturalist.org/observations/37398325 • 1 ♂; Kinabalu Park, Ranau; 6°0′31.1″ N, 116°32′34.2″ E; 23 Nov. 2016; K. O’Brien leg.; iNaturalist.org/observations/42450618 • around 20 individuals; Kinabalu Park, Ranau; 6°0′22.9″ N, 116°32′38.6″ E; 23 Nov. 2016; K. O’Brien leg.; iNaturalist.org/observations/42450617 • 2 ♀♀; Kundasang; 6°0′27.0″ N, 116°32′1. 3″ E; 1 Feb. 2017; V. Volkova leg.; iNaturalist.org/observations/51690441 • 1 ♀; Kinabalu Park, Ranau; 6°1′45.5″ N, 116°32′49.1″ E; 4 Jan. 2020; F. Jarvis leg.; iNaturalist.org/observations/37711505 • 1 ♀; Ranau; 6°1′36.8″ N, 116°36′11.1″ E; 4 Jul. 2020; M. Haffiszul Mohd Said leg.; iNaturalist.org/observations/51878361 • 1 ♀; Kinabalu Park, Ranau; 6°1′38.3″ N, 116°36′11.2″ E; 4 Jul. 2020; tanuki18 leg.; iNaturalist.org/observations/52011854 • 1 ♀; Kinabalu Park, Kota Belud; 6°1′36.7″ N, 116°32′51.8″ E; 13 Mar. 2019; D. Shaw leg.; iNaturalist.org/observations/23278330 .

Additional description (after Ingrisch 1987)

Male

GENITALIA (Fig. 16F). Pseudepiphallus very slender and elongated, distinctly longer than wide, anterior and anterior margins gently concave. Pseudepiphallic lophi slightly longer than wide (at base), subacute and slightly folded dorsally at apex, sclerotized laterally only, widely spaced apart from each other. Rami straight, swollen preapically, slightly diverging. Pseudepiphallic parameres narrow, diverging posteriorly, their basal sclerite short and narrow. Ectophallic lateral sclerites appearing rounded. Ectophallic apodemes straight and parallel. Endophallic sclerite elongated, its posterior lateral arms short.

Female

GENITALIA. Copulatory papilla conical, smaller and stout; apex folded ventrally, elongated, pointed; dorsal face with a weakly sclerotized area; at ventro-anterior end a narrow oblong rim (Fig. 17L–M).

Juvenile (Fig. 28D–E)

Similar to adults in colour patterns, but younger instars differ by pronotal disk grey with dark longitudinal stripes, lateral lobes with a grey longitudinal stripe slightly ventral of the dorsal-third, sometimes in femora with white dorsal stripe, FIII with a white dorsal stripe at basal half. Legs darker in older instars, similar to adults.

Measurements

See Table 9.

Ecology

Adult and nymphal individuals have been observed to aggregate in large number (~20 individuals) on the same plant (Fig. 28E).

Distribution

Borneo (Mount Kinabalu, Trus Madi, Tenompok, Tenom Keningau in Sabah) (Fig. 5).

Type locality

Borneo: Sabah: Mount Kinabalu.

Calling song (n = 1 male, 9 echemes, MNHN-SO-2020-2857)

The calling song consists of long homogeneous bouts formed of very short echemes consisting of doublets of syllables; echeme duration is 29.7 ± 1.1 ms (28.4–31.3 ms); echeme period is 72.2± 2.1 ms (69.8– 76.8 ms); downtime between consecutive echemes is 42.5 ± 2.2 ms (39.4–45.9 ms). Duration for first and second syllables of the doublets are as follows: 7.5± 0.6 ms (6.6–8.1 ms) and 18.7± 1.5 ms (15.8–20.5 ms); with second syllable usually with greater amplitude than the first. The song spectrum consists of a series of harmonics, with two main peaks in the first two harmonics: first harmonic (fundamental frequency) which is also the dominant frequency peaks at 5.46 ±0.03 (5.42–5.51) kHz; second harmonic peaking at 10.93± 0.04 (10.88–11.02) kHz.