Lipotactes (Mortoniellus) sanguineus, Tan & Damit & Japir & Chung & Robillard & Ingrisch, 2025

Lipotactes (Mortoniellus) sanguineus sp. nov.

( Figs 2–7 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 )

Material examined. Holotype: EAST MALAYSIA • ♂; Sabah; Sinipung Hill, near Long Pasia ; N4.43576 E115.72325, 1301.0± 10.6 m.a.s.l.; 20 November 2024, 16h37; calling on branch of small tree; coll. M.K. Tan; SBH.24.166 ( FRC). GoogleMaps

Paratypes: EAST MALAYSIA, Sabah; Sinipung Hill, near Long Pasia • 1♂; N4.44300 E115.71870, 1519.0±8.0 m.a.s.l.; 22 November 2024, 09h03, calling on climber around resam and pandan; coll. M.K. Tan; SBH.24.221 ( ZRC) GoogleMaps • 1♀ ( Fig. 6 View FIGURE 6 ); N4.43667 E115.72379, 1325.0± 7.8 m.a.s.l.; 20 November 2024, 18h19, on branch of small tree; coll. M.K. Tan; SBH.24.171 ( ZRC) • GoogleMaps 1♀; Sinipung Hill, lower forest camp; N4.43013 E115.72554, 1192 m (GPS 24SA13); 20 November 2024, night; on low plant; coll. T. Robillard; TR22-130 (MNHN-EO1301) GoogleMaps .

Additional material examined: 1♀ juvenile; EAST MALAYSIA, Sabah, Long Pasia, Sinipung Hill , lower forest camp; N4.43013 E115.72554, 1192 m (GPS 24SA13); 20 November 2024, night; on low plant; coll. T. Robillard ( MNHN) GoogleMaps .

Subgenus assignation. We assign this new species to the subgenus Mortoniellus , instead of the nominal subgenus, owing to the presence of a pair of distinct sclerotized structures in the male genitalia. It does not belong to Prolipotactes Gorochov, 2021 and Neolipotactes Gorochov, 2021 because the male last abdominal tergite lacks posteromedian lobes or posterolateral lobules; to Sublipotactes Gorochov, 2021 because the cercus is stouter (instead of elongated) and lacks a thin distal part and almost lamellar widened lobule at the base; to Dialipotactes Gorochov, 2021 because the epiproct lacks additional lateral lobules; to Miolipotactes Gorochov, 2021 because of the shape of the male cercus; to Analipotactes because the male subgenital plate lacks a pair of distinct medial spinules near the bases of the styles; to Eulipotactes because of the shape of the male cercus and the male genitalia having only two elongate sclerites instead of three.

Diagnosis. The new species is characterised by the shape of the male last abdominal tergite and the epiproct tongue-shaped and simple lacking lobes; the epiproct also quite large; by the cercus with internal projections including: a ventral process long and slightly curved, having its apical half tapering slightly and inner (basal) margin finely denticulated; and a dorsal lamella inserted craniad to the ventral process, and is stoutly rounded with margin denticulated; by the male genitalia membranous, but having a pair of sclerites that are strongly hooked and lacking denticulated margins.

The new species is similar to Lipotactes (Mortoniellus) karnyi ( Griffini, 1909) from Malay Peninsula and Borneo by the general habitus, colour patterns and shapes of the abdominal apex (including cercus); but differs by the internal projections of cercus having the ventral process longer and mostly cylindrical (rather than irregular finger-shaped); sclerites of the male genitalia lacking denticulated margins. It is also very similar to Lipotactes (Lipotactes) macrognathus ( Ingrisch, 1995) from Sabah by the shape of its cercus (including the internal projections); but differs by the presence of a pair of sclerites in the male genitalia; its cercus with the dorsal lamellae slightly larger and broader (compared to specimens collected by Gorochov [2021]) and the ventral process slightly longer and tapering apically; the male pronotal disc at the posterior end is more narrowly rounded; and the colour patterns (not uniformly green, although there may exist intra-specific colour variants). The new species is also similar to Lipotactes (Lipotactes) digitatus (Karny, 1931) from Sulawesi and Lipotactes (Lipotactes) ovatus ( Ingrisch, 1995) from Kalimantan by its habitus and general shape of cercus; but differs by the shape of the male cercus and its internal projection and presence of sclerites in the male genitalia.

Etymology. The species name refers to the characteristic red colouration of the abdomen; sanguineus = blood red, in Latin.

Description. Male and female habitus typical for subgenus, as in Fig. 2 View FIGURE 2 . Head in frontal view with lateral margins below compound eyes straight and parallel, barely diverging or converging; suddenly constricting below fronto-cylpeal suture ( Fig. 3A View FIGURE 3 ); head in female slightly less elongated than in male ( Fig. 3B View FIGURE 3 ). Fastigium verticis in male not different from female, slightly elevated, faintly furrowed above gradually sloping laterally, distinctly inclined towards vertex ( Figs 3A–D View FIGURE 3 ). Pronotal disc with anterior margin slightly emarginated and raised, bulging before and behind first sulcus, apical area up curved in both sexes ( Figs 3E, 3F View FIGURE 3 ). Metazona distinctly longer than prozona in male ( Fig. 3E View FIGURE 3 ), but of almost equal length in female ( Fig. 3F View FIGURE 3 ). In male, apical area of metazona tapers into relatively narrow apex ( Fig. 3C View FIGURE 3 ); in female, posterior margin somewhat truncated ( Fig. 3D View FIGURE 3 ). Paranota triangular, with ventral margin straight ( Figs 3E, 3F View FIGURE 3 ). Thoracic auditory spiracle of subequal size with first stigma ( Figs 3E, 3F View FIGURE 3 ). Legs typical for genus.

Male. Tegmen with dorsal field 5.1–5.5 mm long and 3.3–3.4 mm wide, veins and membrane mostly transparent except anal margin of mirror black; lateral field strongly folded and infumated ( Figs 4A, 4B View FIGURE 4 ). h1 less wide than mirror width; h2 narrowly broad, mostly slender and substraight, with anal third to half widen broadly, anal margin somewhat truncated; mirror large and about as wide as long ( Figs 4A, 4B View FIGURE 4 ). Stridulatory file of left tegmen on CuPb crescent shaped, ca. 1.29–1.41 mm long, with 46 teeth (with a few rounded indistinct teeth at both anal and basal ends) ( Figs 4C View FIGURE 4 ); teeth length and inter-tooth distance largest at middle, decreasing in size towards both apices ( Fig. 5 View FIGURE 5 ). Apical area of tegmen elongated, about 1.4–1.5 long, mostly infumated, narrow apically, apex rounded ( Figs 4A, 4B View FIGURE 4 ).

Tenth abdominal tergite with apical margin roundly incised in middle ( Figs 4D–F View FIGURE 4 ). Epiproct large, tongue-shaped, apex rounded. Paraproct elongated, with apex rounded ( Fig. 4F View FIGURE 4 ). Cercus conical, internal projections with dorsal lamellae medium-sized, inserted dorsad of ventral process; ventral process long, slender, blunt, curved dorsocraniad, inserted at end of circa basal quarter ( Figs 4D–F View FIGURE 4 ). Subgenital plate faintly or strongly concave between bases of long styli, with narrow medio-longitudinal carinula ( Figs 4D–F View FIGURE 4 ). Phallus with a pair of tooth-like sclerites, their apical half curved and tapering into acute apex, margins smooth ( Figs 4G, 4H View FIGURE 4 ).

Female. Tegmina and wings absent. Tenth tergite with apical margin faintly roundly-incised in middle ( Fig. 4I View FIGURE 4 ). Epiproct somewhat triangular, at middle depressed, with apex rounded ( Fig. 4I View FIGURE 4 ). Cerci conical, apex subacute ( Fig. 4I View FIGURE 4 ). Subgenital plate triangular, slightly broader at base than length, with apex rounded ( Fig. 4J View FIGURE 4 ). Ovipositor ( Fig. 4K View FIGURE 4 ) with dorsal margin smooth, ventral margin finely serrulate in apical area ( Fig. 4L View FIGURE 4 ).

Colouration. Generally yellow to olive green (when alive, Fig. 6 View FIGURE 6 ) or yellow (when preserved, Fig. 2 View FIGURE 2 ), with black patterns on head, pronotum, thorax and legs. Frons between compound eyes with black. Antennal sockets, scapes, fastigium verticis and fastigium frontis also black ( Figs. 3A–D View FIGURE 3 ). Margin around compound eye black, but more defined and complete in female ( Fig. 3F View FIGURE 3 ). Maxillary and labial palpi with apical segments mostly black except basal quarter ( Figs 3A, 3B View FIGURE 3 ). Mandibles black. Ventrad of gena on fronto-clypeal suture with black band, larger in female ( Fig. 3F View FIGURE 3 ). Pronotum with margins black ( Figs 3C–F View FIGURE 3 ); black band broader in female ( Fig. 3F View FIGURE 3 ). Thorax with some black patches, more defined in female ( Figs 3E, 3F View FIGURE 3 ). Coxa mostly black; ventral spurs mostly black; basal half of middle femur also black (expect ventrally). Hind femur only apical part dark coloured, including knees. Hind tibia with spines black. Tarsi dark. Abdomen ventrally bright to blood red ( Fig. 4J View FIGURE 4 , 6 View FIGURE 6 ).

Measurements. See Table 1 View TABLE 1 .

Calling song ( Fig. 7 View FIGURE 7 ). The species was observed to call during daytime and not at night. The calling song is made up of a series of echemes. The echeme is made up of 9–16 syllables, and average of 13±2 syllables. The length of the echemes is probably affected by whether the katydid is disturbed. Depending on the number of syllables, the echeme duration ranges from 0.24– 0.55 s, and average of 0.41± 0.08 s. The down time between consecutive echemes can be variable, ranging from 0.38– 2.71 s, and average of 0.91± 0.59 s. Within each echeme, the first and second syllables are typically more variably and widely spaced apart, and the amplitude is lower than the subsequent syllables. Each syllable is made up of a series of pulses, and the average syllable duration is 18.4±2.2 ms (14.6–23.1 ms). The average down time between consecutive syllables is 10.2±1.6 ms (7.1–14.4 ms).

When the katydid is not perturbed, the calling song can form an echeme-sequence made up of as many as 28 echemes. In such an echeme-sequence, the down time between consecutive echemes is much more consistent, 0.49±0.09 ms (0.38–0.74 ms). The initial echemes are generally shorter in duration and made up of fewer syllables) and are of lower amplitude.

The call has a very broad band spectrum showing a broad energy peak between 8–22 kHz. The average peak frequency is 16.44±1.03 kHz (14.91–18.09 kHz).

The calling song differs from that of (Mortoniellus) karnyi from Pahang (Peninsular Malaysia) in the call structure. Lipotactes (Mortoniellus) karnyi produces long echemes (duration = 1.81± 0.07 s) made up of 86–97 syllables; syllables duration (average = 13.0±0.2 ms) and down time between consecutive syllables (average = 7.1±0.5 ms) are also distinctly shorter.

From other Bornean congenerics, the calling songs is similar to Lipotactes (Lipotactes) kabili Tan, Japir & Chung, 2020 from Sandakan in the similar call structure (i.e., echemes made up of only slightly more numbers of syllables: 9–16 vs. 3–15 syllables), but differs by distinctly shorter echeme duration (0.24–0.55 vs. 0.47– 2.35 s) due to distinctly shorter syllable duration (14.6–23.1 vs. 125–199 ms) and distinctly lower peak frequency (16.4 vs. 28.7 kHz) and frequency spectrum (8–22 vs.>20 kHz).

The species has similar call parameters as song type II of Lipotactes (Lipotactes) alienus Brunner von Wattenwyl, 1898 recorded from Brunei Darussalam, specifically in the echeme (0.24–0.55 vs. 0.18– 0.43 s) and syllable (14.6– 23.1 vs. 18.1–21.9 ms) durations, but differs by the call structure with the initial syllables consistently more spaced apart than the subsequent syllables (instead of by consistent throughout the echeme) and a distinctly lower peak frequency (16.4 vs. 36.6 kHz).

Distribution. Only known from type locality, Sinipung Hill, near Long Pasia.