Tapiena dimidia, Tan & Damit & Japir & Chung & Robillard, 2025

Tan, Ming Kai, Damit, Dayang Fazrinah Binti Awg, Japir, Razy, Chung, Arthur Y. C. & Robillard, Tony, 2025, New species, new locality records and descriptions of calling songs of Phaneropterinae from Sabah, Zootaxa 5604 (4), pp. 505-528 : 519-523

Tapiena dimidia sp. nov.

( Figs 16–18 )

Material examined. Holotype. EAST MALAYSIA; Sabah State • ♂; Maliau Basin Conservation Area, at Maliau Basin Studies Centre accommodation (Keruing); N4.73588 E116.97442; 17 November 2024, evening; attracted to light; coll. M.K. Tan; SBH.24.143 ( FRC).

Paratype. EAST MALAYSIA; Sabah State • 1♂; Maliau Basin Conservation Area , at accommodation (Keruing); 17 November 2024, evening; attracted to light; coll. M.K. Tan; SBH.24.146 ( ZRC) .

Diagnosis. The new species is characterised by the following characters: stout habitus, fore femur and tympanum red, the stridulatory file on the left tegmen has two sets of distinctly different-sized teeth (at its anal half having stouter teeth more widely spaced apart; and at its basal half having slenderer teeth that are more closely spaced together); the male tenth abdominal tergite forms a simple red transverse plate with the posterior margin truncated and slightly emarginated in the middle, instead of an apical process highly modified into a large laterally compressed plate; its cercus elongated, slender, and arcuate with its apex tapering into a small acute claw-liked tooth and an even smaller spine.

The new species is generally similar to Tapiena paraincisa Tan & Wahab, 2018 from Brunei Darussalam and Tapiena?incisa Karny, 1923 from Sabah by its stout habitus, its fore femur and tympanum red and the tenth abdominal tergite incised in the middle along the hind margin; but it differs by the long, arcuate and slender cercus with the apex having a small acute claw-liked tooth and an even smaller spine (instead of a stouter cercus with a larger apical tooth blade-shaped, smaller tooth originating base of apical tooth in T. paraincisa and instead of having a flattened apex with denticulated margin in T.?incisa ); and the teeth distribution on the stridulatory file of the left tegmen.

The new species is similar to Tapiena denticulata Tan, Liu & Artchawakom, 2015 from Thailand by the long, arcuate and slender cercus and it tenth abdominal tergite simple plate-like; but differs by the apex of the cercus simple and having a small acute claw-liked tooth and an even smaller spine (instead of acute and sclerotized and having its dorsal margin denticulate), the tenth abdominal tergite red and slightly emarginated in the middle (instead of green and not emarginated and more posteriorly produced), its fore femur and tympanum red (instead of green).

Etymology. The species name refers to the characteristics stridulatory file made up of two halves of distinctly different-sized teeth; dimidius = half, in Latin.

Description. Habitus as shown in Fig. 16 . Head (with frons and vertex), pronotum, pleurae and tegmina densely and regularly covered with punctures, typical for genus ( Figs 17A–C ). Fastigium in dorsal view narrowly triangular, short, feebly surpassing anterior apex of eyes; furrowed longitudinally; at sulcus as wide as antennal scapus; with apex roundly truncated ( Fig. 17A ). Eye prominent, in dorsal view slightly protruding anteriorly ( Fig. 17A ); median and lateral ocelli prominent, round and large ( Fig. 17C ). Frons slightly punctuated ( Fig. 17C ); dorsum of head ( Fig. 17A ) and genae ( Fig. 17B ) densely punctuated. Pronotum circa 1.1–1.2 times longer than wide, densely punctuated ( Figs. 17A ). Dorsal disc with anterior margin straight; lateral margins straight and nearly parallel (feebly diverging posteriorly); posterior margin broadly rounded; hind lobe after middle, separated by shallow suture; longitudinal furrow absent ( Fig. 17A ). Lateral keel present. Lateral lobe 1.4 times as tall as long; ventral margin short, anterior and posterior margins substraight ( Fig. 17B ). Thoracic auditory spiracle [= thoracic foramen] covered by pronotal lateral lobe ( Fig. 17B ). Prosternum unarmed. Mesosternum triangular with subacute apex; metasternum rectangular with anterior angle obtusely rounded, posterior angle 90° and rounded. Tegmen and hind wing fully developed. Hind wing with apex distinctively projecting beyond tegmen; exposed apex with dorsal and ventral margins straight and tapering to subacute apex ( Fig. 16 ). Legs generally with very short and fine setae. Fore coxa with distinct, long, rather straight (only slightly curved at base) spine. Fore tibia with external tympanum open, oval; internal tympanum slit covered by large conchate swelling ( Fig. 17D ). Hind femur with genicular lobe rounded, without any spine.

Male. Tegmen with anterior and posterior margins feebly convex, feebly widened in the middle before tapering to rounded apex; punctuated with many small transparent cells. Tegminal venation: Radius sector (Rs) originating at mid-length, with fork longer than stem ( Fig. 16A ). Stridulatory file of left tegmen transversely crescent-shaped, 2.6 mm in length ( Fig. 17E ); area around file not swollen; file made up of two sets of distinctly different-sized teeth; at anal half 1.16 mm in length with 43 stouter teeth more widely spaced apart (average inter-tooth distance is 0.027 mm per tooth), and at basal half 1.48 mm in length with 75 slenderer teeth more closely spaced together (average inter-tooth distance is 0.020 mm per tooth) ( Figs 17E , 18 ). Mirror on left tegmen made up of network of inter-crossed veins, parallelogram in shape, with anterior margin distinctly longer than posterior margin ( Fig. 17E ). Mirror on right tegmen longer than broad, pentagonal in shape ( Fig. 17F ).

Tenth abdominal tergite simple, with little or no modification, without tooth or long process apically; forming simple red transverse plate with posterior margin truncated and slightly emarginated at middle ( Figs 17G, 17H ). Epiproct concealed beneath tenth abdominal tergite. Cercus long, slender, cylindrical and setose, arcuate with apex tapering into tooth small acute claw-liked and spine even smaller triangular and stout ( Figs 17G–I ). Subgenital plate very wide basally, tapering sharply into very narrow shaft; anterior margin concave; posterior margin deeply and truncated excised at middle, laterally extended into two long and narrow lobes; styli relatively short, slightly shorter than apical excision of subgenital plate, tapering into obtuse apex ( Fig. 17J ).

Female. Unknown.

Colouration. Generally green when alive, except frontal rostrum and inner part of scapus, labrum, apical segment of maxillary palps having tints of red ( Figs 17A, 17B ). Fore coxa (apical part), fore femur and anterior half of fore tibia (including tympanum) red; area around tympanum black ( Fig. 17D ). Tergites at middle red; tenth abdominal tergite red ( Figs 17G–I ).

Measurements (in mm). See Table 1 .

Figures

FIGURE 16. Habitus of Tapiena dimidia sp. nov. in dorsal (A, B) and lateral (C, D) views of holotype (A, C) and paratype (B, D). Scale bar: 10 mm.

FIGURE 17. Tapiena dimidia sp. nov.: head, pronotum and anterior parts of tegmina in dorsal (A), lateral (B) and anterior (C) views; fore femur and inner tympanum (D); stridulatory area of the left (E) and right (F) tegmina in ventral and dorsal views, respectively; abdominal apex in dorsal (G), posterior (H), lateral (I) and ventral (J) views. Scale bars: 1 mm.

FIGURE 18. Tapiena dimidia sp. nov. tooth distribution on the stridulatory file of the left tegmen based on tooth length (blue) and inter-tooth distance (orange).