Miriatroides luna Tan & Storozhenko, 2023

Tan, Ming Kai, Vu, Trung Thanh, Le, Cuong Viet Canh & Pham, Thai Hong, 2023, Pygmy grasshoppers (Orthoptera: Tetrigidae) from B ạch Mã National Park, central Vietnam, Zootaxa 5319 (2), pp. 199-223 : 212-215

Miriatroides luna Tan & Storozhenko , sp. nov.

( Figs. 15 , 16 )

Material examined. VIETNAM, Th ừa Thiên Hu ễ province, Bạch Mã National Park: •Ô holotype; Summit Trail (forest trail), N16.19667 E107.86169, 1428.0± 5.8 m.a.s.l.; 7 March 2023, 20h15; hiding among rotten tree trunk on the ground; coll. M.K. Tan & V. T. Trung; VIET.23.17 ( VNMN) ( Figs. 15 , 16 ) .

Diagnosis. This new species is most similar to Miriatroides kannackiensis Storozhenko, 2016 from Gia Lai Province, but differs from latter (as well as from all other congeners) by the rostrum more projected in lateral view and the fore femur with margins (especially ventral margin) undulated.

Etymology. This species is named after the moon (in Latin, luna = moon), as the holotype was collected near the summit on a clear night with a full moon.

Description. Habitus as shown in Figs. 15 , 16A, 16B . Different shades of brown, ranging from pale brown, and dark brown to red brown, well camouflaged against leaf litter and tree trunk on the ground.

Head: In frontal view ( Fig. 16C ): antennal groove inserted below lower margin of eyes. Fastigium convex; sinuosoidal on anterior border. Face with numerous nodules. Frontal costa elongated. Bifurcation of frontal costa in line with middle of eye. Facial carinae faintly sinusoidal. Compound eyes hemispheric, not exerted above vertex, 1.55 times taller than wide. Lateral ocelli slightly ventral of bifurcation of frontal costa and slightly above antennal groove. In dorsal view ( Fig. 16A ): apex of fastigium clearly surpasses frontal margin of eyes, emarginated in the middle. Vertex 1.53 times wider than eye width. Lateral carinae of fastigium not distinct; median carina well surpassing apex of fastigium. In lateral view: frontal costa arched and well protruding in front of eyes. Mouthparts mostly brown to grey with small pale-coloured nodules. Maxillary palps pale coloured with tint of grey; with segments stout and apical segment somewhat oval.

Pronotum: Pronotum reaching apex of posterior knee, 2.03 times longer than wide (pronotal lateral lobe width). In lateral view ( Fig. 16B ): with median, humero-apical, and interhumeral carinae irregularly undulated. Infrascapular area broad. Angle of ventral sinus between lateral shoulder and lateral lobe acute. In dorsal view ( Fig. 16A ): median carina distinct throughout length of pronotum, flanked by a network of irregular carinae. Lateral carinae distinct. Interhumeral carina distinct, diverging posteriorly. In dorsal view ( Fig. 16A ), lower margin of lateral lobe of pronotum leaf-shaped. Apical end of pronotal disc acute.

Legs ( Figs. 16A, 16B ): Fore and middle legs: generally brown with either dark- or light-coloured bands. Fore femur with distinct dorsal carina straight, with ventral carina undulated, forming three nodules. Middle femur with less distinct dorsal and ventral carinae, clearly not undulating; lateral external carina undulated, forming two or three small nodules. Hind legs: posterior femur about 3.36 times longer than wide, about 1.34 times longer than hind tibia; with clear carinae along dorsal margin. Knee of hind femur with antegenicular tooth small but acute, genicular tooth rounded. Posterior tibia dark coloured anteriorly, becoming slightly lighter in colouration; with five spines on each lateral margin, with numerous spinules between these large dorsal spines. Basal article of hind tarsus generally pale coloured, 0.78 times as long as apical article; middle article dark coloured and very short; apical article white, except apex being black.

Abdomen: Tergites and sternites typically dark coloured with some sparse patches of pale spots. Subgenital plate triangular ( Figs. 16D, 16E ).

Measurements (in mm). PL = 7.17; PW = 3.54; PH = 1.20; HWL = NA; HFL = 4.53; HFW = 1.35; TL = NA; VW = 0.55; EW = 0.36; SW = 0.14; IAH = 0.52; BL = 7.34; PAW = 1.47; PPW = 2.16; MAL =?; MAW =?; 1 stAW = 0.18; TW = NA; FFL = 1.70; FFW = 0.55; MFL = 1.93; MFW = 0.44; HTL = 3.37; 1 st TaL = 0.49; 3 rd TaL = 0.63; SGPL = 0.56; SGPW = 0.59.

Ecology. Only one specimen was encountered staying still and camouflaging itself in a decaying wood on the ground of a sheltered montane forest habitat at high altitude of Bạch Mã National Park ( Fig. 3 ). Upon disturbance, it remained still.

Distribution. So far known only from type locality.

Type locality. Vietnam, Th ừa Thiên Hu ễ Province, B ạch Mã National Park .

Figures

FIGURE 3. A river in Bạch Mã National Park where many semi-aquatic tetrigids were collected.

FIGURE 15. Miriatroides luna sp. nov. Ô holotype hiding among rotten tree trunk on the ground.

FIGURE 16. Miriatroides luna sp. nov. Ô holotype: dorsal (A) and lateral (B) views of habitus; face in anterior view (C); abdominal apex in lateral (D) and ventral (E) views. Scale bars: 5 mm (A, B), 1 mm (C–E).