Euxestocis menglaensis sp. nov.

Figs. 1 (A–B), 2(A–H), 3(A–B), 4(A–E), 5(A–G)

Chinese vernacular name: 勐Oi光tDzş

Type material. Holotype: CHINA: male, “China: Yunnan, Xishuangbanna Dai Autonomous Prefecture (Ʊ双AE DZ傣Ḧnãṅ), Mengla county (勐Oi县), Xishuangbanna Tropical Rainforest National Park Scenic Skytree (Ʊ 双AEDZIJỀNJü国ẍữüȓ园ª天Ṁā区), 21°37'N, 101°35'E, 763 m, 21.IV.2024, leg. Nan Li ”. Paratypes: CHINA: 4 males, 4 females, same data as the holotype.

Diagnosis: From the illustration of the E. bicornutus (Miyatake 1954, 1982), the first abdominal ventrite bearing a pubescent fovea in the middle. But the Euxestocis menglaensis sp. nov. is without. From the illustration of the E. bicornutus (Kawanabe 2003), the eighth abdominal sternite bears short hairs at two sides of the base, and bearing long hairs around the apical area; the new species without short hairs at two sides of the base, and bears close and long hairs at the middle posterior margin. The new species with the middle margin somewhat emarginate in tegmen, but the E. bicornutus without. The two sides are nearly parallel of the pens of the new species, but the E. bicornutus is narrow at the base and gradually widens and then narrower near the end. From the description of the E. formosanus (Miyatake 1982), the anterior area of the pronotum with two conspicuous, upheaved lateral robust pronotal horns. But the new species with two small pronotal horns. The pronotal disk of the E. formosanus with an impunctate median line which is lacking in the new species. The apical corners produced forward and subacute. But the anterior angles without produced forward, obtuse of the E. menglaensis sp. nov.. From the portrayal of the E. satoi (Kawanabe 2003), The first abdominal ventrite bearing a pubescent fovea, but the new species is without. Eighth abdominal sternite bearing short hairs and relatively long ones along the apical margin. The new species is without short hairs at two sides, and bears close and long hairs at the middle posterior margin. The basal piece is also different the basal piece of the E. satoi is quadratic, and the basal piece of the new species is nearly triangular. The new species with the middle margin somewhat emarginate in tegmen, but the E. satoi without. The pens is longer than the tegmen in the E. satoi, on the contrary, the pens is shorter than the tegmen in the E. menglaensis sp. nov..

Description. With the characters of the genus. Male. Fully pigmented adult. Measurements in mm: TL 2.27, PL 0.81, PW 0.97, EL 1.47, EW 0.99, GD 0.72. Ratios: PL/PW 0.84, EL/EW 1.48, EL/PL 1.81, GD/EW 0.73, TL/EW 2.29.

Body (Fig. 1A) oblong, convex, nearly glabrous on dorsum, reddish brown to dark brown; Tarsi, antennal funicle, and labial palpus are deep yellow. Dorsal shiny.

Head wider slightly than long, partially visible from above, with sparse punctures and extremely short and inconspicuous setae, frontoclypeal ridge strongly elevated forming a pair of broad-based, reflexed at each side semicircle plates with a pilose and subelliptic pit on each side. Compound eyes are finely facetted and suboval, each bearing approximately 75 ommatidia; GW 0.16 mm. Antennae (Fig. 2B) bearing ten antennomeres with the following lengths (in mm): 0.09, 0.07, 0.06, 0.04, 0.02, 0.03, 0.02, 0.06, 0.05, 0.08. Mandibles are asymmetrical (misaligned), with well-developed, transversely ridged molae.

Pronotum (Fig. 1A) is as long as broad and is slightly raised in the middle with clear and uniform size of punctures, The lateral edge is slightly curved, punctures separated by a distance equal to one to four diameters. Lateral margins (Fig. 1A, 1B) are narrow, and not visible for their entire lengths from above. The anterior edge produced forward and formed two small and slightly denser horns. Anterior angles (Fig. 2A) are obtuse, posterior angles rounded.

Scutellar shield developed, with a few punctures and setae; subtriangular, BW 0.09 mm.

Elytra (Fig. 1A) 1.2 times as long as broad, 1.4 times as long as pronotum, punctures slightly rougher than pronotal; only at the top there are a few extremely short setae; sides subparallel in basal two-thirds, then gradually convergent apical.

Protibia (Fig. 2D, 2E) expanded to the apex, outer apical angle with an acute tooth and dentate along the outer edge which are shorter near the base and gradually becoming longer towards the apex. Meso-and metatibia expanded forming a rounded lobe lined with socketed spines.

Prosternum (Fig. 1B) is weakly subcarinate; the prosternal process is flaked and slender somewhat slightly narrow near the apex, slightly higher than the procoxae (best seen in lateral view).

Metaventrite (Fig. 1B) is convex but slightly emarginate in the middle, with sparse punctuation and minimal bristles; discrimen nearly one-fifth length of ventrite. Abdominal ventrites (Fig. 1B) with short setae and shallow and rough punctures, the surface between them microreticulate; the first abdominal ventrite is 2.7 times as long as 2nd, the ventrites without a pubescent fovea. The length of the ventrites (in mm) is as follows: 0.289, 0.107, 0.091, 0.071, 0.137.

Aedeagus 2.9 times as long as ventrite 5. Tegmen (Fig. 2H) is 2.9 times as long as the wide, widest at the end, the narrowest is in the middle; Penis (Fig. 2H) is shorter and narrower than the tegmen, 4.2 times as long as the widest, with a subacute apex and moderately long, sides parallel from basal to below the top. The sternite VIII with the posterior margin slightly emarginate in the middle, anterior margin slightly emarginate close to both sides. And bearing close and long hairs at the middle posterior margin.

Female (Fig. 3). Similar to males, except for the following points: Frontoclypeal ridge slightly subtriangular plates, but without a pilose pit; Pronotum with anterior edge broadly rounded, with two very small projections; The eighth abdominal sternite of females is different from males. The posterior is slightly emarginate in the middle. Female genitalia (Fig. 4B, 4D, 4E) is long and widest at the base; paraprocts (Fig. 4D) is 0.89 times as long as gonocoxites.

Measurements. Males (n=4, including the holotype; mm): TL 1.82–2.27 (1.97 ± 0.21); PL 0.65–0.81 (0.71 ± 0.07); PW 0.82–0.97 (0.87 ± 0.07); EL 1.17–1.47 (1.26 ± 0.14); EW 0.82–0.99 (0.89 ± 0.08); GD 0.69–0.74 (0.72 ± 0.05).

Females (n=4; mm): TL 1.79–2.50 (2.06 ± 0.31); PL 0.62–0.66 (0.65 ± 0.02); PW 0.85–0.91 (0.88 ± 0.03); EL 1.13–1.40 (1.30 ± 0.13); EW 0.85–0.94 (0.89 ± 0.04); GD 0.80–0.83 (0.81 ± 0.02).

Distribution. Xishuangbanna Dai Autonomous Prefecture, Yunnan, China.

Host fungi. Ganoderma sp. and polypore fungus (Fig. 5).

Etymology. The specific name ‘menglaensis’ is taken from the type locality, Mengla county.