Semia pallida sp. nov. (Figs 2 C, 3E���F, 6) Type material. Holotype: ♂, Lam Dong Prov., Bidoup Nui Ba National Park, 2000 m, 12��06���43���N, 108��57���53���E, 10 V 2013 (at light) (VNMN; E-00122). Paratypes: 2♂♂, 1♀, same data as holotype (AM, K493590-92); 3♂♂, 1♀, same location, 20 III 2016; 3♂♂, Khanh Hoa Prov., Hon Ba Nature Reserves, 1500 m, IV 2013 (VNMN; E- 00123-129); 2♂♂, 4♀♀, Thua Thien Hue Prov., Bach Ma National Park, 1400 m, 16��11���51���N, 107��51���36���E, 20 III 2016 (at light); 1♂, Nghe An Prov., Pu Mat National Park, 1200 m, 19��02���21���N, 104��45���50���E, 20 IV 2014 (DE). Other Material. 4♂♂, Lam Dong Prov., Lac Duong, Bidoup Nui Ba National Park, 2000 m, 12��06���43���N, 108��57���53���E, 20 IV 2016, (at light) (DE). Description of male ( Figs 6 A���B). Entire body light grey-brown and covered with whitish pollinosity (Fig. 6 A). Head mostly light grey with black markings between compound eyes and ocelli, black median line, and black spot posterior to eye; ocelli light orange; postclypeus brown dorsally, black medially; ventral postclypeus pale orange with dark brown horizontal striations along transverse grooves mid-anteriorly, brown midline, thin black surrounds, pale brown patch over remainder, and prominent white pollinosity spread; anteclypeus mainly brown; gena and lorum light brown, with medial margin black; rostrum pale brown, black at tip, extending to mid-sternite II; compound eyes reddish brown; antennae light brown; supra-antennal plates light brown. Thorax: Pronotum mostly pale brown-ochraceous with prominent white pillinosity, midline brown markings with black borders; parapsidal sutures black; pronotal collar evenly orange-brown, expanded laterally. Mesonotum olive-brown; submedian sigella margins black, dull black pattern radiating over lateral sigella; scutal depressions black; cruciform elevation light brown, with lateral depressions darker brown and white pollinosity. Metanotum light brown. Legs predominantly light brown; coxa brown; trochanters brown; femora light brown, black at extremities, with primary spine small, obtuse; tibiae similarly patterned to femora, black at centre and extremities, with spines black; tarsi brown anteriorly, blackish at tips; claws black. Meracanthus narrow, pale brown, sharply pointed, overlapping anterior half of corresponding operculum. Wings hyaline; costal vein green-brown proximal to node, olive green distally; veins cream to brown, with white pollinosity proximal to intermodal line; fore wing with infuscations along crossveins r, m, r-m, and m-cu, vein CuA2, junction of veins CuP+1A and 2A+3A, bases and apices of veins RA2, RP, M, M1-4, and CuA1, nodal line intersection, and outer margins of apical cells 1���7; basal membrane uniformly light grey; basal cell translucent; hind wing with 6 apical cells; with infuscations along proximal veins of apical cells 2���3, absent from margins of apical cells 1���6; plaga white, covering jejum, with translucent area near distal margin. Opercula light brown under white pillosity, with black lateral margins; spatulate, not extending beyond posterior margin of sternite II, rounded medially, almost meeting on midline. Timbals (Fig. 2 C) with 5 long ribs; ribs 1���4 dark brown, full length, fused ventrally, thinner through dorsal half to prominent central expansion, thicker ventrally, pale brown to yellow, interspersed by four intercalary ribs; rib 5 discontinuous centrally. Timbal plate prominent; timbal dome pale brown, extending over half width of timbal, inverted distally. Apodeme pit slit-like, conspicuous. Abdomen with tergites mainly brown, darker medially, lighter laterally, with black longitudinal stripe along lateral margins; tergite 1 brown;, timbal covers pale brown, triangulate and convex, covering around two-thirds of timbals; tergites 2���7 brown; tergite 8 dark brown; sternites I���VI pale brown, translucent, white pollinosity over lateral half; sternite VII dark brown to black. Genitalia (Fig. 3 E���F). Pygofer rectangular in ventral view; dorsal beak short, pilose, rounded, not extending posteriorly to anal styles; distal shoulder inconspicuous, rounded, pilose; uncal lobe dark brown posteriorly, becoming pale brown towards apex, short, with inner margins becoming separated from base to apex and lateral margins rounded at apex, bevelled posteriorly towards midline to form a ���V���, strongly curved in lateral view; basal lobe stout, solidly curved inward in ventral view. Aedeagus short, entirely within uncus. Description of female (Fig. 6 C���D). Head and thorax similar to male, with generally darker and greenish coloration; pronotal collar olive green, ampliate laterally; mesonotum olive green with similar black patterns to male. Abdomen dark brown; tergites brown, black on lateral margins; tergite 1 ochraceous; tergites 2���8 ochraceous, darker medially, lighter laterally; sternite I pale brown, sternites II ���VII light brown becoming darker posteriorly; abdominal segment 9 ochraceous, with black stripe adjacent to midline and brown dorsal midline. Ovipositor dark brown, black at tip, not extending beyond abdomen. Measurements (12 males, 6 females). Body length: male 33.0���36.6 (35.3); female 26.2���31.0 (28.3). Length of head + thorax: male 12.4���13.8 (13.4); female 12.2���14.5 (13.4). Length of abdomen: male 20.7���23.0 (21.9); female 14.0���16.51 (14.9). Fore wing length: male 34.4���41.2 (38.9); female 38.2���44.5 (40.4). Head width: male 8.0���9.4 (8.6); female 8.3���9.2 (8.9). Pronotum width: male 9.3���10.9 (10.0); female 9.0���10.4 (9.7). Abdomen width: male 11.5���12.7 (12.0); female 10.1���11.8 (11.0). Etymology. The name ��� pallida ��� (Latin feminine adjective) refers to the pale grey coloration of this species, emanating in part from the extensive white pollinosity over the entire body, giving it a ���ghostly��� appearance. Distinguishing features. The grey coloration of S. pallida sp. nov. distinguishes it from all other Semia species which are pale, olive, or dark brown. Compared to those Semia species lacking continuous infuscations along hind margins of the apical cells 1���6 (S. brevidilata, S. hainaensis, S. spinosa, S. spiritus sp. nov., S. albusequi sp. nov., and S. watanabei), S. pallida sp. nov. (body length 33���37 mm) is smaller than S. hainanensis (body length> 37 mm) and larger than S. spinosa and S. albusequi sp. nov. (body lengths S. pallida sp. nov. is slightly larger than S. gailaiensis (body length 32.8���33.6 mm), the opercula of S. gailaiensis meet in the midline while those of S. pallida sp. nov. are clearly separated. The rounded ventral apices on the uncal lobes of S. brevidilata, the lateral ���spine-like��� projection from the uncus of S. spinosa, the ornate lateral projections of the uncal apices in S. lachna, the darker lateral uncal projections on S. gialaiensis, and the rectangular appearance of the apical lobes of S. watanabei contrast with the ���V-shaped��� angulation produced at the apices of the uncal lobes on S. pallida sp. nov. Semia pallida sp. nov. is distinguished from the single male S. brevidilata by its narrow head width (S. brevidilata) and presence of lateral black stripes on the tergites, which are lacking in S. brevidilata. Semia pallida sp. nov. also lacks the white pollinosity displayed on the terminal tergites of S. watanabei. Distribution, habitat, and seasonality. This species has a wide distribution along the east coast of Vietnam from Bidoup Nui Ba National Park in the south to Pu Mat National Park in northern Vietnam (Fig. 4). Specimens have been collected between March and May., Published as part of Emery, David L., Lee, Young June & Pham, Hong-Thai, 2017, Descriptions of four new species of Semia Matsumura (Hemiptera: Cicadidae: Psithyristriini) from Vietnam, with a key to the species of Semia, pp. 153-166 in Zootaxa 4216 (2) on pages 161-163, DOI: 10.5281/zenodo.230748