Prodasineura sangkhla Keetapithchayakul, Makbun, Ignatius & Phan, 2024, sp. nov.

Prodasineura sangkhla sp. nov. (Figures 1–6) Specimens examined. Holotype. ♂, Takhian Thong waterfall (15.303270 N, 98.452490 E, 205 m elevation), Sangkhla Buri District at the Thai-Myanmar border, Kanchanaburi Province, Thailand, 4.VI.2024, Q.T. Phan leg. [TNHM]. Paratypes. 5 ♂♂, 2 ♀♀, same data as holotype [ZCDTU]; 4 ♂♂, 1 ♀ (in tandem), same data as holotype [NMC, ECNP]. Etymology. The new species is named after the Sangkhla Buri District, where the new species was discovered. The specific epithet is a noun in apposition. The word of "Sangkhla" is a Burmese/Thai language, meaning diversity or combination, reflecting the area's rich ethnic people combination, which similarly corresponds to the diversity of Prodasineura species found this area. Descriptions of holotype. Head (Fig. 2A, 2C). Head and antennae shining black except the base of antennae, the space between eye margins and genae yellowish, and a transverse opaque white band at the level of vertex to eyes margins. Thorax (Figs. 1A, 2C, 2E) black, mostly covered by white pruinescence with some black in the area surrounding thoracic spiracle and metepimeron. Legs (Fig. 2C) mostly black with yellowish marking at the base of femur, and white pruinescence on coxa, trochanter and femur. Wings (Fig. 1A) completely hyaline with black veins. Px 15 in forewings and 13 in hindwings, respectively. Anal bridge vein on both wings has short arch. Pterostigma black. Abdomen (Figs 1A, 5A, 5C) mostly black except the following: yellow spots on lateral and lower margins of S1; tiny yellowish markings on ventro–lateral surfaces of S2–7; S8–9 entirely black; S10 entirely blue on dorsum and extending to upper half of lateral side. Anal appendages (Fig. 5A–F). Cerci hammer-like shaped and paraprocts broad at base, tapering abruptly to a rounded tip; cerci blue with the two robust ventral spines, with the inner spine curved inward, tiny-shaped in lateral view (Fig. 5B, 5D, 5F); paraprocts black with a tiny yellow spot at base (Fig. 5B). Genital ligula (Fig. 3) with a pair of lateral robust flagella with curved tips and two apical robust lobes. Measurements (in mm). Hindwing 19.8; abdomen (including anal appendages) 28.9. Description of female. Head (Fig. 2B, 2D). Labrum yellowish with a black dot beneath upper margin and lower margin black; mandibles and genae yellowish; the yellow color extends from the eyes margin to the level of postclypeus; anteclypeus black, pale yellowish centrally; postclypeus black with two tiny yellow spots at corners of upper margin. Antennae black except for the second segment yellowish anteriorly. Front and rear of head black with a large transverse yellowish stripe at level of anterior ocellus. Thorax. Prothorax black but laterally yellowish, this color forming a large stripe on lateral pronotal lobe, extending to a half of the projections of posterior pronotal lobe. Posterior lobe with a pair of horns which blunt apically and curving upward, and two adjacent ear-like structures (Fig. 4). Synthorax black with three yellow stripes as in Fig. 2D, 2F. Legs (Fig. 1B) black, except for coxae, trochanter and outer femur yellowish. Wings (Fig. 1B) hyaline, forewings slightly longer than hindwings, Px 14 in both forewings and hindwings. Pterostigma black. Abdomen (Figs 1B, 5G–H) black with the following yellowish pattern: S1 with a large spot on the lateral sides; S2–9 with narrow yellowish stripes along lower margins; S3–6 brown–yellowish with an oval yellowish spot on the anterior margin of each segment; dorsal S8–10 with longitudinal yellow stripe centro-dorsally. Cerci (Fig. 5G–H) yellowish except for lower margin black. Ovipositor black with distal end dark yellowish. Measurements (in mm). Hindwing 18.3; abdomen (including anal appendages) 28.3. Variation in males and females paratypes. Other male and female paratypes from the type locality provided no significant differential features from the holotype male and the above-described female, except their measurements: In male paratypes: hindwing ranges from 18.4 mm to 19.4 mm and abdomen including anal appendages is 28.9 mm to 31.2 mm; with Px is 14–15 in forewing and 13–14 in hindwing. In female paratypes, hindwing is 19.3–20.1 mm and abdomen including anal appendages is 28.0– 28.3 mm. Forewing and hindwing of paratype females with Px 13–14 and 12–13, respectively.