Coeliccia hayashii Phan & Kompier, 2016, sp. nov.

Coeliccia hayashii sp. nov.

(Figs. 1; 3A–B; 4A–D, 6A)

Etymology. This species is named after Professor Fumio Hayashi of Tokyo Metropolitan University, Japan; hayashii, a noun in the genitive case.

Type material. Holotype: ♂, Doi waterfall, KaNat, K’Bang district, Gia Lai Province, central Vietnam, 25.IV.2016, Quoc Toan Phan leg. Paratypes: 4♂, same date, location and collector.

Description of holotype male. Head (Fig. 3 A–B). Anteclypeus pale with pair of widely separated black marks adjacent to labrum; mandibles and genae pale yellowish, the genae connected by a horizontal pale yellow stripe over the lower part of the antefrons just above the postclypeus. Postclypeus and labrum shining black. Antennae black, but the tip of the first segment pale yellow. Top of head matte black with two approximately triangle–shaped yellow spots adjacent to the posterior ocelli. Back of head black with two elongated postocular spots.

Thorax (Fig. 3 A). Pronotum of prothorax covered by grey-blue pruinosity. Most of propleuron matte black, lower part yellow. Synthorax largely black. Mesepisternum with narrow yellowish-blue antehumeral stripes, becoming bluish posteriorly. Mesepimeron, metepisternum and mesinfraepisternum black apart from the pale yellow lower part of the mesinfraepisternum and proximal part of the metepisternum above the coxae. Metinfraepisternum yellow. Large rectangular pruinose area covers lower half of mesepimeron and upper half of metepisternum along metapleural suture. Metepimeron entirely yellow.

Legs. Coxae pale yellow. Femora and tibiae pale yellow with flexor surface of femora and extensor surfaces of tibiae black. Tarsi black.

Wings (Fig. 4 D) hyaline with black venation. 19–21 postnodal crossveins in hindwing, and 19–20 in forewing. Pterostigma brown with narrow pale margin, covering 1.5–2 underlying cells.

Abdomen. Black above with pale yellow markings as follows: S1 largely yellow with only the dorsum black; S2–8 black above shading into pale yellow ventrally, but black at the apices of each segmen; proximal half of S9 black, distal half yellow; S10 entirely yellow.

Anal appendages (Fig. 4 A–B) yellow, typical shape of the genus Coeliccia with cerci longer than S10, bearing a basal interior and black ventral tooth at about two-thirds, the latter clearly visible in lateral view; cerci apically in dorsal view tapering to a point. Paraprocts longer than cerci, simple form with black apical tooth.

Genital ligula (Fig. 4 C) structurally simple with terminal segment bifurcated from base into two long flagella, these expanded at tips.

Measurements (mm). Hindwing 29; abdomen + appendages 45.

Female. Unknown.

Variation in paratype males. Male paratypes of Coeliccia hayashii show little morphological variation, but the number of postnodal crossveins varies 20–22 in hindwing, 19–21 in forewing.

Habitat. Apparently very specific choice of habitat. Males held territories sheltered by an overhanging rock surface where water seeped through and over the rock over clay surface with sparse vegetation, sheltered from direct sunlight.