Coeliccia bhriulieci, To & Phan & Tran, 2017

To, Van Quang, Phan, Quoc Toan & Tran, Van Bang, 2017, Description of Coeliccia bhriulieci sp. nov. (Odonata: Zygoptera: Platycnemididae) from central Vietnam, Zootaxa 4341 (2), pp. 279-282 : 279-281

Coeliccia bhriulieci sp. nov. ( Figs 1–3 )

Holotype. ♂ ( Zoological collection of the Southern Institute of Ecology , Vietnam Academy of Science and Technology , Ho Chi Minh City, Vietnam), 15 ° 44’850’’ N, 107 ° 14’237’’ E, 1,299 m a.s.l., Gari commune, Tay Giang district, Quang Nam Province, central Vietnam, 26.X.2016, V.Q. To leg.

Paratypes. 4♂, same date, locality as holotype; 2♂, same locality, 24.VII.2016; 2♂, 15 ° 53’284’’ N, 107 ° 21’585’’ E, 1,899 m a.s.l., Tr’hy commune, Tay Giang district , Quang Nam Province, central Vietnam, 14.IV.2016, V.Q. To leg. Three paratypes from Gari are deposited in the personal collections of the second author and the remainder are in the collection of the first author.

Etymology. The new species is named after Mr. Bh’riu Liec, leader of the indigenous Co Tu minority people, without whose support our project would not have been possible; bhriulieci , a noun in the genitive case.

Description of holotype. Head ( Fig. 2 a-b). Labrum and postclypeus shining black; labium yellow becoming black anteriorly; anteclypeus yellow with two separated black spots; mandibles and genae pale yellowish, this pattern extending to just above postclypeus; antennae black except for yellow apical part of the first segment; epicranium matte black with a yellow spot between lateral ocellus and base of antenna; rear of head black with a transversely elongated postocular spot.

Thorax ( Fig. 2a, c–d ). Dorsum of prothorax including anterior and posterior lobes entirely black; middle lobe black with traces of yellow laterally; posterior lobe unmodified, curved slightly upward in lateral view ( Fig. 2 c-d); notopleural suture and propleuron yellow ( Fig. 2a ). Synthorax: mesepisternum black with a narrow yellow antehumeral stripe; mesepimeron black extending through middle of mesinfraepisternum of which the ventral part is blue; metepisternum, metinfraepisternum and metepimeron mostly blue with black as follows: narrow black subalar ridge extending from black upper end of mesepimeron to metapleural stripe, the latter slightly touching ventral end of metathoracic spiracle and extending ventrally along anterior margin of metinfraepisternum ( Fig. 2a ).

Legs ( Fig. 2a ). Coxae and trochanters yellow; femora and tibiae yellow with flexor and extensor surfaces black; tarsi and spines black.

Wings hyaline with black venation. Px 17–18 in FW and 15–16 in HW respectively. Pterostigma brown with narrow pale margin, covering 1.5–2 cells.

Abdomen ( Fig. 1 ). Black dorsally, pale yellow ventrally with yellow extending as follows: most of S1 except for black apical annulus, dorsal stripe extending to distal half on S2; S3–6 with semicircular expansion just before the posterior end of each segment; S7–S8 largely black excluding ventral narrow yellow stripe in S7 and a yellow marking on lateral sides of S8; S9–10 blue with black on ventral base of S9 and S10.

Genital ligula ( Fig. 3 d-e) with posterior segment quadrate in ectal view, with two long, recurved and slightly spatulate flagella lateroapically, each extending posteriorly with tip slightly recurved.

Anal appendages ( Fig. 3 a-c) entirely black, cercus as long as S10, and armed with a subapical black tooth. Paraproct slightly longer than cercus, tip acutely curved medioventrally.

Measurements (in mm). HW 25; abdomen + caudal appendages 40.

Female. Unknown.

Variation in paratype males. Paratype males show little variation compared to holotype. In some specimens, synthorax laterally pale blue or pale yellow, not blue as in holotype. Middle lobe of prothorax entirely black, not yellow marking as in holotype. Measurements range 24–26.5 mm (HW) and 38–42.5 mm for abdomen + appendages.

Differential diagnosis. The following combination of morphological characters separates C. bhriulieci from other Southeast Asian Coeliccia species: largely pale blue synthoracic pattern with narrow yellow antehumeral stripe, appendages black, and genital ligula with a pair of long recurved flagellae originating apicolaterally on largely quadrate terminal segment.

Coeliccia bhriulieci shares some characters with the following Vietnamese congeners: C. cyanomelas , C. mientrung and C. pyriformis . The synthorax of all four have blue colouration which in C. bhriulieci mainly occupies the metepisternum and metepimeron ( Fig. 2a ) while in other three species the blue extends on to the mesepimeron thus forming a wide arch ( C. pyriformis , C. mientrung ) ( Fig. 1A, E, p . 132 in Kompier & Phan 2017) or extends anteriorly into the middle of it ( C. cyanomelas ) (Fig. 10c, p. 269 in Steinhoff & Uhl 2015); antehumeral stripe in C. bhriulieci is a line more than two times narrower and much longer (reaching the alar ridge) than that of the other species; S9–10 is blue in C. bhriulieci and C. cyanomelas ( Fig. 1 in this paper and Fig. 10d-f, p. 269 in Steinhoff & Uhl 2015) but is yellow in C. pyriformis and C. mientrung ( Fig. 1B, F, p . 132 in Kompier & Phan 2017); anal appendages are black in C. bhriulieci but blue in C. cyanomelas and yellow in both C. pyriformis and C. mientrung ; genital ligula lacks flap-like fold in C. bhriulieci ( Fig. 3 d-e) and C. cyanomelas (Fig. 8c-d, p. 267 in Steinhoff & Uhl 2015) whereas the flap is well developed at the apical end in both C. pyriformis and C. mientrung ( Fig. 2 A-B, p. 133 in Kompier & Phan 2017).

Habitat and ecology. The new species was found in two different habitats within the high mountain forest. At Tr’hy (1,899 m a.s.l.), the habitat was a narrow (about 2–3 m) swampy shallow stream with a sandy bottom shaded by bushy vegetation. This habitat is shared with Caliphaea thailandica Asahina, 1976 . The stream in Gari (1,299 m a.s.l.) was mostly exposed (6–8 m) with a gravel bottom with large rocks and low vegetation along the sides. Only one other congeneric species, the widespread Coeliccia scutellum Laidlaw, 1932 , was found here.

Figures

FIGURE 1. Coeliccia bhriulieci sp. nov., habitus of holotype male. Scale bar is 1 cm.

FIGURE 2. Coeliccia bhriulieci sp. nov., ♂. (2 a) head (dorsal view) and thorax (lateral view); (2 b) head, antero-dorsal view; (2 c) prothorax, lateral view; (2 d) prothorax, dorsal view. Scale bars are 500 µm.

FIGURE 3. Coeliccia bhriulieci sp. nov., ♂. (3 a) appendages, lateral view; (3 b) appendages, dorsal view; (3 c) paraprocts, ventral view; (3 d) genital ligula, ventral view; (3 e) genital ligula, lateral view. Scale bars are 500 µm.