Periaeschna yazhenae, Xu, Qi-Han, 2012

Xu, Qi-Han, 2012, Periaeschna yazhenae sp. nov. from Fujian, China (Odonata: Anisoptera: Aeshnidae), Zootaxa 3526, pp. 72-78 : 72-74

Periaeschna yazhenae sp. nov.

( Figs. 1–6 , 14–15 )

Specimen studied. Holotype: male, Nanjing County (24°38ʹN, 117°11ʹE), Fujian Province, China, emerged 02.V. 2012 in laboratory. Type is deposited in Department of Biological and Environmental Engineering, Zhangzhou City University.

Etymology. The species is named in memory of my mother: Yazhen LIN.

A small-sized Periaeschna species with greenish-brown face and black or brownish-black body, coloured with greenish-yellow markings as shown in Figs. 14–15 .

Head: Face greenish-brown. Labium, labrum, mandibles, maxillae, anteclypeus and postclypeus all greenishbrown. Frons dark greenish-brown but black above along the border of crest, which is cone-shaped at the middle. Vertex brownish-black, covered with long blackish hairs. Occiput black, coated with long blackish hairs. Width of frons a trifle less than half width of head. Frontal view of head as shown in Fig. 1 .

Thorax: Prothorax blackish-brown. Synthorax black, marked with a pair of green dorsal stripes and two broad stripes of the same colour on each side, one across the mesepimeron and the other across the metepimeron. There is a small triangular green spot on the upper end of metepisternum.

Wings hyaline, tinted with brownish-black at extreme base and infumed with pale yellow in all wings. Base of hindwing nearly straight, tornus right-angled; membrane present, short, limited to petiole of wing. Pterostigma greyish-brown, braced at its proximal side, 3 mm in length, covering 3 cells. Arc proximal to distal primary antenodal vein. IR3 forked at a point midway between node and pterostigma, 2 row of cells between the branches of fork; only a single row of cells between IR3 and Rspl; 4 median veins in all wings, 7 cubital veins in forewing and 5 in hindwing; hypertriangle with 5 cells in forewing and 4 cells in hindwing. Nodal index: 18–21:21–17 / 18–17:16–17; triangle 5 celled; anal loop 6 celled; anal triangle 3 celled. The hindwing venation as shown in Fig. 2 . Legs all brownish-black.

Abdomen: Brownish-black with greenish-yellow markings. Basal 2 segments markedly inflated. S1 blackishbrown, marked with a narrow middorsal stripe. Sides of S2 with a greenish-yellow auricle which connects with a basal spot and is adjacent to a small spot above; two irregular spots on distal end. Dorsum of S2 marked with narrow stripe and distal bar. S3 marked with distal bar on dorsum, large basal lateral triangular spot, and small ventrolateral spot at midsegment. S4–5 marked with distal bar on dorsum, small basal ventrolateral spot, and pair of large triangular basal ventrolateral spots. S6–7 marked with small basal ventrolateral spot and pair of large triangular basal ventral spots. S8 marked with middorsal stripe and pair of small basal ventrolateral spots. S9 marked with a linear basal middorsal spot and pair of small basal ventral spots. S10 entirely brownish-black. Cerci yellowish-black and epiproct largely blackish-yellow. Cercus with a ventral triangular lobe on the distal portion when viewed laterally; with narrowed basal and distal portions and a broadened median portion, and a truncated apex with a tip pointed externally when viewed dorsally. Epiproct relatively long and nearly 3/4 length of cerci ( Figs. 3–4 ). Vesica spermalis ( Figs. 5–6 ) yellowish-brown except for entirely black median segment; its distal segment broadly expanded, axe-shaped when viewed laterally, with a pair of long, fine whip-like processes extending from both ental lateral lobes.

Measurements [mm]: Abdomen (incl. appendages) 46.0, Hindwing 41.5.

Figures

FIGURES 1 – 6. Periaeschna yazhenae sp. nov.: (1) head, frontal view; (2) hindwing; (3) caudal appendages, lateral view; (4) caudal appendages, dorsal view; (5) vesica spermalis, lateral view; (6) vesica spermalis, ventral view.

FIGURES 14 – 16. Final stadium larva and adult of Periaeschna yazhenae sp. nov.: (14) male adult, dorsal view; (15) ditto, lateral view; (16) final stadium larva, male, dorsal view.