Macromia unca, Wilson, 2004

K. D. P. Wilson, 2004, New Odonata from South-China, Odonatologica 33 (4), pp. 423-432 : 430-431

MACROMIA UNCA SP. NOV.

Figures 22-30

Material. - Holotype ♂: Maoping (Dadongshan), N Guangdong, China, 5-VII-2000, K.D.P. Wilson leg. — Paratypes: 3 ♀, Maoping (Dadongshan), 5-VII-2000, coll. K.D.P. Wilson; 1 ♂, 1 ♀, ditto, 6-VII- -2000. Holotype will be deposited at Tai Lung Experimental Station , Agriculture , Fisheries and Conservation Department , Lin Tong Mei , Sheung Shui, Hong Kong SAR, China.

Etymology. — The name unca is derived from the Latin word "uncus" meaning hooked, bent in or curved. The name reflects the markedly hooked posterior hamulus.

Description. — Short bodied Macromia with blackish face, yellow labium, broad yellow antehumeral stripe and males with stout pyramidal process on the male abdominal segment 10.

male. — Ochreous yellow labium with diffuse dark brown areas on central lobe and distal borders. Mandibles and labium black, anteclypeus dark brown, postclypeus bright yellow with distal margins dark brown, as illustrated in Figure 22 . Frons dark blackish brown with metallic blue reflections and lower, lateral halves coloured yellow. Frons deeply grooved at centre to form pair of smoothly-rounded, pyramidal processes at apexes, which are slightly protruded frontally with flattish faces. Vertex raised to form a small pyramidal process. Occiput black, slightly raised. Prothorax matt dark brown.

Synthorax ( Fig. 23 ) blackish with shiny metallic green re­ flections and covered in thick coat of fine yellow hairs. Dor­ sum with broad yellow stripe falling short of wing bases by about one quarter the length of the mesepisternum. Dorsal stripe continues onto the meso- katepisternum. Broad yellow stripe covering upper two-thirds of metepisternum, covering the spiracle and continuing across the metakatepisternum. Coxae dark brown. Legs black. Tib­ ia of hind femora with white keel covering three quarters of length. Keels of front and middle legs slightly less than half the tibial lengths. Metaposternum, and minute area immediately adjacent on metepimeron, yellow. Antealar sinuses yellow. Wings hyaline with short blackish-brown pterostigmas subtending two to three cells. Anal field complete with 9-10. Anal comer of hindwing rounded i.e. not sharply pointed. First abdominal segment black. S2 black with basal half, including small oreillet, yellow. S3-5 black with pairs of yellow spots proximal to transverse carina. S6-10 black with basal quarter of S7 yellow and minute yellow spot at basal, ventro-lateral comer of S8. S10 very short less than half width of S9, which is itself half width of S8. S10 with stout, dorsal, pyramidal projection covering basal half as illustrated in Figures 27-28 . Superior appendages black, about twice length of S10, stout and sharply pointed with minute lateral projections, basal to the mid-point Inferior appendage dark brown, slightly longer than superior appendages. Posterior hamulus with remarkably hooked tip as shown in Figures 24-26 .

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FEMALE. — Stouter and slightly larger than male with smoky-brown wing tips. Head and thorax as male. Legs without keels. Abdomen as male with slightly larger yellow markings than male and S6 also with a pair of yellow spots, basal to transverse carina. Anal field 11-14 cells. Wings very pale amber throughout and enfumed with faint smoky-brown at wing tips. Valvular vulvae are minute rounded, peg-like protrusions as illustrated in Figures 29-30.

Measurements (mm): ♂, abd. + app.45.0-45.5;hw.41.5-42.0; ♀ abd. + app.46.5-50.0,hw47.0- -50.0.

DIFFERENTIAL DIAGNOSIS. — The prominent yellow dorsal stripe, stout pyramidal process on the dorsum of the tenth abdominal segment and distinctly hooked-shaped posterior hamulus will serve to separate this Macromia from all other known species. There are no Chinese Macromia which are closely related to this new species. In neighbouring Vietnam, M. cingulata Rambur , also known from India and Nepal, although smaller, has similar body coloration, tenth abdominal process and hooked posterior hamulus. The posterior hamulus of cingulata is not so profoundly hooked as unca and the lateral teeth of the superior appendages are distal to the mid-point (cf. FRASER, 1936: 179-182, figs 57 & 60c).

REMARKS. — Following the publication of the Odonata of Hainan ( WILSON & REELS, 2001) there were 16 species of Macromia known from Chinese territory. Including unca there are now 17 species known from China. The four females and two males were taken on two successive evenings, just before dusk, in a shaded lane adjacent to a Forestry Department field station. No observations of this species were made, during day light for the entire period of the two-week survey conducted in the Shikengkong area.

Figures

Figs 22-30. [22-28] Macromia unca sp. n., ♂: (22) head, frontal; (23) thorax, lateral; (24) secondary appendages, ventral; (25) sec­ ondary appendages, lateral; (26) posteriorhamulus; (27)caudal abdomen, lateral; (28) caudal abdomen, dorsal; [29-30] M. unca sp. n., ♀: (29) caudal abdomen, ventral; (30) valvula vulvae