Rhinocypha chaoi, Wilson, 2004

K. D. P. Wilson, 2004, New Odonata from South-China, Odonatologica 33 (4), pp. 423-432 : 423-425

RHINOCYPHA CHAOI SP. NOV.

Figures 1-3

Material. — Holotype ♂: Dadingshan , Shikengkong, NGuangdong, China, 30-VI-2000, K.D. P. Wilson leg . — Paratypes: 3 ♂ ,, 2 ♀, ditto, 30-VI-2000, coll. K.D. P. Wilson . — Other material: 4 ♂, Nankunshan , Guangdong, 23°35'N by 113°45'E, 26-V-2002, Tong, Xiaoli leg .; — 4 ♂, 1 ♀, Shimentai Provincial Nature Reserve , 7-VIH-2003, coll. K.D.P. Wilson . Holotype will be deposited at Tai Lung Experimental Station, Agri­ culture, Fisheries and Conservation De­ partment, Lin Tong Mei, Sheung Shui, Hong Kong SAR, China.

Etymology. — Named in honour of the late Chao Hsiu-fu.

Description. — Rhi- nocypha with black synthorax, streaked above with large, elon­ gate blue mesothoracic triangle, sides streaked predominately cyan blue above and bright yellow, below and abdomen almost entirely coloured a bril­ liant cyan blue.

MALE. — Labium pale cream with palpi tipped black­ ish-brown. Labrum, genae, clypeus, mandibles, antennae, shiny black. Frons above and top of head, matt black. Five minute pale spots on top of head; a pair of spots of similar size to the lateral ocelli, each lying just to their outer side, a pair of spots each lying at outer ends of the occiput and one lying at

its centre. Prothorax black with three areas of small pale bluish spots laterally, frontal lobe bordered pale bluish and oblong pale bluish spot at centre of the posterior lobe ( Fig. 2 ). Synthorax black with prominent, pale blue, well developed mesothoracic triangle extending to antealar sinus, a pale blue antehumeral stripe above and below the humeral suture, a broad yellow stripe at base of metepistemum and a fine pale blue, curved stripe at posterior, upper comer, and a broad triangular stripe at comer of metepimeron ( Fig. 2 ). Coxae black with posterior border finely pale. Legs black with white expanded inner tibia. Inner face of femora pale. Forewing hyaline. The maximum breadth of forewing is slightly larger than hindwing; typically 5.0 mm forewing and 6.0 mm hindwing; the ratio of hindwing to forewing is 1.2. The hindwing ratio of length to breadth is 4.1-4.3. Slightly more than one-third of the hindwing is coloured blackish inlaid with rectangular windows reflecting metallic violet ( Fig. 1 ). R3 arising two cells distal to the subnodus. Pterostigma finely bordered black with pale bluish-white coloured centres. Abdomen

black with small lateral cyan blue patch segment 1 and 2, large blue rectangular patches on dorsum of segments 2-9 as illustrated in Figure 3 .

female. - Head black with paler yellow markings than male. Base of mandibles, genae, and base of antennae pale yellow. Face of frons with a pair of pale yellow triangular spots. Top of head with same minute pale yellow spots and an additional pair in front of the anterior ocellus. Thorax with similar pattern to male but extent of markings is much reduced and coloured pale yellow. Mesothoracic triangle narrow at base but long, extending to antealar sinus. Legs black without expanded tibia and inner face of femora pale. All wings entirely hyaline with white pterostigmas smoked with brown at proximal and distal areas, subtending 5-6 cells. Abdomen black with fine, interrupted pale yellow stripes at lateral margin and below from 1-7. Very fine interrupted dorsal stripe 2-7.

Measurements (mm). — ♂ abd. + app. 19.0-21.0, hw 23.0-24.5; ♀ abd. + app. 18.5-20.0; hw 26.0-26.5.

DIFFERENTIAL DIAGNOSIS. - Males ofthis species can be separated from all other Rhi ­ nocypha by its well developed mesothoracic triangle, distinctive thoracic and abdominal colouration, its hyaline forewing and broad hindwing with dark apex.

REMARKS. — There are seven species of Rhinocypha known from Chinese territory: (1) R.fenestrella Rambur known from Burma, China (Guangxi, Hainan and Tibet), Laos, Nepal, Peninsular Malaysia, Thailand and Vietnam, (2) R. baibarana Matsumura from Taiwan, (3) R. biforata Selys from Burma, China (Hainan), Indonesia, India, Laos, Nepal, Peninsular Malaysia, and Thailand, (4) R. cuneata Selys from Bangladesh, China, India and Nepal, (5) R. drusilla Needham , known only from Fujian, Guangxi, Hainan (unpub.) and Zhejiang, (6) R. perforata (Percheron) , which is widespread throughout southern China, Indo-China, Thailand and Peninsular Malaysia (including ssp. limbata ) and (7) R. trimaculata Selys from India and Tibet. Indocypha katharina (Needham) , a large brick red species from broad rivers, described from southern China as a species of Rhinocypha , belongs to Indocypha ( WILSON & REELS, 2003).

The subgenus Aristocypha Laidlaw includes baibarana with blue abdomens and others with more or less black abdomens such as fenestrella and cuneata . Both the fore and hindwings of this subgenus are highly coloured with vitreous spots and the hindwing is broader than forewing. R3 arises at the subnodus or occasionally at least 1 cell distal to subnodus. Rhinocypha fulgipennis (Guerin-Meneville, 1831) from neighbouring Vietnam is also a member of this subgenus. The hindwing ratio of breadth to length for fenestrella is 1:3.6 and its ratio of forewing breadth to hindwing breadth is 1:1.24. R. biforata and R. perforata have hindwing and forewing of similar petiolate shape and breadth. They also have short mesothoracic triangles. These two species belong to the subgenus Heliocypha Fraser . The hindwing ratio of breadth to length for biforata is typically 1:5.5. The classification of chaoi at subgeneric level is slightly problematical. It has a long prominent mesothoracic triangle typical of Aristocypha and hindwing slightly larger than forewing but a hyaline forewing. These characters are features of FRASER’s (1934) bifasciata group.

Rhinocypha trimaculata has a black abdomen, lacks a coloured mesothoracic triangle and has highly coloured fiery, coppery red wings. R. drusilla has similar wing shape and venation, but has a red coloured abdomen and short mesothoracic triangle. R. watsoni van Tol & Rozendaal, 1995, which was recendy described from Vietnam, is considered closely related to drusilla . It is a black species with short uncoloured mesothoracic triangle and uncoloured forewing. Both drusilla and watsoni lack the metallic reflecting windows of chaoi . R. seducta HAMALAINEN & KARUBE (2001a), recently described from Vietnam, has similar venation, a hyaline forewing but somewhat proportionately narrower hindwing and the abdomen is almost entirely black. R. orea HAMALAINEN & KARUBE (2001b), also from Vietnam, is another black species with hyaline forewing and opaque, blackish hindwing with violet, green and coppery reflections.

Figures

Figs 1-8. [1-3] Rhinocypha chaoi sp. n., ♂: (1) hindwing; (2) tho­ rax, lateral; (3) abdomen, lateral; [4-8] Megalestes discus sp. n„ ♂J: (4) head, frontal: (5) thorax, lateral; (6) penile organ, ventral; (7) caudal appendages, dorsal; (8) caudal appendages, lateral.