Burmagomphus latescens, Zhang, Hao-Miao, Kosterin, Oleg E. & Cai, Qing-Hua, 2015

Zhang, Hao-Miao, Kosterin, Oleg E. & Cai, Qing-Hua, 2015, New species and records of Burmagomphus Williamson, 1907 (Odonata, Gomphidae) from China, Zootaxa 3999 (1) : -

Burmagomphus latescens sp. nov.

Figures 27–33 , 38–39

Etymology. latescens is a Latin adjective meaning ‘tending to hide’, ‘hiding’, given to this species as its individuals were seen to hide in bank vegetation.

Material examined. Holotype: ♂, Sifangjing (23°38’18’’N, 99°12’11’’E), altitude 530 m ,, Mengding Town, Gengma County, Lincang City, Yunnan Province, China, 19 September 2014, Hao-miao Zhang leg.; Paratype: 1♂, the same data.

Holotype male: Head. Eyes green while alive ( Figs. 38–39 ). Face black with pale yellow markings ( Fig. 27 ). Labium largely pale yellow. Mandible bases pale yellow. Labrum with a pair of large oval pale spots. Anteclypeus entirely black, lower margin of postclypeus with a central yellow stripe. Lateral sides of postclypeus with big rounded spots. Top of frons with a very broad yellow stripe. Vertex black with a transverse, long, low tubercle behind lateral ocelli. Occiput black, its hind margin straight, fringed with long setae.

Thorax. Generally black with pale yellow markings ( Figs. 28 , 38–39 ). Prothorax with a pale spot on each side of middle lobe. Synthorax with mesothoracic collar interrupted at mid point, dorsal stripes oblique, not connecting with collar but fused with a short and oblique antehumeral stipe, thus forming a long oblique stripe. Antehumeral spots very small. Mesepimeron and metepisternum yellow with black markings as follows: a black band along anterior margin of mesepimeron fused below to black on metacoxa and to an incomplete black band extending upwards along lateral suture between mesepimeron and metepisternum (this band occupies half of spiracle) and, dorsally, a slanting black band going from forewing base to middle of metapleural suture, leaving dorsoproximal corner of metepisternum yellow. Metepimeron largely pale yellow with a black band along metapleural suture. Mesokatepisternum and metakatepisternum largely pale. Legs largely black; coxae with yellow spots in all legs, fore leg femur with inner yellow stripes.

Wings. Hyaline, venation black. Forewings: 12 antenodals above Sc and 11 below Sc; 9 (left) and 10 (right) postnodals above R1, 10 (left) and 8 (right) postnodals below R1. Hindwings: 9 antenodals above and below Sc; 9 (left) and 10 (right) postnodals above R1, 11 (left) and 10 (right) below R1. Triangles not crossed. Median space without crossvein. Anal loop one-celled. Anal triangle 3-celled. Pterostigma pale brown, well braced, below covering 5 cells on forewings, 4 cells on hindwings.

Abdomen. Black with pale markings as follows ( Figs. 38–39 ): S1 with a large spot laterally and a dorsal stripe near hind margin; Base of S2 with a yellow ring covering auricles and connecting on either side with a large posterolateral spot extending over ventral half of tergite; S3–7 with a basal spot; S8 with a basal fine stripe dorsally; S9 with a very small lateral spot near posterior margin; S9 with a big dorsal trapezoid spot posteriorly and a strong posterior spine. Cerci about as long as epiproct, slightly curved outwards, tapering and finely pointed, with a small apical spine clearly seen in dorsal view ( Fig. 31 ). Each cercus bears a long tubercle along its lower and outer margins with both ends pointed, thus forming two small teeth: a larger and more acute proximal tooth at about 2/5 of cercus length, visible in dorsal view, and a small but pointed distal, subapical tooth below apical spine, visible in lateral view ( Figs. 31–32 ). The whole tubercle visible only in oblique lateral view ( Fig. 33 ). Epiproct with a deep median concavity, thus forming two relatively long lateral diverging branches. In lateral view their tips are strongly curved upwards; in dorsal view they are broad and blunt, with a noticeably convex inner side. ( Figs. 31–32 ). Posterior hamulus of a leaf-like shape tapering to both ends but with a strong recurved hook on apex; both its sides set with long hairs but not forming tufts ( Fig. 30 ). Vesica spermalis dome-like, with the anterior side longer ( Fig. 29 ).

Female unknown.

Variation in paratype. The very small lateral spot near the posterior margin of S9 is missing in the paratype male.

Measurements (mm). Holotype male: total length 47, abdomen (including anal appendages) 34, hind wing 27; Paratype male: total length 46, abdomen (including anal appendages) 33, hind wing 27.

Differential diagnosis. This species belongs to the conventional group 1, with the dorsal and antehumeral stripes fused into a single kinked stripe. This heterogeneous group is the richest in species, mostly ranging in Southeast Asia. The most unusual character of B. latescens is a slender posterior hamulus with a smoothly tapering and pointed apex. The similar hamulus is found in Burmagomphus pyramidalis Laidlaw, 1922 , widely ranging in Hindustan and Ceylon ( Fraser 1926, 1934; Lieftinck 1940; Bedjanič et al. 2014). B. pyramidalis also has very similar anal appendages, with the subapical and lateral teeth on the cercus and the epiproct branches strongly upturned in lateral view. B. latescens is larger (abdomen 35 mm, hindwing 26 mm) than B. pyramidalis (abdomen ca 30 mm, hindwing 23–24 mm in males of B. pyramidalis ) and has more restricted yellow pattern, namely vertex and occiput black rather than largely yellow, mesothoracic collar interrupted and yellow colour absent from sides of S8 and S9. The mentioned color characters are the same and the size is similar (abdomen 32 mm, hindwing 27 mm) in B. hasimaricus Fraser, 1926 , described from Hasimara, West Bengal and claimed to be closely related to B. pyramidalis . However, its posterior hamulus was reported to be strongly expanded and angled distally, and the epiproct branches are not so upturned ( Fraser, 1926). Benjamin Price kindly provided us photos of the lectotype (male) of B. hasimaricus kept at Natural History Museum, London ( Figs 50-54 ). They confirmed the above mentioned details and revealed one more detail neither mentioned nor depicted by Fraser (1926): three small apical teeth on the posterior hamulus ( Fig. 51 ), absent in both B. pyramidalis and B. latescens . We may conclude that B. latescens is related to B. pyramidalis and B. hasimaricus and shares characters of both (the posterior hamulus and appendages as in B. pyramidalis and the size and coloration as in B. hasimaricus ).

Habitat. The stream in the type locality was about 2–4 m wide, 30–50 cm deep, quite long, with some sections half-shaded. Marginal vegetation was rubber plantation. Individuals of this species perched on leaves close to the water and hidden in vegetation in the semi-shady section. Note that a similar behaviour was observed in the closest species B. pyramidalis : “It is a shy, jungly creature” ( Fraser 1926).

Distribution. Currently only known from western Yunnan province, China.

Figures

FIGURES 27 – 33. Burmagomphus latescens sp. nov., holotype male: (27) head in frontal view; (28) synthorax in lateral view; (29) basal abdominal segments and penile organ in lateral view; (30) posterior hamulus in lateral view; (31) appendages in dorsal view; (32) appendages in lateral view; (33) appendages in oblique lateral view.

FIGURES 34 – 39. Living photos of new species: (34 – 35) Burmagomphus apricus, holotype male, Menglun Town, Xishuangbanna Dai Autonomous Prefecture, Yunnan Province, 18 May 2013; (36) B. magnus, paratype male, Nanxi Town, Hekou County, Hani-Yi Autonomous Prefecture of Honghe, Yunnan Province, China, 0 4 May 2014; (37) B. dentatus, paratype male, Libo County, Guizhou Province, China, 10 June 2010; (38 – 39) B. latescens, holotype male, Mengding Town, Lincang City, Yunnan Province, China, 19 September 2014. Photo 37 was taken by Samson So, all the others by Hao-miao Zhang.

FIGURES 50 – 54. Details of the lectotype (male) of Burmagomphus hasimaricus at Natural History Museum, London: (50) general habitus; (51) secondary genitalia, lateral view; (52) anal appendages, dorsal view; (53) the same, ventral view; (53) the same, lateral view.