Burmagomphus apricus, 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 apricus sp. nov.

Figures 1–5 , 34–35

Etymology. apricus is a Latin adjective meaning ‘sunlit’; this epithet is given to the species for the holotype, which was found perching on an open road during the hottest time of day under fierce sunshine.

Material examined. Holotype: ♂, Xishuangbanna National Nature Reserve (21°57’59’’N, 101°12’37’’E), altitude 630 m, Menglun Town, Xishuangbanna Dai Autonomous Prefecture, Yunnan Province, 18 May 2013, Hao-miao Zhang leg.

Holotype male: Head. Eyes green while alive ( Figs. 34–35 ). Face black with pale yellow markings ( Fig. 1 ). Labium largely pale yellow. Mandible bases pale yellow. Labrum with a pair of very large oval pale spots. Anteclypeus entirely black. Postclypeus largely black with a central pale yellow stripe in its lower margin and a pair of small rounded spots on either side. Top of frons with a very broad yellow stripe. Vertex black with paired crescent tubercles behind lateral ocelli. Occiput with hind margin straight, fringed with long setae.

Thorax. Generally black with pale yellow markings ( Figs. 2 , 34–35 ). Prothorax with a pair of pale lateral spots on middle lobe. Synthorax with mesothoracic collar interrupted at mid point, dorsal stripes connecting with collar stripes forming two 7-shape stripes. Antehumeral stripe extends throughout mesepisternum length but isolated from its continuation on mesokatepisternum. Sides of synthorax largely pale yellow with two broad black stripes, one along interpleural suture, the other along metapleural suture, thus forming three broad yellow stripes. Mesokatepisternum and metakatepisternum with large yellow spots. Legs largely black. Coxae with yellow spots in all legs, fore leg femur with inner yellow stripes.

Wings. Hyaline, venation black. Forewings: 13 antenodals above Sc and 14 below Sc; 10 (right) and 9 (left) postnodals above R1, 10 postnodals below R1. Hindwing: 10 antenodals above Sc, 9 antenodals below Sc; 9 postnodals above R1, 11 below R1. Triangles not crossed. Median space without crossvein. Anal loop one-celled. Anal triangle 3-celled. Pterostigma brown, well braced, below covering 4.5 (left) and 3.5 (right) cells on forewings, 4 (left) and 4.5 (right) cells on hindwings.

Abdomen. Black with pale marking as follows ( Figs. 34–35 ): S1 with a dorsal spot at posterior margin and a large spot laterally; S2 with a dorsal stripe along carina, tapering to hind margin, and laterally with two oval pale spots fused to each other along tergite ventral margin, the proximal one including auricles; S3–7 with a basal ring; S8 with paired very small basal spots; S9 with a very large spot posteriorly, not spined; S10 black. Anal appendages black, as long as S10. Cerci and epiproct equal in length. Cerci slightly divergent, lower margin with a subapical broadly rounded ventrolateral tubercle, situating at about 2/3 of cercus length and visible in dorsal and lateral view but easier to see in lateral view ( Figs. 3–4 ). Epiproct with a deep median concavity, thus forming two lateral broadly divaricate arms, with convex inner margins and very slightly convex, almost straight outer margins ( Fig. 4 ). Posterior hamulus broad, with a slightly convex anterior side and nearly straight apical side hence looking subrectangular, with a robust antero-apical spine ( Fig. 5 ).

Measurements (mm). Holotype male: total length 48.0, abdomen (including anal appendages) 35.0, hind wing 28.0.

Differential diagnosis. This species belongs to the conventional group 3 with two parallel light stripes on the mesepisternum, the dorsal and antehumeral ones. The two complete lateral black stripes along the thoracic sutures make it similar to the Chinese species B. arvalis , B. intinctus ( Needham 1930; Chao 1954, 1990), B. dentatus sp. nov., B. magnus sp. nov. (see below) and B. sivalikensis Laidlaw, 1922 , the only Indian (Uttarakand and West Bengal) representative of group 3 ( Fraser 1926, 1934). However, B. apricus differs from all these species in the dorsal stripe broadly confluent to the light mesothoracic collar (isolated in the three above-mentioned species). B.

apricus also differs from B. arvalis and B. sivalikensis in a completely black occiput (the same in B. intinctus , B. dentatus and B. magnus ); besides, B. sivalikensis has a more extended abdominal yellow pattern. Morphologically B. apricus is well characterised by a considerable ventrolateral projection of the cercus, situating at about 2/3 of its length, seen both from lateral and dorsal view, while B. intinctus ( Figs. 6–7 ) and B. magnus have at this place a weaker and more medially situated swelling seen only in lateral view but not from above. Besides, in B. apricus the inner sides of its arms are somewhat convex, well seen from above ( Chao 1954), while B. arvalis , B. intinctus , B. sivalikensis , B. dentatus and B. magnus have an even incision of the epiproct (but much deeper in B. magnus ). B. apricus has a much shorter and less processed appendages than B. dentatus In B. apricus (and B. intinctus ) the apices of cerci and epiproct arms protrude for the same distance, while in B. sivalikensis , B. dentatus and B. magnus the cerci are more protruding behind the epiproct arms.

B. sivalikensis and the below-described B. dentatus best differ from B. apricus by a strong tooth instead of an oblong rounded swelling of their cerci.

Because of the dorsal stripe fused to the mesothoracic collar, an attempt to apply the key for Burmagomphus provided by Chao (1990) for B. apricus would result in its identification as B. corniger (Morton 1928) , also described from Yunnan. However, this species appeared to in fact belong to another genus and is presently considered as Asiagomphus corniger ( Yang & Davies 1993) . Its differences from B. apricus are obvious in the hamuli shape and the cercus and epiproct outline ( Chao 1990).

Habitat. The holotype male was collected near the main stream in the Xishuangbanna National Nature Reserve. This stream was very long and flowing to deep forest, about 1.5–3.0 m wide; in the dry season (November to June) the water level was very low, about 0.3 m. Not much behavior of the holotype male was observed: it was perching on a leaf in the sunshine during the noontime when the temperature was over 35°C.

The Xishuangbanna National Nature Reserve is aimed to protect the tropical rainforest, and the habitats for dragonflies are very abundant there. About 170 dragonfly species have been recorded there, with many unknown species (unpublished data from the first author’s fieldwork in 2009–2014).

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

Figures

FIGURES 1 – 5. Burmagomphus apricus sp. nov., holotype male: (1) head in frontal view; (2) synthorax in lateral view; (3) appendages in lateral view; (4) appendages in dorsal view; (5) basal abdominal segments and posterior hamulus in 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 6 – 10. Burmagomphus intinctus (Needham, 1930), details of specimens from Jingning, Lishui City, Zhejiang Province: (6) male appendages in dorsal view; (7) male appendages in lateral view; (8) male posterior hamulus in lateral view; (9) female head in frontal view; (10) female S 8 – 10 in ventral view.