Asiagomphus reinhardti, Kosterin, Oleg E. & Yokoi, Naoto, 2016

Kosterin, Oleg E. & Yokoi, Naoto, 2016, Asiagomphus reinhardti sp. nov. (Odonata, Gomphidae) from eastern Cambodia and southern Laos, Zootaxa 4103 (1), pp. 35-42 : 36-41

publication ID	https://doi.org/ 10.11646/zootaxa.4103.1.3
publication LSID	lsid:zoobank.org:pub:DD86F265-0C35-4D17-B306-11D1C14B6339
DOI	https://doi.org/10.5281/zenodo.6068461
persistent identifier	https://treatment.plazi.org/id/03B487E9-FF9B-4E17-91FA-FF474FAAC560
treatment provided by	Plazi
scientific name	Asiagomphus reinhardti
status	sp. nov.

Treatment

Asiagomphus reinhardti View in CoL sp. nov.

( Figs. 1–4 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 )

Asiagomphus sp.1— Yokoi & Souptanthong (2014: p. 15, 64; fig. 62; pl. 14, note 66): ♂, 28/4/2005, Paksong, Alt. 1310 m, Bolaven Plt., Champsak Prov. [ Laos].

Holotype: ♂ (abdomen and hind legs broken) ( Figs. 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 ), Cambodia, Mondulkiri Province, ‘ Loringae brook’ [a working nickname], the left tributary of the main river downstream from Buu Sraa Waterfall, 12°34'01–19'' N 107°24'50'' –25'03'' E, ca 450 m a.s.l., 15 vi 2014, O. Kosterin leg.; deposited in Naturalis Biodiversity Centre, Leiden, the Netherlands ( RMNH). Paratype: ♂ ( Fig. 4 View FIGURE 4 ), Laos, Champsak Province, Bolaven Plateau, Paksong, 1310 m a.s.l., 29 iv 2005, N. Yokoi leg.; deposited in the private collection of N. Yokoi.

Etymology. The new species is named in honour of Klaus Reinhardt, a German odonatologist who contributed greatly to our knowledge of Odonata by taking an active part in establishing the International Dragonfly Fund, including personal donations, editing of Odonatological Abstract Service and numerous papers in IDF-Report.

Short diagnosis. Asiagomphus with S10 with a large inclined caudal lobe expanding between cerci for half their length in dorsal view, and cerci expanded basally to strong median angulation of outer margins.

Holotype male. Body black with pale, dull yellowish markings ( Fig. 1 View FIGURE 1 ).

Head. Eyes green in life ( Fig. 1 View FIGURE 1 ). Face black with pale pattern ( Fig. 2 View FIGURE 2 d–e). Labium blackish brown with squamae yellowish and lateral lobes gradually lightening to yellowish in basal parts ( Fig. 2 View FIGURE 2 h). Mandible bases pale. Labrum centrally with pair of indistinct slanting pale strokes at middle. Anteclypeus dark brown. Postclypeus black. Frons black with an evenly broad straight pale stripe along ridge, its ends at eyes rounded ( Fig. 2 View FIGURE 2 d). Antenna brownish but 1st segment blackish basally. Vertex and occiput black ( Fig. 2 View FIGURE 2 e–g). A paired swelling, with indistinct pale marks, behind each lateral ocellus ( Fig. 2 View FIGURE 2 e–f). Occiput with a small and gentle swelling at middle but hind margin straight ( Fig. 2 View FIGURE 2 g).

Thorax black with a pale pattern ( Figs. 1 View FIGURE 1 , 2 View FIGURE 2 a–b). Prothorax with a pair of lateral spots and a pair of small, nearly fused dorsal spots, its posterior margin laterally outlined with pale streak; posterior lobe black, hairy ( Fig. 2 View FIGURE 2 a). Synthorax ( Fig. 2 View FIGURE 2 b) with following pale pattern: Dorsal stripes broadening anteriorly towards collar forming a pattern of two inverted 7s. Antehumeral stripes not interrupted, broadening at antealar sinus. A broad stripe occupying most of mesepimeron. Mesepisternum with a small upper spot and a tiny lower dot. Metepimeron pale except for its black margins. Inframesepisternum and inframetepisternum pale in posterior parts, gradually turning black to anterior part. Subalar ridges marked with black. Ventral side of thorax pale behind hind coxae from which two diverging stripes sprout, going along poststernum and forming a pliers-like pattern.

Legs entirely black. Mid and hind femora with numerous short spines on adaxial surface diminishing to smaller pointed knobs at sides; these spines and knobs disposed rather irregularly but middle of adaxial surface flat and free from spines, so an impression of two not well-arranged rows of larger spines (and sparse strong setae) on both sides; abaxial side smooth. Tibiae with four sharp lengthwise ridges, of which two adaxial are set with rather sparse strong spines and two abaxial with numerous, dense small spinules. Apices of extended hind femora reach posterior hamuli.

Wings ( Fig. 2 View FIGURE 2 c) hyaline, very slightly tinted brownish; venation blackish brown, crossveins between principal veins at anterior edge partly brown. Antenodals (1st and 5th primary) 15 (right)–16 (left) on forewings, 10 on hindwings; postnodals 14 on forewing, 15 on hindwings. Triangles not crossed. Three crossveins between Arc and R1–R4 junction both above and below Rs on forewing, two above Rs and one below Rs on hindwing. Anal loop not defined. Anal triangle well formed, 3-celled. Tornus strongly sinuose at inner wing margin but obtuse, not pointed; membranule extremely narrow, grey. Pterostigmata brownish black, with black bordering veins, of which lengthwise ones swollen, below covering 4 cells on forewings and 4.5 (right) and 5 (left) cells on hindwings.

Abdomen rather narrow at S3–6, evenly expanding laterally at S7–9, black with pale markings as follows ( Fig. 1 View FIGURE 1 ): S1 with a dorsal triangle directed anteriorly and on either side with a ventral pale area broadly extending dorsally along tergite posterior margin. S2 with a narrowly triangular dorsal spot directed posteriorly and on either side with a pale area composed of a larger anteroventral part including auricle and a smaller posteroventral part forming an irregular up-directed protuberance. S3 with broad anteroventral pale areas extending to ¼ of segment length. S4–7 with anterior semirings incised but not fully interrupted mid-dorsally, not reaching tergite ventral margins. S8 with a pair of narrow dorsolateral streaks along anterior margin and a pair of elongate, slanting, pointed-below dorsolateral spots near posterior margin. S9 with a broad apical spot at posterior margin with a broad rounded incision at middle, occupying 0.25–0.4 of tergite length ( Fig. 3 View FIGURE 3 a–b). Ventral margins of S3–7 tergites marked with yellowish streaks. Dorsal area along posterior margin of S1 tergite set with very dense long brown hairs; posterior margin of S1 sternite and ventral margins of S2 tergite with finer hairs.

S10 projecting between cerci as a striking large subquadrangular lobe with broadly rounded corners, directed at ca 45° down and behind; in dorsal view reaching half length of cerci ( Fig. 3 View FIGURE 3 a, c–d), in lateral view reaching level of lower margin of cercus base ( Fig. 3 View FIGURE 3 b, e). Cerci in dorsal view ( Fig. 3 View FIGURE 3 a, c–d) broad in basal half but tapering in apical half and nearly pointed but extreme tips slightly truncated, with evenly concave inner margins but blunt lateral prominences at middle of outer margins (which are slightly concave before and after it). In lateral view ( Fig. 3 View FIGURE 3 b, e), cercus also broad in basal half and tapering to a poined apex, with its upper margin slightly concave while its lower margin has a strong median prominence. Epiproct extends to same level as cercus, in dorsal view ( Fig. 3 View FIGURE 3 a, c– d) with widely divaricate broad branches, with both margins concave and rounded and with slightly hooked apices; in lateral view ( Fig. 3 View FIGURE 3 b, e) robust with broad up-hooked apices; outer surface of basal half of epiproct arms noticeably concave.

Accessory genitalia black, of a structure typical for the genus and without specific features ( Fig. 3 View FIGURE 3 f–h). Anterior hamulus rather slender, tapering towards apex so that broader part not seen from lateral view, posterolateral margin of apical part with six fine teeth Fig. 3 View FIGURE 3 h). Posterior hamulus smooth, without marked angulations but with slight anterolateral rib on anterolateral surface of its basal part, apices broadly and strongly hooked inside in ventral and subventral views ( Fig. 3 View FIGURE 3 f–g). Vesica spermalis with a long flagellum ( Fig. 3 View FIGURE 3 j–k).

Measurements (mm). Hindwing 35; abdomen without anal appendages 41; total length (with head and appendages) 57; hind femur 8; fore wing pterostigma 4, hind wing pterostigma 3.5.

Female unknown.

Paratype. Similar to holotype, especially in structural characters, but differs in the following traits, mostly related to the pattern: pale elements of body pattern saturated yellow ( Fig. 4 View FIGURE 4 b); paired yellow spots on labrum larger but diffuse; antehumeral stripe completely reduced to a tiny antealar spot (the most noticeable difference) ( Fig. 4 View FIGURE 4 a,b); both pale spots on the metepisternum missing ( Fig. 4 View FIGURE 4 a); 12 postnodals on forewing; 13–14 on hindwing; dorsolateral spots at posterior margin of S8 very small ( Fig. 4 View FIGURE 4 c); large dorsoposterior spot on S9 with a straight anterior margin (occupying about 1/3 of segment length). Measurements (mm): hindwing 33.5; abdomen without anal appendages 38.7; total length (with head and appendages) 54.2; hind femur 8.1; fore and hind pterostigma 3.9.

Differential diagnosis. The large caudal lobe of S10 ( Fig. 3 View FIGURE 3 a, c–d) is unique in the genus. Some moderate roundish expansion of the S10 posterior margin is present in A. coreanus (Doi & Okumura, 1937) ( Lee 2001) , A. hainanensis Chao, 1920 , A. septimus (Needham, 1930) and A. pacificus (Chao, 1953) ( Chao 1990) . Another unique feature of the new species is the cercus shape ( Fig. 3 View FIGURE 3 a–e), with basal half expanded to a median angular projection of the outer margin, well seen in both dorsal and lateral view. In other species the cercus outer margin is smooth even if somewhat expanded. None of the known Asiagomphus species shares either of these two characters with the new species.

Identifying the new species (both the holotype and paratype) using the key by Chao (1990), based on colourpattern characters and hence not so reliable, would lead to A. hainanensis , to which the new species has some similarity of body pattern, but it has only two small pale spots at most on the metepisternum versus a broad pale stripe in A. hainanensis . Note that A. hainanensis demonstrates a variable expression of the antehumeral light stripes ( Chao 1990) as well as A. reinhardti , in which the stripes are complete in the holotype and absent in the paratype. Perhaps this character is environmentally modifiable; note that the holotype was taken at the elevation of 450 m a.s.l. and the paratype at 1310 m a.s.l. The general shape of the hamulus of the new species also resembles that of A. hainanensis and also A. motuoensis Liu & Chao, 1990 ( Chao 1990) , but the cercus shape in the two latter species strongly differs from reinhardti in having a weak subapical expansion rather than a strong submedian expansion.

Another species which A. reinhardti resembles in general habitus is A. xanthenatus , described from Upper Myanmar and reported also from the western Thailand and (as a melanised subspecies A. xanthenatus malayanus Karube, 1990 ) from Fraser Hills in Peninsular Malaysia ( Williamson 1907, Karube 1990, Hämäläinen & Pinratana 1999, Orr 2005, Do et al. 2011). But in this species the cerci have a weak subapical ventral swelling or projection (as in most Asiagomphus spp.) rather than a strong sumbedian projection, and the S10 posterior margin is not at all expanded. A. acco Asahina, 1996 , ranging in Vietnam, Laos and S. China ( Asahina 1996, Wilson 2005, Do et al. 2011, Yokoi & Souphanthong 2014), is no doubt a good species although described as a subspecies of A. xanthenatus ( Wilson 2005, Do et al. 2011). A. acco has the cerci with a sumbedian ventral projection in the position corresponding to the projection in A. reinhardti , but in A. acco it is smooth and not visible in dorsal view ( Do et al. 2011).

If a new key for Asiagomphus species were to be produced, it would be reasonable to start it with the first couplet differentiating A. reinhardti from the rest of the genus, as follows:

1. S10 with a large caudal lobe protruding between cerci; cerci with a blunt submedian ventrolateral prominence ( Cambodia, Laos)...................................................................................... A. reinhardti View in CoL

- S10 without a large caudal lobe; cerci with smooth outlines................................. 2 (the rest of the genus).

Habitat. The old, worn out and not too cautious Cambodian male perched on a sunlit stone at a rocky reach of a forest brook, half shaded by tall evergreen forest, situated downstream from the popular Buu Sraa Waterfalls, at an elevation of about 450 m a.s.l. This brook descends from the left slope of the forested main river gorge crossing hilly terrain originally clad with a deciduous dipterocarp forest but presently mostly replaced by plantations. The Laotian male was found at a small mountain stream about 2 m wide, in relatively pristine environment at the elevation of 1,310 m a.s.l. The new species is obviously rare.

Distribution. The species is so far known from two localities in southern Laos and eastern Cambodia, both situated at the western part of the Annamense Mountains. It is expected from southern Vietnam, the border of which lies just 17 km east of the Cambodian locality.