Leptogomphus pasia van Tol, 1990

Dow, Rory A., Stokvis, Frank & Ngiam, Robin W. J., 2017, Revision of the Genus Leptogomphus Selys in Borneo, including gene trees and a two marker molecular phylogeny (Odonata: Anisoptera: Gomphidae), Zootaxa 4358 (2), pp. 201-257 : 216-218

Leptogomphus pasia van Tol, 1990

( Figs 1 , 2 , 3 , 6 , 14 , 21 , 39 , 56 , 66 , 71 , 81 , 89 , 95 , 101 , 107 , 113 , 119 , 121 , 127 , 130 )

Leptogomphus pasia van Tol 1990: 97 –99, 101, 102, Figs 1–5 (part, original description holotype female Long Pasia, Sabah), Table 2 (part, female characters);— Orr 2003: 96.

Material studied. Type material. Holotype. 1 ♀ (JvT 16524), Sungai Pasia near confluence with Sungai Maga , Long Pasia area, 105 km south of Beaufort, Sabah, Malaysia, 4.4333N, 115.6667E, 1250m, 3 iv 1987, leg. C. van Actherberg, in RMNH.

Other material. Sarawak, Malaysia: 1 ♂ (teneral), Pa’Gelawat, 3.79817N, 115.46537E, 1100–1300m, Pulong Tau NP, Miri Division, 18 iv 2012, leg. R.A. Dow, in collection Dow.

Sabah, Malaysia: 1 ♂ ( SAB 12_GOM1, RMNH.INS.507699, used for description below and illustrations), Kipungit streams, Poring Hot Springs, Mount Kinabalu NP, 6.0886N, 116.7675E (Poring), 11 ix 2012, leg. J. van Tol, in RMNH; 1 ♀ ( RMNH.INS.507715), Silau-Silau stream, Park Headquarters area, same national park, 6.0N, 116.533E (approximate coordinates for Silau-Silau stream), 13 ix 2012, leg. J. van Tol, in RMNH.

Description of male (SAB12_GOM1, RMNH.INS.507699). Head ( Figs 6 , 14 ). Median lobe labium brown, lateral lobes mostly pale, hooks dark brown. Labrum black and very dark brown with pair of small, widely separated yellow basal marks. Mandible bases pale, black area above, more extensive on right side than on left. Genae mostly black except adjacent to mandible bases, where paler. Clypeus black with indistinct dark brown area below antefrons and very small paler patch centrally on anteclypeus. Ante- and postfrons not very sharply divided, antefrons mostly black, postfrons largely occupied by transverse yellow stripe, not quite divided centrally, ( Fig. 14 ). Vertex and occiput black. Pair of rounded transverse tubercles behind lateral ocelli; ocelli whitish, vertex smooth behind tubercles. Occipital plate deepest at eye margins, becoming shallower gradually over most of length, more abruptly centrally where forms “v” shape; raised centrally at rear and slightly along much of rest of rear margin and at posterior corners.

Thorax. Prothorax mostly very dark brown, yellow markings laterally on anterior and middle pronotal lobes, small, very narrowly divided central posterior marking on middle pronotal lobe, posterior pronotal lobe with narrow, faint central longitudinal pale stripe. Middle pronotal lobe with pair of small raised areas bearing tiny tubercles and short setae, placed centrally on dorsum of each half. Synthorax dark brown with pale yellow markings as follows ( Figs 56 , 66 ): short, narrow mesothoracic collar, broadly divided at middorsal carina, joined to narrow ca linear dorsal thoracic stripes that extend beyond level of apex of antealar crest, slightly convergent towards antealar carina, terminating just short of antealar carina. Narrow, irregular antehumeral stripe, separated from spot below dorsal thoracic stripe on mesepisternum, near antealar carina. Irregular, narrow, stripe running most of length of mesepimeron. Metepisternum with irregular stripe running from metakatepisternum, below spiracle, on left broken near antealar carina, on right broken into four patches ( Fig. 66 shows the right hand side, flipped to the left for consistency). Broad stripe on metepimeron, widening toward antealar carina but deeply excised by black on upper margin shortly before antealar carina. Mesokatepisternum yellow to front, metakatepisternum mostly pale, except to rear so narrowly separated from marking on metepisternum. Venter mostly pale with indistinct central brown area near abdomen. Legs (right anterior and middle detached below coxa, right posterior completely removed for DNA extraction) robust and relatively short. Coxae mostly pale with brown areas, remainder mostly brown, becoming paler distally on left anterior tibia and tarsus where claws almost white except brown tips; claws similar on left middle tarsus. Wings: sectors of arculus separated at origin with 5 cross veins up to and at first bifurcation of superior sector in Fw, 3 in Hw. Discoidal field with 2 rows of cells from origin, transitioning to three rows before level of nodus in both wings. 16 Ax in Fw, 11 Hw, 11 (left) or 12 (right) Px in Fw, 13 Px in Hw. Pt brown, covering ca 4-5 underlying cells.

Abdomen. Slender after base of S3, expanding moderately from base of S7, maximum width and height reached apical part of S8, then almost constant. Dorsum of S10 with pair of prominent ca conical protuberances basally ( Fig. 107 ), bearing many small tubercles on posterior faces. Brown with yellow markings as follow: S1 mostly yellow lower laterally, yellow dorsal mark. S2 lateral mark including much of auricle, another lateral mark placed posteriorly, irregular stripe along ventral margin of tergite in posterior ca one-half, narrow yellowish middorsal stripe. S3 with narrow basal lateral marking, S3–7 with very narrow, irregular, middorsal stripe, this also indistinctly present on basal ca one half of S8. S9–10 entirely brown. Cerci ( Figs 100 , 107 ) broad at base in lateral view ( Fig. 107 ), running slightly downwards to tip along upper margin, contracting abruptly on lower margin shortly after base (so basal part appears as ventral spur), then running gently upward to sharp tip; an interior ventral ridge bearing small teeth clearly visible from basal spur to shortly before apex. In dorsal view ( Fig. 101 ) broadest at base, outer margin curved in quite sharply in basal ca one-third, then running gently inwards to sharp tip, where turned slightly out; short blunt basal spur on inner margin, then running straight for much of length, turned out towards tips; the inner ventral ridge expands inwards near tips, visible as ca semicircluar expansion in dorsal view. Pale greyish except basally, extreme tips and teeth of ventral ridge, where dark. Epiproct ( Figs 101 , 113 ) dark brown, black at apex, only just shorter than cerci, somewhat compressed so shape of deep divide not clear, in lateral view ( Fig. 107 ) tapering from moderately broad base, ca straight over much of length, upturned at apex, where sharp. In ventral view arms broad, evenly tapering to apices.

Accessory genitalia as shown in Figures 89 , 95 , anterior hamule small, tapering to sharp tip, hooked to rear in apical ca one-half, ca two-fifths height of posterior hamule. Posterior hamule very large, directed postero-ventrally, anterior margin curving from base to ca three-quarters length, where running approximately parallel to lower margin of tergite of S2, after this abruptly narrowed and directed ventrally to sharp apex, posterior margin more gently and evenly curved from base to apex, apex turned slightly out. Vesical not fully inflated, low, seemingly simple. Penis ( Fig. 95 ) with penultimate segment extended to rear of join with terminal segment, bifurcated in this part. Terminal segment not extending far beyond penultimate segment, dorsal margin almost straight in lateral view, apically with short cornua situated at end of ventrally directed stalk.

Measurements (mm). Hw (possibly not fully inflated) 30, abdomen excluding anal appendages 35.5.

Variation in males. The teneral male from Pa’Gelawat agrees with the male described in most features that can be usefully compared, in particular the cerci, although distorted, have the distinctive basal ventral spur and the interior ventral ridge bearing small teeth; however the semicircular expansion near the tips of the cerci is less evident in this male, although that may be due to the condition of the cerci.

Measurements (mm). 13–16 Ax in Fw, 11–12 in Hw, 13 Px in all wings. Hw (not fully inflated) 29.5, abdomen excluding anal appendages ca 35.

Descriptive notes on the female. A full description of the female holotype was given by van Tol (1990); here we note a few additional points and discuss variation in the female collected on Mount Kinabalu.

The female from Mount Kinabalu has a small mark centrally on the anteclypeus and a pair of small, widely spaced transverse streaks on the postclypeus; van Tol (1990) states that the clypeus is black in the holotype, but there is a small, faint central pale mark on the anteclypeus. Only a single pair of transverse tubercles are present in the female from Mount Kinabalu, the “smaller pair latero-posteriorly”, present in the holotype are absent, but there is peculiar shallow groove in the same position; the smaller pair are very small in the holotype.

In the female from Mount Kinabalu, the antehumeral stripes are broken as they approach the wing bases, leaving a separate pale mark by the antealar carina. It has 18 (right) to 19 (left) Ax in the Fw, 12 (right) to 13 (left) in Hw; 14 (left) to 15 (right) Px in Fw, 14 (right) to 16 (left) in Hw.

The dorsal marking of S1, described as a middorsal stripe in the holotype, is a broad yellow marking occupying most of the dorsum of the segment in the Mount Kinabalu specimen; the middorsal abdominal markings otherwise agrees with that described for the holotype, except that it is only present on the basal ca one quarter of S8. The lateral markings of S2 and S 3 in the holotype are described as “lateral side of segment 2 and antero-lateral side of segment 3 also dark yellow” (van Tol 1990), giving the impression that the entire side of S2 and of the anterior part of S3 are yellow; in the Mount Kinabalu specimen these markings are centrally placed lateral longitudinal stripes, very similar to those seen in other species. However examination of the holotype reveals the same condition as seen in the Mount Kinabalu specimen, and the expression in the original description is misleading. Additionally there is a small yellow mark at the base of S4 and a tiny one at the base of S5 on the left in the Mount Kinabalu female. The vulvar scale in the Mount Kinabalu female is the same as that of the holotype; the sternum of S 8 in this specimen has a slight swelling in the same position as the distinct tubercle seen in L. coomansi females. The cerci of the Mount Kinabalu specimen are rather pale in dorsal view.

Measurements of Mount Kinabalu female (mm). Hw 33.5, abdomen excluding anal appendages 35.5.

Remarks. Both males examined have very pale cerci, although both are teneral this may reflect the mature condition since the anal appendages of teneral individuals of other Bornean Leptogomphus males are typically somewhat darker. The ventral spur on the male cercus is unusual in Bornean Leptogomphus , but a similar structure is evident in, for instance, Leptogomphus gestroi Selys, 1891 , known from Burma, Thailand, China and Vietnam. More significantly, L. lansbergei from Java and Sumatra also has this structure, and in fact the anal appendages of L. l. lansbergei and L. pasia are extremely similar (see Fig. 15 in Ris 1927), although the two differ in their markings. Note that the similarity is less marked when compared with van Tol’s illustrations of L. l. lansbergei ( Figs 30, 31 on page 103). It is also interesting to note that the cerci of L. l. lansbergei are whitish in colour, as they appear to be in L. pasia . Ris (1927), as noted by van Tol (1990), considered that the anal appendages of L. l. lansbergei and L. l. assimilis are different, in which case in our view they should be treated as distinct species. However this is a matter in need of further study.

Laidlaw (1931) recorded a male of L. l. assimilis from Bettotan in Sabah; as already noted by van Tol (1990), this specimen cannot be located now. It is very unlikely that the Bettotan specimen was actually L. l. assimilis, and possibly it was actually L. pasia .

The male of L. pasia was associated to the female based on similarity of markings and the match is supported by the molecular results; the two samples, from separate populations, are identical in COI and have 99.6% identical sites in ITS. In all of our analyses ( Figs 1 , 2 , 3 ) this species is the sister of L. sii , however given the morphological similarity with L. lansbergei , an expanded analysis including L. lansbergei is highly desirable to establish the relationships among these species.

Confirmed specimens of L. pasia are from the Mount Kinabalu, the Long Pasia area of Sabah and the Tama Abu range in Sarawak (almost contiguous with the Long Pasia area of Sabah) ( Fig. 127 ). All records are from upland and montane locations.

Figures

FIGURE 2. ITS gene tree for 20 specimens of Leptogomphus and three outgroup taxon.The best Maximum Likelihood tree is shown, with posterior probabilities from the Bayesian Inference analysis also depicted on the branches. Bootstrap values and posterior probabilities are shown if less than 100 or 1.0 respectively. RMNH collection codes are shown for each specimen, as well as the sex of the specimen and an indication of where it was collected.

FIGURE 3. Phylogenetic reconstruction for 30 specimens of Leptogomphus and three outgroup taxa using the combined COI+ITS dataset. The best Maximum Likelihood tree is shown, with posterior probabilities from the Bayesian Inference analysis also depicted on the branches. Bootstrap values and posterior probabilities are shown if less than 100 or 1.0 respectively. RMNH collection codes are shown for each specimen, as well as the sex of the specimen and an indication of where it was collected.

FIGURE 127. Distribution of L. pasia (white circle) and L. sii (blacksquare).

FIGURE1. COI gene tree for 29 specimensof Leptogomphusand three outgroup taxon.The best Maximum Likelihood tree is shown, with posterior probabilities from the Bayesian Inference analysis also depicted on the branches. Bootstrap values and posterior probabilities are shown if less than 100 or 1.0 respectively. RMNH collection codes are shown for each specimen, as well as the sex of the specimen and an indication of where it was collected.

FIGURES 4–9. Male head dorsal: (4) L. coomansi SAR09_10_GOM4; (5) L. pendleburyi SAR13_14_GOM13; (6) L. pasia SAB12_GOM1; (7) L. sii holotype; (8) L.schieli holotype; (9) L. williamsoni SAR11_12_GOM56.

FIGURES 14–17. Male head frontal: (14) L. pasia SAB12_GOM1; (15) L. sii holotype; (16) L. schieli holotype; (17) L. williamsoni SAR11_12_GOM56.

FIGURES18–23.Female headdorsal:(18) L.coomansi SAR11_12_GOM48;(19)L.mariaeholotype;(20) L.sp.cf coomansi PomS260; (21) L. pasia holotype; (22) L.sii paratype SAR13_14_GOM44; (23) L. species SAR11_12_GOM33.

FIGURES 36–41. Female head frontal: (36) L. coomansi SAR11_12_GOM48; (37) L. mariae holotype; (38) L. sp. cf coomansi PomS260; (39) L.pasia holotype; (40) L.sii paratype SAR13_14_GOM44; (41) L.species SAR11_12_GOM33.

FIGURES 56–59. Male synthorax dorsal: (56) L. pasia SAB12_GOM1; (57) L. sii holotype; (58) L. schieli holotype; (59) L. williamsoni SAR11_12_GOM56.

FIGURES 64–67. Male synthorax lateral: (64) L. sii holotype; (65) L. sii teneral male Gunung Pueh; (66) L. pasia SAB12_GOM1; (67) L.pendleburyi SAR13_14_GOM13.

FIGURES 68–73. Female synthorax dorsal: (68) L. coomansi SAR11_12_GOM48; (69) L. mariae holotype; (70) L. sp. cf coomansi PomS260; (71) L.pasia holotype; (72) L.sii paratype SAR13_14_GOM44; (73) L.species SAR11_12_GOM33.

FIGURES 78–83. Female synthorax lateral: (78) L. coomansi SAR11_12_GOM48; (79) L. mariae holotype, right hand side, flipped for consistency; (80) L. sp. cf coomansi PomS260; (81) L. pasia holotype; (82) L. sii paratype SAR13_14_GOM44; (83) L.species SAR11_12_GOM33.

FIGURES 88–93. Male accessory genitalia, lateral view, all scale bars 1mm: (88) L. coomansi SAR09_10_GOM4; (89) L. pasia SAB12_GOM1; (90) L. pendleburyi SAR13_14_GOM13; (91) L. schieli holotype; (92) L. sii holotype; (93) L. williamsoni SAR11_12_GOM56.

FIGURES 94–99. Penis in lateral view (all scale bars 0.5mm): (94) L. coomansi SAR07_8_GOM18; (95) L. pasia SAB12_GOM1; (96) L. pendleburyi SAB12_GOM3; (97)L. schieli holotype; (98)L. sii paratype SAR13_14_GOM49; (99) L. williamsoni SAR16_GOM1.

FIGURES 100–105. Male anal appendages dorsal view (all scale bars 0.5mm): (100) L. coomansi SAR09_10_GOM4; (101) L. pasia SAB12_GOM1; (102) L. pendleburyi SAR13_14_GOM13; (103) L. schieli holotype; (104) L. sii holotype; (105) L. williamsoni SAR11_12_GOM56.

FIGURES 106–111. Male anal appendages and abdominal S10 in lateral view (all scale bars 0.5mm): (106) L. coomansi SAR09_10_GOM4; (107) L. pasia SAB12_GOM1; (108) L. pendleburyi SAR13_14_GOM13; (109) L. schieli holotype; (110) L. sii holotype; (111) L. williamsoni SAR11_12_GOM56.

FIGURES 112–117. Male anal appendages in ventral view (all scale bars 0.5mm): (112) L. coomansi SAR09_10_GOM4; (113) L.pasia SAB12_GOM1;(114) L.pendleburyi SAR13_14_GOM13; (115) L. schieli holotype; (116) L.sii holotype; (117) L. williamsoni SAR11_12_GOM56.

FIGURES 118–119. Ventral view female abdominal S8 (all scale bars 0.5mm): (118) L. coomansi SAR11_12_GOM48; (119) L. pasia SAB12_GOM2.

FIGURES 120–125. Female vulvar scale (all scale bars 0.5mm): (120) L. coomansi SAR11_12_GOM48; (121) L. pasia holotype; (122) L. pendleburyi SAR13_14_GOM15; (123) L. schieli paratype SAR15_GOM6; (124) L. sii paratype SAR13_14_GOM44; (125) L.williamsoni SAR13_14_GOM51.

FIGURES 130–132. Habitus of some Bornean Leptogomphus species:(130) L. pasia holotype (left hand side, flipped to right for consistency with other images); (131) L.sii holotype male; (132) L. williamsoni male SAR13_14_GOM56.

FIGURES28–31. Female head dorsaldetail; h—occipital horn; ot—occipital tube; p—pit; s—occipital spur; t—tubercle;thtubercle horn: (28) L. coomansi SAR11_12_GOM48; (29) L. mariae holotype; (30) L. sp. cf coomansi PomS260; (31) L. species SAR11_12_GOM33.