Genetic integrity of four species of Leptidea (Pieridae, Lepidoptera) as sampled in sympatry in West Siberia

In southern West Siberia, as many as four Leptidea Billberg, 1820 species are present sympatrically: L. amurensis (Ménétriés, 1859), L. morsei (Ménétriés, 1859), L. sinapis (Linnaeus, 1758) and L. juvernica Williams, 1946. The two latter were recently recognised as nearly sibling species on morphological and molecular characters. Specimens intermediate as to their subtle diagnostic characters occurring in West Siberia and elsewhere were interpreted as resulted from limited introgression. This supposition was tested via populational morphological and molecular analysis of spring brood specimens of all the four species taken from a limited (4.5 × 0.2 km) area in the suburbs of Novosibirsk. The samples were analysed with respect to the genitalic morphology, external characters, three nuclear (CAD, H1 gene and ITS2) and one mitochondrial (COI) molecular markers, infection of the intracellular maternally inherited bacterial symbiont Wolbachia Hertig, 1836 and its wsp gene coding for a hypervariable surface protein. Interspecific variation of the nuclear CAD and ITS2 sequences and the mitochondrial COI gene in L. sinapis and L. juvernica turned out concordant. The absence of molecular evidence of introgression suggests genetic integrity of these two species and allows their reliable identification by molecular characters. The genitalic (lengths of the saccus and valva) and external characters (wing pattern) of males overlap in L. sinapis and L. juvernica, as identified by molecular markers and thus are not so helpful in actual species identification. Only the ductus bursae length showed no overlap and can be used for identification of females. The histone H1 gene appeared five times less variable over the four studied species than COI, and found to be identical in species L. sinapis and L. juvernica. Wolbachia infection was found in all studied species. We identified three wsp variants of Wolbachia: 1) wsp-10 allele in L. amurensis, L. sinapis, L. juvernica; 2) a very similar wsp-687 allele in L. sinapis; and 3) wsp-688, highly divergent to the previous ones, in L. morsei

Microgomphus alani (Odonata, Gomphidae) sp. nov. from Cambodia

Kosterin, Oleg E. (2016): Microgomphus alani (Odonata, Gomphidae) sp. nov. from Cambodia. Zootaxa 4114 (3): 341-350, DOI: 10.11646/zootaxa.4114.3.

First data on Odonata of Prey Long Forest in Cambodian Lowland

Prey Long (Prey Lang) Forest is the largest remaining lowland rainforest in Indochina, shared by Stung Treng, Preah Vihear, Kampong Thom and Kratie Provinces of Cambodia, which has been persisted until present because of the lack of roads. It includes patches of unique evergreen swamp forests. Odonata of Prey Long forest, including Cheum Takong forest swamp, was briefly examined in December 2019, while the already deforested area was examined in June 2018. The former examination resulted in 40 species, the latter in 34 species, 60 species in total. Two species, Copera chantaburii Asahina, 1984 and Burmagomphus williamsoni Förster, 1914, are for the first time reported for Cambodia from the deforested area (Chey Saen District of Preah Vihear Province). The swamped forest of Cheum Takong provided 17 species, 5 of which were not found elsewhere in the considered area, 3 are rare and 4 generally Sondaic. Prey Long Forest should be re-examined in the rainy season soon after the road to Spong village is constructed

Odonata of the Cambodian coastal regions revisited : beginning of dry season in 2010

Results of the odonatological survey of the coastal SW regions of Cambodia on November 28 - December 11, 2001, are presented, including field notes, enumeration of all records by locality, discussion of interesting specimens and their taxonomy and of seasonality aspects. Fifteen (14 named) species have been added to the known fauna of Cambodia: Aristocypha fenestrella (Rambur, 1842), Rhinagrion viridatum Fraser, 1938, Lestes elatus Hagen in Selys, 1862, L. platystylus Rambur, 1842, Aciagrion tillyardi Laidlaw, 1919, Agriocnemis f. femina (Brauer, 1868), Archibasis viola Lieftinck, Ceriagrion calamineum Laidlaw, 1951, Mortonagrion aborense (Laidlaw, 1914), M. falcatum Lieftinck, 1934, Pseudagrion microcephalum (Rambur, 1842), 1948, Paragomphus capricornis (Förster, 1914), Hemicordulia undescr. spec., Macrodiplax cora (Brauer, 1867), Nannophya pygmaea Rambur, 1842, plus a provisionally identified Ceriagrion indochinense Asahina, 1976. The country list now achieves 106 named species (not counting Prodasineura verticalis sensu Asahina, 1983, C. indochinense and Hemicordulia sp.). Coeliccia megumii Asahina, 1984 is synonymised with C. kazukoae Asahina, 1984. The differences between Ceriagrion olivaceum Laidlaw, 1914 and C. calamineum Lieftinck, 1951 are discussed

A short survey of Odonata in Stung Treng Province in northern Cambodia in midsummer 2016

Results are presented of an odonatological survey of 23 localities in Thala Barivat District of Stung Treng Province, northern Cambodia, on July 26 – August 1, 2016. Most localities were situated in areas of open low deciduous dipterocarp forests on gravel soils, some at hillside areas of tall evergreen dipterocarp forest. The great Mekong River right bank was studied within 7 km downstream of its Nimith (Nimet, Khon Thai, Labak Koun, Khone Pha Pheng) Waterfall. In total, 55 species were found, of which 52 identified to species and three to genus. Two species, Gynacantha saltatrix Martin, 1909 and Macrogomphus matsukii Asahina, 1986, were recorded in Cambodia for the first time. Five obligatory lotic species were found at the Mekong River, namely Dysphaea gloriosa, Prodasineura coerulescens, Burmagomphus asahinai, Nychogomphus duaricus and Onychothemis testacea, including tenerals of P. coerulescens and B. asahinai. Most probably these species breed in the Mekong reach which is enriched with oxygen downstream of the great waterfall cascade

New synonyms and a new subspecies of Macrogomphus Selys, 1858 (Odonata: Gomphidae) from continental south-east Asia

Kosterin, Oleg E. (2019): New synonyms and a new subspecies of Macrogomphus Selys, 1858 (Odonata: Gomphidae) from continental south-east Asia. Zootaxa 4615 (1): 57-90, DOI: https://doi.org/10.11646/zootaxa.4615.1.

Prodasineura hoffmanni Kosterin, 2015, sp. nov.

<i>Prodasineura hoffmanni</i> sp. nov. <p>(Figs. 1–2, 3 a,c, 4)</p> <p> <b>Type material. Holotype:</b> ♂ (Fig. 2 a–b,d–h), Cambodia, Mondulkiri Province, 4.2 km SE of Dak Dam village, ‘Seducta brook’ [conventional nickname], 12°23'10–18'' N 107°19' 22–30'' E, 877–878 m asl, 14 vi 2014, O. Kosterin leg., deposited in RMNH. <b>Paratypes:</b> 4♂ (Fig. 2 c,i), 1♀ (Fig.4), data as for the holotype, deposited in BMNH, RMNH, ZMUM and the author’s collection; 1♂ (Fig. 2 j), Cambodia, Mondulkiri Province, Cambodia, Mondulkiri Province, Dak Dam village environs, a rivulet bank, 12°25' N 107°19' E, ~ 780 m asl, 16. VI. 2014, O. Kosterin, in RMNH.</p> <p> <b>Additional datum.</b> A photo of ♀ (Fig. 1 c), the data as for the last paratype.</p> <p> <b>Etymology.</b> The species is named after Joachim Hoffmann as recognition of his activities to promote International Dragonfly Fund; the specific epithet is a noun of the masculine gender in the genitive case.</p> <p> <b>Holotype male.</b> <i>Head</i> (Fig. 2 d): mostly black. Labium blackish but base of mentum and sides of movable hooks yellowish. Genae blue and postclypeus lower parts broadly blue. Vertex with a broad transverse azure blue band with very irregular margins, continuous but nearly interrupted at middle and behind antenna bases. Apex of 1st antennal segment yellowish, that of 2nd brown. Occiput with a straight transverse ridge behind ocelli (Fig. 2 d). Eyes in life with a brownish black upper half and azure blue lower half (Fig. 1 a); <i>post mortem</i> brown (Fig. 2 a,d).</p> <p> <i>Thorax:</i> Prothorax black with a large azure-blue spot on either side of median lobe occupying also lateral corners of anterior lobe; posterior lobe entirely black (Fig. 1 a, 2d). Synthorax (Figs. 1 a–b, 2a,h) black with the following azure-blue pattern ventrally lightening to bluish-white:</p> <p>– mesepisternum with about 40% as narrow antehumeral stripe, narrowing apically but ending bluntly about 0.014 mm before antealar ridge;</p> <p>– metepisternum with a broad stripe occupying most of its breadth, embracing spiracle at its lower margin and having a shallow incision at upper 1/3 of its anterior margin;</p> <p>– metepimeron lower half bluish (but lower margin and posterior corners black); – oval azure-blue spots on sclerites in front of base of each wing and between hindwings; – poststernum whitish at middle, blackish at side.</p> <p> <i>Post mortem</i> antehumeral stripes turn violet while ventral parts of light markings turn yellowish. Legs black but protrochanters, trochanters and bases of femora ventrally yellowish white and each tibia with a yellow stripe along posterior side (Fig. 2 a).</p> <p>Wings hyaline; venation black. Anal bridge present, slightly longer than distance from its distal end to 1st crossvein on forewing, slighly shorter on hindwing. Postnodals 16 (left)–17 (right) on fore wings, 14 (right)–15 (left) on hindwings. Pterostigmata black with faint yellowish rims.</p> <p> <i>Abdomen</i> (Figs. 1 a–b, 2a–b,e–i, 3a): Black with the following light pattern:</p> <p>– S1 with a narrow triangular, with rounded corners, blue spot at posterior margin and a bluish white spot along lower margins (Fig. 2 a);</p> <p>– S2 with a narrow blue dorsal streak and a broad bluish white stripe along lower margins (Fig. 2 a);</p> <p>– S3–7 with a dorsally interrupted semirings along anterior margin (Figs. 1 a–b, 2b); – S3–6 with a pair of small yellowish spot at lower margins at about ¾ of segment length (Fig. 2 b); – S7–8 with yellowish posterolateral corners (Fig. 2 b);</p> <p>– S9 with a very small elongate dorsal blue spot at about ¾ of its length (Fig. 2 f);</p> <p>– S10 dorsal half azure blue, its borders making pointed projections ventrally (Figs. 1 a, 2g –j);</p> <p>Cerci azure blue dorsally, black apically, tips yellowish (Fig. 2 g–j). Paraprocts outer surface black, inner surface brownish (Fig. 2 e–g). Cercus with a very robust blunt ventral tooth, normally not well seen behind paraproct; in lateral view, cercus ventroposterior margin between this tooth and apex only slightly concave, almost straight (Fig. 2 h–j, 3a). In dorsal view, cerci evenly broad in basal half, then processed and very slightly diverging (Fig. 2 g). Paraproct outer margin in lateral view almost parallel to that of S10, in lower part processed and broadened almost as a short club (Fig. 2 g–i, 3a) where paraproct ventral margin wraps inwardly (Fig. 2 e).</p> <p> <i>Measurements (mm).</i> Abdomen without anal appendages 32; hindwing 21; forewing 21; total length 38.</p> <p> <b>Variation in male paratypes.</b> Little. Antenodals 14–17 on fore wing, 13–14 on hindwing. In the paratype from Dak Dam, the transversal stripe on the vertex is completely thrice interrupted with black. The wing membrane is slightly enfumed with brownish in all paratypes but to different extent. Ranges of measurements (mm): abdomen without anal appendages 29–32; hindwing 19–21; total length 35–38.</p> <p> <b>Female.</b> <i>Head</i> (Fig. 4 i–k): Mentum dull-greyish with indistinct dark pattern consisting of triangular central spot, a pair of lateral spots, and an elongate basal streak. Movable hooks brown at bases, black at tips (Fig. 4 k). Labrum yellow with a black central spot and brownish black anterior margin. Mandible bases, genae and lower part of postclypeus yellowish blue so that face is of that colour up to the level of anteclypeus upper margin, but ventrolateral corners of postclypeus black (Fig. 4 j). Rest of head black but vertex with a bluish white transverse stripe as in male but narrowly interrupted in front of central ocellus (Fig. 4 i). Apical parts of antennal segments brown. Eyes in life with a black upper half, interrupted by a narrow greenish horizontal streak (Fig. 1 c), and bluish lower half; <i>post mortem</i> brown (Fig. 4 i–k).</p> <p> <i>Thorax:</i> Prothorax black with a large bluish spot on either side of median lobe extending to lateral corners of anterior lobe; anterolateral margins of the latter with additional yellowish lightening; lateral corners of posterior lobe bluish (Fig. 4 c,e). Posterior lobe with a pair of raised bluntly pointed anterior processes in frontal view resembling dog’s ears, in lateral view smoothly curving anteriorly (Fig. 4 e). Posterior processes broad, rounded, skewed at ca 30–40º to horizontal space, directed behind and converging towards each other, with their axes forming an angle of ca 80º (Fig. 3 c, 4c). Space between posterior processes narrower than their own width, space between anterior processes broader, so that posterior ones disposed almost between them (Fig. 3 c, 4c). Space behind posterior processes yellowish. Synthorax black with a bluish white (becoming yellowish near ventrum) pattern as in male but antehumeral stripes narrow, about 20% as narrow as mesepisternum (Fig. 4 a–b).</p> <p>Legs bicolored: anterior side of coxae, protrochanters, trochanters, base and ventral side (except for distal 1/3) of all femora and dorsal side of all tibiae yellowish white, the rest of legs black (Fig. 4 a).</p> <p>Wings hyaline; venation black, pterostigmata brownish. Postnodals: 16 (left)–17 (right) on forewings; 15 on hindwings.</p> <p> <i>Abdomen</i> (Fig. 4 a, f–h): Black with the following pattern:</p> <p>– S1 patterned as in male but with yellowish (Fig. 4 a);</p> <p>– S2–4 with a very faint bluish dorsal streak (Fig. 1 c);</p> <p>– S2–4 with broad yellowish stripes along lower segment margins (except for their distal parts), obscured (especially on S4) by diffuse melanisation spreading from the very margins (Fig. 4 a).</p> <p>– S8–9 with distinct whitish stripes along ventral margins (Fig. 4 f–g);</p> <p>– S3–6 with a pair of elongate white spots at anterior margin (Fig. 1 b–c);</p> <p>– S6–9 with greyish lightening at posterior margins;</p> <p>– S8 with a whitish dorsal streak and S9 with a spoon-shaped whitish dorsal spot (Fig. 1 c,4h);</p> <p>– S10 whitish at dorsum and along posterior margins, borders of whitish slanting towards lateroposterior corners (Fig. 1 c,4f–h);</p> <p>– cerci whitish above but tips black; paraprocts black (Fig. 4 f–h);</p> <p>– ovipositor black but distal ends of sclerites brownish (Fig. 4 g).</p> <p> <i>Measurements (mm).</i> Abdomen without anal appendages 32; hindwing 21; forewing 22; total length 37.</p> <p> <b>Short diagnosis.</b> A <i>Prodasineura</i> with blue markings in males and whitish markings in females; head with a broad irregular, nearly thrice-interrupted blue/bluish stripe; males with antehumeral stripes about twice as narrow as mesepisternum, in females narrower; in males, blue pattern at end of abdomen confined to a tiny oval spot on S9, dorsum of S10 and cerci; in females, whitish pattern of abdomen confined to dorsal spots on S8 and S9 and dorsum of S10 and cerci; male cercus with a ventral tooth at submedian position, paraproct slightly club-like, expanded ventrocaudally in lateral view; in females, posterior prothorax processes converging.</p> <p> <b>Differential diagnosis.</b> Males of <i>P. hoffmanni</i> differ well from most other blue-patterned Asian species of <i>Prodasineura</i> by the blue colour at the tip of the abdomen almost confined to S10 and appendages (the dorsal side of both entirely), with a tiny oval blue spot on the dorsum of S9. In <i>P. doisuthepensis,</i> the abdominal pattern is similar, but the spot on S9 is much larger, occupying 1/3–1/4 of the segment length. In <i>P. coerulescens, P. fujianensis, P. theebawi</i>, <i>P. y ul an</i> Dow et Ngiam, 2013, and also <i>Elattoneura campioni</i> Fraser, 1922, the blue colour is present on S8–10; in <i>Prodasineura abbreviata</i> Lieftinck, 1951, <i>P. integra</i> (Selys, 1882), <i>P. interruptra, P. hangzhongensis, P. laidlawi</i> and <i>P. quadristigma</i> Lieftinck, 1951, it broadly occupies S9–10; in <i>P. collaris,</i> <i>P. lansbergei</i> (Selys, 1886) and <i>P. si ta</i> it is confined to the appendages only and is absent at the end of abdomen in <i>P. notostigma</i>.</p> <p> The shape of appendages provides important characters: the cercus with one broad and blunt ventral tooth disposed submedially, the paraprocts with inflated and wrapped inwardly apices. This shape resembles <i>P. doisuthepensis</i>, in which the cerci are more pointed and look narrower in ventral view as the inflation with the tooth is oriented more inside (Fig. 3 b), while in <i>P. hoffmanni</i> more downward (Fig. 2 g–i,3a). Also, in <i>P. hoffmanni</i> the paraprocts are somewhat less attenuated apically (Fig. 3 a) than in <i>P. doisuthepensis</i> (Fig. 3 b). The pattern of the end of abdomen is also similar, differing in the S9 blue spot much smaller in <i>P. hoffmanni.</i> In addition, in the Cambodian males of <i>P. doisuthepensis</i> the paraproct apices are yellow, although black, as in <i>P. hoffmanni</i>, at the type locality (Hoess 2007). However, an almost half as wide antehumeral stripe is the striking difference of <i>P. hoffmanni</i> from <i>P. doisuthepensis</i> (which was found about 14 km NW from the type locality of the former, at Sen Monorom).</p> <p> These moderately broad and pointed posteriorly antehumeral blue stripes are less broad and at the same time less gradually tapering to their tips than in <i>P. c o l l ar i s</i> and <i>P. notostigma</i>. <i>P. notostigma</i> has the top the head entirely black, while <i>P. collaris</i> has a blue posterior lobe of the prothorax and a blue labrum, genae and mandible bases, which are black in the new species.</p> <p> Females are not described for many of the above-mentioned species, so truly diagnostic features of the new species in this sex cannot be provided at present. The following characters of the new species female can be mentioned: very uneven, broad but almost thrice-interrupted transverse blue stripe on the vertex; a yellow labrum with a black central spot and black anterior margin; black anteclypeus; S10 with whitish dorsum and distal margin, S8 and S9 with whitish dorsal strokes. The shape of the processes of the prothorax posterior lobe is characteristic: anterior processes are triangular and anteriorly curved, and posterior processes are broadly rounded, directed backward and converging (Fig 3 c,4c). In <i>P. doisuthepensis</i> (see below and Fig. 3 d, 6g –f), the posterior processes are set more widely apart from each other and do not converge. In <i>P. coerulescens</i>, the posterior processes are set far more widely apart from each other, while the anterior processes are narrow and pointed (Asahina, 1984).</p> <p> <b>Remarks.</b> The new species surely belongs to a group of species (certainly not monophyletic) with blue-banded males (Lieftinck 1951) presently attributed to <i>Prodasineura</i>. Most of them differ from each other by some constant features of the blue pattern on the head, thorax and end of abdomen, in spite of some variation (but some species are still known by single specimens only). This group is represented in continental Asia by the following species: <i>P. doisuthepensis, P. coerulescens, P. collaris, P. interrupta, P. laidlawi</i> and <i>P. n ot os t i g m a</i>. <i>Elattoneura campioni</i>, although having a complete anal bridge which was a reason of its current placing in <i>Elattoneura</i>, is most probably related to this group as well, as <i>Elattoneura</i> and <i>Prodasineura</i> in their current state are rather artificial genera demanding revision (Dijkstra <i>et al.</i> 2014). The purely island representatives of this group are <i>P. abbreviata</i>, <i>P. lansbergei</i>, <i>P. quadristigma</i> Lieftinck, 1951, and <i>P. y ul an</i> from Borneo (Lieftinck 1951; Dow & Ngiam 2013), <i>P. integra</i> from the Philippines (Hoess 2007). In <i>P. s i t a</i> from Ceylon, the pattern strongly darkens in mature males (Fraser 1933; Bedjanič <i>et al.</i> 2014). <i>P. theebawi</i>, <i>P. hanzhongensis</i> and <i>P. fujianensis</i> seem to be less closely related to the aforementioned species but related to each other (e.g. all have chrome-yellow colour extensively present on the anal appendages), their light pattern colour varying from blue to yellow.</p> <p> <b>Habitat.</b> The type locality (Fig. 5) is a small, shallow, shady brook with dark bottom and smooth moderate current, difficult to follow because it is crossed by many (each ca 20 m) fallen trees of different age; there are sparse <i>Cyathea</i> sp. tree ferns among understorey at banks. It is situated at 877–878 m asl in a deep and narrow forested dell in a primary forest patch ca 4.3 x 2.5 km in size occupying a valley in a grassy savannah plateau; some of plots of this patch are being currently logged.</p> <p> In this habitat, the new species co-occurred with the second species of the same genus, <i>Prodasineura verticalis</i> sensu Asahina, 1983, nec Selys, 1860 (see Asahina 1983; Hämäläinen & Pinratana 1999), the males of which have an orange pattern. Larger streams and rivers in the same province revealed two other species of <i>Prodasineura, P. autumnalis</i> and <i>P. doisuthepensis</i>.</p> <p> <b>Distribution.</b> So far <i>P. hoffmanni</i> is known only from two very close localities in Mondulkiri Province of Cambodia (at highest elevations within it), which is just 6.2 km NNE from the border of Vietnam (Lâm Đồng Province). The range of the species is expected to occupy the Central Plateau of the Annamese Mountains in E Cambodia and S Vietnam. Probably the species is also present in Laos (see below).</p>Published as part of <i>Kosterin, Oleg E., 2015, Prodasineura hoffmanni sp. nov. (Odonata, Platycnemididae, Disparoneurinae) from eastern Cambodia, pp. 565-577 in Zootaxa 4027 (4)</i> on pages 566-573, DOI: 10.11646/zootaxa.4027.4.6, <a href="http://zenodo.org/record/244060">http://zenodo.org/record/244060</a&gt

Ischnura foylei sp. nov. (Odonata, Coenagrionidae) from the highlands of Sumatra

Kosterin, Oleg E. (2015): Ischnura foylei sp. nov. (Odonata, Coenagrionidae) from the highlands of Sumatra. Zootaxa 4032 (2): 179-189, DOI: http://dx.doi.org/10.11646/zootaxa.4032.2.

Odonata briefly observed on the islands of Bali and Lombok, Lesser Sundas, Indonesia, in the late February 2014

In the second half of February 2014, Odonata were searched for nine days on Bali andfour days on Lombok, the western Lesser Sundas, Indonesia. One species, Orthetrum chrysishas been for the first time recorded for Bali and six species, Nosostictaemphyla, Idionyx murcia, Brachydiplax chalybea, Agrionoptera insignis, Neurothemisramburii, Rhyothemis phyllishave been for the first time recorded for Lombok. The previous lit-erature concerning the two islands is analysed. To the moment, 55 Odonata species (3 unidentified) are known for Bali and 39 for Lombok, although the actual faunas of both islands are supposed to be equally rich, and further studies on Lombok are necessary. Odonata faunas of Bali and Lombok mirror each other in respect of high shares,29 and 23%, of Odonata species ranging to the west and east of the two islands, respectively. Efficiency of Lombok Strait as a biogeographical boundary was estimated as high as 0.6, so Wallace Line is of importance for Odonata. Some diagnostic characters of N. emphyla, N. ramburii, R. phyllis phyllisand Procordulia sambawanaand a taxo-nomical situation around Prodasineura autumnalisand P. humeralis, which is not justified biogeographically, are discussed. Short notes on habitats and assemblages of Odonata are added

Macrogomphus phalantus Lieftinck 1935

Macrogomphus phalantus Lieftinck, 1935 Figs. 12–16 Macrogomphus phalantus, sp. n. — Lieftinck (1935): 201–203, figs 10–12: original description: 2 ♂, 1 ♀, W. Borneo, Singka- wang, swamped forest near Bakoean, low country, 20 vii 1932 (1 ♂) and 15 ix 1932 (1 ♂, 1 ♀), drawings of synthorax, secondary genitalia and anal appendages. Macrogomphus phalantus Lieftinck—Lieftinck (1954): 87: report for the eastern Sumatra, Palembang. Macrogomphus phalantus Lieftinck, 1935 — Dow (2016): 8–9, fig. 3: report for Borneo, Sarawak, Samusan Wildlife Sanctuary, Sungai Samusan, 1 ♀, 18 viii 2015; a habitus photo. Excluded reports: Asahina (1986) as erroneous (see above); Kemp & Kemp (1989), Norma-Rashid et al. (2001) and Norma- Rashid (2009) as doubtful (Dow 2016). Remarks. Macrogomphus phalantus was described, in detail, on the basis of two males and a female from W. Borneo, Singkawang, swamped forest near “Bakoean” (Bakuan, Kalimantan Barat Province of Indonesia), as “closely resembling M. parallelogramma albardae Selys but much smaller and with differently shaped anal appendages’ (Lieftinck 1935: 201). In the diagnosis, such details as “shorter discoidal triangle of the front wing,... narrower and almost parallel-sided yellow bands on each side of the thorax, and... more widely separated and more obliquely placed antehumeral thoracic stripes” were mentioned (Lieftinck 1935: 203). The female was stated to differ from other species by a bifid median prominence on the occipital plate (which was not figured). Lieftinck abstained from verbal description and comparison of the male anal appendages of M. phalantus but made a confusing statement: “The shape of the inner branch of the sup. anal apps. of the male rather suggests M. borikhanensis Fraser, from the Laos country...” (Lieftinck 1935: 203). The (incorrect) drawing of the appendages of M. borikhanensis by Fraser (1933: fig. 6a, c; see Fig. 3c, 8d here) hardly resembles their structure in M. phalantus. In fact, M. phalantus exhibits an unique distinct diagnostic character: in dorsal view, the proximal inner swelling of the cercus is very sharp and prominent, and shifted distally off the cercus cleft into its two branches, as indicated with an asterisk in Fig. 15h (after Lieftinck 1935: fig. 12). As a consequence, two more distal swellings are ‘compressed’ to locate closely to each other (Fig. 15h). In all illustrations and specimens of M. albardae known to the author (Figs. 2b,e–f, 3a–h, 4c, 7a,c, 9a, 11), the proximal inner swelling (indicated by an asterisk in Fig. 1l and 3b) is smoother and invariably located at the level of the cleft, more proximal swellings also being smoother. The importance of this character could be disputable if I had not collect a series of Macrogomphus males with exactly the same cerci as far from the presumed range of M. phalantus as in Cambodia, but in a similar habitat (see below). Later the species was reported for Palembang in eastern Sumatra (Lieftinck 1954). All so scanty reports of this species refer to a habitat unusual for gomphids: swamped forest in low country (Lieftinck 1935; 1955), a river upstream the Nypa stand and mangroves in lowland rainforest (Dow 2016). The ‘snorkel’ of the elongated terminal abdominal segments of the Macrogomphus larvae suggest ability to live in silt low of oxygen, nevertheless other Macrogomphus spp. are usually found near running water at foothills and mountains. While studying Odonata of the great Lake Tonlé Sap in Cambodia I was struck to find numerous Macrogomphus sp. at a temporarily inundated forest margin on its northern bank (at the low water season). The male anal appendages appeared to correspond to M. phalantus and the unusual habitat was exactly as in that species. Certain differences of the collected specimens from the original description by Lieftinck (1935), as well as the huge distance of the newly found population from the presumed range of M. phalantu s in Borneo and Sumatra, suggested a new subspecies which is described below.Published as part of Kosterin, Oleg E., 2019, New synonyms and a new subspecies of Macrogomphus Selys, 1858 (Odonata: Gomphidae) from continental south-east Asia, pp. 57-90 in Zootaxa 4615 (1) on pages 78-79, DOI: 10.11646/zootaxa.4615.1.3, http://zenodo.org/record/399532