taxonID	type	description	language	source
B71D87B4184FFFFEFF5AFB90FEA7279F.taxon	description	(Figs 6, 7)	en	Dow, Rory A., Gesriantuti, N., Lupiyaningdyah, P. (2025): A new species of Amphicnemis Selys, 1863 from Sumatra, Indonesia and first records of two other species of Amphicnemis for the island (Odonata: Zygoptera: Coenagrionidae). Zootaxa 5659 (2): 273-282, DOI: 10.11646/zootaxa.5659.2.8, URL: https://doi.org/10.11646/zootaxa.5659.2.8
B71D87B4184FFFFEFF5AFB90FEA7279F.taxon	materials_examined	Sumatran material examined. All from Kampar Peninsula, Pelalawan, Riau, Sumatra, Indonesia (arranged by location approximately from west to east), all sites in the range ca. 5 – 9 m a. s. l.: 1 ♂, 2 ♀♀ (RER 23 _ COE 180 – 182), PSF around Tasik Anggrek, Pelalawan Estate, 0.5027 N, 102.1893 E, 2 vi 2023, leg. R. A. Dow; 1 ♂, 4 ♀♀ (RER 23 _ COE 187 – 191), flooded PSF in Sungai Turip Riparian Buffer, 0.2921 N, 102.6327 E, 11 vi 2023, leg. R. A. Dow; 6 ♂♂, 2 ♀♀ (RER 23 _ COE 16 – 22, 147), pools in PSF, Meranti Estate Block B Transect, 0.3363 N, 102.6440 E, 7 ii 2023, leg. R. A. Dow; 3 ♂♂, 1 ♀ (RER 23 _ COE 183 – 186), same location, 8 vi 2023, leg. R. A. Dow; 5 ♂♂, 2 ♀♀ (RER 20 _ COE 22 – 28), PSF (flooded by Sungai Serkap) behind fishermen’s huts downstream from ranger post, Sungai Serkap, 0.3613 N, 102.7122 E, 18 i 2020, leg. R. A. Dow; 7 ♂♂, 4 ♀♀ (RER 20 _ COE 29 – 39), same location, 22 i 2020, leg. R. A. Dow; 1 ♂, 1 ♀ (RER 20 _ COE 40 – 41), PSF (flooded by Sungai Serkap) between ranger post and Tasik Limau on Sungai Serkap, 0.3815 N, 102.7154 E, 26 i 2020, leg. R. A. Dow; 1 ♀ (RER 23 _ COE 290), flooded PSF beside Simpang Sianyir (tributary of Sungai Serkap) at 0.5137 N, 102.5508, 1 x 2023, leg. R. A. Dow; 1 ♂ (RER 23 _ COE 33), main trail in PSF from GHGFM tower, 0.3952 N, 102.7646 E, 13 ii 2023, leg. R. A. Dow; 1 ♂ (RER 23 _ COE 34), shorter trail in PSF from GHGFM tower, 0.4006 N, 102.7584 E, 7 ii 2023, leg. RER staff; 8 ♂♂, 5 ♀♀ (RER 23 _ COE 23 – 32, 45 – 46, 148), transect in PSF behind Sangar Pos (Sangar Ranger Post), Sungai Sangar, 0.3952 N, 102.8421 E, 9 ii 2023, leg. R. A. Dow; 2 ♂♂ (RER 23 _ COE 192 – 193), same location, 17 vi 2023, leg. R. A. Dow.	en	Dow, Rory A., Gesriantuti, N., Lupiyaningdyah, P. (2025): A new species of Amphicnemis Selys, 1863 from Sumatra, Indonesia and first records of two other species of Amphicnemis for the island (Odonata: Zygoptera: Coenagrionidae). Zootaxa 5659 (2): 273-282, DOI: 10.11646/zootaxa.5659.2.8, URL: https://doi.org/10.11646/zootaxa.5659.2.8
B71D87B4184FFFFEFF5AFB90FEA7279F.taxon	description	Descriptive remarks. The Sumatran series agrees with the type series of A. bebar in details of, and variation in, colouration and markings. There is however rather extensive variation in the upper branch of the cercus seen laterally, with most individuals having the downturned apical part longer than in the holotype of A. bebar (see Fig. 18 in Dow et al. (2010) and Fig. 6 here), in some cases very much longer; this, together with differences in the female prothorax (see below) initially led the first author to believe that the Sumatran specimens were a separate species. However further investigation revealed a deficiency in the original description of A. bebar – there is actually variation in the cercus in the type series of A. bebar, with at least one paratype having the downturned apical part of the cercus longer than in the holotype (Fig. 7) – the condition in the series from the Kampar Peninsula overlaps with that in the type series (similar variation occurs in the Singapore population of A. bebar), so that they must be considered to belong to the same species. Nevertheless, the variation in the cerci of A. bebar is remarkable. The posterior pronotal lobe of female A. bebar from the Kampar Peninsula is shallower than in the type series, sometimes not completely covering the mesostigmal area of the synthorax in lateral view, unlike the type series where this area is completely covered. There is variation in length in the central horn of the posterior pronotal lobe (as mentioned for the type series) and this horn is sometimes curved forward to some degree. The lateral pale spot on abdominal S 9 is highly variable in size. Measurements (mm). Males: abdomen plus anal appendages 33 – 36.5, Hw 18 – 19. Females: abdomen plus anal appendages and ovipositor 34 – 36.5, Hw 20.5 – 22.	en	Dow, Rory A., Gesriantuti, N., Lupiyaningdyah, P. (2025): A new species of Amphicnemis Selys, 1863 from Sumatra, Indonesia and first records of two other species of Amphicnemis for the island (Odonata: Zygoptera: Coenagrionidae). Zootaxa 5659 (2): 273-282, DOI: 10.11646/zootaxa.5659.2.8, URL: https://doi.org/10.11646/zootaxa.5659.2.8
B71D87B4184FFFFEFF5AFB90FEA7279F.taxon	discussion	Other Remarks. Amphicnemis bebar was found during all surveys conducted in the Kampar Peninsula and was found at more individual sites than either of the other two Amphicnemis species occurring in the peninsula. During the dry conditions of January 2020 the species was only found in PSF flooded by Sungai Serkap but during February / March 2023 and June 2023 it was found at PSF sites that are not typically flooded when water levels in the rivers are high so that surface water is only present during parts of the year with high rainfall. In October 2023 (dry conditions) only a single female was found, in flooded forest around a tributary of Sungai Serkap. It appears likely that A. bebar occurs all year round at sites which are regularly flooded but only during rainy seasons at other sites within the PSF.	en	Dow, Rory A., Gesriantuti, N., Lupiyaningdyah, P. (2025): A new species of Amphicnemis Selys, 1863 from Sumatra, Indonesia and first records of two other species of Amphicnemis for the island (Odonata: Zygoptera: Coenagrionidae). Zootaxa 5659 (2): 273-282, DOI: 10.11646/zootaxa.5659.2.8, URL: https://doi.org/10.11646/zootaxa.5659.2.8
B71D87B4184EFFF9FF5AFA3BFC1D279F.taxon	materials_examined	Sumatran material examined. All from Kampar Peninsula, Pelalawan, Riau, Sumatra, Indonesia, all sites in the range ca. 5 – 9 m a. s. l.: 1 ♂ (RER 23 _ COE 35), flooded PSF beside Simpang Sianyir (tributary of Sungai Serkap) at 0.5035 N, 102.5773 E, 16 ii 2023, leg. R. A. Dow; 1 ♀ (RER 23 _ COE 289), flooded PSF beside Simpang Sianyir (tributary of Sungai Serkap) at 0.5137 N, 102.5508 E, 1 x 2023, leg. R. A. Dow; 1 ♂ (RER 20 _ COE 43), 1 ♀ (RER 20 _ COE 44), PSF (flooded by Sungai Serkap) behind fishermen’s huts downstream from ranger post, Sungai Serkap, 0.3613 N, 102.7122 E, 18 i 2020, leg. R. A. Dow; 9 ♂♂ (RER 20 _ COE 45 – 53), 2 ♀♀ (RER 20 _ COE 54 – 55), same location, 22 i 2020, leg. R. A. Dow; 8 ♂♂ (RER 20 _ COE 56 – 63), 4 ♀♀ (RER 20 _ COE 64 – 67), PSF (flooded by Sungai Serkap) between ranger post and Tasik Limau on Sungai Serkap, 0.3815 N, 102.7154 E, 26 i 2020, leg. R. A. Dow; 1 ♀ (RER 20 _ COE 42), PSF on trail from Eco Camp to Sungai Serkap, 16 i 2020, leg. R. A. Dow.	en	Dow, Rory A., Gesriantuti, N., Lupiyaningdyah, P. (2025): A new species of Amphicnemis Selys, 1863 from Sumatra, Indonesia and first records of two other species of Amphicnemis for the island (Odonata: Zygoptera: Coenagrionidae). Zootaxa 5659 (2): 273-282, DOI: 10.11646/zootaxa.5659.2.8, URL: https://doi.org/10.11646/zootaxa.5659.2.8
B71D87B4184EFFF9FF5AFA3BFC1D279F.taxon	description	Descriptive remarks. The series from the Kampar Peninsular is true to the type series of A. hoisen in most respects, but there are some structural differences in the male: the posterior spines of the genital valves are not quite as long as those of the type series, although they are still remarkably long and overlap the sternite of S 10 to a variable extent. The downturned apical part of the upper branch of the cercus, seen laterally, appears slightly shorter than in the type series on average. All but one of the female specimens are immature, with a largely red thorax and legs, or semi-immature, retaining a reddish cast in the same areas. The females differ from the paratype described by Dow et al. (2010) in that almost the entire posterior pronotal lobe is black, with only a narrow area at the free margin and the lateral extremities paler, and also in that the sides of abdominal S 9 are entirely pale, this extending dorsally apically. The Sumatran individuals are slightly larger on average than those from the type series. Measurements (mm) of the most mature specimens. Males: abdomen plus anal appendages 32.5 – 35.5, Hw 20 – 21.5. Females: abdomen plus anal appendages and ovipositor 32 – 33, Hw 20 – 21.5.	en	Dow, Rory A., Gesriantuti, N., Lupiyaningdyah, P. (2025): A new species of Amphicnemis Selys, 1863 from Sumatra, Indonesia and first records of two other species of Amphicnemis for the island (Odonata: Zygoptera: Coenagrionidae). Zootaxa 5659 (2): 273-282, DOI: 10.11646/zootaxa.5659.2.8, URL: https://doi.org/10.11646/zootaxa.5659.2.8
B71D87B4184EFFF9FF5AFA3BFC1D279F.taxon	discussion	Other remarks. During the surveys in the Kampar Peninsula A. hoisen has only been found in flooded or mostly flooded PSF adjacent to the Serkap River and its tributary Simpang Sianyir. It has not been found in PSF close to other rivers or remote from rivers even during the wettest periods when considerable amounts of surface water are present in the forest. This is in contrast to the habitat in which the type series of this species was collected at Sungai Bebar in Pahang, where it was found at discrete pools in PSF remote from any stream or river. At three of the five locations where it was found, A. hoisen appears to occur at relatively low densities but at the other two sites it was found to be relatively abundant during January 2020, actually during a protracted dry spell, but during a period of high water levels in Sungai Serkap due to tidal effects, so that the PSF was flooded around Sungai Serkap even though it was completely dry at sites remote from the river. The exact sites where the greatest numbers of individuals were found in January 2020 were not revisited during surveys at other times of year in 2023 due to time constraints, so it might be just as abundant at these sites in other periods.	en	Dow, Rory A., Gesriantuti, N., Lupiyaningdyah, P. (2025): A new species of Amphicnemis Selys, 1863 from Sumatra, Indonesia and first records of two other species of Amphicnemis for the island (Odonata: Zygoptera: Coenagrionidae). Zootaxa 5659 (2): 273-282, DOI: 10.11646/zootaxa.5659.2.8, URL: https://doi.org/10.11646/zootaxa.5659.2.8
B71D87B41849FFFAFF5AFCC9FC552113.taxon	description	(Figs 2, 3, 9, 11)	en	Dow, Rory A., Gesriantuti, N., Lupiyaningdyah, P. (2025): A new species of Amphicnemis Selys, 1863 from Sumatra, Indonesia and first records of two other species of Amphicnemis for the island (Odonata: Zygoptera: Coenagrionidae). Zootaxa 5659 (2): 273-282, DOI: 10.11646/zootaxa.5659.2.8, URL: https://doi.org/10.11646/zootaxa.5659.2.8
B71D87B41849FFFAFF5AFCC9FC552113.taxon	materials_examined	Holotype. 1 ♂ (RER 23 _ COE 36, MZB. Odon. 31432), pools in PSF, Meranti Estate Block B Transect, Kampar Peninsula, Pelalawan, Riau, Sumatra, Indonesia, 0.3363 N, 102.6440 E, ca. 5 – 9 m a. s. l. 7 ii 2023, leg. R. A. Dow, deposited in BRIN. Paratypes. All from Kampar Peninsula, Pelalawan, Riau, Sumatra, Indonesia, all sites in the range ca. 5 – 9 m a. s. l.: 2 ♂♂ (RER 23 _ COE 37 - 38), 1 ♀ (RER 23 _ COE 39), pools in PSF, Meranti Estate Block B Transect, 0.3363 N, 102.6440 E, 7 ii 2023, leg. R. A. Dow; 1 ♀ (RER 23 _ COE 194), same location, 8 vi 2023, leg. R. A. Dow; 1 ♂ (RER 20 _ COE 68), PSF (flooded by Sungai Serkap) behind fishermen’s huts downstream from ranger post, Sungai Serkap, 0.3613 N, 102.7122 E, 18 i 2020, leg. R. A. Dow; 6 ♂♂ (RER 23 _ COE 47 - 52), PSF (flooded) around Simpang Sianyir, tributary of Sungai Serkap, 0.5035 N, 102.5773 E, 16 ii 2023, leg. R. A. Dow; 1 ♂ (RER 23 _ COE 41), 1 ♀ (RER 23 _ COE 40), shorter trail in PSF from GHGFM tower, 0.4006 N, 102.7584 E, 8 ii 2023, leg. R. A. Dow; 1 ♂ (RER 23 _ COE 149), same location, 13 ii 2023, leg. R. A. Dow; 1 ♀ (RER 23 _ COE 195), same location, 13 vi 2023, leg. R. A. Dow; 3 ♂♂ (RER 23 _ COE 42 - 44), transect in PSF behind Sangar Pos (Sangar ranger post), Sungai Sangar, 0.3952 N, 102.8421 E, 9 ii 2023, leg. R. A. Dow.	en	Dow, Rory A., Gesriantuti, N., Lupiyaningdyah, P. (2025): A new species of Amphicnemis Selys, 1863 from Sumatra, Indonesia and first records of two other species of Amphicnemis for the island (Odonata: Zygoptera: Coenagrionidae). Zootaxa 5659 (2): 273-282, DOI: 10.11646/zootaxa.5659.2.8, URL: https://doi.org/10.11646/zootaxa.5659.2.8
B71D87B41849FFFAFF5AFCC9FC552113.taxon	etymology	Etymology. The species epithet, reri, is a noun in the genitive case, formed from the acronym of Restorasi Ekosistem Riau (RER), who manage the area in which the species was discovered.	en	Dow, Rory A., Gesriantuti, N., Lupiyaningdyah, P. (2025): A new species of Amphicnemis Selys, 1863 from Sumatra, Indonesia and first records of two other species of Amphicnemis for the island (Odonata: Zygoptera: Coenagrionidae). Zootaxa 5659 (2): 273-282, DOI: 10.11646/zootaxa.5659.2.8, URL: https://doi.org/10.11646/zootaxa.5659.2.8
B71D87B41849FFFAFF5AFCC9FC552113.taxon	description	Description of holotype. Head. Labium entirely pale. Labrum black, cream in lower ca. one quarter except at lateral extremes. Mandible base cream on right, on left with large central brownish mark. Genae cream, this extending beside compound eyes onto the underside of the head for a short distance and narrowly upwards towards the antennae bases. Horizontal surface of clypeus shining black, vertical surface black with small pale lateral marks and narrow central transverse stripe adjacent to labrum. Vertical face of frons shining black with complete, broad cream transverse stripe adjacent to clypeus. Rest of frons, vertex, occiput and underside of head very dark, metallic greenish black. Ocelli whitish. Antenna bases with broad yellowish stripe on anterior face, scape black, yellow at top, pedicel brown, dull yellow stripe running most of length of anterior and posterior faces, flagella brown. Thorax. Prothorax mostly dark metallic greenish black, indistinct pale areas laterally on rear part of anterior pronotal lobe, lower parts of propleuron cream with boundary between two colours irregular. Posterior pronotal lobe (Fig. 2) short, with rear lateral extremities produced as outward, downward and rearward directed, subtriangular projections, rounded at apices; centrally produced at rear into long horn, directed upwards and rearwards, this horn longer than the anterior and middle lobes of the pronotum combined, of almost even width after base. Synthorax: mesepisternum, most of mesepimeron, most of mesokatepisternum, small area of metepisternum adjacent to antealar carina (this continued slightly onto the metepimeron) and upper part of rest of metepisternum dark metallic green, remainder of synthorax cream. Legs (left anterior and middle legs absent below trochanter) cream except flexor surfaces of femur white, dark brown to black spines, small dark mark lowest part femur and immediately adjacent part of flexor surface of tibia, poorly defined dark rings between tarsal segments, tips of claws black; also narrow dark stripe on extensor surface of femur separated from trochanter, thin and faint at top, becoming broader and better defined lower down, continuing to joint with tibia. Remaining anterior tibia also with dark area on upper extensor surface. Metaposternum with clump of moderately long, fine setae conspicuous in lateral view. Wings: 12 (left) or 13 (right) Px in Fw, 11 in Hw. Arculus slightly distal to Ax 2. R 4 arising distal to subnodus in all wings, IR 3 joined to it by a short stalk. Pt almost trapezoidal with costal side shorter than anal side, covering ca. one underlying cell (slightly less in right FW); dark brown with well-defined whitish border, this widest on costal side, narrowest and faintest on subcostal side. Abdomen. S 1 cream laterally, dark and slightly metallic above, this dark colour extending diagonally rearwards laterally; band of setae, slightly shorter on average than those on metaposternum, on tergite on either side of sternite. S 2 metallic dark above, cream below and in narrow basal annulus interrupted dorsally, entirely dark behind posterior carina. S 3 – 6 largely dark brown above, cream lower laterally (e. g. immediately above sternite), with pale basal annulus interrupted dorsally (becoming fainter on successive segments) and dark laterally apically. S 7 similar but almost entirely brown laterally, basal annulus poorly defined. S 8 dark bronzy brown above, paler lower laterally. Tergite of S 9 almost entirely dark bronzy brown, sternite mostly pale, genital valves slightly pointed apically, apices just reaching apex of sternite. S 10 pale laterally with most of dorsum brown. Anal appendages (Figs 9, 11) whitish. Cerci in lateral view (Fig. 9) with upper branch narrow at base, directed gently upwards along lower margin, narrowing slightly to ca. two-thirds length where abruptly expanded on lower margin and turned down, somewhat hatchet like, expanded apical part subrectangular, gently rounded at end with slight ventral notch. Lower branch tapering from base, directed gently and very slightly down, slightly expanding along upper margin at apex with black dorsal interior tooth just before apex. In dorsal view (Fig. 11 is a sketch of this view) upper branch of cercus with well-defined, rearward and inward directed, sharply pointed interior projection before half-length, not visible in lateral view; expanded apical part appearing as broad rounded heal on inner margin, separated from a thumb-like apex by a broad notch. In ventral view lower branch tapering slightly from base, apex abrupt, almost square. Paraprocts short, pale with short, blunt projection directed to rear in dorsal part (lateral view). Penile organ. Examined in detail in the holotype and paratype RER 23 _ COE 149, of typical form for members of the Amphicnemis wallacii Selys, 1863 - group (Figs 4 – 5 show lateral views of the penile organ of two members of the wallacii - group from Borneo: A. annae Lieftinck, 1940 and A. wallacii respectively) with a broad terminal segment without lateral arms but with a robust central flagellum arising from the dorsal surface of the segment, directed back along the shaft, extending well beyond the rest of the terminal segment. The central flagellum is somewhat longer in A. reri and broad towards its apex, otherwise very similar to those shown in Figs 4 – 5. Measurements (mm). Abdomen with anal appendages ca. 36, cercus ca. 1, Hw 20. Female (based on RER 23 _ COE 40; supposition). Overall similar to male except in its non-metallic colouration and as noted below. Head. Lower ca. one-third of labrum pale. Large dark patches on mandible bases. A pair of faint pale marks on occipital ridge behind lateral ocelli. Thorax. Prothorax mostly dull bluish, anterior carina of anterior pronotal lobe black; posterior pronotal lobe (Fig. 3) relatively shallow (not covering the mesostigmal area) with rear lateral extremities slightly broader than in male; horn directed straight up after base, shorter than in male, ca. as long as middle lobe of pronotum. Postepimeral strip slightly, smoothly expanded centrally to rear of propleuron. Synthorax bluish, dorsum with a strong yellow cast, however this is an artefact of preservation, in life a slight greenish cast. Remainder bluish, this extending onto parts of anterior and middle coxae, venter cream. Legs with upper part of dark stripe on extensor surface of femur broader and better defined than in holotype male. Wings with 12 Px in Fw, 11 (left) or 12 (right) Px in Hw. Pt greyish brown, pale border narrower than in male and as narrow and faint on basal side as well as on subcostal side. Abdomen. S 8 more extensively pale laterally. S 9 blackish with poorly defined pale lateral mark in apical half. S 10 mostly whitish, brown ventrally. Cerci whitish, little shorter than S 10, an epiproct between them, just visible even in lateral view. Ovipositor largely pale, not extending further than tips of cerci except for brown and pale styles. Measurements (mm). Abdomen with anal appendages and ovipositor 35.5, Hw 21.5. Variation in paratypes. Males. There is considerable variation in the extent and shape of dark colour on the mandible bases, more extensive pale colour on the labrum and vertical face of the clypeus than in the holotype in some individuals and the pale colour on the genae is frequently more obviously extended narrowly upwards beside the compound eyes. The lateral projections of the posterior pronotal lobe are narrower and more finger-like in some paratypes and the central horn is sometimes curved forward in its upper part so that the apex is directed almost vertically. The extent of dark colouration on the metepisternum is variable. The border of the Pt is fainter and narrower in some individuals, in others it is more well defined and of almost even width on all sides. In less mature individuals the pale colour on thorax, legs and abdomen is strongly yellow, and the Pt is paler. Females. One female paratype is semi-immature with a reddish thorax and legs, also some reddish colour on abdominal S 1 and S 2 laterally. In general there is similar variation in the markings of the head to that seen in the male. The Pt has a broader pale margin than in the female described in two paratypes. The abdominal S 9 pale mark in apical half varies in size from the female described, as does the dark area on S 10 lower laterally. Measurements (mm). Males: 11 – 13 Px in Fw, 10 – 13 (13 in one wing of one individual only, 11 or 12 most common) in Hw, abdomen with anal appendages 34 – 36.5, Hw 19 – 19.5. Females: 12 – 13 Px in Fw, 11 in Hw, abdomen with anal appendages and ovipositor 35 – 36.5, Hw 20 – 21.5.	en	Dow, Rory A., Gesriantuti, N., Lupiyaningdyah, P. (2025): A new species of Amphicnemis Selys, 1863 from Sumatra, Indonesia and first records of two other species of Amphicnemis for the island (Odonata: Zygoptera: Coenagrionidae). Zootaxa 5659 (2): 273-282, DOI: 10.11646/zootaxa.5659.2.8, URL: https://doi.org/10.11646/zootaxa.5659.2.8
B71D87B41849FFFAFF5AFCC9FC552113.taxon	diagnosis	Diagnosis. The male of A. reri is easily separated from all known species of Amphicnemis except A. annae, A. madelenae Laidlaw, 1913, A. pandanicola Lieftinck, 1953 and A. triplex Dow, 2014 (all of which are known only from Borneo) by the long horn of the posterior pronotal lobe, clearly longer than the length of the dorsum of the middle pronotal lobe. Of the species with a very long posterior pronotal lobe horn in the male, A. madelenae and A. pandanicola belong to a different species-group and can easily be separated from A. reri by the completely yellow Hw pterostigma in these species (brown with whitish border in A. reri). Amphicnemis triplex has very different anal appendages, in particular the triple lobed apex of the lower branch of the cercus clearly differentiates it from A. reri. Amphicnemis annae has the most similar anal appendages to A. reri but (compare Figs 8 and 10 with Figs 9 and 11) differs in the form of the upper branch of the cercus – that of A. annae seen laterally expands almost evenly to apex, not appearing at all hatchet like, and has a prominent inward and upward directed interior projection, clearly visible in lateral view, the interior projection on the cercus of A. reri is directed inward but not upward and is not visible in lateral view. The male of A. reri can easily be distinguished from those of all other Amphicnemis species known to occur in Sumatra (and Peninsular Malaysia) by the long posterior pronotal lobe horn (Fig. 2) alone. The (supposed) female of A. reri is similar to those of both A. gracilis and A. bebar but differs in details of the posterior pronotal lobe – shallower than that of A. bebar (even taking the variation in that species noted above) and the slightly downward directed and produced corners of the free margin, different from the corners of the free margin in A. gracilis. The reader should compare Fig. 3 here with Fig. 3 (A. bebar) and Fig. 5 (A. gracilis) in Dow et al. (2010). Separation of female Amphicnemis is generally difficult and we doubt that any combination of characters completely and clearly separates the female of A. reri from that of all other species within the A. wallacii - group.	en	Dow, Rory A., Gesriantuti, N., Lupiyaningdyah, P. (2025): A new species of Amphicnemis Selys, 1863 from Sumatra, Indonesia and first records of two other species of Amphicnemis for the island (Odonata: Zygoptera: Coenagrionidae). Zootaxa 5659 (2): 273-282, DOI: 10.11646/zootaxa.5659.2.8, URL: https://doi.org/10.11646/zootaxa.5659.2.8
B71D87B41849FFFAFF5AFCC9FC552113.taxon	discussion	Remarks. Although none were taken in tandem, the female is associated with the male by reasonable supposition based on, admittedly small, differences from A. bebar females. All specimens of A. reri were collected in PSF, either in seasonally wet formations or in areas around the Serkap River which are flooded whenever the Serkap rises above its banks.	en	Dow, Rory A., Gesriantuti, N., Lupiyaningdyah, P. (2025): A new species of Amphicnemis Selys, 1863 from Sumatra, Indonesia and first records of two other species of Amphicnemis for the island (Odonata: Zygoptera: Coenagrionidae). Zootaxa 5659 (2): 273-282, DOI: 10.11646/zootaxa.5659.2.8, URL: https://doi.org/10.11646/zootaxa.5659.2.8
