ODONATA OF BUMDELING WILDLIFE SANCTUARY, TRASHI YANGTSE, EASTERN BHUTAN, WITH THE DESCRIPTION OF TWO NEW SPECIES Amit Mitra 1 & Phuntsho Thinley 2 1 Senior Lecturer, Department of Zoology, Sherubtse College, Kanglung & 2 Park manager, Bumdeling Wildlife Sanctuary, Trashi Yangtse INTRODUCTION Prasad and Varshney (1995) list 53 species of dragonflies from North Eastern India, 172 species from Nepal and 114 from Bangladesh, but Bhutan, one of the global hotspots of biological diversity has remained virtually unexplored. Only Lieftinck (1977) reported six species, collected by the Expedition of the natural history museum of Basel in 1972. These are Caliphaea confusa, Megalestes major, Lestes (Indolestes) cyaneus, Calicnemia mortoni, Davidius baronii and Cephalaeschna triadica. Tsuda (1991) in his distributional list of world odonata added Lestes concinnus, Aeshna petalura and Anax nigrolineatus to Lieftinck s (1977) list, but without localities. Mitra, (2002) found 23 species and subspecies in the district Trashigang, while Mitra (2006) added another four species viz., Orthetrum sabina, Acisoma p. panorpoides, Brachythemis contaminata and Neurothemis fulvia, increasing the list of Bhutan Dragonflies to 31. In the present study, 29 species and subspecies are recorded from the Bumdeling Wildlife Sanctuary, Eastern Bhutan. Nine species and subspecies are first records for Bhutan and two of them are new to science. PHYSIOGRAPY OF THE AREA Bumdeling Wildlife Sanctuary is located in Northeastern Bhutan between 30 o 24 30 o 28 N and 77 o 40-77 o 44 E (Map 1). It covers 1545 Km 2 with 420 Km 2 of buffer zone encompassing parts of the districts Trashi Yangtse, Lhuntse and Mongar. It borders with China (Tibetan province) in the North and India (Arunachal Pradesh) in the North East. The Sanctuary includes three ecosystems: a) warm and cool broadleaved forests, b) temperate conifer forest, and c) alpine scrub, scree and meadows. The Sanctuary is mostly mountainous with an altitude from 1500m (South) to 6000m (North). Three major rivers originate from its core zone viz., the Kulong Chhu, the Khoma Chhu and the Sheri Chhu. The climate ranges from hot in the south to extreme cold in the north. The monsoon prevails from May to September. Average annual rainfall is 1250mm to 2500mm.
LOCALITIES SURVEYED The localities surveyed are shown in Table 1. Table 1: survey areas with geographical position and date of survey District Place Spot Date GPS reading Altitude BSLK-1 2/9/2005 N: 2741113; E: 9113557 1360m Lhuntse Khoma BSLK-2 2/9/2005 N: 2739499; E: 911237 1182m BSLK-3 2/9/2005 N: 274047; E: 9113085 1260m Mongar Yadhi, BSMS-1 23/4/2005 N: 2719443; E: 9121521 931m Serizong BSMS-2 23/4/2005 N: 2719504; E: 9021466 882m BSMS-3 23/4/2005 N: 2719505; E: 9121477 906m BSMS-4 23/4/2005 N: 2720282; E: 9121322 938m BSMS-5 23/4/2005 N: 2720383; E: 9121335 953m BSMS-6 23/4/2005 N: 2720499; E: 9121298 1028m BSMS-7 23/4/2005 N: 2721049; E: 9121156 1057m BSMS-7 25/6/2005 N: 2721049; E: 9121156 1057m
Trashiyangtse BSMS-8 8/7/2005 N.A. 1560m BSMS-8 9/7/2005 N.A. 1560m BSMS-9 8/7/2005 N.A. 980m BSMS-9 9/7/2005 N.A. 980m BSMS-9 10/7/2005 N.A. 980m BSMS-9 26/6/2005 N.A. 980m BSTB-1 17/4/2005 N: 2736514; E: 9129254 1751m BSTB-1 18/4/2005 N: 2736514; E: 9129254 1751m BSTB-2 26/6/2005 N: 2736560; E: 9129265 1756m BSTB-3 26/6/2005 N: 2737287; E: 9129155 1787m BSTB-4 26/6/2005 N: 2737351; E: 9129241 1831m Bumdeling BSTB-5 26/6/2005 N: 2738176; E: 9128302 1845m BSTB-6 26/6/2005 N: 2738182; E: 9128316 1809m BSTB-7 26/6/2005 N: 2738353; E: 9127580 1922m BSTB-8 26/6/2005 N: 273853; E: 9127587 1817m BSTB-9 3/5/2005 N: 2887152; E: 1098194 1908m BSTB-10 3/4/2005 N: 2890520; E: 1094077 1754m Park Office BSTB-11 18/4/2005 N: 2736489; E: 9129436 1761m BSTB-11 31/5/2005 N: 2736489; E: 9129436 1761m Bumdeling BSTB-12 1/9/2005 N.A. N.A. Old Dzong BSTOD-1 25/6/2005 N: 2735047; E: 9129282 1719m BSTOD-2 25/6/2005 N: 273519; E: 912930 1692m Abbreviations: BSLK Bumdeling Wildlife Sanctuary Lhuntse Khoma; BSMS Bumdeling Wildlife Sanctuary Mongar Serizong; BSTB Bumdeling Wildlife Sanctuary Trashiyangtse Bumdeling; BSTOD Bumdeling Wildlife Sanctuary Trashiyangtse Old Dzong; N.A. Not Available. MODUS OPERANDI Weekly collection from the above localities was done from March to December 2005. The selection of localities was random, all over the park. GPS was been used to determine the position and altitude of the surveyed localities. A total of 132 specimens were collected. All dragonflies were photographed using a SLR camera with close-up attachment and a digital camera. For identification we used Fraser (1933-36) and Lieftinck (1977). All specimens including types were deposited at the Museum maintained by the Park head-office at Trashiyangtse. All measurements in mm; abdomen length does not include the anal appendages. DESCRIPTION OF SPECIES 1. Ceriagrion fallax cerinomelas Lieftinck Material: BSTB-1, 3, 18.IV.2005; BSMS-4, 1, 23.IV.2005; BSTB-2, 1, BSTB-5, 2, 26.VI.2005; BSMS-9, 1, 9.VII.2005. Male: Abdomen: 30 33mm; Hind Wing: 21 24mm. Female: Abdomen: 32 35mm; Hind Wing: 24 25mm.
Habitat: Slow running marshy streams, amidst nearby vegetation, agricultural fields and small channels. Remarks: Our specimens are a little longer, with longer hind-wings, than Fraser s. 2. Aciagrion olympicum aruni ssp. nov. Material: BSTB-2, 1 (Holotype), BSTB-7, 1, BSTB-8, 1, BSTOD-2, 1, 26.VI.2005; BSMS-9, 1, 8.VII.2005. Male (Holotype): Abdomen: 30.5mm; Hind Wing: 20mm. Head: Labium pale brown, labrum carneous, its base with small median black spot in continuation with blackish border. Clypeus, bases of mandibles, genae, and frons up to roots of antennae carneous, anteclypeus finely black at base, postclypeus broadly black along anterior border, vertex and occiput The holotype male black, the latter with large transversely oval bluish-green postocular spots bridged by narrow isthmus of blue across middle line; Eyes pale green, capped with brown. Thorax: Prothorax broadly black on dorsum, reddish-yellow laterally and across anterior lobe. Pterothorax black on dorsum, marked with rather pale blue antehumeral stripes. antehumeral stripes, margins of antealar sinus, and mid-dorsal carina lying in a narrow halo of ferruginous. Laterally pale blue changing to bluish-white below. Upper end of postero-lateral suture finely black. Legs creamy white, femora black on external surface, the two front pair of tibiae black on outer surface. Wings hyaline, discoidal cell with costal side much shorter than lower and with outer end acutely pointed. Arc situated at the level of the distal antenodal nervure, ab (anal bridge) arising from the hind border of wing at the point where ac meets it. Pterostigma Wing Pattern pale brown, framed in light yellow and bordered by the thick black nervures, that of fore wing larger than the hind, covering less than 1 cell. 13 postnodal nervures in the fore wings; 12 in the hind. Abdomen: long and slender. Segment 1 azure blue; with a broad quadrate black spot on dorsum not quite reaching to the apical end; two small rounded azure blue medial spots on the posterior margin of the quadrate. Segment 2 broadly blue at sides and dorsum; the latter contains a broad black sub-apical triangle of black lying in a halo of ferruginous, its apex is prolonged as a very fine mid-dorsal black line towards the base of the segment; a small apical triangle of black at its mid dorsum just below the sub-apical triangle.
Segments 3 to 7 with broad, black, dorsal stripes, which broaden to encircle the apical ends of segments but do not quite reach the base except at the mid-dorsal point; so the pale bluish-green ground colour here forms narrow basal rings interrupted mid-dorsally. The dorsal stripe is greatly extended at the sides of the segment 7, covering little more than the upper half of the segment. Segments 8 to 10 completely azure blue. Anal appendages bluish-white, superiors as long as segment 10, triangular as viewed from above, and bifid at apex as seen from the side; inferiors considerably shorter, broad at base, Male anal appendages Side view bluntly rounded at base. Genitalia: lamina deeply but narrowly cleft; hamules small quadrate plates meeting across the middle line; lobe small depressed; penis broad at apex, the end curling strongly over dorsum to embrace the stem of the organ by a deep bifurcation at the extreme end. Female: Abdomen: 30 32mm; Hind Wing: 20 23mm. Similar to male in colour and markings, the latter differing only on the abdomen as follows: Segment 1 Paratype female with dorsal marking broader, two small rounded azure blue medial spots on the posterior margin are absent; segment 2 with the dorsal marking extending from base to apex of the segment, the apical end narrowing and then broadly confluent with an apical black annule; segment 8 with a black dorsal spot extending from base along mid-dorsum to bifurcate into two processes at the middle of segment, the two bifurcated arms medially interrupted by the blue ground colour; apices of arms touching apical border of segment, ventrally the segment bears an apical spine; segment 9 with broad, black, dorsal stripe extended from base to middle of segment, broad at base and little narrow at the apex. Anal appendages little shorter than segment 10, conical, pointed at apex, pale blue in colour. Vulvar scales moderately robust, extending to end of abdomen. Habitat: Mainly agricultural (rice) fields. Remarks: This slender subspecies significantly differs from the nominal one in: the smaller size of the male; no X-shaped marking on the 10 th abdominal segment; a small apical triangle of black at the mid dorsum, just below the sub-apical triangle of 2 nd abdominal segment; the extension of the dorsal stripe at the sides of the segment 7; the higher index of postnodals in hind wing. In females: the conspicuous markings on segment 8 and 9, and the range of the hind wing length. I name it after Mr. Arun Kanti Mitra, my beloved father and Dr. Arun Kumar, my Ph.D. guide. 3. Ischnura aurora (Brauer) Material: BSTB-2, 1, 26.VI.2005.
Male: Not collected. Female: Abdomen: 19mm; Hind Wing: 14mm. Habitat: Weedy banks of slow-running marshy streams, rice fields and surrounding vegetation. 4. Calicnemia eximia (Selys) Material: BSTB-1, 1, 18.IV.2005; BSMS-6, 3, 23.IV.2005; BSTOD-1, 3, 1, BSTOD-2, 1, 1, 25.VI.2005; BSMS-9, 1, 9.VII.2005, 1, 10.VII.2005; BSLK-3, 1, 2.IX.2005. Male: Abdomen: 30 34mm; Hind Wing: 23 24mm. Female: Abdomen: 32mm; Hind Wing: 24mm. Habitat: Vegetation adjacent to water falls, mainly Apluda mutica, Salix sp., Adiantum sp., Pteris sp. April to October. Oviposition among adventitious roots of some plants (Acanthaceae family) wetted by sprinkling water. The semi-terrestrial larvae occur in the same habitat and among mosses and ferns adjacent to water falls. 5. Calicnemia mortoni (Laidlaw) Material: BSTB-5, 2, BSTB-6, 1, 26.VI.2005; BSMS-9, 2, 9.VII.2005. Male: Abdomen: 30 31mm; Hind Wing: 24 25mm. Female: Abdomen: 28 30mm; Hind Wing: 23 26mm. Habitat: Rare, found only in two places on vegetation adjacent to slow water falls. Remarks: Males shorter than in Fraser, 1933, but like males of Lieftinck, 1977. Both sexes show striking age variations. Above all, the number of cells between the discoidal cell and the oblique nervure descending from the subnode, on the basis of which Fraser, 1933 demarcated Indocnemis (4 cells) and Calicnemia (3 cells) does not seem to be a good character. Our Calicnemia eximia and C. mortoni specimens show a range of 3 to 4 cells between the discoidal cell and the oblique nervure descending from the subnode. Females: The nodal index (18 to 19 postnodals in fore-wings, 15 to 16 in the hind) is as Lieftinck. The major difference from Fraser, 1933 is the presence of a single row of cells between costa and radius in the present females, which again resembles the earlier record by Lieftinck, 1977. 6. Indolestes cyaneus (Selys) Material: BSTB-1, 3, 18.IV.2005; BSTOD-1, 1, 25.VI.2005; BSTB-2, 1, 26.VI.2005. Male: Abdomen without anal appendages: 33 35mm; Hind Wing: 23 25mm. Head: Labium light brown; labrum and base of mandibles turquoise-blue, anteclypeus light brown, postclypeus dark brown; frons, occiput and vertex mat black; the area between antenna and eye with cupreous sheen. Eyes bluish above, olivaceous beneath. Thorax: Prothorax black marked with turquoise-blue as follows: - anterior lobe broadly on dorsum, a broad fascia on each side of the middle and posterior lobe. Pterothorax black on dorsum with coppery reflex; mid-dorsal carina finely turquoise; broad azure-
blue humeral stripe; sides black as far back as antero-lateral suture, beyond which the sides are turquoise-blue with fine black line on postero-lateral suture; beneath pale Male wing pattern brownish. Legs yellow on extensor surface, black on flexor. Wings evenly enfumed pale brown, reticulation darker brown; pterostigma blackish-brown, long and narrow, covering 2 to 3 cells; 12 to 14 postnodal nervures to fore-wings, 10 to 14 in the hind. Abdomen: Segments 1 and 2 azure blue marked with black as Male anal appendages follows:- basal two-thirds on the dorsum of segment 1, in cup shape; segment 2 with two dorso-lateral stripes running from base to the apices, enclosing a bell-shaped azure-blue spot between them. Segments 3 to 5 broadly azure-blue on dorsum and sides, the broad azure blue of dorsum starts converging at sub-apical region and continue as fine mid-dorsal line to the apices; convergence of azure-blue little above in segment 6 than earlier segments; segment 7 with only basal azure-blue spot that converge abruptly and continue as fine mid-dorsal line up to the basal half of segment 9; segment 10 completely azure-blue. Apical annule of most segments azure-blue. Anal appendages: superiors light blue on dorsal surface at least up to half of it, followed by brown and blackish-brown at apex, nearly twice as long as segment 10, with a inwardly directed spine almost near the middle of appendages. inferiors short and tumid. Female: Not collected. Habitat: Swift cold mountain streams. Remarks: Recorded by Lieftinck, 1977. On an incomplete specimen, lacking the last four segments of the abdomen. This is the first description of a complete specimen from Bhutan. 7. Megalestes major Selys Material: BSLK-2, 1, 2.IX.2005.
Male: Abdomen without anal appendages 53mm; Hind Wing: 37mm. Female: Not collected. Habitat: Marshy streams and on bushes. Remarks: Strikingly similar to the description by Fraser (1933) except the colour of the eye (greenish-blue above, olive-yellow beneath) that was described as dark brown. 8. Caliphaea confusa Hagen in Selys Material: BSTB-3, 1, BSTB-5, 1, BSTB-7, 1, 26.VI.2005. Male: Abdomen: 38 39mm; Hind Wing: 30 32mm. Nodal index (23-24) (14-17) (14-15) (24-26) (22-24) 13 (12-15) (21-27) Female: Abdomen: 35mm; Hind Wing: 32mm. Nodal index 26 13 13 26 25 12 12 23 Habitat: Ferns and grasses overhanging streams. 9. Rhinocypha cuneata Selys Material: BSMS-9, 1, 9.VII.2005. Male: Abdomen: 23mm; Hind Wing: 28mm. Female: Not collected. Habitat: Fast flowing hill streams, perching mainly on partially submerged stones. Remarks: Our specimen agrees with Fraser, 1934, except the following extra characters: small oval yellow spots on anterior lobe of prothorax; a short slender upper line of chrome-yellow at antero-lateral suture; and the pair of longitudinal ventro-lateral median spots on 3 rd and 4 th abdominal segments. 10. Rhinocypha unimaculata Selys Material: BSMS-9, 1, 8.VII.2005. Male: Abdomen: 24mm; Hind Wing: 30mm. Female: Not collected. Habitat: Near fast flowing hill streams, perching on partially submerged stones. 11. Anisopleura bella sp. nov. Material: BSTB-3, 1 (Holotype), 1, 26.VI.2005; BSMS-9, 2, 8.VII.2005. Male (Holotype): (BSTB-3): Abdomen: 37mm; Hind Wing: 31mm.
Head: Labium black, pulverulent white on whole of middle lobe and base. Labrum light turquoise, narrowly Holotype bordered with black; Anteclypeus black, postclypeus, bases of mandibles, cheeks as far up as the level of antennae, and a broad band across the lower part of frons greenish A territorial male yellow to light turquoise.; rest of the head mat black, with a large rounded spot on outer side of each lateral ocellus; Eyes blackish-brown above and light-bluish below. Thorax: Prothorax broadly black on dorsum marked with greenish-yellow to turquoise as follows: a small dorso-lateral stripe on each side of anterior lobe, a very large oval spot on each side of middle lobe and a small triangular mark on each side at the outer end of posterior lobe. Pterothorax black on dorsum, marked with citron-yellow changing to greenish-yellow in mature adults as follows: Narrow antehumeral stripes running parallel with the mid-dorsal carina, a narrow humeral stripe running parallel to the former and broadly confluent with it below and narrowly above, enclosing a elongated-oval ground colour spot between them; a small upper spot lying close to outer side of humeral stripe, which gives a hook-like appearance while joining with the broad mesepimeral spot; and the whole of metepimeron. The upper antero-lateral suture, a small round black spot at the middle of mesepimeron and the postero-lateral suture mapped out in black; three pairs of spots on the under surface of thorax, the middle pair larger than others. Legs black, Male wings
outer and proximal portions of femora yellow, these parts are pruinosed. Wings hyaline, apices of the fore wings tipped with dark brown, bases pale saffron. Costa of hind-wing with an obtuse projecting angle between base and node. Pterostigma dark blackish-brown, covering 3 to 4 cells; 3 to 4 cubital nervures in all the wings; petiolation begins at level of or slightly proximal to level of the basal antenodal nervure. Nodal index 20 15 17 21 19 14 12 15 Abdomen: Black, segment 9 and 10 with pruinose dorsum, other segments marked with greenish-yellow as follows: Sides of the segment 1; a narrow bridge on the mid dorsum connecting both the sides and extending little further towards the base of the segment at its middle; a somewhat rounded ventro-lateral spot on each side just below the broad Lateral view Ventral view Male genitalia and penis lobe lateral point at sub-apical region and expands quickly at the apices; narrow lateral stripes on segments 3 to 6, the stripes becoming shorter and narrower as they progress towards the 5 th and 6 th segment; the lateral stripe at segment 3 narrowed down at the sub-apical region and again broaden at the apices giving a hook-like appearance; mid-dorsal carina finely yellow on segments 2 to 6 and apices of 7; a pair of large oval lateral spots at the base of segments 3 and 4 connected with the yellow stripe of mid-dorsal carina; these spots become smaller and rounded on segments 5 to 7 and gets separated from the yellow stripe of mid-dorsal carina. Anal appendages black, pruinosed palely. Superiors, subcylindrical at base, broadened and depressed near apices, which curve in towards each other and overlap; contains a tubercle at the ventro-lateral surface well proximal to the middle of the appendages with a short spine directed analwards. Inferiors Male anal appendages rudimentary. Male 2 (Paratype): Abdomen without anal appendages: 35mm; Hind Wing: 30mm. Dorso-lateral view Dorsal view
As the holotype. There are 4 cubital nervure in fore-wing and 3 to 4 in the hind; petiolation begins at the level of or little distal to the level of basal antenodal nervure. Nodal index 20 16 16 20 19 15 14 19 Male 3 (Paratype): Abdomen 36mm; Hind Wing: 30mm. As the holotype. There are 4 to 5 cubital nervure in fore-wing and 3 to 4 in the hind; petiolation begins at the level of or little proximal to the level of basal antenodal nervure. Nodal index 17 18 17 17 17 16 16 16 Female (Paratype): Abdomen: 31mm; Hind Wing: 32mm. Similar to male but more heavily built; 4 to 6 cubital nervures in all wings; Nodal index 25 18 18 25 21 15 15 22 Body markings: Labrum black with one large greenish-yellow spot on each side; postclypeus black; the yellow band on the frons is broadly interrupted medially; the posterior lobe of prothorax more broadly yellow and an additional band of yellow forming a collar Paratype female to prothorax; trefoil-like spots on coxae; costa of hind-wing without any obtuse angle between base and node; the lateral abdominal markings consist of a long stripe and basal spot narrowly separated, and mid-dorsal carina stripe extending the whole length of segments 2 to 8; segment 8 has a small round apico-lateral spot and 9 a very large irregular lateral spot extending over more than half the segment; segment 10 unmarked, very short and notched on dorsum. Anal appendages black, little longer than segment 10, tapering to an acute point. Vulvar scales moderately robust, not quite reaching end of the abdomen. Habitat: Around torrential hill streams; males perch on partially submerged stones or on over hanging vegetation. Females arrive at the rendezvous during the latter part of the day. Remarks: Anisopleura bella differs from A. lestoides and A. furcata in having more than one (usually 3 to 4) cubital nervures and in the presence of a humeral stripe. It differs from A. comes in having superior anal appendages with spine and with more turquoise colouration in head and prothorax than the citron-yellow in males. The present species is
having an interesting combination of characters of A. comes and A. lestoides as it has also seen in A. subplatystyla (Fraser, 1934). A. bella differs from A. subplatystyla in having longer abdomen and hind-wings, both in males and females; in having broadly confluent antehumeral and humeral stripes above and below in males, enclosing a elongated-oval black spot between them; and in the colour of the eyes, which is dark brown in A. subplatystyla, and blackish-brown above and light-bluish below in the present specimens. 12. Bayadera indica (Selys) Material: BSMS-8, 1, 8.VII.2005; 2, 9.VII.2005. Male: Abdomen 39 43mm; Hind Wing: 34 35mm. Nodal index (21-24) (21-25) (22-25) (21-25) (19-22) (18-21) (18-21) (19-23) Female: Not collected. Habitat: Fast flowing hill streams, perching on stones or overhanging vegetation Remarks: Resembles the description by Fraser, 1934 except that males are longer (39 43 mm) than Fraser s (38 40 mm). Hind-wing little longer. The small dorso-lateral stripe on each side of the anterior lobe of prothorax differs from Fraser. Nodal index little higher in the present males. The fine yellow line on the mid-dorsal carina of first abdominal segment described by Fraser is absent. 13. Davidius baronii Lieftinck Material: BSMS-1, 1, 2, 23.IV.2005. Male: Abdomen: 30mm; Hind Wing: 25mm. Head: Labium dark brown; bases of mandibles, the small sclerite immediately behind it and a transverse band along apical border of labrum, bright-chrome; rest of the labrum and face dark-brown; frons bright yellow, slightly narrowed at either end and not touching the eye-margin, the base of the frons being striped with dark brown; upper surface fringed with long black hairs; vertex with a raised, rounded crest connecting lateral ocelli, behind which the surface is flat and slopes down, a deep sulcus separating it from the occiput. Thorax: Prothorax blackish-brown marked with bright chrome as follows: cervical process, whole of anterior lobe, a crescent dorso-lateral spot on each side at the base of middle lobe and a pair of small, round dorsal spots at the base of the same lobe. Posterior lobe blackish-brown, short, simply rounded and fringed with long hairs. Pterothorax black, marked with yellow as follows:- A complete mesothoracic collar, long, narrow antehumeral spots not confluent with the collar below, nor meeting the alar sinus above, oblique and converging above; a small but prominent upper humeral spot and the sides broadly yellow. Posterior suture narrowly mapped out in black; anterior suture with a vestigial similar line, broadly interrupted in its upper part. Legs black. Wings hyaline, bases bright saffron halfway from base to node. Pterostigma palest brown, framed in darker brown, covering about 2 1 / 2 to 3 1 / 2 cells and 1.8 mm long; discoidal cell of fore-
wing entire, that of hind-wing traversed once; only 1 cubital nervures in all wings. 3 to 4 cells between proximal and distal primary antenodal nervures. Anal triangle 3 celled. Nodal index 10 11 11 11 10 7 6 10 Abdomen: Black, marked with yellow as follows:- Segment 1 with sides broadly yellow; 2 with the dorsal carina very finely so, and two large sub-triangular lateral spots nearly confluent with each other, the basal one of which involves oreillet; 3 with a large triangular baso-lateral spot narrowing apically, where it is limited by the jugal suture, apical to jugum with a narrow elongate subapical spot; 4-8 each with pair of well defined, though small, subcircular spots, one on either side, upon middle of sides at extreme base, largest on segment 4. Anal appendages black, superiors bifid nearly to base, upper branches divaricate, shorter than the length of segment 10, apex rounded, ending in a short point above, inner branch straight, nearly at a right angle to the outer, inclined abruptly downward, its end curved back slightly towards the base and resting on the inferior appendage; the latter paler, slightly longer, triangular, excavate above, with a transverse tooth on each side, apex blunt and slightly bifid. Female: Abdomen without anal appendages: 31 mm; Hind Wing: 27 28 mm. Very similar in colour and markings to the male, differing as follows: - The whole build of insect much more robust; 4 to 5 cells between the proximal and distal antenodal nervure; 2 to 3 nervures between the sectors of arc in the fore wing, and only one in the hind; pterostigma covering 2 to 3 1 / 2 cells and measuring 2 mm in length. Nodal index (10-12) (12-14) (12-15) (10-11) (11-12) (8-9) (8-10) (9-11) Habitat: Vegetation along fast flowing hill streams. Remarks: Emergence was going on during collection and all specimens were teneral. They agree fairly well with the description given by Lieftinck (1977), only except the following differences: - The present male is little longer; nodal index is little lower; and pterostigma (1.8 mm, covering about 2 1 / 2 to 3 1 / 2 cells) little longer. Off course, the other characters seems to be a mixture of Fraser s (1934) D. delineatus or D. z. zallorensis, and the status of these three species needs further 14. Anax nigrofasciatus nigrolineatus Fraser Material: BSTB-1, 1, 18.IV.2005. Male: Not collected. Female: Abdomen 50mm; Hind Wing: 48 mm. Nodal index 9 16 16 10 10 12 13 9 Habitat: Rice fields.
15. Anotogaster nipalensis Selys Material: BSLK-1, 1, 1, 2.IX.2005; BSTB-4, 1, 26.VI.2005. Male: Abdomen: 51mm; Hind Wing: 42mm. Head: Labium ochreous, labrum black bordered with dark ochreous, the black enclosing two transversely oval citron-yellow spots; face and frons dark brownish-yellow, the superior surface of latter blackish-brown; two bright ochreous spots, one in each side, in the space between the base of antenna and ocellus; occiput black, densely fringed with coarse black hairs. Eyes bottle green during life. Thorax: Prothorax black marked with yellow as follows: two linear spots on the anterior border of middle lobe; two round Male wings spots on the dorsum of the same; and two short linear spots on the posterior lobe. Pterothorax black, changing rather abruptly to warm reddish-brown beneath; marked with bright citron-yellow as follows:- Two pyriform antehumeral spots broadening above, tapering below and diverging outwards and downwards; two broad oblique lateral stripes, one bordering the hinder part of humeral suture, the other covering the central portion of metepimeron; lastly, some spots on tergum at bases of wings. Legs black. Wings hyaline, extreme bases tinted with bright amber-yellow, reticulation very close, black; pterostigma blackish-brown, covering about 2 1 / 2 to 3 cells. Nodal index 11 18 19 14 11 13 14 13 Membrane grayish-brown. Discoidal cell 2 celled in fore-wings, divided by strongly curved nervure running from costal to distal side; that of hind-wing entire; supratriangles entire or traversed once; subtriangles entire; 2 cubital nervures in fore-wing, 1 or 2 in hind; anal loop 5 celled; anal triangle 3 to 4 celled. Abdomen: Black, marked with bright citron-yellow rings bordering jugal sutures on segments 2 to 8, all narrowly interrupted by dorsal carina except on segment 2 where the ring is entire. Laterally the rings prolonged obliquely basalwards and becoming confluent with broad cordate spots beneath. Segment 9 with basal subdorsal spot, segment 10 unmarked. Anal appendages black, superiors sub-cylindrical, rather longer than segment 10, constricted at extreme base, tapering to apex, compressed somewhat laterally, armed with robust ventral spine immediately after basal constriction and second, more robust spine situated slightly basal to middle of appendage and directed obliquely inwards. Inner
border of appendage sinuous, outer nearly straight and produced into fine apical spine turning abruptly upwards. Inferior appendage subquadrate, about three-fourths the length of superiors, hollowed out above, shallowly and narrowly notched at apex and with small upwardly directed spine on either side of notch. Female: Abdomen 59 61 mm; Hind Wing: 50 51 mm. Similar in colour and markings to male, differing as follows: more robust, abdomen markedly compressed, tumid from segments 1 to 3, tapering after segment 4; segment 9 aborted, oblique and prolonged below into enormous ovipositor, 9 mm in length, dark reddish-brown at base and black at extreme apices. Wings broader; 2 cubital nervures in all wings; discoidal cell of fore-wing 2 to 4 celled; 2 celled in hind; supratriangles traversed once in all wings; anal-loop 5 to 8 celled. Nodal index 15 (20-21) 21 15 (14-15) 15 13 14 Habitat: Fast flowing hill streams. Remarks: Differences with Fraser (1936): male little shorter; anal triangle occasionally 3 celled; prothorax marked characteristically; females a bit longer and ovipositor shorter (9 mm) (Fraser s females: 10 mm). 16. Orthetrum glaucum (Brauer) Material: BSMS-7, 1, 23.IV.2005. Male: Abdomen 31mm; Hind Wing: 37.5mm. Female: Not collected. Habitat: Adults occur sympatrically with other species of the genus over slow-running marshy streams, side pools or agricultural fields. They oviposit within different types of algal growth viz. Rhizoclonium sp., Oscillatoria sp. etc. along slow running marshy streams or in stagnant water of side pools and agricultural fields. 17. Orthetrum japonicum internum MacLachlan Material: BSTB-10, 3, 3.IV.2005; BSTB-1, 1, 17.IV.2005; 2, 4, 18.IV.2005; BSTB-2, 1 ; BSTB-7, 1, 1, 26.VI.2005. Male: Abdomen 26 28mm; Hind Wing: 32 35mm. Female: Abdomen: 26 27mm; Hind Wing: 32 33mm. Habitat: As Orthetrum glaucum. 18. Orthetrum t. triangulare (Selys) Material: BSMS-4, 2, 23.IV.2005; BSTOD-2, 1, 25.VI.2005; BSMS-9, 2, 9.VII.2005. Male: Abdomen without anal appendages: 30 32mm; Hind Wing: 36.5 39mm. Female: Not collected. Habitat: As Orthetrum glaucum.
Remarks: Agrees fairly well with the description given by Fraser (1936) except: discoidal cell in fore wing occasionally 3 celled, subtrigone of fore wing occasionally 3 celled and pterostigma (2 to 2 1 / 2 cells) little longer. 19. Orthetrum sabina (Drury) Material: BSTB-1, 1, 18.IV.2005; BSMS-9, 1, 9.VII.2005. Male: Not collected. Female: Abdomen 35mm; Hind Wing: 32 mm. Habitat: As Orthetrum glaucum. 20. Orthetrum taeniolatum (Schneider) Material: BSMS-9, 1, 9.VII.2005. Male: Abdomen 25.5mm; Hind Wing: 29mm. Female: Not collected Habitat: Around hill streams (slow or moderate). They oviposit mainly in side pools. Also found near irrigation channels. Remarks: The present male as well as its hind-wing is little longer than the upper limit (25mm and 27mm respectively) as given by Fraser (1936). Body markings and wing venation similar to earlier description. 21. Orthetrum pruinosum neglectum (Rambur) Material: BSMS-5, 1 ; BSMS-7, 1, 2, 23.IV.2005; BSMS-9, 2, 1, 9.VII.2005. Male: Abdomen 30 31mm; Hind Wing: 35 36mm. Female: Abdomen: 30mm; Hind Wing: 37mm. Habitat: As Orthetrum glaucum. 22. Orthetrum luzonicum (Brauer) Material: BSMS-1, 1, 23.IV.2005; BSTB-2, 1, 26.VI.2005; BSMS-9, 1, 9.VII.2005. Male: Abdomen: 28 30mm; Hind Wing: 32 34mm. Female: Not collected. Habitat: As Orthetrum glaucum. Remarks: Hind wing little longer than (32-34mm) in Fraser (1936). 23. Crocothemis servilia servilia (Drury) Material: BSMS-7, 3, BSMS-2, 1, 23.IV.2005; BSTB-1, 1, 18.IV.2005; BSLK-3, 1, 2.IX.2005. Male: Abdomen: 24 28mm; Hind Wing: 30 33mm. Female: Abdomen: 21 22mm; Hind Wing: 28 30mm.
Habitat: Found everywhere, along hill streams, slow-running marshy pools, around side pools and agricultural fields almost throughout the. Oviposition singly by the female among algal growth in slow-running marshy streams or in open water. 24. Diplacodes trivialis (Rambur) Material: BSMS-6, 1, 23.IV.2005; BSTOD-2, 1, 25.VI.2005; BSMS-9, 1, 26.VI.2005, 1, 9.VII.2005; BSTB-2, 1, 26.VI.2005; BSTB-5, 1, 26.VI.2005; BSLK- 1, 1, 2.IX.2005. Male: Abdomen: 19 21mm; Hind Wing: 21 25mm. Female: Abdomen: 18 19mm; Hind Wing: 21 22mm. Habitat: In agricultural fields, near slow-running marshy streams, fast flowing streams, but mostly seen little away from these actual habitats, camouflaging quite well and difficult to locate. 25. Sympetrum hypomelas (Selys) Material: BSLK-1, 1, BSLK-2, 1, 2.IX.2005. Male: Abdomen 24 25mm; Hind Wing: 32 33mm. Female: Not collected. Habitat: Common along streams. Sometimes perching on stones. Females oviposit in tandem. 26. Trithemis aurora (Burmeister) Material: BSMS-9, 1, 8.VII.2005; 1, 2, 9.VII.2005. Male: Abdomen 24mm; Hind Wing: 29 31mm. Female: Abdomen: 23 24mm; Hind Wing: 28 29mm. Habitat: Agricultural fields, slow running marshy streams, fast flowing streams and side pools. May to September. 27. Trithemis festiva (Rambur) Material: BSMS-7, 2, 23.IV.2005. Male: Abdomen 24mm; Hind Wing: 31 32mm. Female: Not collected. Habitat ecology: Sympatrically with T. aurora in agricultural fields, along slow running marshy streams, near fast flowing streams and pools. May to September. 28. Palpopleura s. sexmaculata (Fabricius) Material: BSMS-1, 1, BSMS-2, 1, 1, BSMS-7, 2, 23.IV.2005; BSTB-1, 1, 18.IV.2005; BSTB-9, 1, 3.V.2005. Male: Abdomen: 14 17mm; Hind Wing: 18 21mm. Female: Abdomen: 15 16mm; Hind Wing: 18 20mm.
Habitat: Common during April to September in agricultural fields. Also among vegetation along slow running marshy streams and small side pools. 29. Pantala flavescens (Fabricius) Material: BSTB-1, 1, 17.IV.2005; BSTB-11, 1, 18.IV.2005; 1, 31.V.2005; BSMS-3, 2, 23.IV.2005; BSMS-9, 3, 1, 9.VII.2005. Male: Abdomen 27 33mm; Hind Wing: 37 40mm. Female: Abdomen: 29 32mm; Hind Wing: 39 41mm. Habitat: Common over the terraced paddy fields adjoining hill streams during the rainy season. Oviposition in tandem. CHECKLIST OF THE DRAGONFLIES OF BHUTAN Order Odonata Suborder Zygoptera Family Coenagrionidae (Pond damselflies) Genus Ceriagrion Selys, 1876 1. Ceriagrion fallax cerinomelas Lieftinck, 1927 Genus Aciagrion Selys, 1891 2. *Aciagrion olympicum aruni ssp. nov. Genus Ischnura Charpentier, 1840 3. Ischnura forcipata Morton, 1907 4. I. a. aurora (Brauer, 1865) Family Platycnemididae (Brook damselflies) Genus Calicnemia Strand, 1926 5. Calicnemia eximia (Selys, 1863) 6. C. mortoni (Laidlaw, 1917) Family Lestidae (Reedlings) Genus Indolestes Fraser, 1922 7. Indolestes cyaneus (Selys, 1862) Genus Lestes Leach, 1815
8. Lestes concinnus Hagen in Selys, 1862 Family Synlestidae (Sylphs) Genus Megalestes Selys, 1862 9. Megalestes major Selys, 1862 Family Calopterygidae (Demoiselles) Genus Caliphaea Selys, 1859 10. Caliphaea confusa Hagen in Selys, 1859 Family Chlorocyphidae (Jewels) Genus Rhinocypha Rambur, 1842 11. *Rhinocypha (Aristocypha) cuneata Selys, 1853 12. *R. (Paracypha) unimaculata Selys, 1853 Family Euphaeidae (Gossamer wings) Genus Anisopleura Selys, 1853 13. *Anisopleura bella spec. nov. 14. A. comes Hagen, 1880 Genus Bayadera Selys, 1853 15. *Bayadera indica (Selys, 1853) Suborder Anisoptera Family Gomphidae (Clubtails) Genus Lamelligomphus Fraser, 1922 16. Lamelligomphus biforceps (Selys, 1878) Genus Davidius Selys, 1878 17. Davidius baronii Lieftinck, 1977 Family Aeshnidae (Hawkers) Genus Anax Leach, 1815 18. Anax nigrofasciatus nigrolineatus Fraser, 1935
Genus Aeshna Fabricius, 1775 19. Aeshna p. petalura Martin, 1906 Genus Cephalaeschna Selys, 1883 20. Cephalaeschna triadica Lieftinck, 1977 Family Cordulegastridae Genus Anotogaster Selys, 1854 21. *Anotogaster nipalensis Selys Family Macromiidae Genus Macromia Rambur, 1842 22. Macromia moorei Selys, 1874 Family Libellulidae (Perchers) Genus Orthetrum Newman, 1833 23. *Orthetrum glaucum (Brauer, 1865) 24. *O. japonicum internum MacLachlan, 1894 25. O. t. triangulare (Selys, 1878) 26. O. s. sabina (Drury, 1770) 27. O. taeniolatum (Schneider, 1845) 28. O. pruinosum neglectum (Rambur, 1842) 29. O. luzonicum (Brauer, 1868) Genus Acisoma Rambur, 1842 30. Acisoma p. panorpoides Rambur, 1842 Genus Brachythemis Brauer, 1868 31. Brachythemis contaminata (Fabricius, 1793) Genus Crocothemis Brauer, 1868 32. Crocothemis s. servilia (Drury, 1770) Genus Diplacodes Kirby, 1889 33. Diplacodes trivialis (Rambur, 1842)
Genus Neurothemis Brauer, 1867 34. Neurothemis fulvia (Drury, 1773) Genus Sympetrum Newman, 1833 35. *Sympetrum hypomelas (Selys, 1884) 36. S. commixtum (Selys, 1884) Genus Trithemis Brauer, 1868 37. Trithemis aurora (Burmeister, 1839) 38. T. festiva (Rambur, 1842) Genus Palpopleura Rambur, 1842 39. Palpopleura s. sexmaculata (Fabricius, 1787) Genus Pantala Hagen, 1861 40. Pantala flavescens (Fabricius, 1798) * new records of the present study. CONCLUSION The present study unveils only a small part of the diversity of the dragonflies of Bhutan. With nine new records, 40 species and subspecies are now known from the country (see checklist). However, there is no doubt that many more taxa remain to be discovered, as the centre and west are still unexplored. ACKNOWLEDGEMENTS We thank the Ministry of Agriculture for funding. Dr. Jagar Dorji, Principal, Sherubtse College, permitted the faculty association. All park officials extended support during our visits. Mr. Prakash Timsina, Mr. Mongal Singh Gurung, Mr. Santosh Katwal & Mr. Endrias Rai, Sherubtse students of B.Sc. B Ist and IInd years helped with laboratory work. We are greatly indebted to Prof. Henri Dumont, Ecology Lab, University of Ghent, Belgium for visiting some of the localities as well as for reviewing the manuscript.
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