CONTRIBUTION TO THE ODONATE (INSECTA) FAUNA OF THE ANDAMAN AND NICOBAR ISLANDS WITH DESCRIPTION OF TWO NEW SPECIES

The first mention of an odonate species from the Andaman and Nicobar islands can be traced back. in literature to Selys (1853) where the author described the damselfly Libellago lineata blanaa from the Nicobar islands. Two more species, e. g. Oopera vittata serapica Hagen and Epophthalmia vittata (Burmeister) were subsequently reported from these islands, by Selys in 1863 and 1875. In recent times, Fraser (1924) reported another 11 dragonand damselflies from these islands including some new to science. These wer~ later reported by Fraser in his Fauna of British India publication (1933-1936).


INTRODUCTION
The first mention of an odonate species from the Andaman and Nicobar islands can be traced back. in literature to Selys (1853) where the author described the damselfly Libellago lineata blanaa from the Nicobar islands. Two more species, e. g. Oopera vittata serapica Hagen and Epophthalmia vittata (Burmeister) were subsequently reported from these islands, by Selys in 1863 and 1875. In recent times, Fraser (1924) reported another 11 dragon-and damselflies from these islands including some new to science. These wer~ later reported by Fraser in his Fauna of British India publication (1933)(1934)(1935)(1936).
This study is based on odonate collections obtained during several surveys conducted by the Zoological Survey of India over a number of years. Lahiri (1975) in his brief analysis of the odonate faqnal composition of the South Andaman islands, referred to a detailed account of the same to the present contribution, as it was then, in the Mss. stage. Upon further critical analysis of the available material, a little change of the findings have been incorporated now.
In the present paper 21 new records of o,donate species and subspecies, including two new to science have been reported which brings it to a total of 34 odonate species ·and subspecies known till date from this area. Libellago anaamanensi8 (Fraser) has peen considered here as a subspecies of L. lineata (Burmeister)'. 'Hitherto unknown females of two subspecies, e. g. Libellago lineata andamanen&is (Fraser) and Prodasineura verticalis andamanensis (Fraser) _have been described by comparing with the males. M~asurements, Nodal index, necessary collection data, and a running key for all the species studied have been provided in the text along with taxonomic notes for some of them. Eyes contiguous, or separated by a space not wider than their own diameter; males with single inferior anal appendage; foreand hind wings differing in shape, the latter generally dilated at base. • •• 2. 5 or more antenodal cross veins prasen t; arc situated nearer base of wing than node.
Only 2 antenodal cross veins present; arc situated midway between base of wing and node.

5.
Epistome tumid and markedly projecting; wings petiolated, petiolation extending oppoSite to~ or s1i~htly proximal to the level of arc. anna1tdal-ei Fraser) 6 G. Discoidal cell in hindwing with costal margin less than three fourths as long as the inner margin.
Discoidal cell in hindwing with costal margin more than three fourths as long as the inner margin.
7. Discoidal cell with costal margin one fifth shorter than the inner margin.
Discoidal cell with costal margin subequal to the inner margin. Description: Female: Differs from male as follows: bases of mandibles greenish yellow and a linear stripe of same colour running obliquely across cheeks and genae to frons; labrum marked with oval. greenish yellow spot on either side; epistome on lateral edges of anterior surface bordered greenish yellow and marked with two spots of same colour on either side, viz. an upper large oval and a lower small triangular one; bases of antennae, a triangular elongated spot against each eye at the level of antennae followed. by two pairs of spots of which the anterior pair are small and rounded and the hinder pair transversely oval and a bit larger, are present in addition to those in male, all Recorda oj the Zoological S'urvey o/India greenish yellow; spots against lateral ocelli pear shaped. Prothorax with following yellowish markings: a linear crown shaped spot on anterior lobe; a small mid-dorsal and two large lateral pear shaped spots on posterior lobe. Legs with flexor surfaces of all femora mostly creamy white. Wings enfumed with pale brown which is mote pronounced in distal half; pterostigma medially yellowish in hindwing. Abdomen with following greenish yellow markings: segment 1 with a large triangular spot on dorsum at apex; segments 2 to 5 with basal and apical triangular spots with a narrow stripe (sometimes absent) in between; segment 7 with a lateral stripe which is pointed at apex; segments 8 and 9 with subapical lateral spots; mid-dorsal carina finely yellow throughout but variably obscured in adults.
Measurements (in mm): 0 (8 exs) and ~ (4 exs) respective Iy ; length of abdomen 14.5-15.5, 13.0-14.0; length of forewing 19.0-20.5, 20.5-21.0; length of hindwing 18.5-20.0, 20.0-21.0 ; number of antenodal veins : forewing 5-7, 6 ; hindwing 5-7, 5-6; number of postnodal veins: forewing 11-13 ( ~ ) ; hindwing 12-15, 11-13. Remarks: The males under study vary from the description of L. andamanensis provided by Fraser (1934) in the following points: labium broadly marked with yellow in tenerals; in adults, epistome black, unmarked; prothorax with following yellow markings: a linear mid-dorsal spot on anterior lobe, two sub-dorsal oval ones on middle lobe, a mid-dorsal droplet shaped and two lateral oval ones on posterior lobe; an upper humeral and a few scattered spots beneath synthorax present, beside . . s those mentioned by the author; legs with flexor surfaces of all tibiae and those of anterior femora pruinosed pulverulant white; basal golden tinge on wings more pronounced in costal areas and extending nearly up to nodus in foreWing ; apical opaque area obliquely receded posteriorly being ca 3.25 mm in extent medially; abdomen greenish yellow on proximal segments; segment 1 completely black on dorsum; on segment 2, dorsal and lower lateral stripes confluent at base' and apex.
The female, unknown so far, has been described above shOWing its difference from the male.
While abdominal markings leave no doubt on their identity, the speci mens under study exhibit a closer similarity with Libellago lineata (Burmeister) than andamanensis in respect of markings on frons and fore femora, while a complete range between the two forms ate noticed in respect qf wing markings, number of antenodal crossveins and length of abdomen. It seems most reasonable therefore that andamanensis Fraser is nothing but a distinct form of lineata (Burmeister) charactarised by having a larger size (specially hindwing) and dark abdominal markings. So, andamanensis has been treated here as a subspecies of L. lineata (Burmeister).   Remarks: This is the first record of this species from the Andamans. The male specimens have a few more postnodal veins as compared to the number given by Fraser (1934  Remarks: The single specimen available for study is damaged but from the markings of the body parts present, wing venation and measurements, it seems most likely to be.malabarica Fraser. So, it has been doubtfully identified as such.   Remarks: These specimens have been identified as D. annandalei Fraser with a little hesitation, since there were no associated males and for two other factors, namely (i) much longer abdomen than stated for annandalei (25 mm) by Fraser (1933) and (ii) Ab arising from posterior wing margin at the point where Ac meets it in one of the specimens under study or from a short common stalk in the other specimen, while Fraser stated that in annandalei Ab arises from posterior wing border a little distal to Ac. However, considering the fact that Fraser.' (1924) described annandalei from two males and a single teneral female, the difference in abdominal length could perhaps be treated as a normal variation and on that basis these may be treated as topotypes.
Distribution: South Andamans only (previous and present record).

R"marlcs
The hitherto unknown female of this subspecies is reported here for the first ti~e. The single specimen available for study differs from the female of the nominate species as described by Fraser (1933) in the markings of abdomen and that of thorax on ventral surface, as follows: 'Thorax black beneath with a moderately large yellow spot at centre. Abdomen black beneath but marked with pale green as follows: segments 1-5 with broad ventrolateral stripe; segments 2-6 finely marked 29 Records of th..e ZoologicaZ Survey. oj India along mid-dorsal carina; segments 3·6 with .baso-l«teral suboval sJ?ots.
Ovipositor robust extending to end of abdomen. CUg covering 3i-4 Text- fig. 2, Drepanosticta? annandalei Fraser, hindwings (0)' and 5 cells 'in fore-and hindwings respectively ; pterostigma as described for male above.  12-14 ; hindwing 9-10, 9-11. Remarks: This is the first record of this species from South Andamans. The specimens under study agree with the Indian West Coast forms described by Fraser (1933). However, the male superior anal appendages look obtusely triangular when viewed from dorsum, while the apex of the organ strongly bent inwards is visible only at a dorsolateral angle.
Distribution: South Andamans (present record). It is a well distributed species ranging from SRI LANKA and INDIA to MALAYSIA in the east. Arc situated at the level of the distal antenodal nervure.
2. Ab arising from a point well proximal to Ac ....
Ab arising fronl a point at" or slightly proximal to Ac.
Frons without a ridge as above.
Genus Pseudagri-oD Selys -Remarks: Both specimens available for study -have the-termiJ:~al abdominal segments missing, but from the markings on the· remairrl~g body parts, wing venation and measureme~t~~ they seem' most likely to be andamanicum Fraser. Remarks : This is the first record of this species from the Andamans. It is evidently on account of postmortem changes that the male specimen under study has its thorax mostly brownish instead of green, the ~olour stated in the description of the species provided by Fraser (1933). Records oj tke Zoological SU1'vey of l.ooia Measurements (in mm) 0 (23 exs) and ~ (12 exs) respectively; length of abdomen 17.0-17.5, 17.5-2 .0; length of forewing 9.5-11.0, 11.0-11.5 ; length of hindwing 9.0-10. 5, 10.5-11.5, number of post nodal veins: forewing 6 .. 7,7-8 ; hindwing 4-5,5-7. Remarks: This is the first record of this species from South Andamans. The specimens under study agree with A'. J. oryzae Lieftinck in general and specially in respect of the structure of male anal appendages, but vary a little in size and rather markedly so in respect of the shape of female prothorax.
Distribution: South Andamans (present record). It is also known from Ryukyu Is., Borodino Is., CHINA and TAIWAN.
Distribution: Great Nicobar (present record) ; it is a well distributed _species rang,ing from Sey~helles across entire oriental region to Australia and the Pacific islands in the east. a faint yellowish rounded spot on either side of labrum; anteclypeus and two la~ge oval spots on frQns yellow, these latter covering the crest but for it~ middle, reaching almost the base of sulcus ~nd the ·The species has been named after the name of Lord Ganesh of Hindll lVlythology. lateral marlins on either side of frons. The lateral ocelli gu: ar, ded .hind by a prominent ridge ra'ised on either end into a ' ' pyramid~l em: lDence and thickly beset with long nne hairs. Occiput trapezoidal, bind margin declined sharply downwards. ' Text ... fig. 4. Gomphidia g, a'leshi ap. nQv, ,_ f, or, e-and bind wings (holotype 0)· ThoT, ax blackish brown tl' .arke, d with yellow as follows :-a moderately broa, dmesothoracic collar slightly interrupted in middle; oblon, g oval antehumeral stripes, reaching antealar sinus above,_ but falling far short of mesothoracic collar below; two lateral stripes, of which the first runnin, g just above the spiracle but falling short of the ventral margin ' and the other covering most part of the m, etepim, eron but for its ventral margin; an obscure upper rounded spot in between the lateral stripes. Legs blackish brown, the femora yellow' on inner surfaces.
Abdomen blackish brown marked with yellow "as follows: Segment 1 With a broad mid-d, orsal stripe falling short of the, apex of the s, egment:·; ReC01'M oj the Zoological SU1'·vey of India segment 2 with a triangular mid-dorsal spot at base; segment 7 yellow upto the jugal suture except at ventral margin; segment 8 with an incomplete narrow ring at base; segments 4 to 6 beset with closely set small spicules in dorsal halves'; lateral margins of segment 8 slightly dilated.
Anal appendages blackish brown; superiors widely separated and cylindrical at base, broken shortly thereafter; the base suggests the organs to have initially been much longer than segment 10 of abdomen and of the shape as for genus; inferior much shorter than segment 10 and deeply bifid, the branches rapidly narrowing to pointed apex directed upwards. Genitalia: Lamina arched; anterior hamules narrow, posterior hamules broadly triangular and directed backwards, lobe scoop shaped.

484
Records of the Zoological Survey of 1 nelia, greenish yellow as follows: a longitudinally elongated spot just across bases of mandibles, a narrow line on postclypeus at base, enlarged into a large lateral spot on either side after a short interruption; a moderately broad stripe running across the frons between crest and base of sulcus, interrupted broadly in the middle; frons and vertex covered with thick black hairs ; inter-orbital suture about thrice as long as occipital triangle; diameter of head across eyes slightly less than twice width of frons.
Thorax reddish brown changing to black on dorsum marked with a pair of green~sh yellow lateral stripes on either side, viz. one posthumeral and one covering most of metepimeron. Legs black but proximal half of all femora reddish brown. Wings palely tinted with brown from base, to a line running obliquely inwards from inner end of pterostigma and meeting in inner wing border at a point, where CU z terminates; deeper tint at base up to arculus continued into subcostal ray upto node and a larger subcostal postnodal spot; primary antenodals are first and 5th; discoidal:cell traversed twice; hypertriangle entire in left forewing but traversed thrice in right forewing and twice in hindwing ; anal loop 4-5 celled; pterostigma rather short (2.25 mm), narrow, dark brown and braced; two rows of cells between M4, Mspl and 2 cells between anal loop and inner wing border. Abdomen reddish brown, darker on dorsum and gradually changing to black apically, being mostly black on segments 7-10 and marked with yellow as follows: a large subrounded spot on segment 1 on either side; a complete ventrolateral stripe and 5 spots on segment 2 as follows: a median narrow triangular spot extending shortly from base and one pair each of post jugular and apical subtriangular spots; ventrolateral borders of segments 8 and 9; segment 2 expanded at base narrowed thereafter, but again slightly expanded at apex, the narrowest part being about two-thirds as wide as broadest part; abdomen narrowing apically but segments 8 and 9 broader and laterally compressed. Anal appendages dark brown, broken shortly after base. Apical margin of dentigerous plate sub oval and armed with 15 teeth.    12-13, 12-15 ; hindwing 9-10,9-11 ; number of postnodal veins: forewing 9-11 (either sex) ; hindwing 10-12, 10-13.
Remark: This is the first record of the nominate species from South Andamans. iv. '64.
MetJ8'Urements (in mm): 0 (7 exs) and ~ (12 exs Remarks: The specimens under study are comparatively more melanotic and vary from the description of the species provided by Fraser (1936) in the following points: Male: Prothorax without a mid-dorsal stripe.
Distribution: South Andamans (present and past record); it is a widely distributed species ranging from Seychelle-s across tropical Asia to Australia to the Western Pacific Islands. 1986. Tholymis tillarga, Fraser,F. C.,Fauna Brit. India,Odonata,3 : 411. MateriaZ: 2 exs as follows: 1 0, Maya Bunder, Burmadera, colI. Remarks: This is the first record of this species from South Andamans and Great Nicobar.
DiBtribution: South Andamans and Great Nicobar (present record) ; it is a well distributed species ranging from Africa and Madagascar across south-east Asia to Australia and Oceania.