Dragonflies and damselflies ( Insecta : Odonata ) of Nagaland , with an addition to the Indian odonate fauna

1,2 Indian Foundation for Butterflies. C-703, Alpine Pyramid, Rajiv Gandhi Nagar, Bengaluru, Karnataka 560092, India. 1 Department of Zoology, St. Xavier’s College-Autonomous, Mumbai, Maharashtra, 400001, India 2 National Center for Biological Sciences, Tata Institute of Fundamental Research, GKVK, Bellary Road, Bengaluru, Karnataka 560065, India 1 shantanu@ifoundbutterflies.org (corresponding author), krushnamegh@ncbs.res.in

Nagaland is one of the seven northeastern states of India with a geographical area of 16,527km 2 , of which approximately 56% is forested (Forest Survey of India 2009).Of these, forests on only 222km 2 , or 1.34% of the state's geographical area, are protected as the state's only national park and three wildlife sanctuaries (Forest Survey of India 2009), the remaining majority lie on community-owned land.As part of the globally recognized Indo-Burmese Biodiversity Hotspot, Nagaland boasts remarkable faunal and floral diversity, including many rare, endemic and legally protected species of megafauna and largely undocumented components of insect and plant biodiversity (Grewal et al. 2012).Due to remoteness, biodiversity of Nagaland had been understudied until recently.The state is now considerably accessible, attracting many ecologists and conservation biologists.In the past few years, biodiversity surveys in Nagaland have revealed an impressive concentration of species of national and international conservation importance (Grewal et al. 2012).
Any comparative work involving historical information on Nagaland biodiversity along with the current distribution and state of biodiversity faces a peculiar challenge.Until statehood was conferred in 1963, Nagaland was part of the erstwhile state of Assam, which at that time covered most of northeastern India that is now divided into seven states.Hence, most of the historical (mostly British) records were generally subsumed under "Assam", and only in rare cases were specific localities mentioned.Specific locality records are potentially available from many specimen labels, which have not been studied very well with reference to modern state and national boundaries in this part of the Indian Subcontinent.Therefore, the exact distribution of species in these states is currently poorly documented, especially for invertebrates.This problem is particularly acute for dragonflies and damselflies (Insecta: Odonata), which have not been surveyed extensively in northeastern India.Fraser (1933Fraser ( , 1934Fraser ( , 1936) ) mentioned Naga Hills when characterising the distribution of several species.Since then, Mitra (2002) has done the most comprehensive work on odonates of northeastern India, including a review of all the existing literature.Lahiri (1987Lahiri ( , 1977) ) made notable contributions to odonates of Meghalaya and Manipur.The most recent and complete work is by Subramanian (2009), who presented a taxonomically updated checklist of Indian odonates.Nonetheless, much work needs to be done in northeastern India, and we especially require specific locality and bionomic information.The present paper is an effort at providing important information on the natural history, distributions, and status of odonates of Nagaland.

Materials and Methods
We opportunistically surveyed odonates on random walks along forest paths, roads and streams in the districts of Kohima, Peren and Wokha in Nagaland (Table 1, Image 1).We photographed specimens for Image 1.A reference map of India with the study localities highlighted various identification features in the field.We took voucher specimens where necessary after obtaining required research and collecting permits for protected areas of the state from the Department of Forests, Ecology, Environment and Wildlife, Government of Nagaland (permit no.CWL/GEN/240/522-39), and permission from local village councils on community land.Voucher specimens (Table 2) are deposited in the Research Collections Facility at the National Center for Biological Sciences (NCBS), Bengaluru, India.We identified these specimens mainly with the help of keys provided by Fraser (1933Fraser ( , 1934Fraser ( , 1936)), Laidlaw (1950), Asahina (1967Asahina ( , 1984)), Vick (1986), Mitra (2002), andNair (2011).We followed odonate taxonomy and binomial names by Subramanian (2009), except for Chloropetalia Carle, 1995 in place of Chlorogomphus Selys, 1854 (Schorr & Paulson 2009), and Aristocypha Laidlaw, 1950and Heliocypha Fraser, 1949instead of Rhinocypha Rambur, 1842(as used in Subramanian 2014).Family classification followed Subramanian (2014) and Dijkstra et al. (2013).

Results and Discussion
We recorded 68 odonate species from 13 familes and from 54 genera; from Nagaland, including 42 species previously not reported from the state, and one species-Calicnemia erythromelas Selys, 1891is an addition to the Indian odonate fauna (Table 3).We also observed Ceriagrion rubiae Laidlaw, 1916     genera and 14 families (Table 3, also summarized in Table 4).Among the taxonomic categories, the genus Orthetrum was well-represented with seven species, while 36 of the 54 genera were represented with a single species, and the family Libeluilidae topped the list with 36 species (Table 4).Among Gomphidae, the species mentioned as "Stylogomphus sp." remains unidentified.
It is distinct from the only Stylogomphus (S. inglisi Fraser, 1922) that is reported from India (Subramanian 2009).
We provide below our notes on the distribution, identification and status of a selection of species of special interest, e.g., Data Deficient species and others that have seldom been reported in literature, in the taxonomic order in which they appear in Table 3.This information may be useful when these species are assessed in the future by IUCN and other international and national conservation agencies.We also provide first descriptions of the female of Coeliccia schmidti and partially, a heterochromatic form of the female of Ischnura mildredae. 1.
The only record of this species from India, which is now more than 80 years old, was by Fraser (1936): "two males taken in company with C. preciousus (Fraser, 1924) and C. atkinsoni (Selys, 1878c) at Mungpoo [Darjeeling District], 3600ft., May 1927."Vick (1985) and St. Quentin (1970) added their records from Nepal: "According to Vick, in Nepal the species is "not necessarily rare but is hard to catch and probably missed altogether by nonspecialists"."The lack of recent records from India is likely to reflect a lack of expert sampling in Darjeeling over the last 70 years."(Dow 2009a).We recorded three individuals of this species: one male and a pair in copula, at Khonoma, Nagaland, on 14 May 2013.This species is rather easy to identify as it has segments 9-10 unmarked and segments 3-4 with two pairs of lunules, apical and postjugal.
The genus Burmagomphus Williamson, 1907 is represented in India by five species (Subramanian 2009).A male and a female of this species were observed in Intanki National Park.The teneral male was seen among grass adjoining the Intanki River which was more than 3.6m wide.The female was seen sitting on vegetation at a height of around 2.7m.This species has not been recorded from India for 90 years since the type series was collected from Hasimara, West Bengal.The only other record is from Pokhara, Nepal (Vick 1985).Our record from Intanki extends the range of this species eastward by over 500km and suggests that this species may occur in other northeastern states and northern Myanmar.
This gomphid was observed in Khonoma and Doyang.The abundance of M. martini in Khonoma was significantly greater in May 2013 than in May 2012: only one male was seen in 2012 while more than 17 males were seen in 2013.Adults were often seen resting on vegetation near small streams in the mountains.No female was observed, indicating their secretive habits or genuine rarity.
This species has been reported from Sri Lanka, India, Cambodia, Thailand and Vietnam (Mitra 2010a), although some Indochinese records may be misidentified as A. borneese.From India it is recorded from several localities in southern and central India, and recently from Odisha (previously Orissa; Nair 2011).In the original description of this species, under the name "Aciagrionhisopa (Selys) ?race occidentalis", from Castle Rock, N. Kanara District, Bombay; Parambiculam, Cochin State; Trichur, Cochin State) Laidlaw (1919) stated that it is "characterised by having a black triangle on the dorsum of the eight abdominal segment, with its apex directed towards the end of the segment, and extending nearly to the full length of the segment".However, in his later review of the genus, referring to males of this species from Cochin and Ceylon, he made the following correction (Laidlaw 1924: 6): "My description states that the black mark on segment eight of the abdomen has its apex directed toward the hinder end of segment.This should read "directed towards the base of the segment".He also provided a drawing with a triangle at the segment apex directed towards its base, and also with a black mark at S10 (Laidlaw, 1924: Fig. 16).The pattern of S7 and S10 corresponds to Aciagrion paludense Fraser, 1922, considered Fraser (1933).In our specimens, most females had a small pale spot on segment 8, but never blue as Asahina had noted.We don't think that this character alone is sufficient to treat mildredae as a subspecies.We found this species to be very common around ponds in Khonoma in May 2013.We saw several dozen specimens at a small pond that was used to breed fishes, where several pairs in copulae were also observed.These specimens closely matched the images and descriptions by Fraser (1933) and Vick (1986).All the males had a small blue spot on segment 8 that is characteristic of I. mildredae.Fraser (1933) and Vick (1986) did not mention a heterochromatic form for this species.However, we observed several females of a heterochromatic form, which was similar to the heterochromatic forms of related species, and may be described as follows (also see Images 4, 5): prothorax and thorax broadly black on dorsum.A broad, blackishbrown dark band present between the eyes.Segments 3-10 dorsally black, with pale annules.Segment 2 with a characteristic marking shaped like a mushroom on the dorsal side towards the end of the segment.junior synonym of A. occidentale (Laidlaw 1924;Fraser 1933).In Intanki NP on 24 May 2013 SJ recorded an Aciagrion male with S7 having a black triangle directed to the end of the segment (Image 5), as in the original description of occidentale by Laidlaw (1919).This fact made us suppose that this description was correct and the later correction by Ladilaw (1924) was based on other specimens, with the opposite direction of the triangle.The enigma with two types of the S7 black triangle in Aciagrion spp. is to be investigated.It is not excluded that two species are in fact involved, named A. occidentale and A. paludense, respectively.For the time being we use for our specimen the name A. occidentale which anyway corresponds to the original description by Laidlaw (1919).
This Ceriagrion species has a very interesting disjunct distribution.It occurs in the Western Ghats and in Tamil Nadu (Babu et al. 2013), but has been reported once from Koraput in the Eastern Ghats, Odisha (Srivastava & Das 1987).SJ recorded dozens of specimens of this species around paddyfields and ponds just outside Intanki National Park in May 2013.Several pairs in copulae were also observed ovipositing on aquatic vegetation.This is a range extension for the species by several hundred kilometers, and the first record from northeastern India.The male of this species can be easily separated from the similar C. praetermissum (Lieftinck) by its green eyes, longer abdomen and nonbifid inferior appendages (Asahina 1967).
This species, and possibly the species group, has rather been neglected by most authors.There is considerable uncertainty about the taxonomic status of several species in this group.According to Vick (1986), "Asahina 1970 placed carpentieri, annandalei in synonomy with mildredae, which he considered as a sub-species of rufostigma, considering that the colour pattern differences were due to individual variation and states of maturity of the available material.This decision was followed by Davis & Tobin (1984).However, this analysis does not take into account the structural differences that exist between these four taxa".Vick (1986) provided several diagrams and explanations to treat these four taxa as distinct species, an arrangement that we are following here.Later, Asahina (1991) downgraded mildredae back to subspecies, noting that none of the isochromatic females that he studied had a "large bluish spot on This species has been previously reported in India from Punjab and Simla eastward to Tiger Hills in Darjeeling, and outside in Nepal, Bhutan and Taiwan (Mitra 2002;Dow 2009b).However, it has not yet been formally reported from northeastern India.We observed it in Dzulekie on a tar road from Dzulekie to Benreu but did not find it elsewhere.Males were more commonly encountered than females: seven males and only two females were seen on 4 May 2012.Fraser (1933) had found this species breeding in "swift cold mountainstreams", whereas we observed two pairs in copulae oviposting in a small puddle adjacent to the tar road, at a considerable distance from the forest streams.9.
This species has so far been recorded from Thailand (Hämäläinen & Pinratana 1999), Vietnam (Asahina 1997), China (Sui & Sun 1984) and Myanmar (Fraser 1933).Its type locality is Leiktho, Toungoo District, Myanmar, and Fraser recorded it from several other localities in Myanmar.However, there have not been any prior records from India, and it was not listed among Indian odonates by Subramanian (2009).We recorded one male of this species in Khonoma on a cloudy day on the road from Khonoma to Mezoma on 17 May 2013.Our record represents an addition to the Indian odonate fauna, and the first record of the species from the Myanmar-northeastern Indian region in several decades.However, it is unsurprising to find this species in Nagaland, which adjoins Myanmar, and we suspect that more records will turn up as this area is further surveyed in the future. 10.
This species was described from "Chabong, Khunou, Manipur-Staat, 1200 ft." (Asahina 1984), which is presumably near Imphal, Manipur.SJ observed several individuals at Intanki NP between 15 and 18 May 2012.Unfortunately, all the voucher specimens were destroyed by ants, so we have no specimens to study now.The following observations are based on SJ's photographs and field notes.The characters differing from Asahina's description are given below for the male, and the female is described here for the first time.
Male: Distal half of segment nine and the whole of segment 10 bright yellow, not reddish-brown as mentioned by Asahina (Asahina's description of the color may be ascribed to post-mortem changes).Anal appendages are yellow, the structure matching illustrations in the original species description by Asahina.The color of the paraproct apex was variable: three specimens showed dark apices, two did not.
Female: Head: Vertex with a series of six pale blue spots: two between the anterior and the outer ocelli, two narrowly separated from the spots between the anterior and the outer ocelli and extending on the outer ocelli, and two spots on the outside of the outer ocelli.Eyes: black above, brilliant blue below.The spots on the posterior side of the head are large, similar to the male.Thorax: Prothorax: broadly citron-yellow.Posterior lobe citron-yellow above, black on sides.Pterothorax: two narrow pale blue antehumeral stripes, which gradually turn pale yellow posteriorly in some specimens while remaining pale blue in others (exact data on number of specimens of each type is unavailable due to loss of specimens as mentioned before).Mesepimeron and areas below citron yellow.Abdomen: blackish-brown for most part, pale brown below.Segments 2-8 with paired faint brown spots on dorsum.Segments nine and 10 fully yellow.Anal Appandages: black, short, like in the other female Coeliccia.
Distinguishing Characters: Coeliccia is a fairly large and complex genus, with 11 species so far known from India (Subramanian 2009).Without re-assessment of old specimens and studies of fresh material, a satisfactory key to this genus cannot be made.However, from the information currently at hand, the males of this species can be separated from other Coeliccia species by very large pale spots on dorsum of thorax and four small spots in the ocellar region.Female has a completely yellow prothorax which separates it from females of all Indian Coeliccia except for C. fraseri Laidlaw, 1932 andC. renifera (Selys, 1886).Of these, C. fraseri has segments nine and 10 black and C. renifera has segment 10 black, unlike in C. schmidti where both the segments are bright yellow.C. schmidti resembles C. renifera and C. loogali Laidlaw, 1932 in having six spots in the ocellar region.
The distribution of this species is not well known, very few records have been published, and nothing is known about its habits.Prasad & Varshney (1995) gave the distribution as "India".We observed several males and females of this species at Intanki National Park, including many pairs in copulae that were ovipositing in the submerged vegetation at Intanki River.

Table 1 . Details of the survey localities in Nagaland. Species Sex Date of collection Locality Accession Number
in Intanki, which is the first formal record of the species from northeastern India.The known odonate fauna of Nagaland now consists of 90 species classified in 53