Range extension and larval habitat of Lyriothemistricolor Ris, 1919 (Odonata:Anisoptera: Libellulidae) from southern Western Ghats, India

K.S. Anoop Das ¹, K.A. Subramanian², K.G. Emiliyamma ³, Muhamed Jafer Palot⁴ & K.A. Nishadh ⁵

¹ Centre for Conservation Ecology, Department of Zoology, M.E.S. Mampad College, Malappuram, Kerala 676542, India

^1,5 Wildlife Research and Conservation Trust, Anupallavi, Chungathara P.O., Malappuram, Kerala 679334, India

² Zoological Survey of India, Prani Vigyan Bhavan, M-Block, New Alipore, Kolkata, West Bengal 700053, India

^3,4 Western GhatRegional Centre, Zoological Survey of India, JaferKhan Colony, Kozhikode, Kerala 673006, India

⁵ Environmental Impact Assessment Division, Sálim Ali Center for Ornithology and Natural History, Anaikatty P.O, Coimbatore, Tamil Nadu 641108, India

¹ dasksa@gmail.com, ² subbuka.zsi@gmail.com (corresponding author), ³ kgemily@gmail.com,⁴ palot.zsi@gmail.com, ⁵ nishadhka@gmail.comt

Abstract: Worldwide many species of odonates are known to use phytotelmataas a breeding habitat. Hitherto, no species are known to breed in phytotelmatain India. However, field studies conducted in the southern Western Ghats revealed that Lyriothemis tricolor Ris, 1919 (Libellulidae) uses tree holes as a larval habitat. Here we report the range extension of L.tricolor to southern Western Ghats and describe morphology of the larva, exuvia, and adult female. Based on the present study, we describe the larval habitat of L. tricolorin the southern Western Ghats. Our findings reveal that L. tricolor breeds in the tree holes of evergreen and semi-evergreen forests in the southern Western Ghats.

Keywords: Evergreen forests, Lyriothemis tricolor, phytotelmata, Western Ghats.

doi: http://dx.doi.org/10.11609/JoTT.o3716.5237-46 | ZooBank:urn:lsid:zoobank.org:pub:D6B644A0-CC4A-4101-AFEE-156F1F6260C1

Editor: K.G. Sivaramakrishnan, Madras Christian College, Chennai, India. Date of publication: 26 December 2013 (online & print)

Manuscript details: Ms # o3716 | Received 19 July 2013 | Final received 27 November 2013 | Finally accepted 04 December 2013

Citation: Das, K.S.A., K.A. Subramanian, K.G. Emiliyamma, M.J. Palot & K.A. Nishadh (2013). Range extension and larval habitat of Lyriothemis tricolor Ris, 1919 (Odonata: Anisoptera: Libellulidae) from southern Western Ghats, India. Journal of Threatened Taxa 5(17): 5237–5346; http://dx.doi.org/10.11609/JoTT.o3716.5237-46

Copyright: © Das et al 2013. Creative Commons Attribution 3.0 Unported License. JoTT allows unrestricted use of this article in any medium, reproduction and distribution by providing adequate credit to the authors and the source of publication.

Funding: Funding to ADKS was provided by Critical Ecosystem Partnership Fund, USA under the Western Ghats Small Grant through ATREE.

Competing Interest: The authors declare no competing interests.

Author Details: K.S. Anoop Das works on ecology of tree hole insect communities and conservation biology of birds. K.A. Subramanian works on taxonomy, ecology and biogeography of aquatic insects. K.G.Emiliyamma works on taxonomy of Odonata and Dermaptera. Muhamed Jafer Palotworks on taxonomy and ecology of butterflies, odonates, reptiles and birds. K.A. Nishadhis a research scholar.

Author Contribution: KSAD obtained funding and permissions, conducted field surveys in SVNP and NARF during 2009–2010, collected the larvae and documented physicochemical parameters of tree holes with KAN. KAS identified larvae collected from SVNP, compared the exuviae collected from SABS, analysed the data and wrote the manuscript. KGE identified the female species collected from SABS and described the female. MJP conducted field surveys in SABS, collected the female with exuviae. KAN conducted field surveys with KSAD.

Acknowledgements: The authors extend their gratitude to the Director, Zoological Survey of India for providing facilities to conduct the study. We thank the Department of Forests and Wildlife, Kerala, for permissions and support to conduct this study. ADKS thank Idea Wild, USA, for equipment grant and Principal, M.E.S Mampad College, for support. We also thank Dr. Giby Kuriakose for identification of tree species from Thattekkad.

This article forms part of a special series on the Western Ghats of India, disseminating the results of work supported by the Critical Ecosystem Partnership Fund (CEPF), a joint initiative of l’Agence Française de Développement, Conservation International, the European Commission, the Global Environment Facility, the Government of Japan, the MacArthur Foundation and the World Bank. A fundamental goal of CEPF is to ensure civil society is engaged in biodiversity conservation. Implementation of the CEPF investment program in the Western Ghats is led and coordinated by the Ashoka Trust for Research in Ecology and the Environment (ATREE).

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INTRODUCTION

Aquatic habitats in tree holes are one of the four broad categories of phytotelmata. They are known to support diverse insect orders including Odonata (Orr 1994; Kitching 2000). Worldwide 24 genera and 47 species of Odonataare known to make use of phytotelmata (Corbet 1999). The phytotelmata as a larval habitat has been reported from all major tropical biogeographic regions of the world except the Indian subcontinent (Corbet 1999). Here we report for the first time, the use of phytotelmata as a larval habitat in India by Lyriothemis tricolor Ris, 1919 and a range extension for this species from the Western Ghats.

STUDY AREA

The current discovery is based on field studies conducted at Silent Valley National Park (SVNP) in Palakkad District, New AmarambalamReserved Forest (NARF), Malappuram District and Salim Ali Bird Sanctuary (SABS), Thattekkadin Ernakulam District of Kerala Western Ghats (Image 1). Studies at SVNP and NARF were conducted from December 2009 to September 2010 and at SABS in April 2013. The details of vegetation types and the bioclimatic features of the study area are provided in Table 1.

METHODS

The larvae from SVNP and NARF were collected by the first author and junior co-author in 2010 as part of a study whichinvestigated the insect communities in tree holes (Nishadh& Das 2012). A total of 150 tree holes were sampled from three regions of the SVNP, namely, Sairandhri (n=68), Poochippara(n=34) and Walakkad (n=35) whereas in NARF tree holes were mostly sampled from Panapuzha (n=13) (Image 2).

The physical and structural characteristics of tree holes were documented as follows. For every tree hole sampled, the following were recorded: tree species, height of the tree hole from the ground, GBH of the tree, tree hole diameter measured as two longest hole opening measurements perpendicular to each other (Sota 1998), depth and water volume.

Water in a tree hole was extracted using siphoning, and volume was measured using a measuring cylinder. The contents of the tree hole such as leaf litter and detritus were transferred to a plastic tray and thoroughly checked for the presence of life forms. Thorough checks were made with the aid of a flashlight for elusive organisms in tree hole crevices. The water contents were then sieved with successive sieves from coarse to finer sieves (cc-500μm sieve size) by holding in a plastic tray. The organisms were counted and morpho-species preserved in 5% formalin (Yanoviak & Fincke2005). The collected specimens were sorted out and identified to possible taxonomic level of family or genus referring to Edmondson (1959).

Physicochemical parameters of the water from the tree hole were studied based on Greenberg et al. (1992). Water samples from tree holes were collected using a suction rubber bulb, tube and stored in laboratory cleaned bottles. The samples were taken to the laboratory and analysed immediately. pH, electrical conductivity (EC, μS/cm), total dissolved solids (TDS, ppt), phosphate (mg/l), nitrate (mg/l), turbidity (FAU), sulphate (mg/l), and ammonia concentrations were analysed following standard methods (Greenberg et al. 1992).

During a faunistic survey at SABS, on 03 April 2013, a female specimen was collected from Anachathaparaarea of the sanctuary. A freshly emerged female specimen with exuvia was sighted on the bark of a Lannea coramandelica(Houtt.) tree at a height of about 5m from the ground (Image 3). The collection locality is primarily a degraded semi-evergreen forest, interspersed with Mahogany and Teak plantations. The area is very close to the lake formed by the Boothathankettu Dam. We observed the specimen in a bottle for 10 days. Initially the specimen was pale yellow in colour with light brown markings on the head. After two days the colour drastically changed to darker and brighter.

The Anisopteran larvae collected from SVNP were identified up to the genus level following keys of, Xiufu(1994). Collected Lyriothemis larvae were compared with published descriptions of larval stages of Lyriothemisspecies (Lieftinck 1962; Lien & Matsuki 1979; Kitching 1986; van der Poorten 2009). The adult collected from SABS was identified based on keys of Fraser (1936) and van der Poorten(2009). The larvae were studied and compared with the exuvia collected from SABS. Body measurements and morphological characters of exuvia and larvae were studied under Leica EZ4HD and M205A microscopes.

RESULTS

The adult female collected from SABS was identified as Lyriothemis tricolor Ris, 1919 based on descriptions of Fraser (1936). The morphological characters of the larvae matched the descriptions of Lyriothemis tricolor Ris, 1919 (Lien & Matsuki 1979). However, the larvae had nine palpal setae instead of eight as described by Lient & Matsuki 1979. The morphological characters of the exuvia also matched that of larvae collected from SVNP and NARF which were also identified as belonging to that of Lyriothemis tricolor Ris, 1919. The detailed description of the larvae, exuviaand adult are as follows.

Materials examined: Adult female with exuvia(1 pinned): ZSI/WGRC/IR-INV-2659, 3.iv.2013, (Images 4–6), (10.132256⁰N & 76.685815⁰E; 68m), Anachathapara, Salim Ali Bird Sanctuary, Thattekkad,Ernakulam District, Kerala, India, coll. Md. Jafer Palot.

Exuvia (Images 7–8): Dark brown coloured and similar to the larvae in morphological characters. The measurement of exuviais provided in Table 2. The palpal lobe was dissected out and digested in 10% KOH at room temperature for 24hr and photographed under the Leica microscope. The palpallobe has nine palal setae, similar to that of larvae (Image 17).

Materials examined: Larvae (3 nos. in alcohol) : 4911/H13 (MIO Section, ZSI, Kolkata), 26.vii.2010, (Images 9–16), (11.111⁰N & 76.422⁰E; 1030m), Poochippara, Silent Valley National Park, Palakkad District, Kerala, India, coll. Anoop Das & Nishadh.

Description (Images 9–16): Larvae are uniformly rusty brown in colour and covered with short light brown hairs. Overall body texture is rough. Eyes are conical and pointed outwardly with metallic brown gloss under preserved condition. Antenna is eight segmented with 4^thsegment being the longest. Prementum of labium is an elongated pentagon with two anterio-lateral ovoid projections. Apex of the prementumends in a tubercle-like projection. The inner side of the prementum has 11 premental setae on either side. Palpal lobe is shovel-shaped with nine palpal setae. The anterior end of the palpal lobe has a thick spine. The occiput of the head has nine bald oval patches. In larva-01 the forewing pads extend to the 3^rd abdominal segment and in larvae 02 and 03 it reaches up to the 6^th abdominal segment. The legs are short and abdomen is ovoid. A single row of dorsal spines present from abdominal segments 3–9. The lateral spines of segment 9 reach half the length of paraproct. The cerci are shorter than epiproct and praproct is longer than epiproct. The measurements of larvae are provided in Table 2.

Adult female (Images 4–6)

Body measurements: Hind wing: 38mm. Abdomen: 31mm. Head: Labium yellow, middle lobe dull brown, lateral lobe yellow; mandible yellow with brown at centre; labrumbrownish-black, a thin yellow stripe at base; labium and mandible with golden brown hairs along the border; anteclypeus dull yellow with brown shade medially; postclypeus bright yellow with median oval dark brown mark and dark brown edges; anterior surface of frons bright yellow, upper surface of frons and vesicle metallic green; occiput shining black; clypeus and frons with black hairs. Eyes: Reddish-brown above, bright yellow below and on sides. Prothorax: Yellow with pale brownish shade at the middle lobe. Thorax: dorsum with broad brownish shade; humeral suture with a broad black stripe; two short, oval antehumeral yellow spots as in male; laterally yellow with a thin brown stripe on mesepimeron and a similar stripe on posterolateral suture; tergumyellow; underneath thorax bright yellow with a brownish-black transverse stripe at the middle. Legs: black; all coxae yellow; trochanters yellowish brown. Wings: transparent, extreme base (anal field), cubital space and subcostal up to first nervure bright amber yellow; pterostigmablackish-brown, covering 3 cells; membrane blackish-brown; discoidalcell traversed in all wings; 1 cubital nervure in forewings and 2 in hindwings; subtrigonein forewings traversed once, 2 celled; arc a bit proximal to second antenodal nervure; 3 rows of cells at beginning of discoidal field; nodal index:

12–18 / 17–11

12–16 / 13–11

Abdomen: Bright yellow with brownish-black median ridge from segments 2–7; lateral edges broad blackish-brown from segments 3–8; segments 3–7 with diffused brownish markings (not clear marking, irregular spots and stripes); segments 8–10 yellowish-brown. Anal appendage: brown, short, conical; vulvar scale very small, (not developed properly); segment 8 not dilated.

Habitat ecology

A total of 18 larvae of L. tricolorwere collected from 15 tree holes of Sairandhri(n=8), Poochippara (n=3), Walakkad(n=0), Aruvanpara (n=4) and Panapuzha(n=3). Due to logistic reasons in the field, no attempt was made to raise the larvae to adulthood. Out of 150 tree holes sampled at an altitude range of 40–1175 m, only 10% of tree holes were occupied by the larvae of L. tricolor. No larvae were found in tree holes from Walakkad, SVNP. The tree holes with Odonata larvae were distributed from 600m to 1056m. The structural, water quality and associated biotic communities of the tree holes with the Odonata larvae are provided in Tables 3–6. Since many of the tree holes were remotely located in the forests or samples collected during the rainy days, it was not possible to take back the water sample to the laboratory for analysis. Hence these water samples were not analysed for physical and chemical properties. Tree holes without water quality data are indicated in the tables. All the larvae were collected between March and September 2010 from host trees such as Tetrameles nudiflora R. Br. (Tetramelaceae),Elaeocarpus tuberculatus Roxb. (Elaeocarpaceae), Albizia lebbeck (L.) Benth. (Fabaceae), Myristica dactyloides Gaertn. (Myristicaceae),Holigarna arnottiana J.Hk. (Anacardiaceae) and a few unidentified tree species.

Physicochemical parameters of water collected from the tree holes show that the water is generally acidic with high levels of total dissolved solids, phosphates, sulphates and nitrates. The pH varied from extremly acidic to (pH 3.56) to near neutral (pH 6.48).

A diverse community of invertebrates and vertebrates coexist with L. tricolor larvae (table 6). Larvae and adults of Coleopteraand Diptera were very common in the tree holes. Three tree holes had frogs (Microhylidae: Ramanellasp.) and earthworms. Nematodes, and crabs were found only in one tree hole. It is not known how the different taxa interact in the community. However, the presence of predatory larvae of L. tricolor may significantly influence the community structure of tree holes.

DISCUSSION

The genus Lyriothemis with 15 species are exclusively found in Asia from Western Ghats to Japan (75–127 ⁰E) (Schorr & Paulson 2013). The habitat of five species of Lyriothemis has been reported as marshy forested habitat across its geographic range (van derPoorten 2009). Four species of Lyriothemis i.e., L.bivittata (Thailand), L. cleis(Borneo, Sulwesi), L. magnificata(Malaysia) L. tricolor (Taiwan) are known to use phytotelmata as larval habitat (Corbet 1999). In Taiwan, L. tricolor has been reported using phytotelmata (Lein& Matsuki 1979). Within the Indian subcontinent, four species of Lyriothemis, viz., L. acigastra (Selys, 1878), L.bivittata (Rambur, 1842), L. cleis Brauer, 1868, L. tricolor Ris, 1919 were reported earlier (Fraser 1936; Mitra2002). Recently a new species Lyriothemis defonsekaiwas reported from Sri Lanka (van der Poorten 2009) and the range of L. acigastra was extended to the Western Ghats (Emiliyamma et al. 2013). Within its geographical range in Asia, L.tricolor was known to occur only up to 26⁰N & 89⁰E in Rajabhatkhawa in Buxa Tiger Reserve, West Bengal (Fraser 1936). Our discovery of this species from the southern Western Ghats extends the eastern range of the species to 11⁰N & 76⁰E in the Indian subcontinent.

The larvae and exuvia of L. tricolor collected from Western Ghats has nine palpal setae and 11 prementalsetae similar to that of L. elegantissima Selys, 1883 (Lien & Matsuki1979). However, the final instar larvae of L. elegantissima ismuch smaller (17.6–19 mm) than the L. tricolorlarvae (21.5–24 mm) (Lien & Matsuki1979). Moreover, the characters of adult female match that of L. tricolor andL. elegantissima is not distributed in the oriental region. Hence, L. elegantissima is excluded and the variation observed inpremental and palpal setae of L. tricolor from Western Ghats may be due to intraspecific variation of different disjunctpopulations of the Indian subcontinent. Long isolation of populations may have favoured some genetic changes such as changes in the number of premental and palpal setae. Genetic studies are required to ascertain taxonomic status of Western Ghats populations of L. tricolor.

These recent discoveries highlight the disjunctdistribution of the genus within the Indian subcontinent. It has been proposed that the disjunct distribution of the genus in the southern part of the subcontinent is caused by passive or active wind dispersals (Laidlaw 1951; Dijkstra 2007) or movement along corridors along the east coast of India during the Pleistocene (Laidlaw 1951). In the Western Ghats, in addition to Lyriothemis, libellulids such as Hylaeothemis indica Fraser, 1946, Epithemis mariae (Laidlaw, 1915) and the recently discovered Lyriothemis acigastra(Selys, 1878) (Emiliyammaet al. 2013) are found exclusively in lowland forest swamps. Zygopteranspecies such as Phylloneura westermanni (Selys, 1860), Melanoneura bilineataFraser, 1922 and Calocypha laidlawi (Fraser, 1924) are also restricted to such forest swamps. Currently, these forest swamps and associated odonates are found in small patches in the north and south of the Palakkad gap. Lowland forest swamps once existed extensively throughout the southern Western Ghats. They were drained, deforested and converted for agriculture during early human colonization (Chandran 1997). The extent of lowland forest swamps and associated odonate species are highly fragmented in the Western Ghats.

Recent palynological studies provide evidence that species-rich rain forests and swamps were once widespread in the Indian subcontinent during early palaeogene times (Prasad et al. 2009). After India-Asia collision during the quaternary and recent times, climate changed dramatically and the subcontinent became much drier climatically, leading to the disappearence of wet forests in most parts of peninsular India. Wet forests with a dominance of Dipterocarpaceae disappeared from most parts of peninsular India during the cenozoicperiod (Shukla et al. 2013). However, the southern Western Ghats, with its unique topographic features, high precipitation and shorter periods of dry months provided refugia to sustain lineages of ancient tropical vegetation (Prasad et al. 2009). The existence of many ancient lineages of amphibians, fishes, reptiles and odonates in the southern Western Ghats also support the palynologicalevidence that this part of the Western Ghats was a rainforest refugia during the drier Pleistocene period when most of the tropical rainforests from other parts of the subcontinent disappeared (Abraham et al. 2013). Extant species of Lyriothemis in the southern Western Ghats and Sri Lanka may in fact be the relict populations of Palaeogene times when tropical rainforests and forest swamps extensively covered the subcontinent and not wind dispersals or migration through land corridors as suggested earlier (Laidlaw 1951; Dijkstra 2007). However, detailed molecular phylogenetic studies are required to further investigate this hypothesis.

Larvae of Lyriothemis tricolor being a predator in the tree hole community, may play a significant role in structuring the community composition of tree hole breeding insects. Studies on L. cleisat Sulawesi (Kitching, 1986); L. tricolor and L. elegantissimaat Taiwan (Lien & Matsuki 1979) suggest that they act as top level predators within treeholefood web (Kitching 1986). Similarly, L. cleislarvae were observed in Bornean rain forest tree hole aquatic habitat (Orr 1994). The breeding habitat of L. tricolor is very different from the other species of the Western Ghats. The larvae live in extreme conditions where the pH is as low as 3.6 and with high levels of total dissolved solids, phosphates, sulphates and nitrates (Paradise 1997). High levels of nutrients and low pH is also reported from other tree hole aquatic medium such as in North America (Paradise & Kuhn 1999), Panama (Yanoviak 1999) and Germany (Schmidlet al. 2008). This is due to degradation of litter and and woody debris. Studies have shown that tree hole inhabiting larval species, especially the Odonatahave a broad range of chemical tolerance (Fincke 1999;Yanoviak 1999).

This indicates the specialization of larvae to survive in extreme water quality conditions. The low pH also might influence the growth of certain key inhabitants and impact community interactions by affecting the processing chain commensalisms that occur in tree hole aquatic habitats. Therefore, the usability of tree hole habitats can be considered as a bio-indicator of forest ecosystem towards acidic deposition (Paradise & Dunson1997). The limited availability of suitable tree holes with the right microhabitat and climatic conditions may significantly influence the distribution of L. tricolorwithin the Western Ghats. The discovery of a tree hole breeding dragonfly highlights the importance of tropical forests in conserving Odonatafauna of the Western Ghats and also emphasises the need to consider the larval habitats in conservation action plans.

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