Odonata (Insecta) diversity of Kuldiha Wildlife Sanctuary and its adjoining areas, Odisha, eastern India

A study was carried out to assess the Odonata fauna of Kuldiha Wildlife Sanctuary, Odisha, eastern India from November 2012 to October 2013. During the study a total of 54 species of odonates including 37 species of dragonflies (Anisoptera) and 17 species of damselflies (Zygoptera) were recorded. Among the dragonflies, the family Libellulidae was well represented with 30 species whereas among the damselflies, Coenagrionidae was well represented with seven species. Overall, the odonate fauna of Kuldiha Wildlife Sanctuary accounted for 49.09% of the odonate species known from Odisha and 10.73% of India. Therefore, further long-term studies on these lesser-known insect fauna in Kuldiha Wildlife Sanctuary will be useful in understanding their status over time.


INTRODUCTION
The order Odonata comprising both dragonflies and damselflies are believed to have evolved some 250 million years ago (Subramanian 2005). These aquatic insects being predators in both larval and adult stages are an important and widespread component of freshwater ecosystems (Adarsh et al. 2015) as well as valuable indicators of water quality and landscape disturbance (Watson et al. 1982;Castella 1987;Varghese et al. 2014). Globally around 5,952 species of odonates have been described; of which 503 species have been reported within the geographic limits of India so far (Joshi et al. 2017).
Odisha is one of the eastern coastal states of India and being situated along the amalgamation zone of Chhotanagpur Plateau, Eastern Ghats Highlands, Lower Gangetic Plain and the Eastern Coastal Plain's biogeographic provinces (Ray 2005), represents a mixture of both Indo-Malayan and Afro-Mediterranean biodiversity elements (Das et al. 2015). Odonata research in Odisha dates back to the early 1900s when Laidlaw (1915) andFraser &Dover (1922) studied the faunal diversity of Chilika Lake. Afterwards, as part of faunal expeditions, several collections were made from different parts of Odisha and the results of 58 species were documented in the state fauna series (Srivastava & Das 1987 (2017) reported 24 species from the Regional Institute of Education campus, Bhubaneswar. The vital information on diversity and distribution of odonates, however, is still missing from different parts of Odisha. Moreover, the increasing biotic pressure, deforestation and disappearance of wetlands are becoming major threats to odonates today. Therefore, documentation of Odonata from different geographic regions and habitats of Odisha is crucial for establishing baseline data for future comparison (Nair 2011). In this study, we summarize our findings of odonate fauna of Kuldiha Wildlife Sanctuary (KWS) in Odisha.

Study Area
The KWS ( Fig. 1) is situated along the tropic zone between 21.333-21.500 0 N and 86.500-86.750 0 E covering an area of 272.75km 2 in northern Odisha region. The landscape is characterized by undulating terrain and altitude ranges between 169-682 m. The climate is seasonal, with summer season between March to June, monsoon (July-October) and winter (November-February). The area receives an annual average rainfall of 1,460mm from the south-west monsoon and the temperatures range from 8°C in December to 42°C in June. Vegetation is mostly mixed deciduous type (Champion & Seth 1968). There are numerous perennial and seasonal hill streams and water bodies in and around KWS, which are habitats prefered by odonates.

Methods
While carrying out a biodiversity survey in KWS from November 2012 to October 2013, odonates were observed along hill streams, water bodies and temporary water logged areas. Whenever a species was encountered, its close up photographs were taken and later identified following the keys provided by Subramanian (2009) and Nair (2011); however, the species with confirmed identification were only taken under consideration for the checklist. The taxonomy and nomenclature of all the identified species followed Subramanian (2014). Based on the encounter rate of different species, we categorized them into five different groups such as very common (species encountered during 81-100 % of the survey days), common (61-80 %), occasional (41-60 %), rare (20-41 %) and very rare (less than 20%). To understand the significant difference in species richness between different months and seasons, a Chi-square test (χ²) was performed.

RESULTS AND DISCUSSION
During the survey, 54 species of odonates (Images 1-53) including 37 species of Anisoptera (dragonflies) and 17 species of Zygoptera (damselflies) were recorded from KWS (Table 1). In Anisoptera, the family Libellulidae was well represented by 31 species followed by Aeshnidae and Gomphidae (3 species each). Likewise, in Zygoptera Coenagrionidae was dominated by seven species followed by Calopterygidae and Protoneuridae (3 species each), Chlorocyphidae (2 species), and Platycnemididae and Lestidae with a single species each (Fig. 2). Our observations on family wise species richness are more or less similar with the earlier studies from different protected areas of Odisha (Sethy & Siddiqi 2007;Das et al. 2011;Nair 2011;Debata et al. 2013) and elsewhere in India (Varghese et al. 2014;Adarsh et al. 2015).
During the study period, a maximum of 51 species were encountered during the months of April and a minimum of 12 species during the month of January ( Fig. 3) and the observed species richness varied significantly between the months (χ² = 80.49, df = 11, p < 0.05). Similarly during seasonal analysis, a maximum of 51 species were recorded during summer and a minimum of 16 during monsoon (Fig. 3) and it also varied significantly between the seasons (χ² = 18.76, df = 2, p < 0.05). In terms of species encounter rate, a majority of 16 species were found to be occasional followed by 15 species as very common, 13 species as common, nine species as rare and one species as very rare (      www.threatenedtaxa.org The Journal of Threatened Taxa is dedicated to building evidence for conservation globally by publishing peer-reviewed articles online every month at a reasonably rapid rate at www.threatenedtaxa.org. All articles published in JoTT are registered under Creative Commons Attribution 4.0 International License unless otherwise mentioned. JoTT allows unrestricted use of articles in any medium, reproduction, and distribution by providing adequate credit to the authors and the source of publication.