New locality records and range extensions for several threatened species of Odonata in Sri Lanka

Sri Lanka is a tropical island nation with a rich Odonata fauna. About 50% of the recorded species from the country are currently known to be threatened with extinction at the national level. Many threatened species and newly discovered Odonata species in Sri Lanka lack reliable faunistic data, which is highly important for proper conservation assessments. An ongoing island wide Odonata survey was conducted opportunistically using visual encounter surveys that resulted in faunistic observations for over 80% of known species. We report 24 faunistic observations that result in range extensions for 10 species threatened with extinction, according to the findings of this ongoing survey. These records provide a better understanding of the current distribution of species, thus providing valuable information for future conservation assessments.

Sri Lanka is home to 121 species of Odonata with a valid taxonomic description (Bedjanič et al. 2014;Priyadarshana et al. 2015).These belong to 12 families and 67 genera (Bedjanič et al. 2014;Priyadarshana et al. 2015).Of the species that have been recorded, 47 are known to be endemic to the island.Recent studies have reported that several other species of Odonata are currently in the process of being taxonomically described (van der Poorten and Conniff 2012; Bedjanič et al. 2014).
Even though new species continue to be described from Sri Lanka, there are gaps in the current knowledge of ecology and distribution of these fauna, especially regarding endemic and threatened species.Recent work by Bedjanič et al. (2014) compiled historical faunistic records and recent survey findings, documenting the distribution of Sri Lankan Odonata.However, there are many species with few recorded observations, thus their actual distribution ranges need more research.
Distribution range is an important criterion that has been used in determining National Conservation Status (NCS) of the Sri Lankan odonate fauna.According to the latest national conservation status assessment of Odonata, which followed IUCN Red List categories and criteria version 3.1, there are 61 threatened species (including 40 endemics) and 11 data deficient species (including nine endemics) in Sri Lanka (MOE 2012).An independent assessment carried out by Bedjanič et al. (2014) using a more complete data set and assessing the conservation status of endemic Sri Lankan Odonata listed 39 threatened endemic species and two data deficient endemics.As extent of occurrence (EOO) and area of occupancy (AOO) are the key measures in criterion B of IUCN Red List Categories and Criteria Version 3.1 (IUCN 2012), the more observations of a particular species from different localities the more accurate their conservation status, as EOO and AOO increase with increasing number of faunistic records.The results of the conservation assessment by Bedjanič et al. (2014) have been proposed as the Global Conservation Status (GCS) assessment for Sri Lankan endemic Odonata (Bedjanič et al. 2014).
Understanding the distribution range of a species is critical to determine conservation priorities, plan further studies, and design conservation actions.This is particularly important for poorly known species, such as endemics under extinction risk and recently described species without reliable data.Here, we report new locality records for 10 poorly known species of Odonata, ensuring a better conservation assessment of the taxa and providing a better opportunity for the in-situ conservation of threatened species in the future.
Surveys were carried out as a part of an ongoing island wide survey to document the current distribution of Odonata in Sri Lanka.Locations were surveyed op portunistically.Observations were made using National conservation status of each recorded species was assigned according to the National Red List 2012 of Sri Lanka (MOE 2012).Current Global Conservation Status (Bedjanič 2006(Bedjanič , 2009;;Dow 2009;IUCN 2015) and the Proposed Global Conservation Status by Bedjanič et al. (2014) are also listed for each species.
The surveys resulted in distribution records for over 80% of the Odonata species that have been recorded in Sri Lanka with new records on very rare and highly threatened species.This paper presents the records that extend the known distribution of 10 highly threatened species (Table 1).
visual encounter survey method and specimens were identified in the field using morphological characters.No specimens were collected.Photographs were taken to confirm identifications by comparison with the most updated literature (de Fonseka 2000; Bedjanič et al. 2006Bedjanič et al. , 2014;;van der Poorten 2009van der Poorten , 2012;;Bedjanič 2013;Conniff and Bedjanič 2013).Locations were recorded either by using handheld GPS receiver units or using Google Earth™ software.Published distribution records (Bedjanič et al. 2014;Udagedara and Kularatne 2015) were used to create the previously known distribution ranges for the maps.  1) is a recently described damselfly in the family Chlorocyphidae.It is a small, black damselfly with some yellow markings.Males of this species can be easily identified, as it is the only Sri Lankan Libellago species that does not have a humeral stripe.Libellago corbeti is known from lowland rainforest streams in the southwestern wet zone of Sri Lanka (van der Poorten 2009Poorten , 2011;;Bedjanič et al. 2014).Records presented here (Figure 2) are from Yagirala Forest Reserve (Kalutara district) and Makandawa Forest Reserve (Kegalle district).A single male was sighted at Makandawa Forest Reserve while males, females and oviposition were recorded from Yagirala Forest Reserve.It is an uncommon species that inhabits marshes and pools with riparian vegetation.This species can be identified using the colour patterns on abdominal segment 9 and the structure of the male's anal appendages.A single Indolestes divisus male was sighted at a small water body located inside the dry-mix evergreen forest in Wilpattu National Park (Anuradhapura district).Another male was recorded from a forested home garden in Hakmana, Matara district (Figure 4).This rare species belongs to the family Platystictidae and has a distribution in the montane zones of Sri Lanka between 500−1,400 m.It has been recorded from both the central hills and Rakwana mountain range.The field identification of the species is based on the golden yellow median lobe in the prothorax, a golden yellow thoracic stripe and light blue markings restricted to the last three abdominal segments (Bedjanič et al. 2014).A single Ceylonosticta hilaris male (Figure 7) was recorded near a small seepage running along the road leading to the Riverston mountain peak (Matale district) on the northern flank of Knuckles Mountain Forest Range (Figure 8).Bedjanič, 2013 -endemic NCS: Not Evaluated by MOE (2012) GCS: Not Evaluated (IUCN 2015) Proposed GCS: Vulnerable (Bedjanič et al. 2014) This is a recently described gomphid.It has been recorded from several locations in the dry zone along rivers (Bedjanič 2013;Bedjanič et al. 2014).This species (Figure 9) can be distinguished in the field from the only other Sri Lankan Paragomphus by the presence of two pairs of yellow spots on abdominal segments 3−7, a narrow humeral stripe, more curved superior anal appendages and shorter and strongly up-turned inferior anal appendages (Bedjanič 2013).The records presented here (Figure 10) were made on the bank of Amban Ganga (Amban river) at Orubandisiyambalawa (Matale district) where one male was sighted and at two locations in Pathaha (Badulla district) where three males and one female were sighted.The male observed at Orubandisiyambalawa was perched on a boulder and the males observed at Pathaha were perched either on a   Macromi idae (Carle et al. 2015) that inhabits forest streams in the wet zone (Bedjanič et al. 2014).The field identification of the species can be based on their metallic green eyes, black thorax with a bluish metallic sheen, and yellow markings including a prominent antehumeral stripe.A teneral male (Figure 11) was observed hanging from vegetation along a small irrigation canal located in the Gal Oya National Park (Monaragala district) (Figure 12).zone of the island (Bedjanič et al. 2014).In the field it can be distinguished based on the metallic black thorax and the three short yellow stripes that start from the ventral side of the thorax and extend up to the middle of its lateral surface.The records presented here (Figure 14) are of a female observed close to a stream, resting on an exposed stick approximately 1 m above ground in Morapitiya-Runakanda Forest Reserve (Kalutara district), a female observed ovipositing in a very shallow sandy bottomed area along a large stream at the border of Madakada Forest Reserve (Kalutara district), a male observed resting on a twig at Dombagaskanda Forest Reserve (Kalutara district), and several males observed flying near streams at Makandawa Forest Reserve (Kegalle district).

Paragomphus campestris
Hylaeothemis fruhstorferi (Karsch, 1889) -endemic NCS: Critically Endangered (MOE 2012) GCS: Endangered (Dow 2009) Proposed GCS: Critically Endangered (Bedjanič et al. 2014) This is a rare Sri Lankan species in the family Libellulidae.It was first described from Balangoda (Ratnapura district) but recently it was only known from localities around Kudawa, Sinharaja area (Bedjanič et al. 2014).Hylaeothemis fruhstorferi (Figure 15) can be identified in the field by its slender abdomen, metallic blue frons and black body characteristically marked in yellow or pale blue.Single males of the species were recorded from Makandawa Forest Reserve (Kegalle district), Adawikanda, Erathna (Ratnapura district), Kalugala Proposed Reserve and Yagirala Forest Reserve located in Kalutara district, extending its distribution range (Figure 16).Kirby, 1894 -endemic NCS: Endangered (MOE 2012) GCS: Endangered (Bedjanič 2006) Proposed GCS: Vulnerable (Bedjanič et al. 2014) Tetrathemis yerburii (Figure 17) is widespread across the low country and lower hills in southwestern Sri Lanka, wherever forested habitats are present (Bedjaničet al. 2014).This small dragonfly can be easily identified in the field by its metallic blue-green eyes and characteristic yellow markings on a black thorax and abdomen.The present record was reported from Gal Oya National Park (Figure 18) close to the border of the intermediate and the dry zone of the country (SLSD 2007).A single male was observed in a small stream close to the location where Gal Oya (Oya=large stream) opens to the large irrigation tank, Senanayake Samudraya (Monaragala district).Proposed GCS: Not Evaluated (Bedjanič et al. 2014) In Sri Lanka, this is a rare species from the family Libellulidae.It can be identified in the field by its dark abdomen with thin yellow markings, characteristic yellow thoracic markings, pale colour face, and metallic blue frons.Hitherto it has only been recorded from the forests in the wet zone (Bedjanič et al. 2014).A female Cratilla lineata calverti (Figure 19) was observed at Ritigala (Anuradapura district) and another female was observed in a forested home garden at Hakmana (Figure 20).

Tetrathemis yerburii
Out of the 24 distribution records presented, eight were recorded outside the existing protected area network of Sri Lanka.These observations indicate that not only the protected areas are important for conservation of threatened species, but also habitats outside them.This highlights the importance of public awareness for the protection of critical habitats outside the protected areas.It also highlights the importance of incorporating non-protected areas in species surveys, so areas with rich biodiversity may be identified and included in plans to expand conservation areas.
The record of Cratilla lineata calverti from Ritigala, a location within the dry zone of Sri Lanka with a microclimate comparable with the submontane area (DWC 2008), suggests that this species might also inhabit localities in the dry and intermediate zones.The record of Tetrathemis yerburii at the border of intermediate and dry zone of Sri Lanka also suggests that this species has a wider distribution in the intermediate zone than previously assumed.Seven of the range extensions reported here are from the intermediate zone or the dry   zone of Sri Lanka.This highlights the need for proper odonatological surveys in both climatic zones, especially in the wet habitats and riverine forests.
Most of the threatened species recorded in this study are considered rare species with few reliable distribution records, according to available literature.Three of the species observed (A. lieftincki, P. campestris, and H. fruhstorferi) are known from fewer than 10 localities at present.However, some of the known locality records of these rare species were made several decades ago (de Fonseka 2000; Bedjanič et al. 2014).Thus, it is possible that the species may no longer occur at some of the reported localities, considering the significant habitat loss that has taken place in the country during recent decades (IUCNSL and MOENR 2007).Therefore, records provided here are important for understanding the current distribution and conservation status of these rare and threatened odonates.
All observations reported agree with known flight seasons for the recorded species and many were found during peak months of activity according to previous records (Bedjanič et al. 2014).This helps delimit flight seasons and future surveys on these species will have a better chance of success if carried out in the identified flight seasons.
The new locality records and range extensions presented here reveal a gap in available information on the distribution of rare and threatened Odonata in Sri Lanka.Further odonatological surveys are necessary to more accurately define the conservation status of species.Systematic surveys are needed for protected areas and their vicinity, wet habitat patches in the dry and intermediate areas, and natural habitats outside the established protected area network.Those surveys will help to increase our understanding of the unique Sri Lankan odonate diversity.

Figure 8 .
Figure 8. Distribution of Ceylonosticta hilaris with new localities.Figure 10.Distribution of Paragomphus campestris with new localities.

Figure 20 .
Figure 20.Distribution of lineata calverti in Sri Lanka with new localities.

Table 1 .
Observations on the Odonata species recorded (FR=Forest Reserve, NP=National Park, PR=Proposed Reserve).