New records of odonates from Trongsa and Zhemgang, central Bhutan with a checklist of Jigme Singye Wangchuck National Park

: New records of 43 species of dragonflies and damselflies from Trongsa and Zhemgang districts in central Bhutan are provided. Two of these, Watanabeopetalia atkinsoni (Selys, 1878) and Tetrathemis platyptera (Selys, 1878), are new to Bhutan bringing the number of species known from Bhutan to 125. A checklist of the 60 species known from Trongsa district, Zhemgang district and the Jigme Singye Wangchuck National Park is provided.


INTRODUCTION
In the last few years, an increasing number of studies were published on the dragonflies and damselflies of Bhutan with numerous species being reported new to the country.The checklist published by Gyeltshen et al. (2017) included 92 species and that of Kalkman et al. (2020) contained 114 species.A further nine species were recorded by Gurung et al (2021) bringing the total to 123 species.Rasaily et al. (2021) provided an overview of the odonates of Bhutan with a checklist, distribution maps, data on phenology, and altitudinal distribution for all species.The dragonfly and damselfly fauna of Bhutan compared to adjacent region in the eastern Himalaya, is relatively well known although it is likely that more species remain to be discovered.Most of the studies on Bhutanese odonates were carried out in non-protected areas with limited field survey periods and proximity to the main roads.Data on the occurrence of dragonflies and damselflies in the protected areas is scant in Bhutan.
Here, we present distribution data collected in 2021 of 43 species of odonates from Trongsa and Zhemgang districts.Part of these records originate from the Jigme Singye Wangchuck National Park (JSWNP).These records include two species new to Bhutan.

MATERIALS AND METHOD
Opportunistic sampling was carried out from 23 April 2021 to 20 May 2021 during the pre-monsoon and 18 October 2021 to 05 November 2021 during the post-monsoon season in two districts-Trongsa and Zhemgang in central Bhutan (Figure 1)-along an altitudinal gradient stretching from 400 m to 2,800 m.The survey was conducted from 0900-1500 h in suitable habitats such as brooks, wetlands, ponds, paddy fields, and rivers.Odonates were photographed using a Nikon D5600 DSLR camera attached to Nikkor 70-300 mm zoom lens during the survey.Common species were identified in the field following Gyeltshen et al. (2017).Species which could not be identified in the field were captured using an insect sweep net and brought to the College of Natural Resources, Royal University of Bhutan lab for examination.All specimens collected from this study were deposited in the College of Natural Resources Museum.The specimens were examined under the microscope and were identified using the taxonomic monograph of Fraser (1933Fraser ( , 1934Fraser ( , 1936) ) and Karube (2002).All species identifications are based upon adult specimens except for two records of Perissogomphus stevensi and one records of Neurobasis chinensis which were identified from larvae.

List of localities (Figure 1)
All observations were made by the first author unless specified otherwise.Some localities were visited multiple times and in these cases a, b, c, or d indicates the date on which they were visited (see list of localities).'X' denotes those cases where a locality was visited multiple times but the date on which a species was recorded is unknown.

RESULTS
Our survey resulted in 43 new species records of from Trongsa and Zhemgang, Central Bhutan.In addition, 17 other species were recorded from these dzongkhags (provinces) in previous publications bringing the total to 60 species belonging to 16 genera and 11 families (Table 1).Two of the species recorded by us, Watanabeopetalia atkinsoni and Tetrathemis platyptera, are new to Bhutan bringing the total number of species known from the country to 125.
All 37 localities from which we present records are in Trongsa and Zhemgang districts with the exception of locality 26 which is in Samdrupjongkhar district.This is however included here in order to include a second record of T. platyptera.

List of species recorded Anisoptera (dragonfly) Family Aeshnidae
1. Aeshna petalura (Martin, 1908) or more (Chlorogomphus) cross veins in the median space or both fore and hindwing (none in members of Cordulegastridae).Watanbeopetalia can be distinguished from other species of Chlorogomphidae occurring in the eastern Himalayan region by the presence of two broad yellow stripes, one on mesepimeron and one on metepimeron, on the side of the thorax and by the front of face being light brown without well-defined yellow markings.Four Watanabeopetalia species have been described: W. atkinsoni (Selys, 1878), W. ojisan (Karube, 2013), W. uenoi (Asahina, 1995) and W. usignata (Chao, 1999) (Paulson et al. 2021).From these four species only W. The characters and body coloration of the two male specimens of Bhutanese Watanabeopetalia atkinsoni match well with the original description (Karube 2002).As this species is poorly known we provide additional figures of the species in life and details of the abdomen, wings and appendages (Image 1).Karube (2002) mentions that abdomen S1-8 is black with yellow markings and that S9-10 is either completely black or black with narrow yellow rings (Image 1B).This is also true for the Bhutanese specimens as one of the specimens has S9-10 black without yellow rings and other has yellow markings in last two segments (Image 1D-E).Karube (2002) describes the thorax as darkbrown to black marked on front with a bright citronyellow oblique antehumeral stripe and on the side with two broad yellow stripes with in between them a small yellow upper spot.One of the specimens collected from Bhutan also has second yellow spot between the oblique antehumeral stripes (Image 1A).
Watanabeopetalia atkinsoni specimens were collected from a fast-flowing mountain stream on a sunny day.The riparian vegetation consisted of dense grasses with a tall tree canopy and the streambed consisted mostly of cobbles and sand.The water flow was obstructed frequently by rocks forming pools, cascades, and falls at several sites over which males were observed patrolling.Females were not observed.Other species found in this habitat include Anisopleura comes, Caliphaea confusa, Macromia moorei, and Perissogomphus stevensi.J TT J TT Image 3. Lamelligomphus risi (Fraser, 1922), one male: Habitus, lateral view, male leg.© Mer Man Gurung.

DISCUSSION
With this study the number of species known from Bhutan becomes 125 but it is likely that with the present speed of discovery this number will steadily continue to increase.The Bhutanese odonate fauna is expected to contain at least 150 species.The occurrence of both species found new to Bhutan, Watanabeopetalia atkinsoni and Tetrathemis platyptera, is no surprise as they were known from adjacent areas.Where T. platyptera is mainly found in the lowland, however, W. atkinsoni is confined to mountains occurring from Nepal to the north of Thailand.W. atkinsoni has not been recorded from Burma but undoubtedly occurs there as well.Although the knowledge on the fauna of northeast of the Indian peninsula is clearly increasing there are still many genera which are poorly known and in need of further study and/or revision.These include several genera also found in central Bhutan, such as Cephalaeschna, Davidius, Gynacantha, and Anisogomphus.In many cases more material is needed and comparison with types and/or material from southeastern Asia or China is needed.An increase in number of DNA barcodes available from different regions would make it easier to test if species might be identical or are clearly different.
With 60 species the central part of Bhutan is moderately well explored and more field work is likely to show that the area holds at least 100 species.Especially the lowland areas of Royal Manas National Park (RMNP) are likely to hold many Oriental species not known from Trongsa and Zhemgang districts or even completely new to Bhutan.
to occur in the Indian sub-continent where it has been found in India (west Bengal & Sikkim) and Nepal (Darjeeling & Shiva Puri, north Kathmandu valley) (Karen Conniff pers.comm.01.x.2021).