(Teinopalpus) No. 62（2012） Butterflies of Trashiyangtse Valley, eastern Bhutan (Part 1) Sonam Wangdi1*, Karma Wangdi2*, Sherub2, Rinchen Wangdi3**, Sangay Drukpa3, Motohiro Harada4, Toshiaki Aoki5, Shuhei Yamaguchi5, Motoki Saito6, Yoshiko Igarashi7, Yasuyuki Watanabe8 and Masaya Yago4 1 Department of Forests and Park Services, Ministry of Agriculture and Forests, Royal Government of Bhutan, 1095 Thimphu, Bhutan 2 Ugyen Wangchuck Institute for Conservation and Environment, Ministry of Agriculture and For- ests, Royal Government of Bhutan, Lamai Goempa, Bumthang, Bhutan 3 Research and Monitoring Section, Bumdeling Wildlife Sanctuary, Trashiyangtse, Bhutan 4 The University Museum, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan 5 The Research Institute of Evolutionary Biology, 2-4-28 Kamiyoga, Setagaya-ku, Tokyo, 158-0098 Japan 6 2-16-1-802 Nakamachi, Musashino-shi, Tokyo, 180-0006 Japan 7 1-3-41 Shinoharakita, Kohoku-ku, Yokohama-shi, Kanagawa, 222-0021 Japan 8 3-8-12 Mukonoso, Amagasaki-shi, Hyogo, 661-0035 Japan Correspondence: [email protected] (Motoki Saito), [email protected] (Masaya Yago) Abstract Trashiyangtse Valley is located in far eastern Bhutan, a remote area bordering Tibet to the north and Aruna- chal Pradesh (India) to the east. Apart from a collection made by two English researchers in the early 1930s, the butterfly fauna of this area has been poorly studied. In 2011 and 2012, we had the opportunity to collect material from Trashiyangtse Valley. In total, about 130 butterfly species were recorded. Among these, the following 3 species are recorded for the first time from Bhutan: Apostictopterus fuliginosus, Neozephyrus suroia and Euthalia amplifascia. Our list is the first report on the butterfly fauna of Trashiyangtse Valley. Keywords Biodiversity, butterfly fauna, endemic species, inventory, new record, species richness Introduction is about 500 km from the capital Thimphu (Fig. 1). The Bhutan appears to have a diverse butterfly fauna. The only previous study on the butterfly fauna of this area is country has a wide range of environments, from lowland the collection made by two English botanical researchers, to alpine, and climatic zones, including tropical monsoon, George Sherriff and Frank Ludlow. That collection is now temperate, subarctic and arctic. Previous publications housed in the Entomology collection of the BMNH (The have documented some of the butterflies of Bhutan (e.g. Natural History Museum, London), however, the list of Bingham, 1905; Talbot, 1939; Yazaki & Kanmuri, 1985), species captured was not published. and more recently a few illustrated books and lists have Through the Trashiyangtse Valley, Kulong Chu (Kulong been published (Piet Van der Poel & Tashi Wangchuk, river) runs from north to south in the Eastern Himalayas 2007; Piet Van der Poel, 2010; UWICE, 2010; Yazaki, (Fig. 1, 2) and meets Gamri Chu near Tashigang at ap- 2012). Collectively, these works provide an overview of proximately 70 km south from the source located at a high the butterfly fauna of Bhutan, however, a comprehensive elevation of over 5,000 m. During our work on Ludlow’s list of butterflies is currently not available. For systematic Bhutan Glory, we made opportunistic observations on conservation planning it is desirable that a comprehensive other butterflies and collected many specimens along inventory of the Bhutanese fauna be undertaken. a trail or road running close to the river, particularly in In August-October 2011 and July 2012, we visited Trashi- Bumdeling Wildlife Sanctuary. In this report we present a yangtse Valley in Trashi Yangtse Dzongkhag (District), list of these incidental records, which is the first report on eastern Bhutan, primarily to search for Ludlow’s Bhutan the butterfly fauna of Trashiyangtse Valley.We also briefly Glory, Bhutanitis ludlowi Gabriel, 1942 (Harada et al., discuss the biogeographical characteristics and conserva- 2012). This valley is a difficult place to access because it tion significance of the valley based on these results. * These authors contributed equally to this paper. ** Present address: Canberra Institute of Technology, Vocational College of Canberra, Canberra, Australia. 16 (Teinopalpus) No. 62（2012） Material and Methods <Study areas and habitats> (Fig. 1) The details of our study areas in Trashiyangtse Valley are as follows. GPS data were recorded using eTrex Vista HCx (Garmine). 1. Chazam (1,200 m) (Figs 3, 4) Junction to Trashi Yangtse (north) and Tashi- gang (east). The check point near the bridge crossing Kulong Chu is located there. With hot and dry air coming down from far-south, the Fig. 1. Map of Bhutan. environment is rather dry like a desert. Tropi- cal species such as Catopsilia pomona or Junonia orithya ing good habitat for forest butterflies such as Euthalia spp. were well observed. At the spot just before Bumdeling where Alnus nepalensis 2. Duksum [N 27°28.651 /E 91°32.925] (1,350 m) (Fig. 4) are abundant, Neozephyrus suroia was collected. This is Small village located 10 km north from Chazam. This area first record from Bhutan. Bumdeling village is 1-1.5 hour is dry as in Chuzam, and trees are scarce. by car and 3-4 hours on foot. 3. Duksum — Trashi Yangtse (1,350-1,750 m) (Fig. 5) 6. Bumdeling [N 27°39.498 /E 91°27.261] (1,900 m) (Figs Taking the route along the left bank of Kulong Chu above 9, 10) Duksum for more 10 km, the forest of tall trees begins to This village is located on the broad riverbank of Kulong appear from ca. 1,500 m. Evergreen broadleaf forest of Chu. Flat areas are well cultivated as rice terraces. Near the Quercus sp. or Lithocarpus sp. covers both sides of the village houses, very tall trees of Quercus griffithii are abun- route. The butterfly fauna is quite different from that in dant. These trees have been used as firewood by villagers for Chuzam or Duksum. Just before Trashi Yangtse, the forest a long time. This village is also famous as the wintering spot appears slightly drier, and pine trees are abundant. In some of the Black-necked crane (Grus nigricollis). places, slopes are too steep, and only the short Rhododen- 7. Bumdeling — Tarphel (1,900-2,230 m) (Figs 11) dron sp. barely grows. Near small streams on the route, De- After passing Bumdeling, the trail continues to the north lias sanaca is often seen mud-puddling. On forest canopy, along Kulong Chu. In the first 3 km of the trail, it is rela- several species of Euthalia are observed to fly rapidly. tively flat in a deep deciduous forest. The route goes down 4. Trashi Yangtse (Trashiyangtse) [N 27°36.553 /E once near Kulong Chu. After crossing two iron-bridges 91°29.897] (1,750 m) (Figs 2, 6) over small streams, the trail climbs steeply up a slope. The The headquarter of Trashi Yangtse province. The town environment around there is covered with a mixture of sec- stretches on the broad slope on the left bank of Kulong ondary forest and cultivated field. Chu. To the far-north, the snow-capped Himalayan moun- 8. Tarphel [N 27°44.503 /E 91°25.577] and its surround- tains are seen (Fig. 2). Beautiful rice terraces are here and ings (2,230-2,700 m) (Figs 12, 13) there in the town. A very famous, old monastery called Tarphel is located on a slope of the deep valley. The popu- “Chorten Kora” is located at the entrance of the town. It lation of this village is about 50 people forming eight fami- attracts many pilgrims from India as well as overseas tour- lies. Villagers grow maize, buckwheat or millet. This vil- ists. The monastery school which was formally used as an lage and the adjacent areas are surrounded by a mixture of old Dzong is on the small hill on the right bank (ca. 1,850m). primary forests of evergreen and deciduous broad-leaved An unpaved road runs through the thick deciduous forest trees and secondary forests of Q. griffithii. We surveyed near the building (Fig. 6). Some species are only recorded from this village up to ca. 2,700 m. from here. 5. Trashi Yangtse — Bumdeling (1,750-1,900 m) (Figs 7, 8) <Dates and localities of our survey> Crossing the iron bridge over Kulong Chu at the northern 1. The first survey: summer of 2011 end of Trashi Yangtse town, the unpaved muddy road runs (Participants: all members) along the right bank. Cars are available only in dry season. August 7, Chazam —Trashi Yangtse Evergreen broad-leaf forests cover along the road, provid- August 8, Trashi Yangtse and Bumdeling [divided into two 17 (Teinopalpus) No. 62（2012） groups, Bumdeling team (YI, SM) and old Dzong team (the University of Tokyo, SW = Sonam Wangdi, KW = Karma others)] Wangdi, MH = Motohiro Harada, TA = Toshiaki Aoki, SY August 9, Trashi Yangtse = Shuhei Yamaguchi, Motoki Saito = MS, Yoshiko Igarashi August 10, Trashi Yangtse — Bumdeling = YI, Yasuyuki Watanabe = YW, Masaya Yago = MY. August 11, Bumdeling — Tarphel August 12-18, Tarphel and the adjacent area Results August 19, Tarphel —Trashi Yangtse Annotated checklist August 20, Trashi Yangtse and Duksum [divided into two Hesperiidae groups, Duksum team (SW, KW, MH, YW) and old Dzong H-1. Choaspes benjaminii japonicus (Murray, 1875) team (the others)] 1♂, 17. viii. 2011 (MS); 1♂, 19. viii. 2011 (MY) August 21, Trashi Yangtse — Bumthang This species was observed near the forest. During the 2. The second survey: autumn of 2011 daytime, one male was resting underside of the leaf. (Participants: Karma Wangdi, Sangay Drukpa and Motoki H-2. Celaenorrhinus ratna tytleri Evans, 1926 Saito) 1♂, 17. viii. 2011 (MS); 1♂, 20. viii. 2011 (SY & TA); September 27, Chazam —Trashi Yangtse 1♀, 14. viii. 2011 (MS) September 28, Trashi Yangtse — Tarphel Sparsely seen in the forest at 1,800-2,300 m.