Rhinocypha arguta n. sp., a new jewel-damselfly from north-east Thailand (Odonata: Chlorocyphidae) MATTI HAMALAINEN & SIRICHAI DIVASIRI

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1 Entomol. Z., 107(5), Rhinocypha arguta n. sp., a new jewel-damselfly from north-east Thailand (Odonata: Chlorocyphidae) MATTI HAMALAINEN & SIRICHAI DIVASIRI With 6 figures Abstract: A new damselfly species, Rhinocypha arguta n.sp. (holotyperf: Thailand, Loei province, Phu Kradung, 29.X. 1996) is described and illustrated in the male sex and compared with R. drusilla Needham 1930 from China. Key words: Insecta, Odonata, Chlorocyphidae, Rhinocypha arguta, new taxon, habitat, north-east Thailand. Introduction While studying on the material of Thai calopterygoid damselflies preserved in Division of Entomology and Zoology Museum, Department of Agriculture in Bangkok, the second author detected a specimen of a strange Rhinocypha species with red abdomen and hyaline wings, labelled to be collected in Phu Kradung in October-November He showed the specimen to the first author, who was visiting Bangkok in January As it seemed to represent an obvious undescribed species, we decided to pay a visit to Phu Kradung in the same season when the specimen was found. So, on 28th November 1996 we climbed up to the top of Phu Kradung together with our Norwegian colleague Hans Olsvik and spent one week there for dragonfly collection. Phu Kradung is a sandstone mountain with a top plateau (60 square kilometers in area) at the elevation of m covered with montane pine forests and flowering meadows. It is situated in Loei province in north-eastern part of Thailand and is adjacent to the Dong Phaya Yen mountain range, which extends south from Laos. Phu Kradung was declared a national park in Although the top of Phu Kradung is accessible only on foot, it has become a very popular visiting destination for the Thai youth. From the top plateau a major stream system (Wang Kwang) descends downwards in a gradually widening forested gorge in the north-western direction. A few major waterfalls in the upper section of this gorge are easily approachable. It was below these waterfalls and along a smaller side stream, where we encountered the wanted red Rhinocypha species during the first and last whole day of our stay; the only days with any sunshine. Unfortunately, only males were seen. Two other chlorocyphid species, Aristocypha fenestrella (Rambur 1842) and Heliocypha biforata (Selys 1859), were more abundant and present in both sexes along the stream. We found altogether 47 dragonfly species during our stay at Phu Kradung, also a few other novelties to the known Thai fauna.

2 202 Entomol. Z., 107(5), 1997 Rhinocypha arguta n. sp. Holotype: d, Thailand, Loei province, Phu Kradung mountain, Wang Kwang stream, (altitude ca m), 29.X.1996, M.Hamalainen leg. (holotype at present in Coll. Hamalainen). Paratypes: 2 d, same site and date as in the holotype, S. Divasiri leg. -8d, same site as in the holotype, 2.XI.1996, S. Divasiri (7o*) and M. Hamalainen (Id1) leg.- 1d\t 3405", Phu Kradung, 4000 ft, Loei province, Oct.-Nov. 1969, A. Samruadkit leg. (Division of Entomology and Zoology Museum, Department of Agriculture, Bangkok). - The paratypes from the 1996 series are placed in various museum and private collections in Thailand, Europe and USA; 1 cf in RMNH (Leiden). Description of male: Head: Eyes of living specimens blackish brown above, grey below. Labium black, lateral lobes pale blue at base. Labrum blue with apical border narrowly black. The projecting clypeus black, with small pale blue ventrolateral patch in postclypeus. Base of mandibles, genae and the eye margin pale blue; the blue area extending up to the level of the lateral ocelli, and sending a narrow streak mesad on frons. Second segment of antennae pale blue, the apical segments black. Frons and vertex black, with small oval pale blue spots on side of the lateral ocelli and a pair of pale blue spots beyond (Fig. 1). Prothorax: Black with olive yellow spots on sides as in Fig. 2. Posterior lobe with a narrow median olive yellow streak tapering towards the median lobe. Pterothorax: Ground colour black, furnished with olive yellow stripes, bands and markings as in Fig. 2. In living specimens the narrow middorsal line and the antehumeral stripes with a more greenish tint, the broad lateral band more yellowish. Pterothorax below black. Legs black; coxae with olive yellow stripe. Wings: Rather narrow (Fig. 3), wholly hyaline with black venation. Petiolation ending after the level of the second antenodal. Arculus situated a little distad to the third antenodal. Quadrangle with a variable number (1-4) of crossveins, usually 3. Fore wings with antenodals and postnodals. Hind wing with antenodals and postnodals. Pterostigma covering 4-5 underlying cells; blackish brown, in hind wing somewhat paler in the apical half, but not clearly bicolorous. Abdomen: Conspicuously coloured with flaming red and black. Dorsal side of segments 2-8 predominantly red with black markings as in Fig. 4. (In some specimens the apical black spots on segments 3-6 larger than in Fig. 4, broadly connected with the intersegmental black ring.) Segment 1 black above, with a large triangle shaped olive yellow lateral spot. On side of segment 2 a narrow olive yellow stripe confluent to the dorsal red area and an olive yellow lateral triangle in the apical corner of the segment. Segments 9 and 10 wholly black. Ventral surface of abdomen throughout black. Anal appendages (Figs. 5-6) of the typical shape for the genus; black. Female unknown. Figs Rhinocypha arguta n.sp., paratype d. - 1) Head, dorsal view; 2) thorax, lateral view; 3) shape of wings, with details of venation at the hind wing base; 4) abdomen, dorsal view; 5) anal appendages, dorsal view; 6) anal appendages, lateral view. - Figures are not in the same scale.

3 4 Entomol. Z., 107(5),

4 204 Entomol. Z., 107(5), 1997 Discussion Until now ten Rhinocypha species with predominantly red abdomen in males were known. With the exception of the Chinese Rhinocypha drusilla Needham 1930, they are all insular species known from Borneo, Philippines, Lesser Sunda Islands, Iriomote Island, and Bonin Islands. R, drusilla was described by Needham (1930: ) on basis of a single male (holotype) and a female from Zhejiang and Fujian. Tol & Rozendaal (1995) redescribed and illustrated the holotype of drusilla in detail. In all existing descriptions (Needham 1930, Sui & Sun 1984, Tol & Rozendaal 1995), the abdomen of male drusilla is stated to be brown. However, this is due to poor, discoloured state of the holotype. The first author has studied a series of better preserved drusilla males in a large lot of unidentified Fujian dragonflies in RMNH (Leiden), collected by T. C. Maa in 1940's. In them the basic colour of dorsal surface of abdomen is red. In fact the colour pattern of thorax and abdomen of these Fujian drusilla males is quite similar as in R. ueno/asahina 1964 from Iriomote Island in the Ryukyus. It should be mentioned here that the measurements of the holotype of drusillawere given: hind wing 26 mm, abdomen 16 mm; the latter apparently a mistake. The other drusilla males studied measure: hind wing mm, abdomen mm. The present new species R. argutan.sp. differs distinctly from drusilla in some structural details and in colour pattern. In argufathe pterothorax is more slender and wings narrower. Hindwing of arguta is completely hyaline, whereas in drusilla the apical third is clearly darkened. In the hind wing of drus///athe reticulation at wing apex is denser and pterostigma is clearly bicolorous. There are differences also in the colour pattern of pterothorax and abdomen. Unlike in drusilla, the broad lateral band in pterothorax is unbroken in arguta. In arguta the last two abdominal segments are black on dorsum, whereas red in drusilla. In arguta femora and tibiae are black, but furnished with yellow stripes in drusilla. In Phu Kradung males of arguta were seen only when sun was shining, and they disappeared at once when sun became overcast. The present males were seen between hrs in the afternoon. They perched solitarily on trees and bushes at the stream bank, 1-2 m above the water or on fallen logs and rocks in the stream. Acknowledgements: We are very grateful to Bro. Amnuay Pinratana, who kindly helped us to receive the necessary permit to study dragonflies at Phu Kradung.. References Needham, J. G. (1930): A manual of the dragonflies of China. A monographic study of the Chinese Odonata pp.; Peiping (The Fan Memorial Institute of Biology). Sui, J-z. & Sun, H-g. (1984): Common species of dragonflies in China pp., 26 pis.; Beijing (Agriculture Publishing House) (Chinese, with English title page). Tol, J. van & Rozendaal, F. G. (1995): Records of Calopterygoidea from Vietnam, with descriptions of two new species (Zygoptera: Amphipterygidae, Calopterygidae, Chlorocyphidae, Euphaeidae). - Odonatologica, 24(1): Authors: Dr. Matti Hamalainen, Department of Applied Zoology, P.O. Box 27, FIN University of Helsinki, Finland. - Mr. Sirichai Divasiri, National Biological Control Research Center, P.O. Box 9-52, Bangkhen, Bangkok 10900, Thailand.

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