Amphigomphus somnuki n. sp. from North Thailand (Odonata: Gomphidae) MATTI HAMALAINEN

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1 Entomol. Z., 106(5), Amphigomphus somnuki n. sp. from North Thailand (Odonata: Gomphidae) MATTI HAMALAINEN With 8 figures Abstract: A new dragonfly species, Amphigomphus somnuki n. sp. (holotype cf: Thailand, Chiang Mai province, Doi Suthep, 20.VI.1990; deposited in Coll. Pinratana at St Gabriel's College, Bangkok) is described and illustrated in both sexes. Thailand has a relative rich fauna of gomphid dragonflies; nearly 50 species are already known to occur there. A new Amphigomphus species from the mountains Doi Inthanon and Doi Suthep in Chiang Mai province is described here. It is named after Mr. Somnuk Panpichit (Bangkok), who observed and netted the first specimens. Mr. Somnuk has been assisting Bro. Amnuay Pinratana at surveying Thai butterflies and dragonflies since Also I have had a pleasure to enjoy his company in the field many times. Amphigomphus somnuki n. sp. Holotype: cf, Thailand, Chiang Mai province, Doi Suthep, Khon Ta Than waterfall, 20.VI.1990, Bro. Amnuay Pinratana, Somnuk Panpichit & D. A. L. Davies leg. Deposited in Coll. Pinratana at St Gabriel's College, Bangkok, Thailand. A colour slide of the living holotype is available in Coll. Pinratana. Paratypes: 2 cf, same site, date and collectors as in the holotype (1 cf in Coll. Pinratana, Bangkok; 1 cf in Coll. Davies, Cambridge). -1 cf, Chiang Mai province, Doi Inthanon, downstream Siriphum waterfall, 11.VII.1991, Bro. Amnuay Pinratana & Somnuk Panpichit leg. (in Coll. Hamalainen). -12, Doi Inthanon, downstream Siriphum waterfall, 11.VI.1991, M. Hamalainen leg. (in Coll. Hamalainen). Male. Head. Eyes bluish green. Labium yellowish-grey. Labrum olive green, ventral margin narrowly brown and upper margin more broadly brown, the brown colour extending downwards over halfway in the middle. Base of mandibles, anteclypeus and postclypeus olive green. Lower margin of frons dark brown, frons above brightly olive green. Vertex and occiput black, with an olive green triangle in the middle of occiput. Prothorax blackish brown, with anterior lobe margined with yellow and with four small yellow spots in the posterior part of the middle lobe; the interior two smallest spots very near to each other. Pterothorax. Black with olive greenish stripes as in Figs Legs. Coxae and trochanters pale brown. Anterior femora dark brown, inner surface distinctly pale. Middle and posterior femora brown, getting darker brown apicad. All tibiae and tarsi black.

2 178 Entomol. Z., 106(5), 1996 Fig. 1. Wings of Amphigomphus somnuki n.sp., holotype. Wings. Venation as in Fig. 1. Abdomen. Apical segments distinctly expanded from the apical half of segment 7. Ground colour black, with pale markings as follows. Ventral half of the sides of segments 1-2 olive green. On dorsum of segment 1 triangle shaped olive green marking, continuing as broad undulating mid-dorsal band on segment 2. Auricles olive green. Segment 3 with a triangular ventrolateral band in the basal half of the segment and with an undulating mid-dorsal band, somewhat narrowing apicad, not quite reaching the apex. Segment 4 with a similar, but narrower mid-dorsal band and with a small olive green lateroventral spot at base of the segment. Segment 5 with a nearly complete narrow ring at base, yellowish green. Dorsal carina very narrowly yellowish green in the middle. Segment 6 with a more distinct narrow basal ring, yellow. Mid-dorsal line shorter. Segment 7 with a brightly yellow complete band covering the basal 3/5 of the segment, which extends more apicad on the dorsum. On segments 8-10 the markings are pale brown. A broad ventrolateral band on segments 8 and 9, on segment 9 this band extends more dorsad in the apical third. Segment 8 with a variable shaped mid-dorsal marking at the basal half of the segment. Segment 10 largely pale brown, distinctly margined with black basally and apically. Superior anal appendages brightly yellow, getting dark brown at apex. Inferiors pale brown, the apical half darker brown. Appendages shaped as in Figs Secondary genitalia as in Fig. 6. Anterior hamulus apically produced into two branches (Fig. 7). Measurements: Hind wing mm, abdomen mm. Female. A somewhat robuster insect than the male, the apical segments of abdomen relatively less expanded than in male.

3 Entomol. Z., 106(5), Colour pattern of head, thorax and abdomen very similar as in male. The most notable difference (in the single female available) is the much less extended pale markings on abdominal segments Segment 8 only with a short ventrolateral band in the basal half. Segment 9 with tiny ventrolateral spots in the middle and segment 10 with a small dorsal mark in the apical half. Pale markings are olive green on segments 1-4, yellowish green on segments 5-7 and reddish brown on segments Anal appendages yellow, tips somewhat darkened. Supra-anal plate and inferior anal laminae yellowish brown on dorsum, darker brown ventrally. Vulvar scale sharply bilobed at apex, extending well over midway of the segment (Fig. 8). Occipital margin of simple structure, without spines; in anterodorsal view smoothly curved forwards in the middle. Measurements: Hind wing 34 mm, abdomen 39 mm. \ Figs Amphigomphus somnukin.sp., paratype d". - 2) Colour pattern of pterothorax, dorsal view; 3) colour pattern of pterothorax, lateral view; 4) anal appendages, dorsal view; 5) anal appendages, lateral view.

4 180 Entomol. Z., 106(5), 1996 Figs Amphigomphus somnuki n.sp. - 6) Paratype cf, profile of secondary genitalia, lateral view; 7) same, shape of anterior hamuli; 8) paratype 9, profile of vulvar scale, ventral view. Discussion The generic combination of the new species is not straightforward, since it seems to combine characters of the genera Amphigomphus Chao 1954 and Orientogomphus Chao 1987 as defined in Chao's (1990: 471) key. It is placed to Amphigomphus on basis of the structure of the external genitalia. The bifurcate anterior hamulus and the structure of penis resemble those in Amphigomphus hansonichao 1954 (from Fujian, China), which until nowwasthe only known species in the genus. Also the thoracic colour pattern of somnuki resembles more A. hansoni than any of the known four species of Orientogomphus. On the other hand, unlike in A. hansoni, the superior appendages of male of somnuki are rounded like in all known Orientogomphus species, in fact quite similar to those of O. circularis (Selys 1894), a species also known from Doi Inthanon (Asahina 1986). Some species of Acrogomphus Laidlaw 1925 have also quite similar male anal appendages. Acknowledgements: I am indebted to my colleagues Bro. Amnuay Pinratana and Dr. Allen Davies for loan of the male specimens. References Asahina, S. (1986): A list of the Odonata recorded from Thailand, Part XIV. Gomphidae-2. -Tombo, 29(1-2): Chao, H.-F. (Zhao, X.) (1990): The gomphid dragonflies of China (Odonata: Gomphidae). - Sci. & Technol. Publ. House, Fuzhou, xiv pp. (Chinese, with Engl. summary of 31 PP). Author: Dr. Matti Hamalainen, Department of Applied Zoology, P.O. Box 27, FIN University of Helsinki, Finland.

5 ntomologisch Zeitschrift o> c n o> r ra -3 CO o Herausgegeben von Heinz Schroeder, Frankfurt a^main Alfred Kernen Verlag, Essen