Entomol. Z., 106(5), 1996 177

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

MATTI HAMALAINEN

With 8 figures

A b s t r a c t : A new dragonfly species, Amphigomphus somnuki n. sp. (holotype cf:Thailand, Chiang Mai province, Doi Suthep, 20.VI.1990; deposited in Coll. Pinratana atSt Gabriel's College, Bangkok) is described and illustrated in both sexes.

Thailand has a relative rich fauna of gomphid dragonflies; nearly 50 speciesare already known to occur there. A new Amphigomphus species from the moun-tains Doi Inthanon and Doi Suthep in Chiang Mai province is described here. It isnamed after Mr. Somnuk Panpichit (Bangkok), who observed and netted the firstspecimens. Mr. Somnuk has been assisting Bro. Amnuay Pinratana at surveyingThai butterflies and dragonflies since 1978. Also I have had a pleasure to enjoy hiscompany in the field many times.

Amphigomphus somnuki n. sp.

H o l o t y p e : cf , Thailand, Chiang Mai province, Doi Suthep, Khon Ta Thanwaterfall, 20.VI.1990, Bro. Amnuay Pinratana, Somnuk Panpichit & D. A. L.Davies leg. Deposited in Coll. Pinratana at St Gabriel's College, Bangkok, Thai-land. A colour slide of the living holotype is available in Coll. Pinratana.

P a r a t y p e s : 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 Pinra-tana & Somnuk Panpichit leg. (in Coll. Hamalainen). -12, Doi Inthanon, down-stream 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 colourextending downwards over halfway in the middle. Base of mandibles, antecly-peus and postclypeus olive green. Lower margin of frons dark brown, frons abovebrightly olive green. Vertex and occiput black, with an olive green triangle in themiddle of occiput.

Prothorax blackish brown, with anterior lobe margined with yellow and with foursmall yellow spots in the posterior part of the middle lobe; the interior two smallestspots very near to each other.

Pterothorax. Black with olive greenish stripes as in Figs. 2-3.Legs. Coxae and trochanters pale brown. Anterior femora dark brown, inner

surface distinctly pale. Middle and posterior femora brown, getting darker brownapicad. All tibiae and tarsi black.

178 Entomol. Z., 106(5), 1996

Fig. 1. Wings ofAmphigomphus 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 ofsegments 1-2 olive green. On dorsum of segment 1 triangle shaped olive greenmarking, continuing as broad undulating mid-dorsal band on segment 2. Auriclesolive green. Segment 3 with a triangular ventrolateral band in the basal half of thesegment and with an undulating mid-dorsal band, somewhat narrowing apicad,not quite reaching the apex. Segment 4 with a similar, but narrower mid-dorsalband and with a small olive green lateroventral spot at base of the segment. Seg-ment 5 with a nearly complete narrow ring at base, yellowish green. Dorsal carinavery narrowly yellowish green in the middle. Segment 6 with a more distinctnarrow basal ring, yellow. Mid-dorsal line shorter. Segment 7 with a brightly yel-low complete band covering the basal 3/5 of the segment, which extends moreapicad on the dorsum. On segments 8-10 the markings are pale brown. A broadventrolateral band on segments 8 and 9, on segment 9 this band extends moredorsad in the apical third. Segment 8 with a variable shaped mid-dorsal markingat the basal half of the segment. Segment 10 largely pale brown, distinctly margi-ned with black basally and apically.

Superior anal appendages brightly yellow, getting dark brown at apex. Inferiorspale brown, the apical half darker brown. Appendages shaped as in Figs. 4-5.

Secondary genitalia as in Fig. 6. Anterior hamulus apically produced into twobranches (Fig. 7).

Measurements: Hind wing 30-32 mm, abdomen 38-39 mm.

Female.A somewhat robuster insect than the male, the apical segments of abdomen

relatively less expanded than in male.

Entomol. Z., 106(5), 1996 179

Colour pattern of head, thorax and abdomen very similar as in male. The mostnotable difference (in the single female available) is the much less extended palemarkings on abdominal segments 8-10. Segment 8 only with a short ventrolateralband in the basal half. Segment 9 with tiny ventrolateral spots in the middle andsegment 10 with a small dorsal mark in the apical half. Pale markings are olivegreen on segments 1-4, yellowish green on segments 5-7 and reddish brown onsegments 8-10.

Anal appendages yellow, tips somewhat darkened. Supra-anal plate and infe-rior anal laminae yellowish brown on dorsum, darker brown ventrally. Vulvar scalesharply bilobed at apex, extending well over midway of the segment (Fig. 8).

Occipital margin of simple structure, without spines; in anterodorsal viewsmoothly curved forwards in the middle.

Measurements: Hind wing 34 mm, abdomen 39 mm.

\

Figs. 2-5. Amphigomphus somnukin.sp., paratype d". - 2) Colour pattern of pterothorax,dorsal view; 3) colour pattern of pterothorax, lateral view; 4) anal appendages, dorsalview; 5) anal appendages, lateral view.

180 Entomol. Z., 106(5), 1996

Figs. 6-8. 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, ven-tral view.

D i s c u s s i o n

The generic combination of the new species is not straightforward, since itseems to combine characters of the genera Amphigomphus Chao 1954 and Ori-entogomphus Chao 1987 as defined in Chao's (1990: 471) key. It is placed toAmphigomphus on basis of the structure of the external genitalia. The bifurcateanterior hamulus and the structure of penis resemble those in AmphigomphushansoniChao 1954 (from Fujian, China), which until nowwasthe only known spe-cies 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 otherhand, unlike in A. hansoni, the superior appendages of male of somnuki are roun-ded 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 analappendages.

A c k n o w l e d g e m e n t s : I am indebted to my colleagues Bro. Amnuay Pinratana andDr. Allen Davies for loan of the male specimens.

R e f e r e n c e s

Asahina, S. (1986): A list of the Odonata recorded from Thailand, Part XIV. Gomphidae-2.-Tombo, 29(1-2): 7-53.

Chao, H.-F. (Zhao, X.) (1990): The gomphid dragonflies of China (Odonata: Gomphidae).- Sci. & Technol. Publ. House, Fuzhou, xiv + 486 pp. (Chinese, with Engl. summary of31 PP).

Author: Dr. Matti Hamalainen, Department of Applied Zoology, P.O. Box 27, FIN-00014University of Helsinki, Finland.

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