PIatycnemis phasmovolans sp. nov. an extraordinary damselfly from Laos with notes on its East Asian congeners (Odonata: Platycnemididae)

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1 TOMBO, Matsumoto, 46 (1/4): 1-7. Dec. 30, 2003 PIatycnemis phasmovolans sp. nov. an extraordinary damselfly from Laos with notes on its East Asian congeners (Odonata: Platycnemididae) Matti Hamalainen Department of Applied Biology, P. 0. Box 27, FIN University of Helsinki. Finland Received 2003 Nov. 111 Revised and accepted 2003 Dec. 24 Abstract: Platycnemis phasmovolans sp. n. from Lak Sao area in central Laos is described and illustrated in both sexes. The new species is characterized by possessing the most highly expanded tibiae so far known in Odonata. Its habitat is briefly described. The other species found from the same stream include Philoganga vetusta Ris, 1912 and Zygonyx takasago Asahina, 1966, both of which are recorded from Laos for the first time. The forgotten Japanese taxon Platycnemis bilineata Bartenef, 1910 from Matsuyama, Shikoku, is synonymized with Copera annulata (Selys, 1863). Preliminary taxonomic notes on other East Asian taxa described as Platycnemis species are provided. Introduction The knowledge of the insect fauna of Laos started to increase rapidly after Laos opened its borders to foreign visitors in the early 1990's after long isolation. Japanese entomologists especially started to visit the country regularly. Much of the recent knowledge of Laotian odonates is based on the activity of Dr Naoto Yokoi, who has made several collecting trips to the country since So far he has found and reported already over 100 odonate species new to Laotian territory in different papers published in Gekkan-Mushi and Tombo. According to Dr Yokoi (pers. comm.) presently over 200 spp., including several undescribed new species are known from Laos. The total number may ultimately reach 300. With Dr Yokoi's help I was able to make a brief visit to Lak Sao area for three days at the end of April 2002 and collect dragonflies at a few streams near the Vietnamese border. Although my main interest was to observe Archineura hetaerinoides (Fraser, 1933) and other Caloptera species, my first encounter with a male of this new Platycnemis species remains one of the most thrilling sights of my visit. In a dark bush near a stream I saw first just a bunch of white dancing fans approaching very slowly. At first I did not realize what this ghostly thing was, but then at close range I saw that it was a damselfly with tremendously wide tibiae! In the beginning of May 2001 Dr Yokoi had already found a few specimens of the same species at the same stream. I am very grateful to him for allowing me to describe this fascinating insect - a flying ghost. Its tibiae are proportionally much broader than in those of P. phyllopoda Djakonov, 1926, P. foliacea Selys, 1886 and the MadagascanP. alatipes McLachlan, Platycnemis phasmovolans sp. nov. (Figs. 1-10) Holotype :<?, Laos. Bolikhamsay Prov.. Kaew Neua Pass area, alt. 650 m, 28. IV M. Hamalainen leg. Deposited at the National Museum of Natural History Naturalis, Leiden (RMNH). - Paratypes (from the same site as the holotype); 2 <?, 1 ^, IV. 2002, M. Hamalainen (rf") and Vilay Sak Souphanthong (^) leg. - Other material from the same site (studied by Naoto Yokoi): 3 J\, 29. IV. -3. V. 2001, N. Yokoi leg. Etymology. Derived from the words Phasma (Greek) = ghost and volans (Latin) = flying, denoting the ghostly appearance of the slowly flying male insect with white feather-like tibiae of extraordinary width. Male (Fig. 1). Head. Labium white, tips of lateral lobes black. Labrum black, anteclypeus obscurely bluish, postclypeus pale bluish. Face crossed by a broad pale bluish stripe, disconnected in the middle above the postclypeus, but together with blue postclypeus forming a blue band across the face. Base of mandibles partly obscurely blue. Head above shining black, with a faint metallic lustre. Tiny pale spots beside the lateral ocelli and the eye border 1

2 Matti Hamalainen Figs Figs Platycnemis phasmovolans sp. nov. 1. holotyped\. paratype?. 3. head, thorax and legs of holotype ct Platycnemis phasmovolans sp. nov. paratype f. Anal appendages : 4. dorsal view. 5. oblique lateral view. Penis head : 6. lateral view. 7. dorsal view behind the level of the lateral ocelli narrowly pale. Antennae black, only the top of the 2nd segment (pedicel) pale. 2nd segment shorter than 3rd. Thorax (Fig. 3). Prothorax black with narrow, sinuous dorsolateral bands, pale blue. Synthorax black with distinct metallic shine and pale bluish stripes. Antehumeral stripe narrow, slightly tapering towards the wing base. A broader lateral stripe crossing the stigma and a stripe along the ventral part of metepimeron. Ventral side of

3 A new Platycnemis from Laos Figs Platycnemis phasmovolans sp. nov. 8. wings of paratype <?, 9.? photographed perching on a twig Fig. 10. Relative size of c^tibiae. a. Platycnemis phasmovolans sp. nov.. middle and hind tibiae ; b. Platycnemis phyllopoda (S. Korea, teneral specimen), hind tibia ; c. Platycnemis foliacea sasakii (Hyogo). hind tibia : d. natural size of the tibiae synthorax wholly pale blue. Legs. Fore legs with trochanters black in the upper half, white in the lower half: coxae white : femora white, except its anterior side black in the apical third ; tibiae and tarsi black. Middle and hind legs with trochanters largely black, anterior side white ; coxae, femora and tibiae wholly white, except for the black spines, claws dark brown. Middle and hind tibiae enormously widened, feather-like (Figs. 3, 10 a). Hind tibiae 5.5 mm long and 2 mm broad at the widest point. Wings (Fig. 8). Hyaline. Pterostigma dark brown, costal side slightly longer than the anal side. Arculus at a trifle distal to Ax 2. Quadrangle long and narrow. Abdomen. Black with pale bluish markings as follows. Sides of S 1 broadly pale in ventral half; S 2 narrowly pale at ventral edge and with two tiny lateral markings : S 3 - S 6 with basal rings, smallest on S 3 and largest on S 6 ; that on S 3 and S 4 incomplete dorsally. Obscure, short streaks on the lower side of S 3-S 5 in the apical third of each segment. S 7 - S 7 black, with a tiny basoventral streak on S 7. S 10 broadly blue apically. Anal appendages whitish-blue, inferiors tipped with black ; shaped as in Figs [Note. The figured specimen was preserved in absolute alcohol. When the tip of abdomen was dried for SEM photography, the inferior appendages turned crosswise ; in the holotype and the other papered paratype the tips of inferiors approach each other, but do not cross]. 3

4 Matti Hamalainen Head of penis as in Figs Measurements. Abdomen (incl. appendages) mm ; hind wing 19 mm. Female (Figs 2, 9). Head and thorax black with similar pale patterns as in male, but stripes on thorax yellowish in colour. Legs of normal structure, tibiae not dilated. Colour pattern of coxae and trochanters as in male, but yellow instead of white. Outer side of all femora black, except at the very base, inner side yellow. Fore tibiae black on the outer side for the whole length, in middle tibiae the blackish brown colour on the outer side does not extend to the apex of tibiae, in hind tibiae outer side darkened only at base. Pterostigma paler than in male, grayish brown. Abdomen black, with pale lateral stripes as in Figs. 2 and 9, in live specimens the stripes on S 1-2 yellow, on S 3-7 pale blue. On S 3 - S 6 the pale stripes extend dorsad at base, but do not form complete rings. S 10 largely whitish blue, anal appendages above whitish blue. Length of abdomen 31 mm, hind wing 20 mm. Habitat. All specimens were found on a tributary of the Nam Phao River (cf. Yokoi & Kano 2002, Fig. 5) along Route 8 at an altitude of 650 m. This area, close to the Vietnamese border, is at the northern edge of Nakai-Nam Theun national protected area and is still largely covered by dense forests. Yokoi & Kano (2002, Table 1, locality A) listed many interesting odonate species from this area, including several new records for Laos. In addition to those listed, several as yet undescribed species have been found there (Yokoi, pers. comm.). My material from the same Platycnemis stream collected on April 2002, include at least two new records for Laotian territory : Philoganga vetusta Ris, 1912 (1 <?) and Zygonyx takasago Asahina, 1966 (2 ct). Comparative notes. With the exception of the rare Japanese endemic P. echigoana Asahina, 1955, the males of the known East Asian Platycnemis species have more or less broadened and flattened tibiae in the middle and hind legs. In P. phasmovolans sp.n the tibiae are proportionally very much wider than in P. foliacea and phyllopoda (cf. fig. 10). Unlike P. foliacea and P. phyllopoda males, P. phasmovolans male has the middle and hind femora white throughout and the sides of the synthorax below the stigma largely black. The discovery of P. phasmovolans in Laos extends the range of Platycnemis (s. str.) deep into the Oriental region. Platycnemis and Copera -distinct genera? Presently, the platycnemidid subfamily Platycnemininae is considered to contain two genera Platycnemis Burmeister, 1839 (type species Libellula pennipes Pallas, 1771) and Copera Kirby, 1890 (replacement name for the preoccupied name Psilocnemis Selys, 1863 ; type species Platycnemis marginipes Rambur, 1842). The genus Proplatycnemis Kennedy, 1920 originally erected for two Madagascan species (type species Platycnemis hova Martin, 1908) has generally been placed as synonym of the genus Platycnemis. Pseudocopera Fraser, 1922 (type species Pseudocopera arachnoides Fraser, 1922 = syn. of Copera ciliata (Selys, 1863) was synonymized with Copera soon after it was erected. Over 30 Platycnemis species have been recognized from disjunct areas in the Western Palearctic region, East Asia, Equatorial Africa and Malagasy and ca 10 Copera species from the East, South-east and South Asia. For a distribution map of these genera, see Martens (1996, p. 21). In the original definition of Psilocnemis [Copera], Selys (1863) points out only one difference to separate it from Platycnemis. The second antennal segment is as long as the third segment in Psilocnemis, whereas in Platycnemis the third antennal segment is as long as the first two together. Surprisingly this minor character seems still to be the only available straightforward difference for separating adult insects of these two genera. Other proposed differentiating characters, i.e. the proportional length of 2nd and 3rd abdominal segments (Selys, 1886) and the venational difference pointed out by Munz (1919) have proven undiagnostic. Due to the minor differences some authors have doubted the feasibility of keeping Platycnemis and Copera as distinct genera. Ris (1915) wrote "... obgleich der Gattungsunterschied von Platycnemis und Copera zweifelhaft erscheint". In his China manual Needham (1930) sunk Copera as a synonym of Platycnemis on the following grounds : "After rearing the nymph of Copera annulata and finding it in all respects similar to that in Platycnemis, I regard these as one genus and rele- 4

5 gate Copera to synonymy". A new Platycnemis from Laos Eraser (1957) wrote "there is a tendency to regard these two genera as synonymous but I am inclined to restrict Copera to those species in which the ground colour is some shade of yellow, orange or reddish, and the tibiae of the males show but little dilation. Species of Platycnemis are heliochromatic and live in the open, whilst those of Copera are phantochromatic and lurk in undergrowth or beneath the deep shade of bushes". However, at least Platycnemis phasmovolans sp. n. behaves like a Copera in Eraser's definition. Needless to emphasize here that this generic question is still unsettled and that the subfamily is in need of a phylogenetic study and a taxonomic revision. The following taxa, originally placed in Platycnemis, have been described from East Asia : foliacea Selys, 1886, bilineata Bartenef, 1910, phyllopoda Djakonov, 1926, ulmifolia Ris, 1930, foliosa Navas, 1932, hummeli Sjostedt, 1933, rubripes Navas, 1934, pierrati Navas, 1935, sasakii Asahina, 1949 [as ssp. of foliacea ], echigoana Asahina, 1955 and phasmovolans Hamalainen, sp. n. Platycnemis bilineata Bartenef, 1910 a forgotten Japanese taxon In a bilingual (Russian and English) publication in a obscure journal, available only in a few libraries outside Russia, Bartenef (1910) described two new species from Japan - Gynacantha japonica and Platycnemis bilineata, both from Matsuyama, Shikok [Shikoku]. In connection with his treatment of the Platycnemis foliacea-group, Ris (1930, p. 22) commented briefly P. bilineata as follows : "Die Beschreibung einer P. bilineata durch Bartenef nach einem ctvon Matsuyama muss etwas weit verschiedenes betreffen ; die Angabe "four front tibiae moderately broadened (less than in the species P. pennipes)" wobei fiber die dritten Tibien nichts ausgesagt 1st, erscheint sonderbar und es ist nicht recht ersichtlich, wohin das Expl, dem die terminalen Segmente fehlen, iiberhaupt gehort." Here Ris pointed out the facts that the type specimen of P. bilineata was incomplete (the terminal abdominal segments [S 7-S 10] were missing) and that the description of tibiae was inadequate. So, Ris left its identity open. Then, referring to the brief statement in Ris (1930), Asahina (1939) included the species in the list of the 8 described East Asian Platycnemis species as follows : "2. Platycnemis bilineata Bartenef (1909) 'Matsuyama' ", and wrote in the Japanese text".... the description of No. 2 seems very inadequate and does not justify its correct identification. Or it may belong to the genus Copera. Anyway for the present I leave this open". Asahina did not have Bartenef's paper available at that time and it was not included in the reference list. Later, the Japanese origin of P. bilineata and its taxonomic status has not been discussed in the literature. In the catalogues of the world Odonata P. bilineata has been listed as a valid species and its type locality "Sikok" linked to Russia. Interestingly, Asahina (1984 a) later provided a complete copy of Bartenef's original (English) description and illustrations of G. japonica. Similarly, Bartenef's original English text (pp ) on P. bilineata is copied below literally (with printing errors). No figures were provided of this species. (p. 15) 3. Platycnemis bilineata sp. n. (?)2) The head black above, light blue in front; the nasus (with a light blue line) and the base of the upper lip are black. 2> The auther had not to hand the literature burring on this genus ; thus the determination of this specimen remains oppen to question. (p. 16) There are 2 small yellow spots on the sides of the outer ocelles ; 2 large light blue spots just behind the eyes ; 5

6 Matti Hamalainen and 2 very small light blue spots at the back of the head on a line with the outer width of the prothorax. The upper part of the hinder surface of the head is black, the under part-blue ; the margin between them forming a straight line, precisely as in the species,,lestes barbara" Fabr. and,,lestes virens" Ch. The prothorax is black. The thorax is black above ; blue below and at the sides, where there are narrow black stripes (broader above) on the 2-d side sutures. Along the entire length of upper surface of thorax pass two light blue humeral stripes which are continued along the upper surface of the prothorax. The 1-st segment of the abdomen is light blue, with a broad bronze coloured stripe along the middle ; the 2-d segment also light blue with the middle stripe narrow at the base ; segments 3-6 (others are broken) bronze coloured above, with a blue margin at the base. The thighs are white with the black outer side at thpe end farter from the base. The fore tibiae are white with the black stripe outside. The 2-d and 3-d pairs of tibiae are white with only the remains of the black stripe at the base and the end. The tarsi are black. Four front tibiae are moderately broadened (less than in the species Platycnemis pennipes Pal.). Sizes of the specimen (c?) in collection : Length of six segments of the abdomen : 33 mm "-ofthehindwing 24,, From the above description and its occurrence in Shikoku it is certain that P. bilineata is identical with the common Copera annulata. The statement in the last sentence ' Four front tibiae are moderately broadened may be a translation error or simple lapse, with "hind tibiae" intended. Thus, Copera annulata (Selys, 1863) Platycnemis bilineata Bartenef, 1910, syn. nov. Bridges (1994) pointed out the interesting fact that Bartenef s Platycnemis bilineata is a junior homonym of P. bilineata Selys, an available species-group name in Platycnemis, presently synonym of Platycnemis latipes Rambur, Selys in Selys & Hagen (1850, p. 389) introduced this useless and later completely forgotten name "une variete bilineata %-" for specimens from Montpellier. France. Bridges (1994) urged the need to replace the name for Bartenef s bilineata. However, since it is a synonym, there is no need for a replacement name. Preliminary notes on the Chinese taxa In his papers on Chinese odonates, Navas ( ) described three new Platycnemis species - P. foliosa Navas, 1932, P. rubripes Navas, 1934 and P. pierrati Navas, (Navas followed Needham (1930) and did not recognize Copera as a distinct genus). At present the three species are still listed as valid in the world Odonata catalogues. The holotype of P. foliosa (cffrom Zo-Se in Shanghai area) is available for study in the National Museum of Natural History Naturalis (RMNH) in Leiden. The whereabouts of types of P. rubripes and P. pierrati is unknown. Judged from the descriptions they are both Copera species. Copera rubripes was described from a single teneral female from Shanghai area (Zo-Se). Two other Copera species are known from this area, C. annulata (Selys, 1863) (Asahina, 1984 b) and C. tokyoensis Asahina, 1948 (Asahina, 1979). Thus, P. rubripes may be conspecific with one of these two or (less likely) with C. ciliata (Selys, 1863), the range of which is known to reach northwards at least to Fujian and Taiwan. C. pierrati, described from (at least) two male specimens from Guangdong and Jiangxi, is obviously a teneral male of C. marginipes (Rambur, 1842). However, I prefer to leave any formal decisions of the identity of these Navasian species for a future revisor. Asahina (1949) downgraded Platycnemis ulmifolia Ris, 1930 and P. hummeli Sjostedt, 1933 to synonyms of P. phyllopoda Djakonov, 1926 without detailed reasons, and he presented the same view also in some later publications, e. g. in Asahina (1992). However, figures of the male appendages and female prothorax P. ulmifolia in Ris 6

7 A new Platycnemis from Laos (1930) show clear differences with P. phyllopoda, which suggests that they are distinct species. Types of P. ulmifolia and P. hummeli are available in Stockholm (NRS). This group is in need of revision. Acknowledgements I am grateful to the following colleagues for various help in different phases of this study : Mr Dirk Gassmann, Mr Sami Karjalainen, Mr Haruki Karube, Dr Bastiaan Kiauta, Dr Bert Orr, Dr Reijo Pitkiiranta, Mr Akihiko Sasamoto, Mr Vilay Sak Souphanthong, Drs Jan van Tol, Mr Matti Viitasaari and Dr Naoto Yokoi. References Asahina, S., 1939 : Notulae Odonatorum Japonicorum, IV. Zool. Mag., Tokyo, 51 : (In Japanese with Engl. Summary) Asahina, S., 1949 : Odonata from Shansi Province (North China). Mushi, 20 : 27-36, pis. 1-2 excl. Asahina, S., 1979: Notes on the Chinese Odonata, VIII. Three small collections in the U.S. National Museum of Natural History. Kontyu, 47 : Asahina, S., 1984 a : Gynacantha japonica and G. incisura. New Entomologist, 33 :1-12. Asahina, S., 1984 b : "Copera annulata (Selys)" composed of two different species! Cho-Cho, 7 : Asahina, S., 1992 : Records of some Pekingese dragonflies taken by three members participated in the 19 th International Entomology Congress, I. Gekkan-Mushi, (260): Bartenef, A. N : Collection of Matsuyama (Japan) dragonflies. [List of Invertebrata collection in the Zoological Museum of Imperial University of Tomsk published under the editorialship of N. E. Kastchenko, XI], Izv. gosud. Tomskogo univ., 37 (11): 1-16, pi. 11 excl. (pp in Russian, pp in English). (Obviously the publication year is 1910, not 1909 as given in earlier references). Bridges, C. A., 1994 : Catalogue of the Family-Group, Genus-Group and Species-Group Names of the Odonata of the World, 3rd edn, Bridges. Urbana, 111. Fraser, F. C., 1957 : A reclassification of the Order Odonata. Royal Zoological Society of New South Wales, Sydney. Martens, A., 1996 :Die Federlibellen Europas. Die Neue Brehm-BUcherei Bd. 626, Magdeburg. Munz, P. A., 1919 : A venational study of the suborder Zygoptera (Odonata) with keys for the identification of the genera. Mem. am. Ent. Soc., 3 :1-78, pis 1-20 excl. Navas, L., 1932 : Nevropteres et insectes voisins. Chine et pays environnants, 3. Notes Ent. chin., 1:1-11. Navas, L., 1934 : Nevropteres et insectes voisins. Chine et pays environnants, 7. Notes Ent. chin., 2 : Navas, L., 1935 : Nevropteres et insectes voisins. Chine et pays environnants, 8. Notes Ent. chin., 2 : Needham, J. G., 1930 : A manual of the dragonflies of China. A monographic study of the Chinese Odonata. Fan Memorial Institute of Biology, Peking. Ris, F., 1915 : Eine kleine Sammlung Libellen von den Comorischen Inseln (Odonata). Ent. Mitt., 4 : Ris, F., 1930 : Drei Notizen iiber ostasiatische Agrioniden (Odonata). Ark. zool., 21 A (31): Selys Longchamps, E. de, 1863 :. Synopsis des Agrionines, Quatrieme legion : Platycnemis. Bull. Acad. Belg. (II), 16 : (sep. 1-32). Selys Longchamps, E. de, 1886 : Revision du Synopsis des Agrionines. Premiere partie comprenant les legions Pseudostigma - Podagrion - Platycnemis et Protonevra. Mem. cour. Acad. Belg. (Cl. Sci), 38 (4): i-iv Selys Longchamps, E. de & H. A. Hagen, 1850 : Revue des Odonates ou Libellules d'europe. Mem. Soc. r. Sci. Liege, 6 : xxii+408,11 pis and 6 tbl excl. Yokoi, N. & K. Kano, Odonata collected in Lak Sao and its neighboring regions, central Laos, in spring. Tombo, Matsumoto, 45 : (In Japanese with Engl. Summary) n