Vanuatubasis santoensis, Ober & Staniczek, 2009

Ober, Stefan V. & Staniczek, Arnold H., 2009, A new genus and species of coenagrionid damselflies (Insecta, Odonata, Zygoptera, Coenagrionidae) from Vanuatu, Zoosystema 31 (3), pp. 485-497 : 487-490

Vanuatubasis santoensis n. sp.

( Figs 1-3 ; 4C, F, I, L ; 5B )

HOLOTYPE. — Vanuatu. Sanma Province, Espiritu Santo, surroundings of Penaoru, Penaoru River , 14.96105°S, 166.63316°E, 90 m, 13.XI.2006, leg. A. H. Staniczek & M. Pallmann, ♂ ( SMNS: ODO 000242 K).

PARATYPES. — Vanuatu. Sanma Province, Espiritu Santo, surroundings of Tasmate, Mamasa River , 15.20976°S, 166.67705°E, 20 m, 9.XI.2006, leg. A. H. Staniczek & M. Pallmann, 2 ♂♂ ( MNHN) ; 2 ♂♂ ( SMNS: ODO 000243 K, ODO 000244 K). — Sanma Province, Espiritu Santo, surroundings of Tasmate, Paé River , 15.21751°S, 166.68706°E, 139 m, 11.XI.2006, leg. A. H. Staniczek & M. Pallmann, 1 ♂ ( SMNS: ODO 000245 K). — Sanma Province, Espiritu Santo, surroundings of Penaoru, Penaoru River , 14.96105°S, 166.63316°E, 90 m, 13.XI.2006, leg. A. H. Staniczek & M. Pallmann, 2 ♂♂ ( SMNS: ODO 000246 K, ODO 000247 K). — Penaoru, Camp de base, 17.XI.2006, leg. F. Durand & E. Boitier, 2 ♂♂ ( MNHN) .

ETYMOLOGY. — The species is named after Santo, the shortened colloquial form of Espiritu Santo.

ADDITIONAL MATERIAL. — Vanuatu. Sanma Province, Espiritu Santo, surroundings of Tasmate, Mamasa River , 15.20976°S, 166.67705°E, 20 m, 9.XI.2006, leg. A. H. Staniczek & M. Pallmann, 1 ♀ ( MNHN) ; 4 ♂♂, 1 ♀ ( SMNS: ODO 000248 K-ODO 000251 K, ODO 000252 A). — Sanma Province, Espiritu Santo, surroundings of Penaoru, Penaoru River , 14.96105°S, 166.63316°E, 90 m, 13.XI.2006, leg. A. H. Staniczek & M. Pallmann, 2 ♂♂, 2 ♀♀ ( SMNS: ODO 000253 K-ODO 000255 K, ODO 000256 A). — Penaoru, Camp de base, 17.XI.2006, leg. F. Durand & E. Boitier, 2 ♂♂ ( MNHN) .

DISTRIBUTION. — The species is only known from the island of Espiritu Santo.

DESCRIPTION OF THE HOLOTYPE

Preserved dry, pinned. In good condition.

Head

Labium light beige; labrum aquamarine, with a very small, central brown spot at the basal margin (colour layer below the cuticula due to preservation broken and partly shifted); genae, anteclypeus, and postclypeus aquamarine; postclypeus medially brownish at base and anteriorly with a blackish triangle, on each side flanked by two brown stripes; frons aquamarine, medially changing to yellowish with slight whitish pruinosity,dorsal part blackish;basal joints of antennae aquamarine with pale end rings, each scapus black with pale end rings, pedicelli brown, paler medially, flagella dark brown; vertex and occiput black with bronze shimmer, except for a small, creamy brown spot in front of the median ocellus and the central hind margin of the occiput, diminutive postocular spots, composed of bluish-white pruinosity; head dorsally brownish, posteriorly creamy-yellowish with slight whitish pruinosity; eyes dark brown.

Thorax

Prothorax dorsally black with slight greenish metallic shimmer, laterally brownish and slighty covered with bluish-white pruinosity in its lower half; hind lobe of pronotum raised, each side of upper rim slightly curved and forming an acute apex, lower rim broadly V-shaped and slightly protruding posteriorly, surface between both ridges concave ( Fig. 5B ). Synthorax: mesanepisternum with green-black metallic median band, reaching the mesopleural suture in its hindmost fourth, but elsewhere separated from it by a pale olive-green band, dorsal carina black; mesostigmal lamina slightly triangular, posterior margin proximally with a rounded protuberance; apex of lamina forming a slightly overhanging process ( Fig. 5B ); mesokatepisternum brown to dark brown in the upper two-thirds, pale aquamarine in its lower third, entire mesokatepisternum with slightly bluish-white pruinosity; mesepimeron yellow-brown to pale aquamarine posteriorly, with blackish median stripe; metanepisternum pale aquamarine, brownish yellow anteriorly, posteriorly with small, elongate blackish spots at the intersegmental and metapleural suture; metakatepisternum brownish, covered with a bluish-white pruinosity in its lower half; metepimeron pale aquamarine becoming brownish yellow anteriorly, slightly bluish-white pruinose posteriorly; poststernum dark brown to blackish, partly bluish-white pruinose; sternum brownish with bluish-white pruinosity. Legs dark brown, coxae, trochanters, and tarsi paler, each femur basally with a whitish ring; coxae, trochanters, and femora slightly covered with bluish-white pruinosity; spines black.

Wings

Hyaline; venation dark brown, costa and radius black at base; pterostigma dark brown, with narrow pale margins, centrally a trace of bluish-white pruinosity, less than one cell long, rhomboidal; 15/15 postnodal crossveins in the left and 15/14 postnodal crossveins in the right forewing, 13/12 postnodal crossveins in hind wings.

Abdomen

Segment 1 dorsally dark brown to blackish, slightly covered with bluish-white pruinosity, brownish laterally; segment 2 dorsally blackish with greenish metallic shimmer, laterally pale to dark brown, centrally glaucous; secondary genital apparatus with terminal segment of ligula broadened towards its apical end, medially emarginated, basal third of terminal segment with longitudinal row of setae on each side ( Fig. 2 ); segments 3-6 brown to dark brown,becoming paler laterally and turning yellowish ventrally, brown colouration darker at the segment borders, segments on the dorsum slightly metallic; segments 7-9 dark brown to blackish dorsally and laterally, ventrally yellow-brown; segment 10 dorsally brown, posterior margin blackish, elevated and dorsomedially excised, laterally and ventrally yellow-brown. Superior anal appendages brown, short, in dorsal view roughly resembling a paisley pattern ( Fig. 4C, F ); in dorsocaudal view paisley-like shape more obvious, appendages broad, with convex, bulging upper margins and slightly concave, flattened lower margins, inner margins ending ventrally in bevelled edges, laterally each upper and lower margin is converging to a prominent tip directed posteriorly; in lateral view the appendages appear roughly triangular ( Fig. 4I, L ). Inferior anal appendages yellow-brown, in dorsal view forceps-like, incurved, ending in a black tip which is directed inwards; about three times as long as the superior appendages ( Fig. 4C, F ); in lateral aspect broad at base, narrowing to an acute tip ( Fig. 4I, L ). Each inferior anal appendage bears basally on its inner side a strong, rounded process fringed with hairs ( Fig. 4C, F ).

Measurements

Length of abdomen: c. 35 mm (not completely elongated), length of hind wings: 22.3 mm.

VARIATION

Colouration of mature males only with minor variations. Colour of face in two males pale greenish-blue,in four males light blue, and in three males dull aquamarine; the pruinose postocular spots are completely missing in four males.Yellow-brownish to olive-green colouration onprothoraxdorso-laterallysometimesmoreexpanded. Green metallic shimmer on dorsum of thorax in six specimens lacking; the lateral thoracic colouration varies between pale aquamarine and brownish-olivegreen; brown to black colouration on mesepimeron is differently developed and ranges from small, elongate, pale spots to broad, dark stripes, three males without any spots; extension of bluish-white pruinosity very variable, two males without any pruinescence.Segment 1 and 2 laterally often brighter pale aquamarine and less brown than in holotype.Segment 9 and 10 in three males dorsally and laterally with more extensive light brown to beige colouration. Superior and especially inferior anal appendages uniformly coloured. Three teneral males are straw-coloured with the exception of following parts: head dorsally green-black metallic, prothorax and synthorax dorsally brown to dark brown, abdominal segments 1-8 brown dorsally and at segment borders, segments 9 and 10 whitish dorsally. Males also differ slightly in the shape of pronotal structures. In two males the upper rim of pronotal hind lobe is curved with rounded apex, in four specimens the rim is more conspicuously curved forming a very acute tip medially. The median apex of the upper rim is connected with the lower rim by a more or less prominent keel in several males. There are also considerable differences in the extension of the inner process of inferior anal appendages. In six males the strong basal process on the inner side of each inferior anal appendage is only very small to small and more or less directed inwards.It is not clear at present if this is an artefact of preservation.

The female of V. santoensis n. sp. could not be identified with certainty. Therefore we refrained from designing female paratypes. However, we tentatively assign four females to the new species, as they generally match the male colouration with following exceptions: aquamarine colouration of face paler or more glaucous, legs yellowish-brown, and apical two-thirds of segment 9, and segment 10 creamy or glaucous dorsally (light blue in life, see Fig. 3 ). One female has a slightly darker face and greenish eyes, and the pruinosity is more developed than in the other females. Pronotal hind lobe of females erected, rounded, not curved and not forming an apex medially; on the posterior rim of each mesostigmal lamina there is only a very inconspicuous protuberance. Cerci shorter than segment 10; ovipositor finely serrate at ventral border and slightly extending beyond segment 10.

The paratype series varies in dimensional and venational characters as follows: abdomen length: c. 30-37.5 mm, hind wing length: 19.6-22.9 mm, 12-17 postnodal crossveins in forewings, 10-14 postnodal crossveins in hind wings.

REMARKS

At first glance, males of V. santoensis n. sp. resemble males of V. malekulana n. comb., but a closer view reveals differences in the shapes of pronotal hind lobe, mesostigmal laminae,and superior anal appendages.In V.santoensis n. sp. the upper hind rim of the prothorax is more raised and only slightly curved, the lower ridge is not or only marginally protruding posteriorly. The protuberance of each mesostigmal hind ridge is less prominent and the superior anal appendages are paisley-shaped, contrary to the crescent-like form in V. malekulana n. comb. In lateral view, the flattened inner angle of the superior anal appendages is not visible in V. santoensis n. sp. Moreover, V. santoensis n. sp. is larger in size and the pterostigmata are dark brown versus light brown in V. malekulana n. comb.

The shape of the cerci is also a significant difference to V. bidens n. comb., in which the superior anal appendages are ovate and bidentate.

Figures

FIG. 1. — Vanuatubasis santoensis n. gen., n. sp., paratype, ♂ (SMNS: ODO 000246 K), right fore- and hind wing. Scale bar: 5 mm.

FIG. 2. — Vanuatubasis santoensis n. gen., n. sp., paratype, ♂ (SMNS: ODO 000244 R), ligula in ventral (A) and lateral (B) views. Scale bars: 200 μm.

FIG. 3. — Vanuatubasis santoensis n. gen., n. sp., ♀ at Mamasa River, Espiritu Santo, Vanuatu.

FIG. 4. — A, D, G, J, Vanuatubasis bidens (Kimmins, 1958) n. comb., holotype,♂ (BMNH), anal appendages in dorsal and lateral view; B, E, H, K, V.malekulana (Kimmins,1936) n. comb.,holotype,♂ (BMNH),anal appendages in dorsal and lateral view;C, F, I, L, V.santoensis n. gen., n. sp., holotype, ♂ (SMNS: ODO 000242 K), anal appendages in dorsal and lateral views. Scale bars: 0.2 mm.

FIG. 5. — A, Vanuatubasis malekulana (Kimmins,1936) n. comb.,paratype,♂ (BMNH),hind lobe of pronotum and mesostigmal laminae in dorsal view; B, V. santoensis n. gen., n. sp., holotype, ♂ (SMNS: ODO 000242 K), hind lobe of pronotum and mesostigmal laminae in dorsal view. Scale bar: 0.2 mm