Drepanosticta seramensis, Tol & Bedjanič, 2018

Tol, Jan Van & Bedjanič, Matjaž, 2018, A new Drepanosticta species from Seram, Moluccas (Odonata: Platystictidae), Zootaxa 4461 (1), pp. 127-133 : 128-131

Drepanosticta seramensis sp. nov.

( Figs. 1–6 , 9–11 )

Type material. Holotype: 1♂ (mature) (JvT no. 32749)— (1) Small stream in the forest 5 km SE of Sawai village at the north-western border of Manusela National Park, 36 km SW of Wahai, Seram island, Moluccas, Indonesia; S 2.9768, E 129.2269. 02-xii-1996, alt. 20m; M. Bedjanič leg. (in RMNH).— Paratypes (3♂ 3♀, in RMNH, except JvT nos 32752 and 32754, in collection M. Bedjanič): 1♀ (mature, allotype, JvT no. 32750): Small swampy areas and pools in the primary forest at the path from Raleigh Expedition Base Camp at Kali Wasamata River to Roho village, 6 km SE of Roho village, Manusela National Park, 31 km SSW of Wahai, Seram island, Moluccas, Indonesia; S 3.0623, E 129.4217. 27-xi-1996, alt. 300m, M. Bedjanič leg.— 1♂ (teneral male, JvT no. 32751), Kali Mapa stream 4.5 km SE of Sawai village at the north-western border of Manusela National Park, 38 km SW of Wahai, Seram island, Moluccas, Indonesia; S 2.9879, E 129.2133. 01-xii-1996, alt. 50–100m, M. Bedjanič leg.— 1♂ (mature, JvT no. 32752), 1♂ (teneral, JvT no. 32753), 2♀ (teneral, JvT nos 32754-32755), Small streams in the primary and secondary forest at the path from Raleigh Expedition Base Camp at Kali Wasamata River to Kanikeh village, 1.5 km SE of Raleigh Expedition Base Camp, Manusela National Park, 32 km SSW of Wahai, Seram island, Moluccas, Indonesia; S 3.0749, E 129.4290. 26-xi-1996, alt. 300–400m, M. Bedjanič leg.

Etymology. The species epithet is an adjective; seramensis , after the island of Seram, the type locality of new species.

Description of holotype. Male. Head ( Fig. 1 ). Labium dark yellow, with brown markings (presumably by discoloration); labrum, mandibles and anteclypeus shiny pale cream, possibly bluish in living specimens; labrum with anterior half dark brown, dark stripe tapering towards antero-lateral corners; mandibles with anterior one-sixth dark brown; gena yellowish; rest of head brown, semi-matt, but postocular lobe and occiput distinctly paler; a conspicuous pale transverse stripe between antennae, somewhat constricted at level of anterior ocellus; fine longitudinal striae between eyes and lateral ocelli; rest of head coriaceous; transverse occipital carina poorly developed, without lateral extremities. Antennae with scapus pale brown at base, rest of scapus and pedicellus pale cream; flagellum brown (right flagellum broken). Eyes in preserved specimen middle brown.

Thorax ( Fig. 1 ). Pronotum erect, without conspicuous processes, predominantly brown; anterior lobe with paired oblong pale cream markings, lateral corners of this lobe dark brown, rest brown; median lobe middlebrown, flat; lateral lobes dark brown, brownish black in ventro-lateral corners; posterior lobe flat, dark brown, with small, but distinct and somewhat erect, triangular projections in lateral corners ( Fig. 11 ). Synthorax dark brown; mesepimeron distinctly darker, and metepimeron somewhat paler than other parts. Legs dirty yellow, with narrow, but distinct dark annulae distally on all femora; bases of tibiae somewhat darker than rest of legs. Wings hyaline, venation brown ( Fig. 6 ); Arculus just distal to Ax2; Px in fore wing 15½ (the last one incomplete), in hind wing 14½ (the last one incomplete); R4+5 at subnodus; IR3 arising halfway first cell distal to subnodus; Ab vein meeting Ac at hind margin of wings (Y sessile); CuP reaching hind margin of fore wing at level of Px4, in hind wing at level of Px5; ten cells between Arculus and place where CuP meets hind margin of hind wing; pterostigma rather pale, oblique, wider than high.

Abdomen. Brown, posteriorly somewhat darker; paler markings anteriorly on segments as follows: one-tenth of segment 3, one-eighth of segment 4, one-sixth of segment 5 and one-fifth of segment 6. Anal appendages with superiors brown, inferiors dirty yellow ( Figs. 2, 3 , 9, 10 ); superiors basal two-fifths robust, distal three-fifths dorsoventrally compressed, elongate club-shaped, tip rounded, a distinct dorsal tubercle at two-fifths from base; inferiors in ventral view rather robust, diverging, distal part of each appendage compressed and tip curved inward, more similar to D. moluccana from Buru than to D. amboinensis from Ambon.

Measurements (including appendages) (mm). Total length 43.5, abdomen 36.0, hindwing 24.0.

Variation in paratypes. One mature male: abdomen 36 mm, hindwing 22.5 mm. Other males teneral, hindwing 21–22 mm.

Female. Coloration of head and thorax similar to the male ( Fig. 4 ), somewhat better defined than in holotype. Wings as in male, Px in forewing 14½ (or 15), hindwing 14½; R4+5 arising at (forewing) or just anterior (hindwing) to nodus; IR3 arising halfway first cell distal to subnodus; Ab vein meeting Ac just before hind margin of wing (Y shortly stalked); CuP reaching hind margin of forewing at level of Px4, in hindwing at level of Px5; nine cells between Arculus and place where CuP meets hind margin of hind wing. Pterostigma middle brown. Abdomen stouter than in male. Valves and terebra short, not surpassing level of anal appendages ( Fig. 5 ).

Measurements (variation of paratypes in brackets). Abdomen 33 (other specimens not measured), hindwing 23 (22–23).

Diagnosis. Closely related to D. moluccana Lieftinck and very similar to D. amboinensis van Tol ; the male differs from the latter species by its sharp, somewhat erect lateral edges of the posterior lobe of the pronotum, its more elongate ventral club of the superior anal appendages (rather similar to D. moluccana , whereas it is more triangular in D. amboinensis ), and its more robust and subterminally constricted inferior appendages as compared with D. amboinensis ( Figs. 7–11 ).

Distribution and habitat. Seram ( Moluccas, Indonesia). The distribution of the Platystictidae of the Moluccas is presented in Fig. 12 . Based on a figure in van Tol (2007), we have added the records of two recently described species ( D. pararudicula Theischinger et al., 2015 from Halmahera, and D. batanta Kóvacs & Theischinger, 2015 from Batanta) (see Kóvacs et al. at. 2015), and of D. auriculata (Selys) (previously reported from the northern Bird’s Head Peninsula of New Guinea), and the record of D. seramensis sp. n. (with red symbol).

Drepanosticta seramensis was collected on various small streams in and around Manusela National Park, between 20 and 400 m ( Fig. 13 ).

Figures

FIGURE 12. Distribution of Drepanosticta species of the Moluccas (records from Sulawesi and New Guinea not indicated). After van Tol (2007), new records with coloured symbols.

FIGURE 13. Small stream in forest along path to Kanikeh village, Manusela National Park, Seram. Locality of Drepanosticta seramensis. Photo M. Bedjanič.

FIGURES 1–6. Drepanosticta seramensis sp. nov. (1) head and thorax, lateral view [holotype male]; (2) anal appendages, ventrolateral view [holotype male]; (3) anal appendages, dorsal view [holotype male]; (4) head and thorax, lateral view [allotype female]; (5) ovipositor, lateral view [allotype female]; (6) wings [holotype male].

FIGURES 7–11. Drepanosticta species. (7–8) D. amboinensis van Tol: (7) superior appendage, left lateral view; (8) inferior appendage, ventral view. (9–11) D. seramensis sp. nov.: (9) superior appendage, left lateral view; (10) inferior appendage, ventral view; (11) pronotum, dorsal view (Figs 7–8, JvT 23548, Figs. 9–11, JvT 32749, holotype male).