Gynacantha pupillata Dijkstra

Dijkstra, Klaas-Douwe B., Kipping, Jens & Mézière, Nicolas, 2015, Sixty new dragonfly and damselfly species from Africa (Odonata), Odonatologica 44 (4), pp. 447-678 : 549-552

Gynacantha pupillata Dijkstra sp. nov. – Spectacled Duskhawker (Type Photo 26, Photo 40, Fig. 15)

Taxonomy

First recorded as an unidentified female from Liberia by Lempert (1988). Recent material shows it is widespread and genetically and morphologically distinct: thus treated as a good species by Dijkstra & Clausnitzer (2014). Belongs to the bullata -group of Gynacantha Rambur, 1842 with G. bullata Karsch, 1891 , G. congolica sp. nov., G. manderica , G. nigeriensis (Gambles, 1956) , G. usambarica Sjöstedt, 1909 , and G. victoriae ( Pinhey, 1961) . Dijkstra (2005 b) synonymised the last with G. bullata on account of their (a)small size, Hw 35.0–44.0 mm; (b) pale legs with dark rings around the joints; (c) the absence of denticles in the posterior portion of the genital fossa border; and (d) the ventral carinae of S 6–8 lacking denticles. However, G. victoriae is genetically distinct ( Tree 4) and has (1) the antennal sockets on the frons usually not blackened and thus contrasting with the black vertex ( Fig. 15); (2) broad blackish smears over the humeral sutures; (3) blue markings with maturity on the plate between Hw bases, dorsally on apex of S 2 and laterally on base of S 3; and (4) shorter cerci, 5.0– 5.5 mm and less than 3 x as long as the epiproct, distinctly shorter than S 8–10 combined ( Fig. 15) [rejected synonymy].

Material studied

Holotype ♂. RMNH.INS.502124 , Congo-Kinshasa, Province Orientale, Lower Aruwimi, Bomane, Village on Aruwimi River and old oil palm plantation, 427 m a.s.l. (1.27 ° N 23.73 ° E), 23 -v- 2010, leg. K.- D.B. Dijkstra, RMNH .

Further material. CAMEROON (Littoral Province): 1 ♀ ( RMNH.INS.500174 ), 30 km SW of Edéa, Douala-Edéa Reserve, about 3 km east of Marienberg , narrow forest strip along a grassy swamp beside the Sanaga River, 10–20 m a.s.l. (3.62 ° N 9.91 ° E), 18 -vi- 2008, leg. K.- D.B. Dijkstra & K. Schütte, RMNH . CONGO-BRAZZAVILLE: 1 ♀, 36 km north-east of Pointe-Noire, Hinda area , stream forest and good Hallea swamp forest, 17 m a.s.l. (4.5937 ° S 12.1309 ° E), 23 -vi- 2014, leg. L. Niemand & C. Ngou- lou, RMNH . CONGO-KINSHASA (Province Orientale): 4 ♂ ( RMNH.INS.502176 ), as holotype, RMNH . LIBERIA (Grand Gedeh County): 1 ♂ ( RMNH.INS.501580 ), 1 ♀ ( RMNH.INS.501581 ), Putu Iron Ore Mining concession, near former village of Boloweah , sandy and gravelly stream running from rainforest into tangly clearing, 260 m a.s.l. (5.6891 ° N 8.1678 ° W), 05-ii- 2011, leg. K.-D.B. Dijkstra & A. Dayeker, RMNH . 1 ♀, NE of Zwedru , high forest away from water near the Cavalla River , 06-iii- 1982, leg. & coll. J. Lempert . SIERRA LEONE (Eastern Province): 1 ♂ ( RMNH.INS.503152 ), Gola Forest, 1 km NE of Mayengema , small stream in forest, 131 m a.s.l. (7.6504 ° N 10.7838 ° W), 04-iii- 2011, leg. K.-D.B. Dijkstra & A. Dayeker, RMNH .

Genetics

Five unique haplotypes (n= 6) are very distinct but nearest to G. usambarica ( Tree 4).

Male morphological diagnosis

Belongs to the bullata -group by (a) the distinct black mark on the frons; (b)the pale rim of the metastigma; (c) the presence of brace veins below Pt; (d) the genital fossa border with distinct rows of 8–14 denticles; (e) S 3 distinctly waisted near its base; (f) the lateral carinae of S 8 normally with denticles, like the ventral carinae; and (g) the cerci of rather even width throughout ( Fig. 15). Nearest to G. nigeriensis and G. usambarica by (h) the uniformly pale legs; and (i) the ventral carinae of S 7–8 and sometimes S 6 with denticles. However, is (1) smaller, Hw 41.0–44.0 mm (n= 7) rather than 43.0–48.0 mm (n= 33); (2) duller in colour, with an olive rather than grass green thorax, and at most the plate between Hw bases and a dorsal pair of spots on the apex of S 2 blue; (3) the frons bears an isolated black dot anterior to each antenna ( Fig. 15); (4) the wing bases have distinct dark rays to Ax 1–2; and (5) all wings have 5–14 cells doubled between R 2 and R 3 proximal to the brace vein, i.e., forming 2 cell rows. The dull colour, dotted frons and doubled cell rows are unique within the group.

Etymology

Named for the pair of pupil-like dots on the frons (feminine adjective).

Range and ecology

Rather localised but widespread in rainforest from sea level to 430 m a.s.l. in Sierra Leone, Liberia, Cameroon, Congo-Brazzaville and central Congo- Kinshasa, but precise breeding habitat unknown ( Map 7).