Elattoneura aurifex Dijkstra & Meziere, sp. nov.

Elattoneura aurifex Dijkstra & Mézière sp. nov. – Goldsmith Threadtail (Type Photo 8, Photos 14 –15, 26, 52, 62, Fig. 5)

Taxonomy

Morphologically and genetically nearest to the unresolved vrijdaghi -complex of Elattoneura Cowley, 1935, but clearly distinct on both accounts. Legrand (1980) synonymised E. tsiamae Aguesse, 1966 with E. vrijdaghi Fraser, 1954 but Dijkstra & Clausnitzer (2014) treated them separately on account of specimens attributable to two species found in sympatry in central Congo- Kinshasa and south-eastern Gabon. However, these regional forms also differ from each other while the holotype of E. vrijdaghi in MRAC has paraprocts and ante-humerals more like as illustrated for E. tsiamae by Dijkstra & Clausnitzer (2014) and thus further study of the complex is needed (Fig. 5).

Material studied

Holotype ♂. RMNH.INS.502487, Gabon, Haut-Ogooué Province, 34 km E of Franceville, Franceville-Léconi Road, NE of Bongoville, small streams and swamp at forest edge, 417 m a.s.l. (1.6131 ° S 13.9056 ° E), 31 -xii- 2009, leg. K.- D.B. Dijkstra, RMNH.

Further material. GABON (Haut-Ogooué Province): 1 ♀, 5 km after Bongoville towards Léconi, Andzaba River, Ekala, sandy and swampy stream, 389 m a.s.l. (1.6319 ° S 13.8888 ° E), 28 -iii- 2010, leg. N. Mézière & J. Renoult, RMNH. 1 ♂, 31 -viii-2010, 1♂, 26 -xi-2011, 1♂ (RMNH.INS.508775), 09- iii- 2013, all same locality, all leg. N. Mézière, RMNH. 2 ♂ ♀, 34 km E of Franceville, Franceville-Léconi Road, NE of Bongoville, small streams and swamp at forest edge, 417 m a.s.l. (1.6131 ° S 13.9056 ° E), 31 -xii- 2009, leg. K.- D.B. Dijkstra, RMNH. 1 ♂, Bongoville-Léconi road, Boubou River, Ekala, swamp close to the river, 421 m a.s.l. (1.6116 ° S 13.9116 ° E), 19 -xi- 2011, leg. N. Mézière, RMNH. 2 ♂ (RMNH.INS.502422, RMNH.INS.502425), Bongoville-Léconi road after Ekala, old village of Boubou, stream (2 m wide) with gravel bottom, 393 m a.s.l. (1.6114 ° S 13.9105 ° E), 20 -ix- 2009, leg. N. Mézière, RMNH. 3 ♂, 30 -xii-2010, 1♂, 05-ii-2010, 1♂, 28 -xii- 2010, all same locality, all leg. N. Mézière, RMNH. 2 ♂ 1 ♂ ♀, Léconi road, Souba, little sandy stream in gallery forest (2 m wide, 30 cm deep) and another bigger stream (3 m, 1 m), 413 m a.s.l. (1.5689 ° S 14.0382 ° E), 28 -i- 2012, leg. N. Mézière, A. Günther, J. Kipping & H. Krahnstöver, RMNH. 1 ♂, 50 km N of Franceville, Franceville-Okondja Road, Léconi River at bridge N of Onvouri-Olounga, large sandy river, 307 m a.s.l. (1.1776 ° S 13.5389 ° E), 10 - i- 2010, leg. K.- D.B. Dijkstra, N. Mézière & C. Vanappelghem, RMNH. 1 ♂ (RMNH.INS.508088), Batéké Plateau, small sandy stream near Souba Lake, 413 m a.s.l. (1.5688 ° S 14.0388 ° E), 27 -i- 2011, leg. N. Mézière, CJKL. 2 ♂ 1 ♀, same locality, same dates, CJKL. 1 ♂ ♀, Batéké Plateau, 18 km NW of Léconi, sandy stream in dense gallery forest, tributary to Léconi River, 425 m a.s.l. (1.4472 ° S 14.1661 ° E), 30 -ix- 2013, leg. J. Kipping, CJKL.

Male morphological diagnosis

Fairly small damselfly (Hw 20.0– 21.5 mm; n = 8) that is nearest to E. tsiamae / vrijdaghi by (a) the entirely brightly coloured labrum, clypeus and antefrons, as well as a broad band across the black dorsum of the head between the antennae and lateral ocelli; (b) the mesepisterna with little black; (c) the dull pale legs with blotchy dark markings, rather than uniformly red or black legs; (d) the double pair of finger-like lobes placed closely to each other at the penis apex; and (e) the triangular ventral process of the cerci, with its anterior border at an acute angle to the posterior border (Fig. 5). However, (1) the colour on the head and mesepisterna is warm yellow, rather than dark ochre yellow to reddish; (2) the eyes in life are brown rather than red; (3) the pronotal dorsum and mesepisterna are almost wholly yellow, contrasting with the largely black sides of the pronotum, mesokatepisterna and mesepimera; (4) the metapleural suture typically has a broad black stripe along its entire length; (5) only the dorsa of the cerci and S 9–10 are yellowish, contrasting with the largely black abdomen, rather than most of these segments and the appendages rufous; (6) the ventral process of the cerci is less drawn out; and (7) the apical process of the paraprocts is more slender and rounded (Fig. 5).

Etymology

Latin “goldsmith” refers to the yellow coloration (noun in apposition).

Range and ecology

Shady spots along clear sandy streams in gallery forests between 300 and 425 m a.s.l. on the Batéké Plateau in south-eastern Gabon (Photos 15, 26, 52, 62). CUMZ has specimens from Djoumouna, a river at 375 m a.s.l. 20km southwest of Brazzaville in Congo-Brazzaville, and the species is likely to occur widely across the sandy soils of this region.