Neodythemis infra Dijkstra, Diedericks & Mézière, 2015

Dijkstra, Klaas-Douwe B., Kipping, Jens & Mézière, Nicolas, 2015, Sixty new dragonfly and damselfly species from Africa (Odonata), Odonatologica 44 (4), pp. 447-678 : 625-628

Neodythemis infra Dijkstra, Diedericks & Mézière sp. nov. – Blackwater Junglewatcher

(Type Photo 48, Photos 52, 70, Fig. 30)

Taxonomy

This rather nondescript species is easily overlooked, but the combination of morphological features that superficially recalls the related genus Micromacromia Karsch, 1890 is unique in Neodythemis Karsch, 1889 , as are the COI sequences.

Material studied

Holotype ♂. RMNH.INS.508825 , Gabon, Haut-Ogooué Province, Bongoville-Léconi road, Ekala , herbaceous swamp close to Boubou River (Photo 70), 421 m a.s.l. (1.6116 ° S 13.9116 ° E), 19 -v- 2013, leg. N. Mézière, J. Renoult & J. Lekogo, RMNH .

Further material. CONGO-BRAZZAVILE (Sangha Region): 1 ♂, 61 km NE of Quesso , blackwater swamp on sand in half open forest, 353 m a.s.l. (1.9501 ° N 16.4899 ° E), 19 -ix- 2014, leg. & coll. G. Diedericks . 1 ♂, 59 km NE of Quesso , forest road with stagnant blackwater on sand, 373 m a.s.l. (1.9441 ° N 16.4699 ° E), 25 -ix- 2014, leg. & coll. G. Diedericks . CONGO- KINSHASA (Province Orientale): 1 ♀ ( RMNH.INS.502275 ), Lilanda & Baombo streams at and upstream of Lilanda & Yafake villages , sandy clear and blackwater streams and river, 390–450 m a.s.l. (0.83 ° S 24.34 ° E), 04-v- - 2010, leg. K.-D.B. Dijkstra, RMNH .

Genetics Two unique haplotypes (n = 2) are very distinct but nearest to N. klingi (Karsch, 1890) . Male morphological diagnosis

Combines characters of three sympatric Neodythemis species. Recalls N.preussi (Karsch, 1891) by (a) the broad and complete pale ante-humeral stripes; and (b) the absence of black interpleural stripes, although there is a small dark smudge at the dorsal border of the metastigma ( Fig. 30). Similarly to that species and N. klingi has (c) Fw discoidal field of 1 cell-row at and distal of node, and 2 cells wide on wing border; (d) 4 cells in Hw anal loop; (e) 1 Cux in Fw and 2 in Hw; (f) 0 cross-veins in Fw triangle and 1 in Hw; (g) 12–14 Ax in Fw. Similarly to the latter and N. afra (Ris, 1909) has (h)black central lobe and inner borders of the lateral lobes of the labium; (i) the hook of hamule lying in a horizontal plane, not erect, and thus invis- ible in lateral view; and (j) slender apices of the cerci ( Fig. 30). Also notably small, Hw 22.2–24.3 mm (n = 3) at low end of 22.0–31.0 mm range of genus, and has brown rather than blackish Pt as is usual in the genus. Also recalls Micromacromia , especially M. camerunica Karsch, 1890 and M. zygoptera (Ris, 1909) , but differs by the presence of an anterior cleft on the hamule (the most reliable character for Neodythemis ) and in details of the markings and venation, as well as the wholly black labrum (see Dijkstra & Vick 2005).

Etymology

As the new species is small and easily overlooked, its name is a pun based on the species name of N. afra and the Latin word for “below”, which is to be treated as a noun in apposition.

Range and ecology

The holotype perched two metres above a swamp in gallery forest on the Batéké Plateau in Gabon ( Photo 70). The Congo-Kinshasa female was caught at a sandy blackwater forest stream and is genetically nearer to the holotype, but lacks the metapleural black stripe. The Congo-Brazzaville males confirm that this species favours blackwater swamps on sandy soils between 350 and 450 m a.s.l ( Map 10).