Elattoneura lapidaria Dijkstra & Bjelke

Dijkstra, Klaas-Douwe B., Kipping, Jens & Mézière, Nicolas, 2015, Sixty new dragonfly and damselfly species from Africa (Odonata), Odonatologica 44 (4), pp. 447-678 : 489-493

Elattoneura lapidaria Dijkstra & Bjelke sp. nov. – Rock Threadtail ( Type Photo 9, Photos 16–17, Fig. 6)

Taxonomy

Dijkstra & Clausnitzer (2014) discussed this species and provided a photograph but no characters for identification. It belongs to the genetically and ecologically distinct glauca -group of pruinose-faced Elattoneura species, which includes E. cellularis (Grünberg, 1902) , E. frenulata (Hagen in Selys, 1860), E. glauca (Selys, 1860) , E. nigra Kimmins, 1938 , E. tarbotonorum sp. nov. and presumably E. pasquinii Consiglio, 1978 ( Tree 1). Occurs with its nearest relative E. glauca , differing in behaviour, coloration, structure and genetically. Note however, that COI data suggest that E. cellularis and E. glauca conceal additional species ( Tree 1).

Material studied

Holotype ♂. RMNH. 5007711, Zimbabwe, Manicaland, 16 km E of Chimanimani village, Chimanimani National Park, Bundi Plain and Valley, rocky sections of Bundi in grassy and boggy plain and sheltered gorge, 1510 – 1577 m a.s.l. ( 19.784 ° S 33.029 ° E), 01-xii- 2013, leg. K.- D.B. Dijkstra & U. Bjelke, RMNH .

Further material. 3 ♂ ( RMNH.5007732 , RMNH.5007751 ), 5 ♀ ( RMNH.5007715 , RMNH.5007753 , RMNH.5007764 , RMNH.5007785 ), as holotype, RMNH .

Genetics

Three unique haplotypes (n = 7) nearest to but well-separated from E. glauca from the Eastern Cape (South Africa) and even more distant from specimens of that species from northern South Africa, Tanzania, Zambia and Zimbabwe, including syntopic ones ( Tree 1).

Male morphological diagnosis

Nearest to E. glauca by (a) the pruinose face with maturity; (b) the penis with pointed apical lobes as well as slender filament-like lateral branches; and (c)the ventral process of the cerci that is wide at base, with a conspicuous subapical tooth next to the single apical tooth ( Fig. 6). However, is (1)larger, Hw 21.5–22.2 mm (n= 4) rather than 17.5–19.5 mm (n = 6); (2)darker with pruinosity on face, S 8–10 and especially thorax less dense, with only narrow ante-humeral stripes of pruinosity rather than largely pruinose mesepisterna; (3) has the penis with broader apical lobes that are laterally more round- ed and less abruptly narrowed to their fine tips; (4) the cerci with relatively shorter apex but broader ventral process; and (5) the basal part of the paraprocts longer dorsally than ventrally in lateral view; however, the appendage shape may fall within the variation of E. glauca ( Fig. 6).

Etymology

Latin “belonging to stones” refers to the adult behaviour of perching consistently on rocks (feminine adjective).

Range and ecology

Unlike most Elattoneura species, the glauca -group is associated more with exposed and/or elevated habitats than with lowland rainforest. This species occurs along open rocky streams between 1 500 and 1 600 m a.s.l. in the Chimanimani Mountains of eastern Zimbabwe ( Photo 17). Both sexes always perched flat on rocks, probably to warm up in their often misty habitat. Its sister-species E. glauca was less numerous at the same sites and rested on vegetation like grasses.