Metreletus balcanicus (Ulmer, 1920)

Martynov, Alexander V., 2018, New records of some rare mayflies (Insecta, Ephemeroptera) from Ukraine, Ecologica Montenegrina 16, pp. 48-57 : 56

Metreletus balcanicus (Ulmer, 1920)

Metreletus balcanicus is a rare stenobiotic species distributed in South-Central Europe ( Soldán & Zahrádková 2000). For the first time it was given for Ukraine from Kharkiv Region ( Martynov 2011): this is the most eastern known point within the whole species distribution. Present research revealed a new locality of M. balcanicus in Ukraine, at Zakarpattia Region ( Figs 14, 18 ).

Habitat: In Kharkiv Region M. balcanicus inhabits the hipopotamal zone of middle-sized Lukonovakha River that dries up periodically. In Zakarpattia Region this species was found in the Salva River, which looked like a cascade of puddles connected with shallow streams in May, 2017 when material was collected ( Fig. 18 ). Additional parameters of waterbody in sampling place were: water temperature 14°C, water hardness 52 ppm, pH 7.1. All larvae ( Fig. 11 ) were gathered from stones or silted stones at the bottom and roots in puddles. We had also found the fresh exuvia and imagoes ( Fig. 12 ) that confirms the fact of emergence for M. balcanicus at this period.

Material: 16 larvae, 4 exuviae, 9 imagoes (3♂ + 6♀), Ukraine, Zakarpattia Region , territory of Bukove village, Salva River, 48.198433, 23.090850, h – 181 m a.s.l., Martynov A. V. leg., 11.05.2017 – IN Zkp 10 Metbal /1–4 .

Recommendations for conservation: Metreletus balcanicus is rare and stenobiotic in Ukraine and whole its areal, it has the restricted distribution within Ukraine; therefore we think that the species should be considered as perspective for including in the Red Data Book of Ukraine. Detailed investigation (also genetic affinity to other populations) of Ukrainian populations of M. balcanicus continues.

Figures

Figures 14–18. New collection sites of the investigated species within Ukraine: 14. – map showing new sites (red circles – Palingenia fuliginosa (Georgi, 1802); yellow circles – Isonychia ignota (Walker, 1853); green circle – Baetopus tenellus (Albarda, 1878); blue circles – Brachycercus harrisella Curtis, 1834; red quadrates – Siphlonurus aestivalis Eaton, 1903; yellow quadrate – Metreletus balcanicus (Ulmer, 1920)); 15. – Styr River, (vicinity of Stara Rafalivka village, July 2017); 16. – Stvyga River (vicinity of Poznan’ village, July 2017); 17. – bay of Desna River (vicinity of Prydesnyans’ke village, May 2017); 18. – Salva River (territory of Bukove village, May 2017).

Figures 9–13. Larvae and imago of some registered species: 9. – Isonychia ignota (Walker, 1853), total view of larva, scale bar 2 mm; 10. – Baetopus tenellus (Albarda, 1878), total view of larva, scale bar 1 mm; 11. – Metreletus balcanicus (Ulmer, 1920), total view of larva, scale bar 2 mm; 12. – the same species, genitalia and posterior part of abdomen, male imago, ventral view, scale bar 1 mm; 13. – Brachycercus harrisella Curtis, 1834, total view of larva, scale bar 2 mm.