New records of some rare mayflies (Insecta, Ephemeroptera) from Ukraine Author Martynov, Alexander V. text Ecologica Montenegrina 2018 2018-02-23 16 48 57 https://www.biotaxa.org/em/article/view/em.2018.16.6 journal article 54611 10.37828/em.2018.16.6 daad5c44-2db2-4e54-b6e2-89ba8a3937bb 2336-9744 8028193 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.