Epistrophe olgae Mutin, 1990

Prokhorov, A. V., Popov, G. V. & Zaika, M. I., 2018, New Records Of Hoverflies (Diptera, Syrphidae) From Ukraine. Iii. Pipizinae And Syrphinae, Vestnik Zoologii 52 (3), pp. 241-250 : 246-248

Epistrophe olgae Mutin, 1990 (figs 19, 20, 23–25)

M a t e r i a l e x a m i n e d. Ukraine. Kyiv Region: Potashnia env., 50.71 N 29.74 E, Tal River floodplain ,

9.05.2016, 1 ♀; Kotsiubynske env., 50.47 N 30.30 E, clearing in mixed forest, 17.04.2016, 1 Ơ (A. Prokhorov).

D i s t r i b u t i o n: uncertain, due to confusion with Epistrophe nitidicollis (Meigen, 1822) , already known from Norway, Sweden, Finland, France (Rhine valley in Alsace), Switzerland and Far East of Russia (Kamchatka Peninsula, Khabarovsk Region, Primorsky Region, Kuril Islands ( Mutin, 1990; Mutin & Barkalov, 1999; Speight, 2017); Ukraine (first record).

Diagnosis. Epistrophe olgae is most similar to Epistrophe nitidicollis (figs 21, 22, 26– 28), having the second basal cell of wing 20% or more bare of microtrichia, mesoscutum brightly shining, undusted, and tergite 5 partly black ( Speight & Sarthou, 2017). Both sexes can be separated from it by the orange-brown arista (figs 23–25) (in E. nitidicollis , arista black or dark brown, as on figs 26–28) ( Speight & Sarthou, 2017), and the mesonotum shining with an olive or golden tint (in E. nitidicollis , the mesonotum shining black with a bluish tint) ( Mutin & Barkalov, 1999). Male can be distinguished from E. nitidicollis by the frons with a grey or golden ( Mutin, 1990) or faint yellow-gray dust (in E. nitidicollis , the frons with a distinct grey dust) (Bartsh et al., 2009; Speight & Sarthou, 2017); in the Ukrainian specimen of E. olgae , the frons with distinct golden dust (fig. 23), while in E. nitidicollis the frons with a yellowish-gray dust (fig. 26). Female differs from E. nitidicollis by the frons almost entirely dusted brownish-grey (in E. nitidicollis , the frons with a pair of brownish-grey dust spots, though these dust spots may be joined in the mid-line), the vertex pollinose with a brownish-grey dust, lateral to the ocellar triangle (fig. 25) (in E. nitidicollis , the vertex shining black, undusted, lateral to the ocellar triangle, as on fig. 28) ( Speight & Sarthou, 2017). In the Ukrainian specimen of E. olgae , the frons with a pair of almost separated (figs 24, 25), yellowish-grey dust spots (but the frons between these spots faintly pollinose, not shining), whereas in E. nitidicollis , these yellowish-grey dust spots are distinctly separated, and the frons between this pollinose spots is shining (figs 27, 28).

N o t e. It is noteworthy that the descriptions ( Mutin, 1990; Mutin & Barkalov, 1999) do not mention that E. olgae has an orange-brown arista. Mutin (1990) describes it as a brown arista, but it has not been included among distinctions of E. olgae from E. nitidicollis . This remarkable character (among others) clearly differentiates these two species among the Ukrainian specimens.