M a t e r i a l e x a m i n e d. Ukraine. Rivne Region: Bushcha env.: 50.301 N 26.299 E, edge of deciduous forest, on flowers of Anthriscus sylvestris, 17.05.2018, 1 {; idem, Mizotskyi Kriazh, 50.30 N 26.30 E, deciduous forest, 20– 22.05.2019, on flowers of Anthriscus sylvestris, 6 {, 1} (A. Prokhorov); Ivano-Frankivsk Region: Tatariv env.: 48.385 N, 24.511 E, Zhenets River valley, 12.06.2018, 1}; Yaremche env.: 48.443 N, 24.507 E, Zhonka River valley, coniferous forest, on flowers of Chaerophyllum aromaticum, 21.06.2019, 1}; Volyn Region: Kivertsi env.: 50.829 N 25.379 E, road in mixed (pinus/oak) forest, on flowers of Anthriscus sylvestris, 08.06.2019, 1 {(V. Shparyk).
D i s t r i b u t i o n: Belarus, Bulgaria, Estonia, Finland, France, Germany, Great Britain (Scotland), Hungary, Latvia, Nothern Macedonia, Montenegro, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Sweden, Switzerland; Russia (European part, Siberia, south of Far East); Transcaucasia; Nearctic Region (from Alaska south to Arizona) (Peck, 1988; Dirickx, 1994; Holinka & Mazánek, 1997; Reemer, 2000; Stubbs & Falk, 2002; Stănescu & Pârvu, 2005; Bartsch et al., 2009; Mielczarek, 2009; Tóth, 2011; Van Steenis et al., 2013; Haarto & Kerppola, 2014; Barkalov & Mutin, 2018; Speight, 2018; Wakkie, 2019); Ukraine (first record).
Diagnosis. Both sexes of H. ferruginea clearly differ from H. ingrica (figs 5–8) by the longer body, 9.0– 13 mm (in H. ingrica, body length 5.5–8.0 mm), and plumose arista (fig. 3), with its branches> 2× as long as the maximum diameter of the arista (in H. ingrica, arista with shorter microtrichia (fig. 7), the longest branches slightly longer than the maximum diameter of the arista). Additionally, H. ferruginea can be separated from H. ingrica by: hind coxae covered with numerous short black setae (Mutin & Barkalov, 1999) as well as katepisternum with several (8–12) long black setae posteriorly (fig. 4) (in H. ingrica, katepisternum without black setae, and hind coxae mostly with 2–3 long black setae only in outer posterior corner laterally and the same amount at the posterior edge, as on fig. 8); female tergite 2 (fig. 2) usually with pale anterolateral part that do not look like separate maculae (in H. ingrica, female tergites 2 and often 3 with pale maculae that look like a separate maculae (fig. 6), especially on tergite 2).
N o t e. The only representative of the genus in Ukraine. In Great Britain, this species is listed under the UK Biodiversity Action Plan and qualifies as Endangered (Ball & Morris, 2014).