(Figs 4 b, 7 c –d)
Hylaeus pallescens Cockerell 1924 a: 279 –280, Ƥ (holotype—Ƥ, “Okeanskaja, Siberia” [Vladivostok, Primorskiy Terr., Russia], VIII. 1923, leg. T. Cockerell [USNM]).
Hylaeus stentoriscapus Dathe 1986 a: 271 –273, Ƥ, 3 (holotype— 3, “Charchiraa uul, Ulaangom Umgebung” [Mongolia]). Syn. nov.
Hylaeus stentoriscapus: Konusova & Yanyushkin 2000: 284; Proshchalykin 2003 a: 26; 2004: 3; 2007 a: 882; 2007 b: 89; 2008: 6; 2010: 509; Ignatenko 2004: 112; Ignatenko & Proshchalykin 2005: 244; Eremeeva et al. 2006: 26; Konusova et al. 2007: 213; Quest 2009: 123; Ebmer 2011: 13.
Prosopis stentoriscapus: Osytshnjuk & Romankova 1995: 486.
Material examined: 83 Ƥ, 80 3. Russia. Altai Republic (30 km SE Ongudai, 20 km NNW Aktash, 20 km N Shchebalino, 20 km E Tyungura); Irkutsk Prov. (15 km E Ust'-Ordynskiy, Sarma River); Buryatia (Naushki, Kharankhoi, Kaykhta, Gusinoe Lake, Baraty); Zabaikalskiy Terr. (20 km SSE Krasnokamensk, Kalga); Amurskaya Prov. (Khingan Nature Reserve); Jewich AP (Amurzet, Radde, Izvestkovyi); Primorskiy Terr. (Kedrovaya Pad Nature Reserve, Barabash-Levada, Dmitrievka, Andreevka, Evseevka, Vysokogorsk, Zanadvorovka, Spassk, Krounovka, Vityaz); Khabarovsk Terr. (Komsomolsk on Amur, 50 km SE Snezhniy).
Distribution in Russia. Tomsk Prov., Kemerovo Prov., Khakasia Republic (Konusova & Yanyushkin 2000; Konusova et al. 2007), *Altai Republic, *Irkutsk Prov., Buryatia, Zabaikalskiy Terr., Amurskaya Prov., Jewich AP, Primorskiy Terr., Khabarovsk Terr.
General distribution. Mongolia, Asian part of Russia.