(Figs 3 d, 11 a –b)
Hylaeus confusus Nylander 1852 b: 232, Ƥ, 3 (type locality: Europe); Davydova 2002: 94; Davydova & Pesenko 2002: 583; Proshchalykin 2003 a: 26; 2004: 3; 2005: 30; 2007 a: 883; 2007 b: 89; 2008: 6; 2009: 6; 2010: 509; Proshchalykin et al. 2004: 158; Ignatenko & Proshchalykin 2005: 244; Eremeeva et al. 2006: 26; 2009: 118; Konusova et al. 2007: 213; Quest 2009: 126; Proshchalykin & Quest 2009: 239.
Prosopis sublaevis Schenck 1853: 215, Ƥ (neotype—Ƥ, designated by Straka & Bogusch 2011: 53, “Klánovický les –V, Praha- Klánovice” [Czech Republic] [Forschungsinstitut Senckenberg, Frankfurt am Main]).
Hylaeus xanthocnemis Förster 1871: 969, Ƥ (neotype—Ƥ, designated by Straka & Bogusch 2011: 53, “Klánovický les, Praha- Klánovice” [Czech Republic] [Forschungsinstitut Senckenberg, Frankfurt am Main]).
Hylaeus nigriceps Förster 1871: 977, Ƥ (holotype—Ƥ, Aachen, Germany).
Hylaeus similatus Förster 1871: 994 –995, 3 (type locality: Piesting, Austria).
Prosopis pallididens Dalla Torre 1896: 28, nom. nov. pro H. pallidens Curtis 1831.
Hylaeus monticola Bridwell 1919: 155, Ƥ, 3 (type locality: Chuzenji, Tochigi Prefecture, Honshu, Japan); Kuwayama 1967: 208; Proshchalykin 2003 b: 5; 2004: 3; 2007 a: 883; Chen et al. 2010: 119. Syn. nov.
Hylaeus wilmattae Cockerell 1924 a: 280 –281, Ƥ, 3 (holotype— 3, “Kudia River, Siberia” [Primorskiy Terr., Russia], VI. 1923, leg. W. Cockerell). Synonymized by Warncke 1981: 157.
Prosopis confusa: Osytshnjuk & Romankova 1995: 487.
Hylaeus confusa: Konusova & Yanyushkin 2000: 284.
Material examined: 78 Ƥ, 98 3. Russia. Altai Republic (Talda, 20 km NNW Aktash); Khakasia Republic (Shira Lake); Irkutsk Prov. (Bratsk, Sosnovyi I.); Zabaikalskiy Terr. (12 km N Darasun, Tura River); Yakutia (Amga, Michailovka, Khaptagai, Zhemkon, 75 km SE Yakutsk, Pilka River, Olekminsk); Amurskaya Prov. (Kundur, 20 km SW Fevralsk, Talakan); Primorskiy Terr. (Lazovskiy Nature Reserve, Anisimovka, Spassk, Kievka, Andreevka, Novokachalinsk, Blagodatnoe, Novovladimirovka, Lozovoi, Rudnaya Pristan, Preobrazhenie, Evseevka, Khorol); Khabarovsk Terr. (Pivan, Sulak, Bychikha, Komsomolsk on Amur); Sakhalin (Kholmsk, 10 km E Boshnyakovo, Tymovsk); Kuril Islands (Kunashir: Tret'yakovo, Stolbchatyi, Alekhino, Dubovoe, Lagunnoe Lake, Goryachee Lake, Sernovodsk, Yuzhno-Kurilsk).
Distribution in Russia. European part (Osytshnjuk et al. 1978), Tomsk. Prov., Kemerovo Prov., Khakasia Republic (Konusova & Yanyushkin 2000; Konusova et al. 2007), *Altai Republic, Zabaikalskiy Terr., Yakutia, Amurskaya Prov., Primorskiy Terr., Khabarovsk Terr., Sakhalin, Kuril Islands (Kunashir) (Kuwayama 1967).
General distribution. Transpalaearctic up to Kuril Islands; Japan (Hokkaido, Honshu, Tsushima) (Ikudome 1989); China (Jilin, Xizang); all over Europe to 66 ° north, south to Greece; China (Xizang), Asia Minor, Caucasus.
Remarks. Until now Hylaeus confusus Nylander 1852 has been considered to be very common in the Russian Far East, but absent on the Japanese islands; in Japan, until now, only a similar species, H. monticola Bridwell 1919, was recorded. We have now compared the taxa in question, using material from Russia and Japan that includes the type of H. monticola (3, type no 50734, NMNH Department of Entomology, Smithsonian Institution). It was also necessary to consider new insights on the taxonomy of the Hylaeus gibbus species-group provided by Straka & Bogusch (2011). The result is clear: the Japanese specimens belong to the common and widespread H. confusus Nylander.