Elachista occidentalis Frey, 1882

Elachista occidentalis Frey, 1882: 372 . Type locality: Switzerland, Vaud, Crassier (Frey 1882: 372). Lectotype ♂, in NHMUK, designated by Parenti (1977: 28).

Biselachista buvati Traugott-Olsen, 1994: 327 . Type locality: Italy, Piemonte, Val Curone (Traugott-Olsen 1994: 328). Holotype ♂, in ZMUC. Synonymized by Kaila & Varalda (2004: 226).

Biselachista ruthae Traugott-Olsen, 1994: 330 . Type locality: Austria, Teriolis meridionalis., Kreuzberg (Traugott- Olsen 1994: 331). Holotype ♂, in ZMUC. Synonymized by Kaila & Varalda (2004: 226).

Biselachista occidentalis: Traugott-Olsen (1994: 331) .

Subgenus: Elachista; tetragonella species group.

Distribution: Palearctic. Austria, Bulgaria, Croatia, Czech Republic, Estonia, Finland, France, Germany, Greece, Hungary, Italy, Latvia, Montenegro, Norway, Poland, Russia (Caucasus), Slovakia, Sweden, Switzerland.

Larval host plant(s): Carex digitata L., C. ericetorum Pollich (Cyperaceae) (Kaila & Varalda (2004).

Figs.: Traugott-Olsen & Nielsen (1977) (as Biselachista freyi), Traugott-Olsen (1994), Kaila & Varalda (2004).

Remarks: Parenti & Pizzolato (2015b) suggested that E. occidentalis is probably conspecific with E. juliensis Frey, based on extensive variation on genitalic characters. However, their conclusion was based on a misinterpretation of Kaila & Varalda (2004). DNA barcodes (unpublished) strongly suggest that two clusters of taxa are involved, in accordance with the view of Kaila & Varalda (2004). The suggested but not formalized synonymy of E. juliensis and E. occidentalis by Parenti & Pizzolato (2015b) is not followed here.