Chrysura dichroa

69. Chrysura dichroa (Dahlbom, 1854)

Chrysura nitidula Dahlbom 1845: 7. Holotype ♀; Sweden (ZMUL) (examined), nec Chrysis nitidula Fabricius, 1775, nomen oblitum.

Chrysis Gyllenhali Dahlbom 1854: 143. Holotype ♀; Sweden (ZMUL) (examined) (also holotype of Chrysura nitidula). Thomson 1870: 106, Mocsáry 1889: 272, Aurivillius 1911: 11.

Chrysis dichroa Dahlbom 1854: 146. Lectotype ♀ (designated by Rosa, in prep.); Hungary: Buda (MSNT) (examined). Erlandsson 1971: 88.

Chrysura gyllenhali: Kimsey & Bohart 1991: 490.

Chrysura dichroa: Soon 2004: 46.

Distribution. Sweden.—Westpalearctic: southern and central Europe, Southeast Asia (Linsenmaier 1997).

Remarks. Dahlbom (1845) reported this species first from Sweden with the name Chrysura nitidula. He attributed the authorship of the species to Spinola (" Chr. nitidula Spin. "), but Spinola did not mention any species with this name in his work Insectorum Liguriae (1806). Later Dahlbom (1854) mentioned in the description of Chrysis gyllenhali that he had used the name " Chr. nitidula Grmr. " for this species. The taxon Chrysis nitidula Germar, 1817 is, however, currently known as C. germari Wesmael, 1839. As it is obvious that Dahlbom's species Chrysura nitidula is the same as C. gyllenhali, which is a synonym of C. dichroa, and the description is valid (not Chrysis nitidula Fabricius, 1775 nor C. nitidula Germar, 1817), Chrysura nitidula Dahlbom is the oldest name for C. dichroa. However, as it can be regarded as a homonym and it has not been used as a valid name within the scientific community since 1899, it is rejected and considered as a nomen oblitum (ICZN 1999, article 23.9.).

According to Dahlbom (1854) one specimen of this species was collected from Westrogothia (= Västergötland) by L. Gyllenhaal. The specimen, which is the holotype of Chrysura nitidula Dahlbom, 1845 and Chrysis gyllenhali Dahlbom, 1854, is preserved in Dahlbom’s collection in Lund. Later Thomson (1870), Mocsáry (1889) and Aurivillius (1911) reported the species from Sweden based on Dahlbom’s publication. Erlandsson (1971) and Soon (2004) listed the species from Sweden as Chrysis / Chrysura dichroa, following Trautmann’s (1927) synonymization of gyllenhali with dichroa. Kimsey & Bohart (1991) considered gyllenhali as a separate species, but we have followed the interpretation of Trautmann, because we could not find any valid morphological character to separate the holotype from C. dichroa.

C. dichroa was removed from the Swedish fauna in Dyntaxa (2013), as Dahlbom’s record was considered doubtful and no other specimens were known from Sweden. However, the species might have occurred in southern Sweden in the mid 19th century and possibly later gone extinct. The mason bee Osmia aurulenta, which probably is the main host of the species in central Europe, is still found in many places in southern Sweden. The closest records of C. dichroa from outside the Nordic and Baltic countries are from central Germany (Kroupa et al. 2012), southern Poland (Galicia) (Banaszak 1980) and Belarus (Shljachtenok 2006).