This report presents the fourth part of the results of a taxonomic revision and examination of the actual, reputed or potential type material of bees of Swedish origin. Focus is on the status, depository, type locality, condition and history of name-bearing specimens. Here, 35 bee taxa based on material in the collection of the leading Swedish entomologist Carl Gustaf Thomson (1824 – 1899) have been examined. After a biographical sketch of Thomson and a summary of his contribution on bees and his legacy, lectotypes are designated for the specific taxa (bold= valid epithet) Colletes picistigma Thomson, 1872, Hylaeus clathratus Thomson, 1870, H. genalis Thomson, 1872, H. marginatus Thomson, 1870, Andrena curvungula Thomson, 1870, A. integra Thomson, 1870, A. morawitzi Thomson, 1872, A. nasalis Thomson, 1870, A. nigrospina Thomson, 1872, A. violascens Thomson, 1870, Sphecodes crassus Thomson, 1870, Megachile curvicrus Thomson, 1872 (now subspecies of M. nigriventris Schenck), M. lapponica Thomson, 1872 and Epeolus glacialis Alfken, 1913 (here identified as a distinct subspecies, stat. nov., of E. alpinus Friese). Already labelled but unpublished lectotypes of Hylaeus submarginatus Thomson, 1872, Andrena albo-fasciata Thomson, 1870, Epeolus productus Thomson, 1870 and E. rufipes Thomson, 1870 are validated. Further taxa examined (including more syntypes designated whenever located) are Andrena intermedia Thomson, 1870, Sphecodes pilifrons Thomson, 1870, S. puncticeps Thomson, 1870, S. reticulatus Thomson, 1870, Coelioxys obtusispina Thomson, 1872, Osmia claviventris Thomson, 1872 (now Hoplitis c.), O. truncatula Thomson, 1872 (now subspecies of O. leaiana (Kirby)), Nomada bifida Thomson, 1872, N. glabella Thomson, 1870, N. laeta Thomson, 1870, N. punctiscuta Thomson, 1870, N. 5-spinosa Thomson, 1870, N. rufilabris Thomson, 1870, N. villosa Thomson, 1870, Apathus lissonurus Thomson, 1872, Bombus arenicola Thomson, 1872 and B. brevigena Thomson, 1870 (now subspecies of B. wurflenii Radoszkowski). The typifications and validations define authentic material, type localities and establish correct synonymies, e.g., Andrena violascens Thomson is a synonym of A. fulvida Schenck, 1853.
2010. Vol. 131, no 1, 73-94 p.