The Chrysididae are a group of cleptoparasitic and parasitoid aculeate wasps with a large number of rare and endangered species. The taxonomy of this group has long been confusing due to the similarity of species and extensive intraspecific variation. We present for the first time a comprehensive dichotomous key for all 74 species found in the Nordic and Baltic countries. In addition to diagnostic characters, information on the distribution and biology of each species is also presented. A new species, Chrysis borealis Paukkunen, Ødegaard & Soon, sp. n. is described on the basis of specimens collected from Fennoscandia. Chrysis gracillima Förster, 1853 is recorded as new to the Nordic and Baltic countries.
Introduction 2
Material and methods 4
Systematics 6
Key to chrysidid genera of the Nordic and Baltic countries 6
I. Subfamily Cleptinae 9
Genus Cleptes Latreille, 1802 9
II. Subfamily Chrysidinae 13
Tribe Elampini 14
Genus Omalus Panzer, 1801 14
Genus Pseudomalus Ashmead, 1902 18
Genus Philoctetes Abeille de Perrin, 1879 23
Genus Elampus Spinola, 1806 25
Genus Holopyga Dahlbom, 1845 29
Genus Hedychrum Latreille, 1802 33
Genus Hedychridium Abeille de Perrin, 1878 39
Tribe Chrysidini 45
Genus Pseudospinolia Linsenmaier, 1951 45
Genus Spinolia Dahlbom, 1854 47
Genus Chrysis Linnaeus, 1761 48
Genus Trichrysis Lichtenstein, 1876 95
Genus Chrysura Dahlbom, 1845 96
Tribe Parnopini 102
Genus Parnopes Latreille, 1797 102
Acknowledgements 106
References 106