An illustrated key to the cuckoo wasps (Hymenoptera, Chrysididae) of the Nordic and Baltic countries, with description of a new species Author Paukkunen, Juho Author Berg, Alexander Author Soon, Villu Author Odegaard, Frode Author Rosa, Paolo text ZooKeys 2015 548 1 116 http://dx.doi.org/10.3897/zookeys.548.6164 journal article http://dx.doi.org/10.3897/zookeys.548.6164 1313-2970-548-1 D5D7B51E5AC6460D9B3C7584E46F9B3F D5D7B51E5AC6460D9B3C7584E46F9B3F Taxon classification Animalia Hymenoptera Chrysididae Chrysis zetterstedti Dahlbom, 1845 Figs 90, 113, 135, 152 Chrysis sexdentata ? Dahlbom, 1831: 30, not Christ, 1791. Chrysis Zetterstedti Dahlbom, 1845: 11. Chrysis fasciata of authors, not Olivier, 1790. Diagnosis. Length 6-9 mm. The species resembles Chrysis equestris , but differs from it by the following characters: the black spots of S2 are broader, extending to the lateral and anterior margins of the sternite (Fig. 113), T5 of the female is narrower and does not have a longitudinal medial groove (Fig. 90), the head is narrower (the shortest distance between the compound eyes is shorter or as long as the diameter of an eye) (Fig. 152), the gonostyle is more elongated, as long as the cuspis, the cuspis is apically straight (not curved) (Fig. 135), and the propodeal tooth is weakly lobate ventrally (not convex or straight). Distribution. Estonia, Latvia, Lithuania, Sweden. Rare. - Trans-Palearctic: from North Europe to Siberia. Records from the East Palearctic Region refer to Chrysis fasciata daphne Smith, 1874 ( Rosa et al. 2014 ). Biology. Habitat: forest margins and clearings with sun-exposed dead tree trunks and stumps (e.g. Quercus ). Flight period: probably similar to that of Chrysis equestris , most specimens have been collected in July. Host: unknown, possibly Euodynerus notatus (Jurine) (N. Johansson pers. obs.). Remarks. Several authors have considered Chrysis zetterstedti to be either a synonym (e.g. Trautmann 1927 , Kimsey and Bohart 1991 ) or a subspecies ( Linsenmaier 1959 , 1997 , Rosa and Soon 2012 ) of Chrysis fasciata . However, molecular and morphological studies have shown that Chrysis zetterstedti most likely represents a valid species ( Paukkunen et al. 2014 ). The occurrence of Chrysis zetterstedti in central and southern Europe is still uncertain.