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 Taxon classification Animalia Hymenoptera Chrysididae Elampus constrictus ( Foerster , 1853) Figs 42, 45 Notozus constrictus Foerster , 1853: 336. Elampus productus of authors, not Dahlbom, 1854. Ellampus spina of authors, not (Lepeletier, 1806). Notozus panzeri of authors, not (Fabricius, 1804). Elampus constrictus : Morgan 1984 : 7. Diagnosis. Length 4-7 mm. The species differs from Elampus panzeri and Elampus foveatus by the structure of the apical truncation of T3, which has pointed margins ventrally and resem bles a sickle or a boomerang in shape (Fig. 45). Sometimes the apical truncation is very narrow, similar to that of Philoctetes truncatus . The lateral margins of T3 are shallowly concave anterior to the apical truncation. As opposed to Elampus panzeri and Elampus foveatus , the scrobal carina reaches the angle of the omaulus (Fig. 42). Both sexes are usually bicoloured with a blue or greenish head and mesosoma, and a reddish metasoma. Entirely greenish or blue specimens are found occasionally. Distribution. Denmark, Estonia, Finland, Norway, Sweden. Relatively rare. - Trans-Palearctic: widely distributed in the Palearctic Region, from Europe to China ( Rosa et al. 2014 ). Biology. Habitat: sparsely vegetated sandy areas, heaths. Adults occasionally visit flowers of Apiaceae and Rosaceae ( Linsenmaier 1997 , Rosa 2004 ). Flight period: May to July. Host: Mimesa bicolor (Jurine), Mimesa equestris (Fabricius) and Mimesa lutaria (Fabricius) ( Crabronidae ) ( Benno 1950 , Lomholdt 1975 ). Figures 38-46. Metascutellum, propodeum and T1, lateral view (arrow indicating metascutellar projection): 38 Elampus foveatus ♀. T3, lateral view: 39 Elampus panzeri ♀ 40 Elampus foveatus ♀. Head, lateral view (arrow indicating genal setae): 41 Elampus panzeri ♀. Mesopleuron, lateral view (arrow indicating junction of omaulus and scrobal carina): 42 Elampus constrictus ♀ 43 Elampus foveatus ♀. T3, postero-dorsal view: 44 Elampus panzeri 45 Elampus constrictus ♀ 46 Elampus foveatus ♀. Scale 0.5 mm.