Abstract
(1) From 1963 to 1967 153 Hymenoptera Aculeata (34 species) wcre captured on lightships of the North Sea and the Baltic, with a clear dominance of social species. (2) The combination of species corresponded neither with the species' inventory of coast biocenoses nor with the depressed profile in the frequency distribution of this group in terrestrial biocenoses of North West Germany in general. (3) In Hymenoptera Aculeata, calm weather or faint winds together with warm air seemed to favour overflights, whereas insolation was of little importance. (4) Whereas the seasonal appearance of the social species at sea corresponded to their population dynamics in terrestrial ecosystems, nearly all the solitary species were registered near termination of their nighttime in North West Germany. (5) Due to the specific behaviour of hibernating ♀♀in late summer, these are no doubt underrepresented in the coloured dish catches. (6) The ♀♀ and ♂♂ of the social and social-parasitic species exhibit migratory behaviour in midsummer or autumn. However, the ♀♀, as well as ♀♀ and ♂♂ of the solitary species, are classified as "vagrants". (7) Even solitary Hymenoptera Aculeata can travel long distances; surprising, since the Aculeata — with exception of social and social-parasitic species — are often denied any considerable spread of distribution intensity. (1) From 1963 to 1967 153 Hymenoptera Aculeata (34 species) wcre captured on lightships of the North Sea and the Baltic, with a clear dominance of social species. (2) The combination of species corresponded neither with the species' inventory of coast biocenoses nor with the depressed profile in the frequency distribution of this group in terrestrial biocenoses of North West Germany in general. (3) In Hymenoptera Aculeata, calm weather or faint winds together with warm air seemed to favour overflights, whereas insolation was of little importance. (4) Whereas the seasonal appearance of the social species at sea corresponded to their population dynamics in terrestrial ecosystems, nearly all the solitary species were registered near termination of their nighttime in North West Germany. (5) Due to the specific behaviour of hibernating ♀♀in late summer, these are no doubt underrepresented in the coloured dish catches. (6) The ♀♀ and ♂♂ of the social and social-parasitic species exhibit migratory behaviour in midsummer or autumn. However, the ♀♀, as well as ♀♀ and ♂♂ of the solitary species, are classified as "vagrants". (7) Even solitary Hymenoptera Aculeata can travel long distances; surprising, since the Aculeata — with exception of social and social-parasitic species — are often denied any considerable spread of distribution intensity.