Habitatkeuze van de Noordse winterjuffer (Sympecma paedisca) in Nederland

Summary K ETELAAR , R., E.J. R UITER , H.M.G. U ILHOORN , R. M ANGER & E.P. DE B OER , 2007. Habitat choice of Sympecma paedisca in the Neth-erlands. Brachytron 11 (1): 21-33.In the Netherlands, reproduction of Sympecma paedisca occurs in marshes with mesotrophic to eutrophic water. The presence of vegetation succession stadia with abundant Typha angus-tifolia, T.latifolia and Phragmites australis is essential. Eggs are predominantly deposited in floating dead leaves, stems and roots of these plants. Reproduction sites are mostly sheltered against wind and cold and warm up easily in early spring when oviposition takes place. S.paedisca is very scarce at localities that are too open and on sites with encroachment of trees that became too shady.The most important reproduction site in the Netherlands is the peat reserve De Weerrib-ben in the province of Overijssel. After emer-gence, a part of the population stays within the nature reserve and hibernates in moist forests in tussocks of Molinia caerulea. Another part migrates to drier heath lands, sometimes at tens of kilometres distance where they hibernate in either Molinia caerulea or Calluna vulgaris.After hibernation, the first active individuals of S.paedisca were seen on February 27th. Along the edges of the woods and on sheltered sites small insects are caught and eaten, providing energy for the reproduction period from March-May.KeywordsOdonata, Sympecma paedisca, habitat, habitat structure, reproduction, oviposition, larval habi-tat, emergence, hibernation, The Netherlands.