LAUSR

Using Moericke's yellow dishes we studied the Hymenoptera (Aculeata) fauna (with the exception of Formicoidea) in spruce (Picea abies) stands of the colder region of Northern Bohemia. We collected 103 species and the most important species in this spectrum were Vespula vulgaris (56.4%), Vespula rufa (4.7%), Dolichovespula norvegica (3.1%), Dolichovespula saxonica (4%), Nysson spinosus (1.8%), Andrena lappona (1.9%), Cleptes semiauratus (5.9%), Halictus sp. (6.7%) and Trypoxylon minus (2.2%). Comparisons made in 1990-1994 and 1995-1999 indicated a recession of species of the genus Halictus, of Andrena nitida (Apidae), Pemphredon lugubris, Trypoxylon clavicerum and T. minus (Sphecidae), and an increased abundance of Cleptes semiau- ratus (Cleptidae), Nysson spinosus (Sphecidae), Vespula vulgaris and V. rufa (Vespidae). Compared to closed stands, open spruce stands had a greater species diversity and lower number of captured specimens.