AbstractIn an abandoned grassland ecosystem (megaphorbe meadow: Valeriano‐Filipenduletum,Carex acutiformisEhrh. type) in Eastern Switzerland, orb‐weaving spiders dominated the spider community of the field layer (ca 60% of the yearly total of spiders in sweep samples). The orb‐weavers of this grassland comprised predominantly the six speciesArgiope bruennichi(Scop.),Araneus quadratusClerck,Araneus diadematusClerck,Nuctenea cornuta(Clerck),Meta segmentataClerck, andTetragnatha extensa(L.), which combined formed a guild of insectivorous predators. The orbweaving spiders in that grassland captured a variety of insect taxa (generalist predators); their major prey were Diptera (diverse species) and Homoptera (primarily leafhopperStenocranus major[Kbm.] and aphids of theAnoecia cornigroup). Araneae constituted a very small fraction (99% Insekten in der Beute; Nahrungsgeneralisten mit Hauptbeute Diptera und Homoptera). Von Interesse ist, daß sich ‐ gemäß unserer Nahrungsanalyse ‐ unter den von der Radnetzspinnengilde getöteten Insekten die landwirtschaftlich schädlichen BlattläuseAphis fabaeScop.,Myzus persicaeSulz.,Hyalopterus pr