CARABID BEETLES (COLEOPTERA, CARABIDAE) AS BIOINDICATORS IN BIOLOGICAL AND CONVENTIONAL FARMING IN AUSTRIAN POTATO FIELDS

Carabid beetles were sampled in 1980 and 1981 by pitfall trapping in two biologically and two conventionally farmed potato fields in B. Zell, Upper Austria. The cultivation differences consisted mainly of a herbicide application to one conventional field in 1980 and higher fertilization levels in both conventional fields in both years. The total carabid catch was 7428 beetles, representing 48 species. In both years the numbers of total carabids and numbers of species were higher in the biologically farmed fields. Of 16 dominant species (representing 96% of all carabids) only 5 (e.g., Platynus dorsalis, Poecilus cupreus) showed similar activity densities under both types of cultivation. Five species (e.g., Carabus spp., Amara consularis, Harpalus rufipes) were frequent only in one field. Pterostichus melanarius was the only species more numerous in the conventional fields, whereas five species occurred either more frequently or exclusively in the biological fields. Of these five species, Poecilus versicolor, Dyschirius globosus, Calathus fuscipes and, only regionally, Harpalus aeneus are considered to be bioindicators for biologically farmed agroecosystems. The frequencies of Amara consularis and Harpalus rufipes are apparently related to weed vegetation. © 1990 Springer-Verlag.