THE GROUND BEETLE FAUNA (COLEOPTERA, CARABIDAE) IN RELATION TO SOIL PROPERTIES AND FOLIAR FLUORIDE CONTENT IN SPRING CEREALS

Carabid beetles (Coleoptera: Carabidae) were collected with pitfall tr aps from sixteen spring cereal fields representing three fluoride-poll ution zones around a fluoride-emitting fertilizer plant in central Fin land. Near the emission source fluoride accumulated in the barley leav es, but not in soil, barley grain or in the bodies of carabid beetles. Total catch of carabids was highest at the background area. Patrobus atrorufus (Strom), Pterostichus melanarius (Illig.) and P. niger (Scha ll.) were the dominant carabid species caught in traps. The 64 trappin g plots were organized to five clusters according to their carabid com munities. The carabid communities in each cluster were separated by th e environmental factors in the following decreasing order: fluoride ac cumulation on crop plant > soil clay content > soil type > soil water content > soil organic content > soil pH. In a canonical correspondenc e analysis the ordination of carabid communities was most strongly rel ated to soil type and water content of the soil. The results indicated that fluoride and other pollutants emitted from industrial sources ma y have an influence on the structure of carabid communities in cereal fields. However, in interpretation of pitfall trap catches one must be extremely cautious, because soil properties around pitfall traps in a rable fields strongly affect the species of carabids caught.