The studies were carried out at the Agricultural Experimental Station at Pawlowice near Wroc³aw (Poland) in 1998-00. The main aim of the study was to compare the natural reduction of the black bean ...aphid by predators in sugar-beet crop surrounded by strips of mixture of cultivated plants, weedy strips or bare soil.The lowest number of Aphis fabae in sugar beet crop was observed at the plots surrounded by strips of mixture of Sinapis alba, Phacelia tanacetifolia and Coriandrum sativum, and at those surrounded by weedy strips. The greatest number of aphids was recorded on sugar beet plots surrounded by bare soil. The relationships between the pest and its predators were the least stable in bare soil treatment. Significant pressure of predator activity in all treatments was shown in the first several days of the observation
