EN
A four-year study was conducted on the experimental fields of the Wroclaw University of Environmental and Life Sciences. The observations aimed at identifying the prey species structure of Theridion impressum and assessing its role as a factor reducing the abundance of herbivorus insects within the crop. The predator`s webs were sampled weekly since the end of main raceme flowering stage until the pod maturity (BBCH 7.0–8.9). The mean density of the webs (1.7 per 1 sq m) and the species composition of the prey of T. impressum were determined every year. The majority of fauna found in the webs were the oilseed rape pests (> 90%). These were mostly aphids accompanied by brassica pod midge, pollen beetle and seedpod weevils. The remaining 10% were, beneficial insects (up to 5%) and other insect species. Also a negative influence of intensive rainfall on webs’ density within the crop were observed.