Pollen beetles (Meligethes aeneus F.) and their hymenopterous parasitoids were studied in standard and integrated cropping systems of the spring oilseed rape field in Estonia in 2004. In standard cropping system rape plants had a greater number of flowers, therefore the pollen beetles population was higher than in integrated copping system. Pollen beetles population peak was related with the new young generation emergence. Three parasitoid species of M. aeneus larvae - Phradis morionellus (Holmgren), Phradis interstitialis (Thomson) and Diospilus capito (Nees) were found, the latter was the most common. The number of parasitoids were greater in the standard cropping system because of greater number of hosts. Meligethes aeneus (Nitidulidae) : Host Diospilus capito (Braconidae) : Parasite Phradis interstitialis (Ichneumonidae) : Parasite Phradis morionellus (Ichneumonidae) : Parasite Nutrition; Diet; Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Ecology; Population dynamics; Land zones; Palaearctic region; Eurasia; Europe Diospilus capito; Phradis interstitialis; Phradis morionellus; Coleopteran hosts; Parasite prevalence in relation to host density on food plant; Meligethes aeneus; Estonia Meligethes aeneus; Food plants; Oilseed rape; Hymenopteran parasites; Parasite prevalence in relation to host population density; Diospilus capito & Phradis; Population density; Estonia none