In 1993–1995 from the cabbage aphid colonies, fed on nine different varieties of Brassica oleracea L. syrphid larvae and pupae were collected. The remaining emerged adults of Syrphidae were classified to eight species. The parasitization varied within the years of observation and oscillated from 14,4% to 46,4%. Four parasitic Hymenoptera: Diplazon laetatorius (F.), Diplazon sp., Pachyneuron grande (Thoms.), and Syrphophagus aeruginosus (Dalm.) were reared. The parasitoids identified belong to the following three families Ichneumonidae, Pteromalidae, and Encyrtidae. The largest group of reared parasitoids belonged to the family Ichneumonidae of which the most frequent was Diplazon laetatorius (F.). It occurred in each year of observations. The parasitization by D. laetatorius reached 21,7%.
In1993–1997 the occurrence of predatory syrphids inthe cabbage aphid (Brevicoryne brassicae L.) colonies was observed on the nine different cabbage vegetables: savoy cabbage cv. Vertus, white cabbage cv. Amager, red cabbage cv. Langendijker, brussels sprout cv. Maczuga, cauliflower cv. Pionier, blue kohlrabi cv. Masłowa, white kohlrabi cv. Delikates, kale cv. Zielony Kędzierzawy and broccoli cv. Piast. The number of aphids as well as amount of aphidophagous Syrphidae feeding in their colonies on the different cabbage vegetables were compared. The species compositionwas also estimated. Eight species of Syrphidae were collected: Episyrphus balteatus (Deg.), Sphaerophoria scripta (L.), S. rueppelli (Wied.) S. menthastri (L.), Metasyrphus corollae (Fabr.), Scaeva pyrastri (L.), Syrphus vitripennis (Meig.), Paragus quadrifasciatus (Meig.). In the all years of observation the dominant species were E. balteatus (Deg.), S. scripta (L.) and S. rueppelli (Wied.). The highest number of syrphid larvae were collected from cabbage aphid colonies on the white and savoy cabbage.