During the years of observations pedatory arthropods of Arachnida, Chrysopidae, Heteroptera, Coccinellidae, and Syrphidae were collected from Myzocallis coryli Goetze colonies. Arachnida constituted the most numerous group followed by predatory bugs of Heteroptera.
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.
In 1993–1997 the occurrence of cabbage aphid (Brevicoryne brassicae L.) and predators from Cecidomyiidae, Coccinellidae and Chrysopidae was observed on the nine different late cabbage vegetables; Savoy cabbage cv. ‘Vertus’, white cabbage cv. ‘Amager’, red cabbage cv. ‘Langendijker’, brussel sprouts cv. ‘Maczuga’, cauliflower cv. ‘Pionier’, blue kohlrabi cv. ‘Masłowa’, white kohlrabi cv. ‘Delikates’, kale cv. ‘Zielony Kędzierzawy’ and broccoli cv. ‘Piast’. Among the examined predators only the cecidomyiid – Aphidoletes aphidimyza Rond. (Cecidomyiidae) played an important role in reducing the number of cabbage aphids. The cruciferous species had no impact on the density of A. aphidimyza population, and females laying eggs. The size of aphid colonies on cabbage leaves played the most important role.