The role of Chinese cabbage as a trap crop for flea beetles (Coleoptera: Chrysomelidae) in production of white cabbage

During the years 2002 and 2003, preference of flea beetles, Phyllotreta spp., to white and Chinese cabbage, grown in monoculture and in mixed crop, was tested. The aim of the research was to determine if Chinese cabbage is an appropriate trap crop for this pest in the production of white cabbage, an important vegetable in Europe and in North America. The number of beetles on Chinese cabbage in monoculture and in mixed crop did not differ significantly. In both treatments the number of adults of flea beetles on Chinese cabbage and the percentage of damaged leaf area they caused, were significantly higher than that on white cabbage. Statistically significant and positive correlation was established between leaf damage and number of flea beetles. It was stronger in 2003, which was less favorable for the crop with regards to the weather conditions (drought and high air temperatures). No significant differences were found in the number of adults and in most evaluations also in the damage assessments on white cabbage when grown in monoculture and in mixed culture. Therefore, we concluded that Chinese cabbage grown in mixed crop with white cabbage is not a suitable control measure for reducing the damage caused by flea beetles.