Effect of intercropping carrots and onions on damage caused by the carrot fly, Psila rosae (F.) (Dipt., Psilidae)

In small-scale field experiments carried out in southern Finland in seven successive years, rows of carrots were grown a) between carrot rows, b) between a carrot and an onion row, and c) between onion rows. The damage caused by the carrot fly, Psila rosae (F.) was slightly less in carrot rows adjacent to onion rows than in those adjacent to carrot rows. The infestation by the carrot fly was generally very low