The occurrence of Syrphidae in Aphis fabae Scop. (Hemiptera) colonies on broad bean intercropped with Phacelia (Part II)

During the 2008-2009 time period, the effect of phacelia grown with broad bean on the presence of Syrphidae in colonies of Aphis fabae Scop. as well as the attractiveness of phacelia flowers for syrphid adults was researched. In A. fabae colonies, 9 Syrphidae species were collected. On plots with phacelia, less aphids and more syrphid larvae, compared to the homogenous crop, were observed. The dominant species were: Episyrphus balteatus, Shaerophoria scipta, Syrphus ribesii and Epistrophe eligans. Among the 9 species of Syrphidae collected from tansy phacelia flowers, the same species dominated as those noted in A. fabae colonies on broad beans intercropped with phacelia. Sowing plants of value to Syrphidae, such as phacelia, is probably the ideal habitat management option for early occurrence of syrphids. Such a practice result in the reduction in crop damage by aphids.