Phacelia tanacetifolia flower strips: their effect on beneficial invertebrates and gamebird chick food in an integrated farming system.

Abstract

The impact of Phacelia tanacetifolia field margins on populations of Syrphidae, polyphagous predators, parasitoids and gamebird chick food was investigated at one of the LINK Integrated Farming Systems (IFS) sites in southern England. Phacelia strips were sown along the edge of winter wheat plots farmed using an integrated system and comparisons were made to the paired conventional farming system plots. Phacelia was attractive to Syrphidae and cereal aphid parasitoids, and populations in the adjacent winter wheat IFS plot were enhanced to some extent, but this was not sufficient to influence cereal aphid population development. Carabidae, Staphylinidae and Linyphiidae favoured the wheat crop in preference to the Phacelia strip. Gamebird chick food insects were more abundant in the Phacelia strip, primarily due to high densities of Miridae.