Phacelia tanacetifolia flower strips as a component of integrated farming.

Abstract

The impact of a Phacelia tanacetifolia field margin on aphid-specific predators in winter wheat was investigated at one of the MAFF/LINK Integrated Farming Systems (IFS) sites. Syrphidae were attracted to the Phacelia strip and gut dissections confirmed they were feeding on the pollen before distributing up to 100m into the field. No evidence of improved fecundity as a result of feeding on Phacelia was found. Ichneumonidea were also more abundant in the Phacelia strip compared to the adjacent wheat crop. There were trends towards higher numbers of Braconidae, Proctotrupoidea and Platypalpus spp. in the IFS plots whereas Chalcidoidea were more numerous in the conventional farming system plots. Aphid abundance and percentage parasitism were unaffected by differences in aphid-specific predator distribution.