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

  • Published source details Holland J.M. & Thomas S.R. (1996) Phacelia tanacetifolia flower strips: their effect on beneficial invertebrates and gamebird chick food in an integrated fanning system. Acta Jutlandica, 71, 171-182.


This study is summarised as evidence for the following.

Action Category

Plant nectar flower mixture/wildflower strips

Action Link
Farmland Conservation
  1. Plant nectar flower mixture/wildflower strips

    A replicated, controlled study in June-July 1993 and 1994 using four pairs of adjacent winter wheat plots in Hampshire, UK (Holland & Thomas 1996) found higher numbers of total cereal parasitoids (average 33 vs 5/0.5 m2), gamebird chick food insects (25 vs 2) and parasitic wasps Aphidius spp. (13 vs 12) in phacelia Phacelia tanacetifolia sown strips than in the adjacent crop in one of the study years, 1994. In the same year, the abundance of braconid waps (Braconidae) was higher in plots with a sown phacelia strip (but not in the phacelia strip itself) than in plots without a strip. No significant differences in numbers of any other arthropod group considered were found between phacelia strips and the other habitats. Four pairs of winter wheat plots (minimum size 5 ha, minimum width 100 m) were either managed according to the integrated farming system (IFS) or conventionally managed. At IFS plots, 1 m-wide strips of phacelia were sown (1 g/m2) along the longest edge of the plot (300-400 m) in April each year. Conventional control plots did not have phacelia strips. Invertebrates were sampled either using fluorescent yellow water traps (19 cm diameter) located at different distances into the phacelia strip/field edge or using a D-Vac. Traps were emptied weekly, D-Vac samples (two set-ups) were taken once a year in each plot. Tiller counts were made to assess aphid numbers, species, life-stage and aphid mummies five times yearly in each plot. This study used an extended version of the experimental set-up in Holland et al. 1994.

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