Effects of seed mixture and management on beetle assemblages of arable field margins

Published source details Woodcock B.A., Westbury D.B., Tscheulin T., Harrison-Cripps J., Harris S.J., Ramsey A.J., Brown V.K. & Potts S.G. (2008) Effects of seed mixture and management on beetle assemblages of arable field margins. Agriculture, Ecosystems & Environment, 125, 246-254.
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This study is summarised as evidence for the following.

	Action	Category
	Plant grass buffer strips/margins around arable or pasture fields Action Link
	Plant nectar flower mixture/wildflower strips Action Link

Plant grass buffer strips/margins around arable or pasture fields

A replicated study in summer 2002-2004 and 2006 in England, UK (Woodcock et al. 2008) (extension of Woodcock et al. 2005) found higher abundance and species richness of predatory beetles (Coleoptera) in margins containing tussock grass species than in margins with fine grasses only (independent of the presence of wildflowers). However the abundance of herbivorous beetle species was lower in margins containing only grass species and higher in grass mixtures with a wildflower component. Soil scarification had a positive effect on species richness of predatory beetles. Three different seed mixtures were sown: grass only, tussock grass and wildflowers, fine grass and wildflowers. Each of the seed mixtures was randomly sown on three of nine experimental plots in each of five blocks on three farms in autumn 2001. Plots measured 25 x 5 m. From 2003, three different management practices were applied in each replicate block in May each year: cutting the vegetation to 10–15 cm; application of grass-specific herbicide (fuazifop-p-butyl) at 0.8 l/ha; and scarification of 60% of the soil surface. Plant diversity and cover and vegetation structure were surveyed yearly in June using 0.5 x 0.5 m quadrats and vertical drop pins. A Vortis suction sampler (75 suctions of 10 seconds each) was used over a fixed area (equivalent to 1.45 m²) in each plot on each sampling date to collect beetles. Rove beetles (Staphylinidae), ground beetles (Carabidae), ladybirds (Coccinellidae), leaf-beetles (Chrysomelidae) and weevils (Curculionoidea) were determined to species level and categorized as either herbivorous or predatory.
Plant nectar flower mixture/wildflower strips

A replicated study in summer 2002-2004 and 2006 on three farms in England (Woodcock et al. 2008) (study extended from Woodcock et al. 2005) found a greater abundance (but not species richness) of herbivorous beetle species (Coleoptera) in seed mixtures including wildflowers than in grass-only mixtures. However there were more predatory beetle species and individuals in margins containing tussock grass species regardless of whether the mixture also included wildflowers. Margin management (i.e. soil scarification) also had a positive effect on species richness of predatory beetles. Three different seed mixtures were sown: grass only, tussock grass and wildflowers, fine grass and wildflowers. Each of the seed mixtures was randomly sown on three of nine experimental plots (25 x 5 m) in each of five blocks on three farms in autumn 2001. From 2003, three different management practices were applied in each replicate block in May each year: cutting the vegetation to 10–15 cm, application of grass-specific herbicide (Fuazifop-p-butyl) at 0.8 l/ha, and scarification of 60% of the soil surface. Plant diversity and cover and vegetation structure were surveyed yearly in June using 0.5 x 0.5 m quadrats and vertical drop pins. Beetles were sampled using a Vortis suction sampler (75 suctions of 10 seconds each) over a fixed area (equivalent to 1.45 m²) in each plot on each sampling date. Rove beetles (Staphylinidae), ground beetles (Carabidae), ladybirds (Coccinellidae), leaf-beetles (Chrysomelidae) and weevils (Curculionoidea) were determined to species level and categorized as herbivorous or predatory.