(a) Field margin types: At the local scale, three types of field margins were chosen to represent

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1 Appendix S1. Supplemental Methods (a) Field margin types: At the local scale, three types of field margins were chosen to represent different levels of structural complexity: (i) grass margin, a perennial grass buffer strip without any nearby tree; (ii) simple hedgerow, a grass buffer strip adjacent to a single storied hedge ( i.e. treeline of full grown trees, formed by a few dominant species, either plane tree Platanus hybrida Brot., white mulberry Morus alba L., or white willow Salix alba L.); (iii) complex hedgerow, a grass buffer strip with a multi-storied hedgerow on the edge (averaged number of tree and shrub species 7.7 ± 2.3; included representative species: elder Sambucus nigra L., common dogwood, blackberry Rubus fruticosus L., Cornus sanguinea L., field maple Acer campestre L., black locust Robinia pseudoacacia L., common hornbeam Carpinus betulus L., field elm Ulmus minor Mill., or wild cherry Prunus avium L.) (Sitzia et al. 2013). Each field margin was characterized by sampling plant species composition. Sampling was conducted in three plots of 1 3 m located along a transect parallel to the field margin. One plot was placed in the middle part of each field margin with the largest side parallel to the field margin. The other two plots were placed at the two margins at least 10 m away from the central plot. For hedgerows, the plots were placed in order to both the trees and the grass buffer strip. Vascular were recorded to species level (presence/absence data) and once before the first cut of the grass buffer strip at the end of May. (b) configuration: We calculated the following configuration metrics: (i) number of hedgerow patches within each buffer; (ii) hedgerow edge density within each buffer, calculated as (total edge length) / (buffer area); and (iii) the shape of hedgerows patches, as defined by (patch perimeter) / 4* (patch area), calculated as the mean of patches within each buffer. (c) Exclusion experiment: The cages (plastic net with a mesh size of 5 5 mm; diameter: 0.3 m; height: 1.20 m) were inserted in a plastic ring (diameter: 0.3 m; height: 0.25 m) dug 10 cm into the

2 soil. The cages were ed with sticky glue to prevent the access of flying natural enemies. In all cages, a visual inspection was performed to search for and remove by hand any natural enemies before placement of the cages. A pitfall trap filled with a water detergent mix was added inside the cage to catch the natural enemies that were not detected. Aphids were provided by Katz Biotech AG. The exclusion experiment started at the beginning of wheat fruit development (the main period of aphid reproduction in the fields). As suggested by Chaplin-Kramer & Kremen (2012), the aphid predation index could underestimate total mortality because it does not account for aphid colonization in the open cages. However, in our case the exclusion experiment started at the beginning of ripening stage, when alate individuals had already disappeared from the crop. (d) Sampling of ground-dwelling predators: The pitfall traps were filled with 150 ml of 50% ethylene glycol and a plastic roof positioned 10 cm above each trap was used to prevent flooding by rain. The pitfall traps were left out for 10 days concurrently with the exclusion experiment. Invertebrates were preserved in 70% ethanol. (e) Phytometer experiment: On 25 th March 2014, ten seeds of radish were sown into each pot (5-L, 20 cm diameter) filled with clay soil of the Experimental farm of University of Padova. During the leaf development stage, all but two out of the ten were removed. Radish were cultivated in a greenhouse for 8 weeks (20 May), when they were moved to the field. Before the beginning of the flowering period three pots per field were bagged. Pots were placed into holes in the ground at the field edge, leaving the base of the at the level of the ground surface. Plants were periodically watered. Surveys of flower-visiting insects took place between 9:30 and 17:30 under sunny weather conditions with temperatures above 17 C. To avoid any systematic effect of time of the day the sequence of surveys was randomized in the three sampling rounds.

3 References Chaplin-Kramer, R. & Kremen, C. (2012) Pest control experiments show benefits of complexity at landscape and local scales. Ecological Applications, 22, Sitzia, T., Trentanovi, G., Marini, L., Cattaneo, D. & Semenzato, P. (2013) Assessment of hedge stand types as determinants of woody species in rural field margins. iforest, 6,

4 Appendix S2. Supplemental Tables Table S1. Mean values ± standard deviation and results of the analysis of variance (ANOVA) testing differences in land proportions between the three classes of field margins. Grass margin Simple hedgerow Complex hedgerow 0.5 km (%) 3.0 ± ± ± Arable 0.5 km (%) 76.5 ± ± ± km (%) 2.6 ± ± ± Arable 1 km (%) 71.9 ± ± ± F P

5 Table S2. Pearson correlations between explanatory variables. Nectar Annual (0.5 km) Arable (0.5 km) (1 km) Annual ** (0.5 km) * ns Arable (0.5 km) ns ns ns (1 km) ns ns *** ns Arable (1 km) ns * ns *** ns ns not significant, * P < 0.05, ** P < 0.01, *** P < 0.001

6 Table S3. Statistical models used in the analyses. Response variable Model 1 Distribution Transformation Fixed effects 2 Random effect Pest control Predation index LMs Gaussian log(y+0.01) FM AR H + NP Parasitism rate GLMMs Binomial FM AR H + AP + NP Site Vegetation-dwelling predators LMMs Gaussian log(y+1) FM AR H + AP + NP Site Ground-dwelling predators LMMs Gaussian log(y+1) FM AR H + AP + NP Site Weed control Species GLMs Poisson FM AR H + AN Cover LMs Gaussian log(y+1) FM AR H + AN Pollination Visitation rate LMMs Gaussian FM AR H + NP Site Δ Seed set LMMs Gaussian FM AR H + VS + NP Site 1 Model abbreviations: GLMs, generalized linear model; GLMMs, generalized linear mixed models; LMs, linear models; LMMs, linear mixed models. 2 Fixed effect abbreviations: AN, number of annual plant species; AP, aphid abundance; AR, arable land ; FM, field margin type; H, hedgerow ; NP, number of nectar plant species; VS, visitation rate.

7 Table S4. Performance of (a) pest control, (b) weed control, and (c) potential pollination service models using arable land and hedgerow calculated at the two landscape scales (0.5 or 1 km). Table shows the Akaike Information Criterion (AIC). The most explanatory radius was selected based on minimized AIC values. Landscape scale 0.5 km 1 km (a) Pest control Predation index Parasitism rate Vegetation-dwelling Ground-dwelling (b) Weed control Species Cover (c) Pollination Visitation rate Δ Seed set

8 Table S5. Estimates and model weights of the selected models with ΔAICc < 7. Intercept Field margin type Aphid abundance Annual Selected models Nectar Visitation rate Arable land Predation index ΔAICc Model weight Parasitism rate

9 Intercept Field margin type Aphid abundance Annual Selected models Nectar Visitation rate Arable land Vegetation-dwelling predators ΔAICc Model weight Ladybirds Web spiders

10 Intercept Field margin type Aphid abundance Annual Selected models Nectar Visitation rate Arable land Web spiders ΔAICc Model weight Ground-dwelling predators Carabid beetles

11 Intercept Field margin type Aphid abundance Annual Selected models Nectar Visitation rate Arable land Carabid beetles ΔAICc Model weight Rove beetles

12 Intercept Field margin type Aphid abundance Annual Selected models Nectar Visitation rate Arable land Rove beetles ΔAICc Model weight Cursorial spiders

13 Intercept Field margin type Aphid abundance Annual Selected models Nectar Visitation rate Arable land Cursorial spiders ΔAICc Model weight Weed species Weed

14 Intercept Field margin type Aphid abundance Annual Selected models Nectar Visitation rate Arable land Weed ΔAICc Model weight Visitation rate Δ Seed set

15 Intercept Field margin type Aphid abundance Annual Selected models Nectar Visitation rate Arable land Δ Seed set ΔAICc Model weight Hoverflies Wild bees

16 Intercept Field margin type Aphid abundance Annual Selected models Nectar Visitation rate Arable land Wild bees ΔAICc Model weight Butterflies

17 Intercept Field margin type Aphid abundance Annual Selected models Nectar Visitation rate Arable land Other groups ΔAICc Model weight

18 Table S6. Sum of model weights (Σwi) for each variable estimated by the multi-model inference procedure for vegetation-dwelling and ground-dwelling predators. In bold are reported the Akaike weights of the most important explanatory variables (sum of model weights > 0.6 or unconditional CIs that did not include 0). The direction of the relationship is indicated by (+) or (-) for the most important continuous variables. Vegetation-dwelling predators Field margin Aphid abundance Nectar plant Arable land Ladybirds (+) ( ) 0.26 Web spiders (+) Ground-dwelling predators Carabid beetles (+) 0.26 Rove beetles Cursorial spiders

19 Table S7. Sum of model weights (Σwi) for each variable estimated by the multi-model inference procedure for pollinator groups (abundance of flower-visiting insects). In bold are reported the Akaike weights of the most important explanatory variables (sum of model weights > 0.6 or unconditional CIs that did not include 0). The direction of the relationship is indicated by (+) or (-) for the most important continuous variables. Pollinator groups Field margin Nectar plant Arable land Hoverflies (+) Wild bees (+) Butterflies (+) Other groups Including other Diptera and other species (mainly coleopterans).

20 Appendix S3. Supplemental Figures Figure S1. Scatterplot showing the distribution of the three field margin types along the two landscape gradients: (i) proportion of arable land and (ii) proportion of hedgerows in a 1 km buffer.

21 Figure S2. Mean (± SE) number of aphids, Sitobion avenae, per pot in the cage and the open treatments at the beginning (day 0) and the end (day 5) of the experiment. No significant differences were found between the two treatments at day 0 (Paired t-test: t = 1.66, P = 0.108), while significant differences were found between the cage and the open treatment at day 5 (Paired t-test: t = 11.93, P < 0.001).

22 Figure S3. Total abundance (number of individuals) of flower-visiting insects surveyed during the three visits.

23 Figure S4. Model-averaged effect sizes and 95% confidence intervals for the landscape parameters included in strongly supported models (ΔAICc 7) explaining the abundance of flower-visiting insects for (a) hoverflies, (b) wild bees, (c) butterflies, and (d) other groups (other Diptera and other species - mainly coleopterans). Open and closed symbols reflect model estimates ± averaged confidence intervals.

24 Figure S5. Mean ± SE of (a) wild bee and (b) butterfly abundance derived from visitation rate in relation to margin type (grass margin, simple hedgerow, and complex hedgerow).

Hedgerow restoration and pollinators: bee communities, costs, and benefits

Hedgerow restoration and pollinators: bee communities, costs, and benefits Photo by R. Long Lora Morandin, Claire Kremen, and Hillary Sardinas University of California, Berkeley Diversified Farm Systems