Figure 2. Effects of landscape complexity and natural enemy exclusion on (A) aphid parasitism rate and (B) syrphid fraction at three sampling dates (dates 1–3; 10 day intervals).

The top half of each figure shows mean values ± s.e.m. per exclusion treatment and sampling date. The lower half shows variation of predicted values across the gradient in landscape complexity, measured by percent seminatural habitat in a 200 m and 900 m radius around fields for parasitism rates and syrphid fractions, respectively. Data points per treatment and date are provided in Figs. S4 and S5. See Table S3 for slope multiple comparisons. Different letters indicate significant differences between treatments. Detailed legend description is provided in Fig. 1.