Fig. 3
Results of generalised linear models on parasitoid abundance. (a) The BACI-effect on the number of parasitoids per road light (Abundance, points) between control and impact sites (colours) before and after the intervention. Error bars show model predictions (points) and 95% Confidence intervals. (b) Pairwise differences in the total number of parasitoids per road light (Abundance) between treatment groups (control before, control after, impact before, impact after). In each group, there were 14 luminaires. Letters refer to a Tukey post-hoc test. Different letters indicate significant differences. 2021 (Before): n = 26 samplings, (Site 1: eight samplings, Site 2: eight samplings, Site 3: ten samplings; 2022 (After): n = 29 samplings (Site 1: nine samplings, Site 2: seven samplings, Site 3: 13 samplings). Treatment groups: Control sites (before): (conventional LED 4000 K (c), HPS 2000 K (d, e)); Control sites (after): (conventional LED 4000 K, HPS 2000 K), Impact sites (before): (conventional LED 4000 K, HPS 2000 K); Impact sites after (tailored and shielded LED 4000 K (f)/HPS 2700 K (g, h) in 2022). Error bars show model predictions (points) and 95% Confidence intervals. Parasitoid drawings derived from Goulet et al. (1993).
