Fig. 9

Meta-analyses on different taxonomic levels for untreated Bt and non-Bt maize (by target order). Only Lepidoptera-active (A), Coleoptera-active (B), or stacked Lepidoptera- and Coleoptera-active (C) Bt proteins were included. Records with any red flag in the critical appraisal were excluded. For each taxon, the effect size estimate and the 95% confidence interval is given (negative effect sizes indicate lower populations in Bt compared with non-Bt maize and vice versa). Significant intervals (red) do not include 0. On the right side is the number of records (rec.), experiments (exp.), and articles (art.) included in each analysis. Het indicates significant (P < 0.05) heterogeneity. See Additional file 7: Table S7.2 for details. Results of moderator analyses for individual Bt proteins (Additional file 7: Table S7.3) are indicated with arrows. ↑: higher values in Bt compared with non-Bt treatment (positive effect size), ↓: lower values (negative effect size), 0: no effect