3.5 Predation intensity on sticky cards and aboveground ant activity
Predation rate on fruit flies glued on sticky cards (see Fig. 6a) was highest for sampling plots in cereal crop far from new grasslands and lowest for new grasslands, but showed no significant differences among the four tested habitats (p ≥ 0.09 for all comparisons, see Table S9). However, predation rate was significantly lower on sampling plots with high mean vegetation cover (p < 0.001, see Table S10) and these results relate to significantly higher mean vegetation cover on sampling plots in old and new grassland habitats compared to both cereal habitats (p < 0.001 for all comparisons, see Table S11).
Aboveground ant activity (number of observed workers, see Fig. 6b) was significantly highest on sampling plots in old grasslands (p < 0.001, see Table S12). Moreover, ant activity was significantly increased on sampling plots in new grasslands compared to near cereal crops (p = 0.016) and showed a strong trend for an increase compared to cereal crops far from new grasslands (p = 0.0529). Aboveground ant activity was not significantly different between the two cereal crop habitats (p = 0.905). There was no significant effect of mean vegetation cover on aboveground ant activity (p = 0.085, see Table S13) and further no significant correlation between aboveground ant activity and predation intensity on sticky cards (R²m ≤ 0.001, R²c = 0.49, p = 0.913).