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).