Figure 1: Clearing made by Pseudomyrmex spinicola ants around their host plant Acacia collinsii (center, diameter of 4 cm marked by the scale bar), showing three acacia sprouts (white arrows). A small portion of the clearing of a second acacia is also visible (top right corner). Growing outside the clearing is the grass species (Oplismenus sp., Poaceae) used as control in the experiments.