GIVE AND TAKE

Sun (Auckland), Volume IV, Issue 1061, 27 August 1930, Page 14

GIVE AND TAKE

Many plants live in fear of insect foes who desitroy their leaves. Away in the tropics, armies of leaf-cutting ants often strip the trumpet tree of all its foliage. One contingent ascends the branches to saw off the leaves so that they fall on the ground, where another squad of workers cuts them into small pieces for the transport ants to carry away. Some travellers say the ants use them for thatching their underground ramifications, which are many yards across. So the tree, anticipating attack, sometimes takes arms against the marauders by inviting a fierce race of enemy ants to live in its stems, which are already hollow. These allies it feeds with solid “food bodies” on the leaf-stalks. Should the leaf-cutters approach, the mercenary fighters sally forth and slay them. The acacia, of which mimosa is a relative, houses ants in the hollow thorns at the base of its leaves. It, too, provides free nectar and “food bodies” for the guests, and the ants in return keep away caterpillars and other undesirables. But many of our everyday trees, such as maple and ash, attract useful mites by the honeydew glistening on their foliage. These crawl continuously over them, though they do not find a tenement there.