Lily caterpillars

These black caterpillars with white and yellow markings attack strappy-leafed plants such as agapanthus, crinum, hippeastrum, clivia and other lily relatives in the warm months. Tiny grubs start grazing on the top surface of the leaves but eventually eat their way down to devour the entire clump. They feed at night, so go out after dark with a torch to pick off and squash the grubs. If the problem is severe, spray with an organic caterpillar control.