Eucalyptus is a genus of over seven hundred species of flowering trees, shrubs or mallees in the myrtle family, Myrtaceae. Its foliage is relatively immune to attack by plant-eating animals because of the toxins found in the essential oil present in the leaves. Different species of Eucalyptus contain a range of differing compounds; koalas, possums and other marsupial herbivores make food choices based on the smell of the leaves.
This photograph shows sawfly larvae from the family Pergidae feeding on Eucalyptus leaves in the Bogong High Plains in Victoria, Australia. The larvae are naturally gregarious, and some species can cause serious damage to Eucalyptus by defoliation.Photograph credit: Fir0002