Small, roughly circular lesions on the green stems of several eucalypt species (dubbed 'measles' by some eucalypt growers) have aroused some interest of late. Several samples, particularly of Eucalyptus nitens , have found their way to the laboratory for examination. The lesions are usually quite shallow and a proportion will disappear altogether as the bark begins to flake and peel away. Others remain visible but the dead tissue does not penetrate sufficiently far into the stem to pose a problem. Several different fungi can be isolated from such lesions but the most common is Cytospora eucalypticola.