Number of lesions at the four localities each month.

At Gnesta, Österbybruk and Åkersberga one lesion per tree was surveyed, and additional trees were included in the survey during 2008. At Ultuna, all lesions were included in the survey as they emerged on the tree. Lesions were lost during the survey due to the death of the tree or a part of the tree due to another lesion girdling the branch or shoot. At Ultuna, lesions were also lost due to fusion of lesions.