|Late season marking on olive fruit.|
This is an unknown disease on olive fruit found in Barnea on the Fleurieu Peninsula south of Mt Compass. The markings looks similar to Lepra fruit rot caused by Phlyctema vagabunda but Lepra fruit rot is not recorded in Australia.
"The symptoms on the photo appeared to Peacock spot disease. Infection and development of olive scab disease, peacock spot on olive fruits caused by Fusicladium oleagineum." says Dr Vera Sergeeva from - http://www.olivediseases.com/ ."It is always better to see samples and check spores under microscope."
SARDI have published their olive disease guide - http://www.sardi.sa.gov.au/__data/assets/pdf_file/0006/46707/olive_fruit_poster.pdf