It is On both my blood orange and my mandarin/orange fruit salad tree.
29 October 2020 01:31 PM
It looks like it could be a sap-sucking insect causing the damage, although it doesn't appear to be too widespread. You can control most sap-suckers with Yates Nature's Way Citrus & Ornamental Spray.
Click here more information:
https://www.yates.com.au/product/garden-pest-control/yates-natures-way-citrus-ornamental-spray