Can anyone tell me what has caused this on my satsumas, and will it in turn ruin the flesh?
Citrus Tree Problem
I don't know what it is, but I am curious as well. I have similar stuff on the fruit of my Minneola Tangelo. Do any other parts of your tree look affected by it? As far as I can tell, it's just on the one little fruit I have.
I have researched it and as far as I can tell it is a fungus called Scab. It is from too much rain sort of an atheletes foot on citrus lol. a good fruit fungicide should be applied.