Does anyone know what this could be? I've never seen it before.
Yes, unfortunately that's not a good sign. Take that fruit off, cut it open and you'll see it's attacked by worms. There's a possibility I may be wring, but usually that's what happens when worms find their way to the fruit.
In any case, congrats as the garden is looking great and let me know.
I've seen it on my plum tree too. I just looked it up and seems it could be moth grubs.
I didn't know how it's called, but I know when I buy plums, sometimes I see this thing on it and it's never good. Thanks for the term.
Nooooo! My delicious plums.
It's indeed the plum moth.
There is a way to protect them I see, but these are doomed already :(
They don't seem to get all of ours, so I hope you still get a crop.