Insect damage on Plums
I have just picked my plums and discovered that something is eating them from the inside out. There is usually a divot or some spots on the outside of the plum. Then when I cut into it there are red tunnels leading out from the stone, there is usually red around the stone, and sometimes a larger darker red spot. Almost every one of the fruit I picked has this! I was unable to identify any grubs or insects themselves. I and didn't even think to take pictures! Can you point me in the right direction for identification and control?
Marshall County Minnesota
You probably had Plum Curculio damage. Here is a link with information on this pest. https://www.gardeningknowhow.com/edible/fruits/plum/plum-curculio.htm