Baby Ladybug and PC bites

I was out in the orchard and noticed a strange bug on my plums. It seemed to be focused on the PC bites which were leaking sap. After squishing a couple, I realized that they might be going after the PC, so I left the rest (including all in the pic below) alone.

There was a bit of resemblance to a lady bug and when I googled it, I came up with some pics which seem to match this picture from:

My question is- are they just eating (drinking?) the sap, or are they going after the PC? I would think that it would take a bit of digging to get them out…Either way, I’d never noticed these before, let alone 4 to the plum.

And yes, my PC spraying (Spinosad) this year wasn’t sufficient. At least I have a few of each plum bagged, which seem to be OK so far.