Don't know if you have them out west, but could be a harlequin bug. They seem to take advantage of any "openings" in damaged fruit. They don't seem to cause the damage, but exploit it. I have seen these harlequins on tomatoes, zuchinni, watermelon, and probably more. Remove and discard damaged/overripe fruit. Not a major problem in my garden, only a nuisance to see these bugs eating fruit I could've been.

Yes, harlequin bugs are in the west. But they're red on black, not all black.

Also the pest was noted as less than 1/8" inch long -- too small for a harlequin bug. unless it was a very nymphal stage. But again, not all black.