[Grub]

In my neck of the (no) woods that's fruit fly for sure. The buggers are especially good at getting in the stem end, as your first pic shows. Often, even if you spray with pyrethrum, it doesn't cover the area under the green thingy on the top of the fruit. So I spray around here with extra diligence.

There should be maggots inside when you cut it open. You need to get some traps that at least remove the male flies.