My pawpaw fruited for the 3yrs without any pet problem. Maybe this is a one time thing.

I have never seen a larvae inside any of mine though I have seen on a very few fruits tunneling from a seed where it looked like one could have been. I remember seeing a video/youtube by Chris Chmiel of Integration acres in Ohio where he is picking up pawpaws on his property and he breaks one open to eat and knocks out a larvae in the fruit. I am not sure what type larvae this would be but Kirk Pomper at KSU likely would. I sure hope this remains a rare sight.
I have noticed on the few fruits with tunneling from the seed there will be a small dark rough spot on the surface of the fruit where the larvae/insect/whatever has exited.

It wouldn't shock me (to see them in paw paw), especially if there wasn't much fruit around for them to chose from...although given that paw paw is a native N American fruit and so are PC, you've got to wonder if the plant has evolved to keep PC awaY?

Thanks for the replies and suggestion to ask Dr.Pomper. I would have expected paw paw to be resistant to PC as its toxins seem to prevent most insect pests quite well. Maybe you're right, Franktank, that the absence of preferred host plant fruits pushed a few to that which would otherwise be avoided. I was quite surprised, though, since I've never encountered it before. I've seen ants on them when the skin was breeched and slugs work on them on the ground, but never anything inside the fruit before.