Just a thought: Are you sure it is a beetle? While doing my studying up on growing tomatoes, I learned that thirsty birds will sometimes poke holes in tomatoes (and I imagine other soft, juicy fruit) to get a drink. The solution isn't so much to protect the tomatoes (fruit) from the birds in a mechanical sense, but to give the birds something better/easier to drink. The suggestion was to add a birdbath near where you plan on growing your crop. This not only gives the birds something to drink, thus 'protecting' your crop, but since it attracts birds to the bath, those birds are more likely to see and catch any bugs that might be around your crop.

Either way, I hope you get it figured out. It's always frustrating when you have a crop plant but never get to enjoy it.

Slopfrog - My harvest was kind of late and the fruit were smaller this year. I sprayed a couple of times with neem and I had not trouble with bugs, my tree is also in a pot.

Today's star fruit harvest

Silvia

They are definitely little beetles. Brown things that look like a flea. I also have had problems with fire ants boring into them as well, believe it or not. But they can be controlled well with a sprinkling of Amdro.

Silvia, I never sprayed my fruits with Neem. I think I'll try that next time. They also seem to be getting some type of scab fungus on them too, so maybe the Neem will help with that as well. Also, I'm trying to wait till the last possible second... Even Kari doesn't taste sweet enough to me usually, and they seem to taste better when you barely touch them and they fall off the tree. Of course that makes them more susceptible to pests as they ripen.