first of all, thanks for taking time looking into my problem, it is greatly appreciated.
I need help identifying and combating a new pest on my tomato plants. I'm growing in a big city (Buenos Aires, Argentina). I took photos of the suspects and of the affected fruits, with cuts.
EDIT (December 24th 2017):
More and new pictures by request:
This is how I noticed (this ones are new victims, but same simptoms), first it looked like this,then they looked like getting more red and afterwards it's like the first pictures.
Answering the other questions, I do grow in pots in my patio. They are all the same seeds and the variety on the packaging said "Tomate Roma".
A more detailed picture of the pots I use:
Pots are with a mix that always worked for me and was recommended by the store. I make them with some small rocks at the bottom to get the best drainage possible.
The plastic things around the plants inside the pots are just cylinders which get no more than 3 cm into the dirt to avoid ants and other insects.