I always leave my bananas with the rest of the fruit in my basket until they have their first brown spots, then they immediately go in the fridge. This rule began after a particularly bad fruit fly problem a few years ago. So bad I had to stop leaving anything out, even my filtered compost bin!
Well apparently pomegranates attract fruit flies too! Never had a problem with apples or oranges but two days after the pomegranate is in my fruit basket there they are! So my trap was made again.
I take a mason jar with a few pieces of banana in the bottom (fresh banana, frozen doesn't really work). Make a cone with paper and tape it to the jar so the tip is near the bottom but above the banana. And voila!