If you want to kill the fruit flies quickly try to put out a bowl of vinegar, some sugar and a little bit of dish soap. I found this to be super effective.
The sugar and vinegar kinda mimics the scent of rotten fruit which they are drawn too and the dish soap will destroy the surface tension, so that they just drown.
I've tried that and found that they will drown even without the dish soap, but the problem for me is getting them to go for the liquid instead of just hanging out all around it.
People have mixed feelings but having just moved to a place with a disposal unit this year has made trash accumulation so much easier. Never realized how much foodstuffs I would throw in the trash.
Yes you should. I was washing mine because of all the fungicide they are coated in while growing, but then I learned from someone on reddit one day that it will clear the fruit fly eggs that are typically around the bud end. You should wash every fruit or vegetable you buy at the store first before eating.
I keep them in a bag that’s tied off until I can wash them, but try to wash them as quickly as possible. The bag can also be a useful way to get the bananas to ripen faster if they’re too green.
Any fruit can have fruit fly eggs. They're attracted to overripe fruit, and even though what you bought was fresh, it might have been on the dock next to something turning into wine. I avoid fresh fruit from Walmart because they seem to be particularly bad, but flies are in high end groceries and farmers markets too. Every grocery store is in a constant, if discrete war with the creatures.
They can be quite annoying and breed famously quickly. A friend went on vacation for a week with some banana peels or something in the trash and came home to a swarm of thousands.
Perhaps you live in a cool climate? It's sub-tropical where I am and the flies usually disappear with the fall weather.
I do live in a cool climate, though it's not as though it stays cold all year. We still have hot summers, but even then I have never noticed this and I buy produce pretty often. Didn't even know this sort of thing could occur for not-overripe fruit.