Banana peels serve as an effective deterrent for aphids. However, there are some caveats when it comes to their effectiveness. First, the peel should remain intact and not be broken into pieces because it becomes brittle after being peeled and will eventually break off from the fruit. Second, it has been found that peels will not prevent infestations of aphids in orchards where they have been planted nearby as they spread easily through stems and leaves and onto the fruit itself.