passion fruit flowers being eaten after 1 or 2 days
Certified GKH Gardening Expert
You can spray them with neem oil. Just wait until the sun is not bright and full, such as early morning or late afternoon. This will keep it from burning them.
Here is a collection of articles that will give you information on making your own pesticides, among other useful articles: https://www.gardeningknowhow.com/special/organic/