Certified GKH Gardening Expert
There are many ways to do this. I recommend neem oil, but the leaves of grapes are sensitive to it, if applied in bright light. There are many other ways as well. Rosemary oil, or chrysanthemum extract work very well also.
This link will take you to more articles that will help you out: https://www.gardeningknowhow.com/special/organic/