Soap Solution for Flies on Grape Vines

Check with www.Jerrybaker.net. He gives you recipes for tonics for pests in the garden, as well as other issues. Most of the ingredients you already have in your home, so the cost is reasonable. I purchased a 20 page phamplet from him more than 25 years ago and had such great success, that I have purchasd several other books. His website has some tonic recipes and you can e-mail him for answers to your specific questions also. I hate to send you to just another site, but I can attest to fact that his advice is sound. Good Luck!

Your "flies" I imagine are Whiteflies. You could also just purchase and organic product like Safer's insecticidal soap and not chance using regular soaps that that can burn leaves once exposed to sun.
Soaps MUST come in direct contact with the pests to be any use because there is no residual effect. You will need to apply more than once because the adult flies will fly off when disturbed. Be sure to hit both tops and undersides of the leaves.
Whiteflies are not easy to control. Good luck!

http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7401.html

"Liquid soap" meaning something like Ivory soap, not harsh dish detergents. I use Dr. Bronner's liquid soap which can be found in some health food stores, supermarkets, or drug stores.

I sug to mix 1 teaspoon of liquid soap to 1 quart of water, in a spray bottle.I get them at Dollar store for a dollar, if that's not strong enough add more soap, good luck.