Q.Grapefruit Leaf Drop
I live in Stuart, FL. and have a small grapefruit tree, which was infested with Sri Lanka weevils. I sprayed the tree with dish soap and water, the same as I did when my gardenias had aphids. A few days later the tree had severe leaf drop and fruit drop. Will the leaves grow back, and did the soap make the leaves fall off, or could it have been the hot, dry weather or the weevils or what? I would like to avoid this ever happening again.

Certified GKH Gardening Expert
Try using neem oil. Here is more information: https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm