How to Cure Sticky Leaves on a Kaffir Lime
The leaves on my kaffir lime tree are really sticky and it is dropping sticky goop on the floor. A lot of leaves have fallen off already. I have sprayed it several times with a systemic insecticide which seems to help a little but hasn't cured the problem.
This article has some good information: https://www.gardeningknowhow.com/plant-problems/pests/homemade-aphid-control-a-natural-way-to-kill-aphids.htm
And even though it deals primarily with outside plants, aphids remain the same.
Neem oil works, as does soap and water. Use the neem oil according to package directions. If you use anything that has no residual effects, still use according to package directions, or devery 5-7 days. Soap and water will kill the adults, but the aphids will reappear when the eggs hatch. Make sure you break their life cycle.