I bought a lime tree in a plant exhibition in Kuala Lumpur. I planted it in a big pot, It has not many fruits yet but it was growing healthy until white stuff, like foam, started building on the leaves. I don't want to use any chemicals but I will like to find any homemade remedy that will help out. . . Thanks.
This could be Spittle Bug or Mealybug.
Here is a few links with more information.