What we do is apply neem tree granules to the soil around the affected fruit tree in the winter. The guava moth over-winters in the soil. Then in spring and summer we spray Btk (Bacillus thuringiensis kurstaki) over the leaves of the tree – Btk is sold as Organic Caterpillar Bio Control in garden centres. This is all that’s available as an organic solution at the moment and will keep your tree clear. You just have to hope the neighbours are doing the same!