Q.calla lily
My calla lily leaves are puckering and there is a white substance on the leaves. What should I do?

This could be a Thrip infestation or a fungus caused by Thrips. Isolate your plant from others.
Use an application of Neem Oil on the plant. Make sure you treat all parts of the plant, top and bottom of leaves.
Remove any damaged parts of the plant and discard of.
Repeat the treatment every 7 days until the problem is resolved.
Here are some links with more information.
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
https://www.gardeningknowhow.com/plant-problems/pests/insects/controlling-thrips.htm