I am not sure what caused the white patches. Freeze damage or sunburn are both possibly causes. Damage from a chemical spray or something sprayed on the home could also be the cause. The worms are easy to control with most insecticide sprays. If they are caterpillars a spray of B.t. would work. If they are some other kind of larvae you may need to consider a pyrethrin spray (which would also work on caterpillars for that matter).
I suggest you take a sample from the plant along with a photo of the plant in its growing location (if possible) to your County Extension Office to see if they can help diagnose the problem and recommend an appropriate course of action.
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