You have been dealing with unusually hot temperatures, not to mention appalling smoke pollution.
As Daisy said, you fried 'em. I learned quickly that if I used oil of any sort on roses, and the temps got above about 75, the foliage would be toast. Literally. Toast.
If, after they grow new leaves, you again have a spider mite infestation, try just hose-washing them, using a strong spray of water, from UNDER the leaves (because the little creeps live on the underside of leaves).
