Answer: As long as there is some green left on the leaves they are still busy manufacturing carbohydrates for the plant roots. I'd leave them alone until they drop off naturally, then pick them up or rake them up to remove them from the garden (just in case they are harboring insect eggs). It might be that the insects are already gone now that they have feasted on the leaves of your plants, so don't use any sprays unless you actually see insects feeding. If you do, try hosing them off with a strong stream of water, or using an organic product such as Bonide?s Total Pest Control product. It provides excellent, long-lasting control of problem insects around buildings, in turf, on ornamentals, on vegetables, fruit, shrubs, and trees.
The active ingredient is a pyrethroid type insecticide called Permethrin.
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