I have in the past had a beautiful show of Impatiens absolutely decimated in no time by caterpillars.

I have learned that they are the Hawkmoth caterpillar and my internet research tells me that they come from a large nightime moth.

I find that by the time I notice the caterpillars they are large, having stripped the plants. I can pull them off the plant by then, but the plants don't seem to recover. Should I cut them right back at this point? Fertilise with something ? In order top save them .

Do you have any information on this pest ? eg. is this a problem for certain times of year ?...that I may be more observant at these times . Or can I break the life cycle somehow ?

I have also found them in gardenias and ficus in a pot.

If you have no info, could you refer me to someone who may please.

Thank you for your time,
Gayle Wyborn