Damage is already done. What now?
I have a potted Passiflora incarnatum on my patio. I came home today to find it completely defoliated and (to my new-to-such-things-eyes) swarming with caterpillars. (We counted 15 at the time.) Today there are fewer and they don't seem to be eating stems, but there's a lot of leafless vine left on the trellis.
Since the damage is already done, I'll probably leave them be to do their butterfly thing and find a good pesticide or something once the plant starts growing again to prevent round 2.
1) Will the caterpillars eat the stems, and/or will they eat them down to the root? If they will, should I remove them now?
2) What would have prevented this?
3) Would a pesticide affect the plant's ability to grow back?
4) Should I leave the vines on the trellis and hope they grow new leaves, or cut it back to the ground and let the whole thing grow back?
5) Will it grow back before next spring or is it pretty well done for this year?
I understand that the butterflies are pretty and help pollinate other plants, but I value the greenery on my patio and the gorgeous flowers I was seeing on this plant more. My other plants are mostly succulents, so I don't think the butterflies will help them much, anyway. This was my first non-succulent plant to flourish, so I really hope to get it green and vibrant again.