Tomato Plant Destroyer

When watering my beloved garden tonight, I found that my tomato plants in one planter had all lost their leaves. Yesterday they were beautiful plants. Now they are green sticks. I found this beautiful culprit on one plant. I didn't have the heart to destroy it. Such a beautiful caterpillar might turn into an even more beautiful butterfly or moth.

So I took its picture and put him in the alley behind our house where there are some weeds it can munch on. I wonder how long it will take for it to find its way back and destroy my remaining 3 tomato plants?