The huge caterpillar

This huge caterpillar on my car bonnet

Check out the small black pellet at one end of this caterpillar..it is actually her feces!

I am surprised to notice that one of the plant in my house garden is dying.. Most of the leaves in that plant are shrivelled and some of them appeared bitten! After taken a closer look all over that plant, I was shocked to see a huge caterpillar on one of the branch! It is no doubt the biggest caterpillar I have ever seen, which I thought would measure upto about 2.5 inches in length! I had tried to remove it from the branch, but found her anchored tightly and refused to be shuffled! I have no other way but to cut off the branch and discard it together with the stalk. I also noticed there were hundred of small black pellets scattered on the ground right below that plant. Those are actually the feacal excretion from the caterpillar! These feces are quite big and appeared disproportionate to the size of the caterpillar! I also observed something interesting when I saw the caterpillar excreting two feces within a span of five minutes! I am just wondering how long the caterpillar has been there living on that plant..and how fast a caterpillar can grow and metamorphosize into a butterfly..
I have tried to understand more about caterpillar by looking up the wikipedia, and I have found this information..
Caterpillars are the larval form of a member of the order Lepidoptera (the insect order comprising butterflies and moths). They are mostly herbivorous in food habit, with some species being insectivorous. Caterpillars are voracious feeders and many of them are considered pests in agriculture. Many moth species are better known in their caterpillar stages because of the damage they cause to fruits and other agricultural produce.
Some caterpillars are fuzzy and hairy.. and they are most likely to cause itching of the hands if touched.(Caterpillar dermatits).
Have you heard of edible caterpillar? Well.. "Gonimbrasia belina" is a species of moth found in much of Southern Africa, whose large edible caterpillar, the mopani or mopane worm, is an important source of protein for millions of indigenous Southern Africans!