It is about 3-4 inches in length. Luckily I took some pictures of it as later on I found a Scarab beetle in put it in the same box.
A while later, I look in and found to my dismay that the beetle had attacked the caterpillar.
A white, almst jelly-like substance came out of the wound and no matter how the caterpillar twisted and turned, the beetle held on.
The longer the battle went on, the more fluid came out and it got me thinking as to what it was. It was not thin like you exprect blood to be.
After about 30 minutes, the battle was still going on although it seemed as if the caterpillar was slowing down some.
It eventually crawled into this leaf which had curled up and the beetle fell off.
On closer examination I found that both the beetle and the caterpillar had died. In order to ward of predators, this fluid must be a poison it exudes. You can see from the picture below that the Scarab has huge mandibles and this is what helped it to hang on. I do question why hit never let the caterpillar alone once the fluid started coming out. Surely it senses that it is a danger to him? I wish I knew more about things like this.