Problem:

I think I once saw a video of a caterpillar that could get infected by a parasite, and could die of that, unless a specific kind of spider would eat the parasite, and so once the caterpillar is infected it goes looking for that spider.

I can't find that video anymore though, nor any reference on this, so I'm beginning to doubt myself.

Question: Does this behaviour really exist?

Any ideas? Or better yet, pointers to places where this has already been answered?