Recently got an infestation of manamites. How do I get rid of them?

When I came back to my hut this evening after collecting some ingredients I found SEVERAL manamites gnawing at my orb. Luckily I was able to get them away before they caused any real damage, but I've checked around and found them in several places.

I'm afraid I have an entire infestation and I'm unsure of how to get rid of them. They just keep eating my spells!