Answer:
I am an insect half of my name is another insect. I am similar to the name of a famous band.
I am all around yet to me you are half blind. Sunlight makes me invisible and difficult to find.
There is one in a minute two in a moment and none in a thousand years. What is it?
Part carbon, part water, I am poison to the fishes. Many falsely claim my name, I am the pause that refreshes. What am I?
I carry you down a gentle stream.
No matter how little or how much you use me, you change me every month.