Hey, I know there is a book, but I don't know which one. Which of the SR4 books has anything on the insect spirits?

That would be Street Magic and Conspiracy Theories, as well as a few hints in other books, but nothing big.
Bugs where a big 2nd edition theme.

Street Magic has a fair amount on them, including rules.

For fluff:
Bug city
Universal brotherhood
Double exposure
Queen Euphoria

All of it older edition stuff, but the fluff is still really good and will make you love those buggers garantueed.

Also check out the invae section in the link in my sig.

What sig?

The thingie that show up after every post?

No on your posts.

It doesn't show up for you?

Oops, I have them turned off. Sorry about that.

There's also some stuff in Feral Cities in the Chicago chapter, if memory serves.

IIRC, Digital Grimoire also has some info on them.

Guess its time to hit up the stores. Spend money, do research, yeah! Thanks guys.

For fun, do a google search for the Real Life ™ Universal Brotherhood. Not the same organization, but there's a lot you can nab for background color if you use the organization in game. The two mesh quite well, actually.

Really? I never even heard of the buggers.

You'd be surprised how much of SR have real life counterparts.
Learned about Ares defense systems a while back and had a minor freak out.

True enough. I like to use RL or information to flesh out interactions with organizations and places in game.