Conundrum

Here's the larva on an erigeron flower again. I admire it's sturdy little feet that are such efficient support. The blossom is about the size of a nickel, or a thumbnail. It's staggering to think that this is just one flower out of the thousands on this bush, and there are several bushes in the yard. Does each one have such a universe of abundant life? I think twice about pruning now--how much do I destroy to make things look tidy?