Yes, and other pollinating insects. This is not just sentiment but practicality - if you reduce the number of bees in your garden, then many of your crops will not set.

You need also to remember that insecticides in general are not specific - they will also kill the insects that might otherwise be eating the creatures you want to get rid of - eg not just the aphids, but also the ladybirds whose larvae will eat the aphids.

Plants cam tolerate low levels of predation - it's being swamped by psests which is the problem. Therefore, the idea of picking off the tender tops is a good one. If you can do it *before* they have been covered by blackfly, they make a tasty vegetable.