This is going to work by coating the soft bodies of insects -
especially the young - and suffocating them. To the degree that any of
this stuff works, it doesn't just work on the insects you want to get
rid of, but on all insects. It also affects the birds that eat the
insects.

It might be a better idea to ask yourself why you are trying to kill
things in your garden. If you wait and do nothing - and if you garden
organically throughout - the balance will be restored and you won't
have any problems. Or so I have found.