Bad idea. Without insects, you wouldn't get any fruit, squash, peppers,
cucumbers, etc. (Tomatoes and corn are wind pollinated.) The bees in
this country have enough problems with natural predators without having
to worry about people spraying their space indiscriminately.

Some fungi protect plants against other diseases. There are predatory
mites that protect plants against other insects.

A much better approach would be to understand what is going on in your
garden. When you have a problem, address that problem specifically and
in such a way as not to generate more problems.

To answer your specific question: no, there is no general purpose
substance that will eliminate the rascals without also eliminating the
useful organisms.

Walter R. wrote:
Is there an effective general purpose insecticide, fungicide, miticide that
will get most of those rascals out there? It is troublesome to spray for all
those critters separately. I am pretty sure I've got them all.

Anything close?