if you dont know what you have or if you have it, then no. there is no
"general insecticide" because different insects require different
control. It dosent make sense to spray for mites unless you have
them, since you will harm the beneficial mites. "im pretty sure ive
got them all" isnt a good argument, you need to know what the problem
is. The doctor wouldnt give you a general medicine and say, well, you
could have the flu, or maybe a cold, or maybe pnuemonia, but this will
take care of whatever you have would they? This is why you cant buy
very many chemicals anymore, homeowners who have no idea what they are
doing just spray everything they can get thier hands on with little
understanding of what they are actually doing. On a final note, we
only have one earth, spraying mass amounts of chemicals will not help
to preserve it.

Toad