The trouble with spraying insecticides (both natural and synthetic) is that you kill both the targeted bugs and also some of the beneficial insects. in some cases you can use good bugs to control some of the not so good bugs. I am a big fan of preventive action but in some instances, curative action is required.
The bugs Wells Brother’s carries are Ladybugs (curative) for the control of aphids, scale and mites. Ladybugs wil stay in a given environment as long as the food supply lasts.
Beneficial nematodes (preventative) control grubs, fire ants and flea larva to name a few. The mighty praying mantis (curative) eats everything from grasshoppers down to ants; and the trichogramma wasps (preventive) will take care of webworms.
Application rates and productes are different for each of these. Find out more at http://beneficialinsects101.com/