I've had a problem with caterpillars lately. I've solved the problem with some pesticide I got from the store. I know that in a SHTF situation grocery stores probably won't be available. This is a problem I need to take more seriously!
Lets say that the stores are gone and there's no way to buy pesticides.
What is the best way to stop pests in the garden and in the house when we lose modern conveniences?