You need to start spraying well before you get caterpillars, bugs, PM, etc... Prevention is key. It's called IPM "Integrated Pest Management." Once you have a problem it's already too late.
I spray weekly with a potassium silicate/sesame oil spray during veg and into the first couple weeks of flower and then I stop any use of oils. After that I spray with a citric acid based foliar and some other stuff. What I've done is looked around the garden and identified plants that were not affected by pests. Garlic and onion are plants that pests don't seem to like so I make a tea of those and add it to my foliar. Other things that I use are rosemary, hot peppers, and peppermint. The type of mint is important as bugs seem to like spearmint but don't bother the peppermint.
I stop all sprays of anything other than a citric acid foliar after about 5 weeks of flower. The citric acid kills pests and prevents PM and mold.
That's what I do and it seems to work. And it works very effectively. At least in my experience. I'm still using the same potassium silicate and citric acid I bought years ago for around $20 for both and have a few years of each left. The other stuff I grow myself.
Some of the commercial products have started to become ineffective as pests adapt and become resistant. Natural remedies can be more effective and are not as easily to allow pests to become resistant to.
I have no scientific data to support my claims and I'm not going to share my methodology in detail but what I've been doing has been very effective and economical at the same time.
Get on top of things early and prevent issues before they occur.
Happy growing and good luck next season.