Predatory insect ecosystem

So as while breaking ground on my greenhouse continues to be delayed I have even more time to stew about what techniques I'll be implementing. For reference, I'm in zone 7 and the greenhouse will be 150sqft and 14ft tall, growing tropical food producing plants.

So biocontrol of pests. It seems to me the issue is that after the pest is eliminated, then your predatory insects are out of food. I'm wondering in the closed system of a greenhouse if it's possible to assemble a balance of predators like in the wild. So I expect to have populations of lacewings and ladybugs preying on the various smaller pests as well as adult black soldier flies emerging from the compost and I'm sure stinkbugs wandering in for warmth in the fall. So could these support larger predators like spiders and praying mantis?

My thinking is the larger predators would keep the intermediate predators under control so they don't overpopulate.
Has anyone heard of or tried anything like this?
Any other suggestions for the system?

Bugs always seem to find their way in. I doubt you will run out of creatures trying to eat the plants in your greenhouse. If for some reason you do, then some of the predators will die back and then the 'pests' will return. If not, open a window/door for a bit and I am sure you will acquire some new ones. Probably of both varieties.