I have observed that a particular weed that grows in the bottom of the seasonal stream on this property hosts a large number of ladybugs. And I notice that I have had almost no problem with aphids on my roses. So I'm thinking that I need to cultivate this weed... or at least allow it to thrive a number of places.
Had a similar thing with arugula. Two weeks ago black beetles of some sort had overrun my arugula patch, gnawing holes in almost every leaf. Instead of nuking them, I waited. And now I have a couple of very fat and happy lizards, and no new holes in the arugula. Sometimes nature works.
Still waiting for the gopher traps, though.