Locusts cannot eat plants that have developed complete protein. Aphids also are attracted to crops where the farmer uses liquid Nitrogen and nitrates as a Nitrogen source. Use cover crops. Soil biology and earthworms will convert Nitrogen into an amino acid which your plants can absorb. To achieve immunity to most insects: 1) your plants must increase photosynthesis by 200 to 300%. If you lack Manganese, your plants cannot perform hydrolysis which splits H2O into H and OH which must be done before photosynthesis can begin. Also need cobalt and boron and other minerals. 2) Your plants must convert ammonia and nitrates into amino, acids, peptides and proteins. Your plants have 10,000 enzymes to achieve that. Soil biology, earthworms and cover crops can convert all N into amino acids and save that step for your plants. You can make worm bins and feed the worms coffee grounds to get N into an amino acid which your plants can absorb directly.
I recommend this video for an in depth study in how to raise crops that are immune to aphids, locusts and most diseases. https://www.youtube.com/watch?v=D1wJefaFrVI&t=4167s
We are entering a period of Global Cooling we can expect more bad weather, crop losses, earthquakes and volcanoes. This can cause severe food shortages, riots, rebellions and civil wars. I wrote this:
2020s: Surviving The Cold, The Quakes And Volcanoes