Ladybugs are a natural way to keep plant pests in check... sorta. There is an organic gardening push to purchase ladybugs and release them in your garden as a natural way to eliminate pests like aphids. There is a problem. When you release them, they fly away. They go many miles away because ladybugs naturally spread out so they don’t overcrowd one another's territory so there is enough food to survive.
An alternative is green lacewings, but they can become a problem if their population grows too much. If you have to buy a helpful bug, get green lacewings. An okay solution if you are trying to do organic gardening is to make a ladybug friendly environment. They will come to you. Grow a large variety of plants. Let some aphids live. It will attract ladybugs to your garden. Use manual removal on your plants if things start to bug out too much.
If you are trying to grow an organic garden, the best advice is to grow plants that do the best in your environment. I know this sounds pretty simple, but a lot of people do not follow this advice. Trying to grow your favorite variety of tomato may taste the best to you, but will be near impossible to grow if it is swarmed by insects daily. Choose the easiest variety of what you want grown and you will be much more successful as an organic backyard farmer.