About 75% of our crops today rely on insect-based pollination. We typically use bees for this purpose. Bees drink nectar from the plant's flowers, getting pollen all over themselves in the process. The pollen then fertilizes the plants, which then produce the fruit and seeds that we eat. Everyone wins.
Except that bee colonies are in trouble. We're not sure why, but something is killing off all the bee hives. Some think that it is a disease not yet identified, other think that it is stray insecticidal chemicals from farms. In any case, without bees, no fruit.
Many of these plants can be manually pollinated with a cotton swab, but that's a waste of human labor. So instead, I think we should make robot bees. These would fly around getting and injecting pollen, and occasionally returning to the hive for a recharge. These robots would be immune to all diseases and chemicals, but unfortunately would not make honey.