How do we feed the world after all the bees have gone?

Recommendable! The future of artificial pollination is near! Drones would be another option and it is under development.

"Its two-stage artificial pollination service mirrors the action of honeybees – that is, collecting and distributing pollen. The system separates viable pollen from mechanically harvested flowers and stores it for over a year, which overcomes the problem of desynchronization of different cultivars’ blooms.
During blooming, the stored pollen is loaded into an artificial pollinator, which disperses dry pollen on the trees using LIDAR sensing and use electrostatic deposition to get the pollen to the targeted trees and individual flowers."

How do we feed the world after all the bees have gone? - ISRAEL21c: Israeli agritech startup Edete has developed artificial pollination technology that will soon be tested on Californian almonds.