Scientists estimate that 4.7% of the world’s total production of fruit, 3.2% of vegetables, and 4.7% nuts is now lost because of inadequate pollination. SOURCE
https://thenextweb.com/news/tiny-flying-robot-could-work-as-artificial-pollinator
https://thenextweb.com/news/tiny-flying-robot-could-work-as-artificial-pollinator