https://earthobservatory.nasa.gov/Features/Bees/bees.php Source:   By Rebecca Lindsey, NASA Earth Observatory For Investigation:   10.3 Excerpt: ...Will Plants and Pollinators Get Out of Sync? ...the changes aren’t just dramatic, they’re also kind of scary. The fertility of most flowering plants, including nearly all fruits and vegetables, depends on animal-mediated pollination. As the pollinators move from flower to flower for nectar--a high-energy, sugary enticement—the plants dust them with pollen, which the animals transfer from flower to flower. “Flowering plants and pollinators co-evolved. Pollination is the key event for a plant and for the pollinators in the year. That’s where pollinators get their food, and that’s what determines whether the plant will set fruit. Some species of pollinators have co-evolved with one species of plant, and the two species time their cycles to coincide, for example, insects maturing from larva to adult precisely when nectar flows begin,” says