Without bees, the availability and diversity of fresh produce would decline substantially, and human nutrition would likely suffer. Crops that would not be cost-effective to hand- or robot-pollinate would likely be lost or persist only with the dedication of human hobbyists.
If all of the world’s bees died off, there would be major rippling effects throughout ecosystems. A number of plants, such as many of the bee orchids, are pollinated exclusively by specific bees, and they would die off without human intervention. This would alter the composition of their habitats and affect the food webs they are part of and would likely trigger additional extinctions or declines of dependent organisms. Other plants may utilize a variety of pollinators, but many are most successfully pollinated by bees.