Why bees matter

The numbers, stated carefully

The IPBES assessment is the most substantial synthesis available, and its headline figures are frequently repeated without the qualifications that make them meaningful.

• Around 75% of leading global food crop types benefit to some degree from animal pollination. This counts crop types, not the volume of food eaten, and 'benefit to some degree' spans everything from a small yield improvement to total dependence.
• Those crops account for roughly 35% of global food production by volume. The staples that feed most people — wheat, rice, maize — are wind-pollinated or self-pollinated and do not need insects at all.
• The crops that do depend on pollinators are disproportionately the nutritionally interesting ones: most fruit, many vegetables, nuts, coffee, cocoa, and the seed crops behind several oils.
• Animal pollination is estimated to be worth hundreds of billions of dollars annually to global agriculture, with wide uncertainty around any specific figure.

Beyond agriculture

The food argument is the one that gets made, and it is not the largest one. The great majority of wild flowering plants — commonly estimated at around 87% of species — depend on animal pollination to reproduce. Those plants are the base of terrestrial ecosystems: they feed herbivores, structure habitats, hold soil, and support the insects that birds eat.

A collapse in pollination would not present as empty supermarket shelves. It would present as a slow simplification of wild plant communities, running upwards through everything that depends on them, and it would be well advanced before it was obvious.

Why honey bees are not a sufficient answer

It is tempting to conclude that pollination is a solved problem because honey bee colonies can be manufactured and moved. Three things are wrong with that.

• Capability. Honey bees cannot buzz-pollinate, cannot reach deep flowers, and are poor in cold or wet weather. For a substantial list of crops they are simply not the right animal, which is why glasshouse tomato growers buy bumblebee colonies rather than adding hives.
• Yield. Multiple studies across many crops have found that wild insect visitation improves fruit set in ways honey bee visitation does not fully replicate, even at high honey bee densities. Diversity of visitors is itself a variable.
• Risk. A pollination system resting on one managed species is one disease away from failure. Varroa demonstrated exactly how fast a single parasite can move through a globally traded monoculture of one insect.