The world after the last visit
Imagine a spring in which flowers open but no bee, hoverfly, moth or beetle arrives. The landscape would not instantly become a lifeless desert, and humanity would not suddenly run out of bread. Wheat and other major cereals do not rely on insects in the way many fruits do. But the disappearance of pollinating insects would unsettle a vast set of relationships linking flowers, seeds, animals, farms and diets.
Pollination is the transfer of pollen from the male part of a flower to a receptive female part, allowing fertilisation and often the production of seeds and fruit. Some plants use wind; some can fertilise themselves; many gain from animals that carry pollen between flowers while collecting food. Bees are famous for the job, but flies, butterflies, moths, wasps and beetles also contribute. The Food and Agriculture Organization describes a remarkably varied cast of insect pollinators, alongside birds and bats in some regions.¹
What would vanish from a shopping basket?
An estimated three-quarters of the world's leading food-crop types depend at least partly on animal pollination. That does not mean three-quarters of the food we eat would disappear. The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, or IPBES, distinguishes the number of crop species from the volume of production: staples that provide much of the world's calories often use wind or self-pollination.²
The sharpest food effects would fall on many fruits, nuts, vegetables, seeds and oils. Some crops would produce much less; others might still fruit but have poorer yields or quality. Cocoa depends on tiny midges, not a familiar honeybee, for example.³ Farmers could attempt hand pollination or managed substitutes for some high-value crops, but doing it across landscapes would be costly and uneven. The loss would be about variety, nutrition, livelihoods and price as well as calories.
Wild insects and managed honeybees are not interchangeable. In a study spanning 41 crop systems, visits by wild insects were associated with improved fruit set even where honeybees were abundant.⁴ Different pollinators work at different times, temperatures and flower shapes. A diverse community can offer a form of insurance when conditions change. The loss would also be uneven between neighbours. An orchard with access to wildflower margins and nesting habitat might retain more visitors than a field surrounded by bare ground. Weather could magnify that difference: a species active in cool conditions may pollinate when another stays sheltered. This is why measuring one hive's strength cannot tell a farmer whether all the relevant flowers received enough pollen.
The wilder consequences
The larger ecological story begins beyond the farm gate. IPBES estimates that nearly 90 per cent of wild flowering plant species depend to some extent on animal pollination.² That does not mean every one would go extinct if insects vanished: dependence varies, and some could reproduce by other routes. But many would set fewer seeds, making it harder to replace ageing plants and colonise new ground. A global analysis of pollination experiments found substantial variation in how strongly plant seed production relies on animal visitors.⁵
Plants are food and shelter for other life. Fewer fruits and seeds would affect birds and mammals; shifts in vegetation would change habitat for insects and many other organisms. Those knock-on effects would take years and differ by place. An ecosystem with specialist plants and specialist pollinators may be more vulnerable than one with several possible partners. A recent synthesis found that lower pollinator diversity generally reduced measures of reproductive success in wild and cultivated plants.⁶
The thought experiment is useful precisely because it is extreme. There is no credible forecast that every pollinating insect will disappear at once. Real declines are patchy: some species fall, others remain stable or increase, and data are much better for certain groups and regions than for others. Britain's pollinator indicators, for instance, track bees and hoverflies but reveal differences among species and periods rather than one universal trajectory.⁷
Why would numbers fall?
The pressures often arrive together. Removing hedges and flower-rich grassland reduces food and nesting places. Intensive land use can leave few blooms between crop flowering periods. Pesticides can harm pollinators directly or alter the resources they need; pathogens and parasites affect some species; climate change can shift where flowers and insects thrive or when they appear. IPBES identifies these interacting drivers rather than a single culprit.² A honeybee hive alone cannot repair a landscape that no longer supports wild insects. Larvae and adults may need different resources, and insects that pollinate by night or in early spring can disappear from an assessment focused only on sunny summer afternoons.
Protection therefore needs more than a symbolic patch of flowers. Connected habitat, varied native plants flowering across the season, suitable nesting sites and careful pesticide use can all matter. Agricultural and urban land must be considered together because insects move across their boundaries. Measures should be judged by whether diverse pollinators persist and plants reproduce, not simply by whether a site looks colourful for a week.
If pollinating insects vanished, we would still have many staple foods. We would lose much of the abundance and reliability of flowering life, with costs borne unevenly by ecosystems and people. The real decision is being made before that hypothetical spring: whether landscapes can keep enough kinds of insects visiting enough kinds of flowers for the relationships to endure.