Pollinating insects are the unsung heroes of global food production and ecosystem health. While bees receive the most attention, a diverse community of insects — including butterflies, moths, hoverflies, beetles, and wasps — collectively pollinate the vast majority of the world's flowering plants. Without these pollinators, terrestrial ecosystems would collapse and human diets would be reduced to wind-pollinated staples like wheat, rice, and corn.
What Is Pollination?
Pollination is the transfer of pollen grains from the anther (male part) of a flower to the stigma (female part), enabling fertilisation, seed production, and fruit development. While some plants are pollinated by wind, water, or birds, the majority of flowering plants depend on insect pollinators. The insect visits the flower to collect nectar or pollen as food, and in doing so inadvertently transfers pollen between flowers.
Pollination by the Numbers
- 87.5% of all flowering plant species depend on animal pollination
- 75% of leading global food crop types benefit from animal pollination
- 35% of global food production by volume depends on pollinators
- $235–577 billion (USD): estimated annual global value of insect pollination
- £690 million: estimated annual value to UK agriculture
The Key Pollinating Insect Groups
| Insect Group | Key Species | Pollination Style | Crops Pollinated |
|---|---|---|---|
| Bees (Hymenoptera) | Honeybees, bumblebees, solitary bees | Deliberate pollen collection; highly efficient | Apples, strawberries, almonds, oilseed rape |
| Hoverflies (Diptera) | Episyrphus, Eristalis, Syrphus | Incidental pollen transfer while feeding on nectar | Carrots, onions, some fruit crops |
| Butterflies (Lepidoptera) | Various species | Long-tongued; access deep tubular flowers | Limited crop pollination; important for wildflowers |
| Moths (Lepidoptera) | Hawk-moths, noctuid moths | Nocturnal pollination of night-scented flowers | Some tropical crops; important for wild plants |
| Beetles (Coleoptera) | Soldier beetles, pollen beetles | "Mess and soil" pollination — clumsy but effective | Magnolias, water lilies; some crops incidentally |
| Wasps (Hymenoptera) | Fig wasps, various species | Incidental pollination while foraging | Figs (essential); other crops incidentally |
Beyond Bees: The Overlooked Pollinators
While bees are rightly celebrated as the most important pollinators, other insect groups make crucial contributions that are often undervalued:
Hoverflies
Hoverflies (family Syrphidae) are the second most important group of pollinators after bees. The UK has over 280 species, many of which are excellent pollen vectors. Unlike bees, hoverflies do not collect pollen deliberately but transfer it incidentally on their hairy bodies while feeding on nectar. Research has shown that hoverflies make a disproportionately large contribution to the pollination of crops such as carrots, onions, and some fruits.
Moths
Moths are increasingly recognised as important pollinators, particularly of night-scented flowers such as honeysuckle, evening primrose, and night-flowering catchfly. A 2020 study found that moths visit a wider range of plant species than previously thought and transport pollen over longer distances than many daytime pollinators, making them important for maintaining genetic diversity in plant populations.
Did you know? Chocolate depends on pollinating insects. The cacao tree (Theobroma cacao) is pollinated almost exclusively by tiny midges of the family Ceratopogonidae. Without these barely visible flies, there would be no cocoa beans and, consequently, no chocolate.
Threats to Pollinating Insects
Pollinator populations worldwide are in serious decline. The main threats include:
- Habitat loss: The destruction of wildflower meadows, hedgerows, and diverse farmland has removed essential foraging and nesting resources
- Pesticides: Neonicotinoid insecticides, fungicides, and herbicides (which destroy wildflowers) all harm pollinators directly or indirectly
- Climate change: Altered flowering times, shifting species ranges, and extreme weather events disrupt the synchrony between plants and their pollinators
- Disease: Managed honeybee diseases can spill over into wild pollinator populations
- Invasive species: Non-native plants and animals can disrupt pollination networks
- Light pollution: Artificial light at night disrupts nocturnal pollinators, particularly moths
What Would Happen Without Pollinators?
The loss of pollinating insects would have catastrophic consequences:
- Most fruits, nuts, and many vegetables would become scarce and expensive
- Wild plant diversity would collapse, triggering cascading effects on all wildlife that depends on those plants
- Diets would be restricted to wind-pollinated crops (cereals, corn) and self-pollinating species
- Vitamin deficiencies and malnutrition would increase globally
- The economic cost would run into hundreds of billions of pounds annually
- Plant pollinator-friendly flowers: Native wildflowers and garden plants that bloom from spring to autumn provide continuous nectar and pollen.
- Reduce pesticide use: Avoid spraying insecticides whenever possible, and never spray open flowers.
- Create diverse habitats: Hedgerows, wildflower strips, and rough grassland provide foraging and nesting resources.
- Support organic farming: Buy organic produce when possible to support farming systems that protect pollinators.
- Reduce light pollution: Turn off unnecessary outdoor lights to protect nocturnal pollinators.
- Get involved: Join pollinator monitoring schemes and support conservation organisations working to protect these essential insects.
Key Takeaway
Pollinating insects — including bees, hoverflies, moths, butterflies, beetles, and wasps — are essential for the reproduction of 87.5% of flowering plants and the production of approximately one-third of our food. Their decline, driven by habitat loss, pesticides, and climate change, threatens both wild ecosystems and global food security. Protecting pollinators requires action at every level, from individual gardens to international agricultural policy.