Insects keep the planet’s ecosystems running. They pollinate the crops we eat, recycle dead matter back into soil, feed the animals above them in the food chain, and contribute to medicine in ways most people never hear about. With roughly 5.5 million species estimated to exist (only about 1 million have been formally described), insects are the most diverse group of organisms on Earth. Their importance touches nearly every aspect of human life.
Pollination and the Food Supply
About 75% of the world’s leading pollinator-dependent crops account for 35% of global food production. The financial contribution of insect pollinators to agriculture is estimated at €153 billion (roughly $170 billion) per year, and the agriculture sector’s vulnerability to losing those pollinators sits at about 9.8% of total production value. That number sounds modest until you consider which foods disappear or become scarce without them.
Almonds, apples, blueberries, cherries, avocados, cucumbers, watermelons, pumpkins, and tomatoes all require bee pollination for productive yields. So do peaches, pears, plums, kiwi fruit, cranberries, and raspberries. Many of these crops rely on managed pollinators, meaning farmers actively bring in bee colonies because wild pollinator populations alone can’t meet demand. Even crops like carrots, onions, broccoli, and cabbage depend on insect pollination for seed production, which keeps future harvests possible.
Without insect pollinators, your grocery store would still have grains, but the produce section would look dramatically different. Most fruits, many vegetables, and several oilseed crops would see sharp yield drops or vanish entirely from commercial farming.
Feeding Nearly Every Land Bird on Earth
Insects are the foundation of terrestrial food webs. In temperate, boreal, and arctic regions, an estimated 90% of all individual land birds are insectivorous during the breeding season. In the tropics, that figure is around 60%. The global community of insect-eating birds represents roughly 3 million tons of biomass, all sustained by the insects they consume.
Freshwater ecosystems depend on insects just as heavily. Aquatic insect larvae are a primary food source for fish, amphibians, and other freshwater species. When insect populations shrink in a river or stream, the effects ripple upward through every species that feeds on them. Birds, bats, frogs, lizards, and small mammals all rely on insects as a protein source, making them an irreplaceable link between plants and larger animals.
Recycling Nutrients Back Into Soil
Insects are among the planet’s most efficient decomposers. When beetles, flies, and other insects feed on dead plants and animals, they break organic matter into smaller pieces that soil microbes can process further. Their excrement releases nutrients quickly, creating what ecologists call the “fast cycle” of nutrient return. This is significantly faster than waiting for plant litter to decompose on its own, which follows a much slower path.
Herbivorous insects like grasshoppers also shape nutrient cycling in a less obvious way. When they preferentially eat plants whose litter decomposes slowly, they reduce the abundance of those plants and effectively speed up the overall rate at which nutrients return to the soil. This selective feeding changes the composition of plant communities and accelerates the availability of nitrogen and other elements that remaining plants need to grow. The result is that ecosystems with healthy insect populations tend to have more productive soils.
Natural Pest Control
Predatory and parasitic insects provide billions of dollars in free pest suppression every year. Ladybugs, lacewings, parasitic wasps, ground beetles, and hoverflies all prey on crop-damaging species. Research on UK cereal and oilseed crops found that even a modest 10% reduction in the community of natural pest enemies could cost farmers between £37 and £171 per hectare depending on the crop. Scale that across millions of hectares worldwide and the value becomes enormous.
This natural pest control reduces the need for chemical pesticides, which in turn protects water quality, soil health, and the beneficial insects themselves. Farmers who maintain hedgerows, wildflower strips, and other habitat for predatory insects often see measurable reductions in pest damage without additional chemical inputs.
Contributions to Medicine
Insects have been used in medicine for centuries, and modern research is uncovering why many traditional practices work. Maggot therapy, where disinfected blowfly larvae are placed on wounds to selectively remove dead tissue, is now a recognized clinical treatment for chronic wounds that resist conventional care. The larvae clean the wound without damaging healthy tissue.
Bee venom contains a peptide called melittin that shows promise in treating inflammation linked to rheumatoid arthritis and multiple sclerosis. It works by blocking the expression of genes that drive inflammation. Other bee products, including propolis and royal jelly, are being studied for potential effects on neurodegenerative conditions like Parkinson’s disease.
Blister beetles produce a compound called cantharidin, historically used across Europe. Modern derivatives of this compound are now used in anti-tumor medicine. A peptide isolated from wasp venom has shown the ability to kill breast cancer cells while leaving healthy cells intact in laboratory studies. Extracts from certain cockroach species used in traditional Chinese medicine have yielded proteins with documented anti-tumor properties. These aren’t fringe curiosities. They represent active areas of pharmaceutical development built on compounds that insects evolved for entirely different purposes.
Advancing Genetics and Human Health Research
The common fruit fly has been one of the most important tools in the history of biology. Eight Nobel Prizes have been awarded for research conducted using fruit flies, starting with Thomas Hunt Morgan’s 1933 prize for discovering the role of chromosomes in heredity. Subsequent breakthroughs made with fruit flies span immune function, the biology of circadian rhythms, how organisms develop from embryos, and how the sense of smell works.
In 1981, researchers demonstrated that fruit fly populations could be selectively bred for longer lifespans, proving that aging is under genetic control and can be studied in the lab. That finding launched the modern era of aging research. Because fruit flies share a surprising number of genes with humans and reproduce quickly, they remain one of science’s most valuable model organisms for understanding disease, development, and genetics.
Waste Conversion and Sustainability
Insects are increasingly being used as a practical solution to organic waste. Black soldier fly larvae can convert food waste, agricultural byproducts, and even slaughterhouse waste into protein-rich and lipid-rich biomass suitable for animal feed, biodiesel, and fertilizer. Their efficiency varies by waste type, with fast food waste producing the best conversion rates, but larvae reared on slaughterhouse waste and pig manure also yield protein-rich results.
The residue left behind after the larvae feed, called frass, works as fertilizer whose nutrient profile mirrors the original waste. Protein-rich waste produces protein-rich fertilizer. This approach solves two problems at once: it diverts organic waste from landfills while producing valuable feed and soil amendments. Commercial-scale black soldier fly operations are now running in dozens of countries.
The Scale of Insect Decline
A 2025 study published through the Ecological Society of America found an average annual decline of 6.6% in insect abundance, even in ecosystems that appeared untouched by direct human activity. Over the 20-year study period, that rate compounded into a 72.4% drop in total insect numbers. These losses don’t just threaten insects themselves. Every role described above, from pollination to pest control to feeding birds, degrades as insect populations shrink.
With 80% of insect species still undescribed by science, we are losing species and populations before we fully understand what they do. The causes are familiar: habitat loss, pesticide use, light pollution, climate change, and the spread of invasive species. What makes insect decline uniquely dangerous is how many other systems depend on them. Losing insects doesn’t just mean fewer bugs. It means less food, poorer soil, collapsing food webs, and the disappearance of ecological services that would cost trillions of dollars to replace artificially.