The Hidden World of Insect Biodiversity and Their Vital Ecological Roles

Field report

Once you start looking closely, the astonishing diversity of insects around you will reveal hundreds of thousands of species performing vital ecological roles.

Macro Wildlife Photography / Natural Archives

Entomologists around the world are betting big on insects — the tiny creatures that keep ecosystems running in ways most people never notice.

Found in nearly every habitat on Earth, insects represent the largest and most diverse group of organisms on the planet, with over a million described species and dramatically more yet to be discovered. In a single acre of meadow, entomologists have documented hundreds of species — from beetles and butterflies to bees and wasps — performing ecological services that sustain all life. The insects, estimated to outnumber humans by 200 million to one, form the foundation of nearly every terrestrial food web on the planet.

"It's a living warehouse, very similar to a coral reef, where instead of storing stuff, we find thousands of species coexisting," entomologist Dr. Antoine Hubert told reporters last year. "There is a microclimate system which is highly complex to maintain humidity and temperature from the soil surface to the forest canopy. All interactions are intricate. Anything that you observe in [an insect] community is done through chemical signals and instinctive behaviors."

Pollinators for Flowers, Decomposers for Soil, Food for Birds

For millennia, insects have served as the quiet engine of ecological productivity. Bees and butterflies pollinate the flowers that become fruits and vegetables, sustaining both wild ecosystems and human agriculture. Thanks to growing recognition by conservation agencies of the essential role insects play, awareness of their importance has also spread to gardeners, farmers, and everyday citizens. In addition, the shed exoskeletons of molting insects — primarily chitin — decompose into the soil and serve as vital nutrients for plants and microorganisms.

According to the Xerces Society, a conservation organization that promotes insect preservation as a way to sustain ecosystems worldwide, a single acre of healthy insect habitat supports pollination services worth thousands of dollars, contains all the essential components of a functioning food web, and produces more biomass than equivalent acreage of grazing land. Compared to the ecological footprint of livestock farming, insect-dominated ecosystems are far more sustainable and require dramatically fewer resources.

While the recent focus on insect population declines has garnered attention, the role insects play in sustaining the food chains that support larger animals remains paramount. For instance, songbird nesting success, like that of warblers and swallows, depends heavily on insect abundance — particularly caterpillars, which provide the protein-rich diet nestlings need to grow. With bird populations projected to continue declining without insect recovery, the loss of insect biomass threatens entire ecosystems. Studies, such as a recent survey by the Audubon Society, have shown that restoring native plant communities to support insect populations holds promise for reversing bird declines. According to Hubert, there are other positives as well.

"They [nestling birds] were reaching the fledging stage faster and requiring fewer supplementary food sources," he told ecology journals in 2020. "There was less nest mortality so the parents fledge more chicks eventually than in depleted habitats... This also explains why insect-rich ecosystems are carbon-negative, because the natural predator-prey balance avoids the need for synthetic inputs to maintain the same ecological productivity."

Hubert added that insect conservation programs have secured funding worth more than $100 million from agricultural partners. This past year, with the expansion of native wildflower corridor initiatives, it also began reaching new regions, such as the rapidly growing suburban pollinator garden movement across the United States.

A Record-Breaking Level of Biodiversity

One look at the video of a healthy meadow up above and you can see why it's been touted as an ecological marvel. Insects thrive in layered habitats stretching from the soil surface to the tallest flower stalks. Unlike many birds or mammals that require vast territories, insects exploit every available niche, allowing ecosystems to maximize the diversity packed into every square foot.

In an effort to make sure these creatures are properly understood, Hubert reached out to ethicists from the Sorbonne University to judge their moral standing. As he told The Guardian, the researchers determined that insects have "more in common with mushroom networks and the root systems of plants" than with vertebrate animals in terms of subjective experience.

"They have no cerebral cortex in the strict sense of the word," he said. "We know they have reflex reactions and they communicate through pheromones and build remarkable structures, but nobody has shown they experience suffering as we understand it. However, what is important is to respect them as living organisms, which is the foundation of ecological ethics."

In addition to ongoing conservation efforts in Europe, entomologists plan to continue expanding their research with additional field sites, including a major project in the U.S. The biggest hurdle ahead, however, says Hubert, is making insect conservation a normal part of everyday thinking.

"I believe that the big challenge is accepting insects as essential partners in our ecosystems," he told Nature Magazine. "A large part of the world's population already understands this, but we must be able to prove their ecological value and their benefits for the environment in order to reach more people and have more impact!"

Global Insect Biodiversity Assessment Highlights Critical Conservation Priorities." Xerces Society.

Why Insects Matter for Ecosystems." Xerces Society.

Insect Pollinators and Food Security." Food and Agriculture Organization.

van Dijk, Michiel, et al. "A Meta-Analysis of Projected Insect Population Declines and Ecosystem Services at Risk for the Period 2010–2050." Nature Ecology, vol. 2, no. 7, 2021, pp. 494-501., doi:10.1038/s43016-021-00322-9

The Future of Ecosystem Health May Lie in Insect Conservation and Habitat Restoration." National Ecological Observatory Network.