The insect apocalypse: why it matters and what can be done

A neon skimmer (Libellula croceipennis). Dragonflies are among the most visible insects lost as wetlands are drained and waterways decline.

How bad is it?

The numbers are striking enough that researchers have taken to calling it an insect apocalypse, which is not a term scientists use lightly. A 27-year study in German nature reserves found that flying insect biomass had declined by more than 75%. Three quarters of the actual physical mass of flying insects, gone, even in protected areas where no one was directly trying to kill them.¹

In 2025, a study from the University of North Carolina looked at flying insects in a remote subalpine meadow in Colorado, a site with 38 years of weather data and minimal direct human impact. Insects had declined by an average of 6.6% per year over the 20-year study period. That compounds to a 72.4% drop. In a place with almost no farming, no pesticide use, no urban development. The researchers found the decline was strongly associated with rising summer temperatures.²

In the UK, the charity Buglife counted insects splattered on car number plates between 2004 and 2021. The count was down 58.5%. In England the decline was 65%. In Wales, 55%. There is something unusually direct about this measure. Bugs on a windscreen is not an abstraction. It is a thing people of a certain age remember, and younger people do not.³

2024 was the worst year for bumblebees since records began in Great Britain. Twenty-four species declined by an average of 22.5%, with some dropping by nearly 40%. Butterfly numbers across North America have fallen by roughly 22% over the past two decades. Across the Global South, data is patchier, but what exists is not reassuring.⁴

A global meta-analysis estimates that about 40% of insect species face extinction in the coming decades. Insects make up around 75 to 80% of all known animal species. Around 80% of insect species haven't even been formally described yet. We are losing things we have not even identified yet.⁵

Why insects matter

The standard answer is pollination, and it is a good one. About a third of the food we eat depends on insect pollinators. Pollinator-dependent crops contribute somewhere between $235 billion and $577 billion to the global economy each year. In the US, more than 90 commercial crops rely on pollination. The list of foods that would become significantly scarcer or more expensive without insects is long and includes coffee, almonds, blueberries, and apples.

But the pollination story is a small part of the problem. Insects are the base layer of almost every food web on land and in freshwater. Birds eat insects. Bats eat insects. Fish eat insects. Amphibians eat insects. When arthropod biomass in Puerto Rico's Luquillo rainforest fell by up to 60-fold between 1976 and 2012, populations of insectivorous lizards, frogs, and birds collapsed alongside it. The cascade was direct and rapid.⁶

Insects also do the work that keeps soils alive. Dung beetles and other decomposers break down organic matter, cycle nutrients, and aerate soil. Without them, organic waste accumulates instead of being processed, soils compact, and the foundation of plant growth weakens. And aquatic insects like mayflies, caddisflies, and stoneflies connect river systems to the land around them, transferring energy from water to the birds, bats, and spiders that feed on them.

We also rely on insects for pest control. Many of the species eating our crops are kept in check by other insects that prey on them or parasitize them. Remove the predators and parasitoids, and pest pressure increases. This historically leads to more pesticide use, which kills more insects, which reduces pest control further. It is a loop that is not easy to escape from.

What is driving the decline?

The causes are multiple and they interact, which is part of what makes this hard to address. No single fix will reverse a problem with four or five major drivers pulling in the same direction.

Habitat loss is the primary driver. Modern intensive agriculture has replaced varied landscapes with monocultures that support very few insect species. Hedgerows have been removed. Field margins have been eliminated. Wildflower meadows that once covered large areas of Europe and North America have been ploughed under. Insects that depend on specific host plants, specific soil conditions, or specific structural diversity in vegetation have nowhere to go.

Pesticides compound the problem significantly. Neonicotinoids, now the most widely used class of insecticide in the world, are systemic -- they permeate the entire plant, including pollen and nectar -- at concentrations that impair bee navigation, reduce reproduction, and suppress immune function. They persist in soil for years. They contaminate waterways.

Climate change is increasingly a driver in its own right, as the Colorado study showed. Warmer temperatures drain insect energy for reproduction. Extreme droughts dry out breeding sites. Shifting seasonal timing breaks the synchrony between insects and the plants or other organisms they depend on. A bee that emerges two weeks before its host flowers open has a serious problem.

Light pollution is less discussed but well-documented. Most insects are nocturnal. Artificial light disrupts navigation, feeding, and reproduction. Fireflies are disappearing from Pennsylvania not primarily because of pesticides or habitat loss but because LED streetlights drown out their bioluminescent mating signals. Moths drawn to lights exhaust themselves and become easy prey. Aquatic insects, attracted to the glow of lit buildings, die far from water.

What rewilding can do

The research on insect recovery is consistent on one point: the more varied and connected the habitat, the better insects fare. Studies in Europe have found that the combination of low-intensity agriculture and nearby natural habitat provides the best protection against insect losses. Landscape connectivity matters -- an insect population in a restored meadow surrounded by intensive farmland is far more fragile than the same population connected to wider natural areas.

Rewilding addresses several drivers simultaneously. Reducing or eliminating pesticide use removes one of the heaviest pressures on insect populations. Restoring native plant communities rebuilds the structural diversity and host-plant availability that specialist insects need. Reconnecting habitat patches allows populations to mix, recover, and recolonize areas where they have been lost. Reintroducing grazing animals that create varied vegetation structure produces the mosaic of microhabitats that supports the greatest diversity of insect life.

Even small interventions at garden scale add up. Planting a wildflower patch, building a log pile, installing a small pond, turning off unnecessary outdoor lights. These individually modest actions become significant when they are replicated across millions of gardens. The research on urban green networks consistently finds that connected gardens and green spaces can support surprisingly high insect diversity, sometimes higher than the intensively farmed countryside around cities.

The policy gap

Despite the scale of the problem, insects receive remarkably little formal policy attention. The Global Biodiversity Framework agreed at COP15 in 2022 addresses insects only obliquely, through general restoration goals and pesticide reduction language. There is no dedicated global monitoring program for insect populations. We are tracking the collapse largely through individual research projects rather than coordinated systematic surveillance.

This is partly a data problem. Around 80% of insect species haven't been described. You cannot easily set conservation targets for species you don't know exist. But it is also a political and cultural problem. Insects do not attract the same public sympathy as mammals or birds. Campaigns to save bees have been more successful than campaigns to save flies, even though flies are arguably more ecologically important.

The windscreen test is a blunt instrument, but it is a useful one. If you are old enough to remember the insect-covered car windows of summer drives thirty years ago, you are old enough to have witnessed one of the largest ecological shifts of the modern era. It happened quietly, in the background, while attention was elsewhere.

Frequently asked questions