You have probably seen the headlines. "Insect apocalypse." "Windscreen phenomenon." "Where have all the bugs gone?" The language is dramatic, and some of the coverage has been oversimplified, but the underlying science is real. Insect populations across much of the world are declining, and the consequences matter far beyond the insects themselves.
As someone who keeps invertebrates, you are already more aware of this than most people. Here is what the data actually says and what you can reasonably do about it.
What the science shows
The most widely cited study is the 2017 Krefeld paper, which found a 75% decline in flying insect biomass over 27 years at nature reserves in western Germany. That number has been repeated so often it has become shorthand for the entire issue. It is a real finding from a real long-term dataset, but it describes one geographic area. Global patterns are more varied.
A 2020 meta-analysis in Science by van Klink and colleagues looked at over 160 long-term surveys worldwide. They found terrestrial insects declining at about 0.92% per year overall, but freshwater insects actually increasing at about 1.08% per year, possibly due to improvements in water quality. The terrestrial decline is real but not uniform. Some groups are declining faster than others. Lepidoptera (butterflies and moths) and some Hymenoptera (bees, wasps) are particularly hard-hit. Others, like some fly families, are more stable.
In the UK specifically, the State of Nature reports have documented declines across multiple invertebrate groups. The 2023 report found that 13% of assessed invertebrate species are threatened with extinction from Great Britain. Pollinator declines have been most studied, but ground beetles, moths, and other less charismatic groups are also in trouble.
What is causing it
Habitat loss is the primary driver. Agricultural intensification has removed hedgerows, meadows, and field margins that supported invertebrate populations. The UK has lost 97% of its wildflower meadows since the 1930s. That is 97% of a habitat type gone in less than a century.
Pesticides are a significant factor. Neonicotinoids have received the most attention because of their effects on bees, and several have been restricted or banned in the UK. But pesticide use extends well beyond neonicotinoids, and the cumulative effect of multiple chemicals at sublethal doses on invertebrate communities is poorly understood.
Light pollution disrupts nocturnal invertebrates, particularly moths. Artificial light at night interferes with navigation, feeding, and reproduction. Climate change is shifting ranges and disrupting the seasonal timing between species and their food sources. A bee that emerges before the flowers it depends on are blooming has a problem, even if neither the bee nor the flower population is directly declining.
What keeping invertebrates does not do
I want to be honest about this. Keeping a colony of Porcellio laevis in a tub on your shelf does not directly help wild invertebrate populations. Captive breeding of exotic species for the hobby is not conservation breeding. These are different things, and conflating them overstates the contribution hobbyists make.
The species most commonly kept in the UK hobby are largely tropical or non-native. Breeding Pachnoda marginata in Birmingham does not help African flower beetle populations. Maintaining Cubaris cultures does not reduce pressure on wild isopod populations in Thailand. The connection between hobby keeping and wild conservation is indirect at best.
What keeping invertebrates does do
It changes how you think. Keepers pay attention to invertebrates in a way that non-keepers do not. You notice the moths at the window. You look at what is living under logs when you walk in the woods. You understand, on a practical level, that these animals have specific needs and that getting conditions wrong kills them. That awareness translates into behaviour.
Keepers are more likely to garden in ways that support invertebrates, more likely to avoid pesticides, and more likely to talk about invertebrates to people who would otherwise never think about them. That cultural shift matters because invertebrate conservation gets almost no public attention compared to mammals and birds.
Practical things you can actually do
Garden for invertebrates. Plant native wildflowers. Leave areas unmown. Keep log piles, leaf litter, and dead wood. Do not use pesticides. A single garden is small, but gardens collectively cover a huge area of the UK and can provide meaningful habitat if managed sympathetically.
Reduce light pollution where you can. Turn off outdoor lights you do not need, or switch to motion-activated lighting. Use warm-coloured LEDs rather than cool-white ones, which attract more nocturnal invertebrates.
Participate in citizen science. The UK has excellent recording schemes for many invertebrate groups. The Biological Records Centre coordinates national recording for insects. The Big Butterfly Count, the National Moth Recording Scheme, and iRecord all generate data that feeds into conservation assessments. You do not need to be an expert. You need to turn up, count what you see, and submit your records.
Support the organisations doing this work. Buglife, Butterfly Conservation, and the Bumblebee Conservation Trust are the big three for invertebrate conservation in the UK. Local wildlife trusts also run invertebrate projects. Even small regular donations fund survey work and habitat management that would not happen otherwise.
And talk about it. Not in a preachy way. Just honestly. When someone asks about your isopod colony, mention that wild invertebrate populations are declining and that these animals are more interesting and more important than people tend to realise. That conversation, repeated across thousands of keepers, adds up.