Three-quarters of wild flying insects have vanished from Germany in the last three decades. Monarch butterfly populations have fallen by ninety percent. Fireflies are disappearing from regions where they were once so abundant they could be read by. Oliver Milman's The Insect Crisis is the most comprehensive account yet of what is happening to the invertebrate world — and why its consequences for humanity may exceed any other environmental crisis we face.
What Is This Book?
The Guardian’s environment reporter Oliver Milman spent years reporting on insect decline before writing this book, and it shows. The Insect Crisis moves from the German studies that first alarmed scientists to the global picture — documenting how pesticides, habitat loss, light pollution, invasive species, and climate change are combining to collapse insect populations worldwide.
But the book is not only about loss. Milman also profiles the entomologists, farmers, and conservationists working to understand and reverse the decline — and makes the case that insect conservation is possible if the political will exists.
Why Insects Matter More Than We Think
Milman excels at translating ecological abstractions into concrete consequences. Without insects: no pollination for most crops and wild plants; no food for birds, bats, freshwater fish, and countless other vertebrates; no decomposition of dead organic matter; no natural pest control. The insect world is not a peripheral feature of ecosystems — it is the engine.
If we lose the insects, we lose the ecosystems that support us. It's not a metaphor or a distant threat — it's a process already underway, measured in decades, not centuries.
— Oliver Milman, The Insect Crisis
The Pesticide Chapter
The most politically charged section of the book concerns neonicotinoids — the systemic pesticides that coat seeds and persist in soil and water long after application. Milman documents the regulatory failure that allowed these chemicals to become ubiquitous before their effects on non-target insects were understood, and the industry lobbying that has blocked restrictions even as evidence has accumulated.
6 Key Ideas From This Book
Longitudinal studies in Germany and elsewhere show insect biomass falling by 70–80% over thirty years — faster than any previous model predicted and faster than any recovery is possible.
Systemic pesticides applied to seeds leach into soil and waterways, contaminating habitats far beyond treated fields and persisting for years. They are now detectable in honey and wild flowers across the Northern Hemisphere.
Artificial light at night disorients nocturnal insects, disrupts mating and feeding behaviour, and attracts them to lethal fixtures. It is one of the most widespread and least regulated environmental stressors insects face.
Isolated habitat patches cannot support viable insect populations — many species need connected corridors to maintain genetic diversity and recolonise after local extinctions.
The uncultivated edges of fields — hedgerows, wildflower strips, ditches — support disproportionately high insect diversity. Their removal for agricultural efficiency has had outsized ecological consequences.
Countries and regions that have restricted neonicotinoids, reduced light pollution, and restored habitat have seen partial insect recovery. The damage is not irreversible if action is taken quickly enough.
Any Weaknesses?
The book focuses heavily on the Northern Hemisphere — particularly Europe and North America — and gives less attention to tropical insect diversity, which may be both more threatened and less studied. Some readers may find the chapter structure slightly episodic; the book moves between case studies rather than building a single cumulative argument. The solutions section, while present, is less developed than the diagnosis.
Who Should Read This?
Anyone who wants to understand an environmental crisis that is happening faster than climate change and receiving a fraction of the attention.
Entangled Life for the fungal network perspective, or Silent Spring as the foundational text on pesticide harm to non-target species.
Gardeners — the actions available to individual householders (wildflower patches, reduced lighting, no pesticides) are among the most effective insect conservation interventions available.
Statistics that are genuinely alarming. This is not a comfort read. Milman is honest about the scale of decline and the inadequacy of current responses.
Frequently Asked Questions
Is The Insect Crisis worth reading?
The most important environmental book most people haven't read. Milman documents a crisis with direct consequences for food security, ecosystem function, and human welfare — and he does it with the rigour of a journalist and the urgency the subject demands. Read this alongside Silent Spring and ask why we are still having the same arguments sixty years on.
Who should read The Insect Crisis?
Anyone who wants to understand an environmental crisis that is happening faster than climate change and receiving a fraction of the attention.
What is The Insect Crisis about in one sentence?
Three-quarters of wild flying insects have vanished from Germany in the last three decades.
The Verdict
The most important environmental book most people haven't read. Milman documents a crisis with direct consequences for food security, ecosystem function, and human welfare — and he does it with the rigour of a journalist and the urgency the subject demands. Read this alongside Silent Spring and ask why we are still having the same arguments sixty years on.
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