As recently as 30, even 20 years ago, when at night across Ireland, by the time you reached your destination, the front of your car would be caked in hundreds, even thousands, of dead insects. Commonly known as ‘bug splat’ it was a minor inconvenience usually remedied with soapy water to clean off the windscreen. This is now a thing of the past. After aeons of abundance, the world’s insect populations are in a state of accelerated collapse. I filed this book review for the Business Post recently.
IT IS A MARK of the enduring resilience of the insect kingdom that in the course of its 400 million year reign, it has weathered four of the Earth’s great mass extinction events relatively unscathed. Today, however, the world’s insect populations face an array of existential threats far greater than at any time in the past.
“Our Pyrrhic victory at the very last gasp of Earth’s history means for the first time that a single species is the primary cause of an extinction episode to impact the only known life in the universe”. This is how Guardian journalist Oliver Milman summarises the bleak state of affairs that confront what he calls the “tiny empires that run the world”.
His book, titled ‘The insect crisis’ takes an unflinching look at the alarming decline in insect numbers and range, and what it means for both biodiversity and humanity.
Milman’s research included interviews with many of the world’s leading experts. Despite the diversity of their fields of study, the scientists’ stories are remarkably consistent. “The consequences are clear: if insect declines are not halted, terrestrial and freshwater ecosystems will collapse, with profound consequences for human wellbeing”, according to entomologist, Prof Dave Goulson.
When considering human impacts on our planet, much media and scientific scrutiny has fallen on the plight of so-called charismatic megafauna, namely telegenic species such as giant pandas, tigers or elephants. In contrast, the vast insect kingdom remains largely unexplored and unappreciated.
Given their small size, elusiveness and ubiquity, many insect species are notoriously difficult to study, yet a silent apocalypse is nonetheless sweeping through nature’s hitherto most resilient kingdom. While we may mourn the disappearance of the last northern rhino, our relationship with the insect world is more complex. Our cupboards, Milman notes, “are full of an arsenal of chemicals designed to kill insects”, while terms like “creepy crawlies” also convey our reflex distaste, even fear, of insects.
However appalling it might be, wiping out species like rhinos “would not threaten the viability of global food production”, Milman observes. Nor would the crime of driving orangutans to extinction “provoke widespread child malnutrition, trigger the demise of dozens of bird species or cause the landscape to be covered in rotting cadavers”. Humans depend utterly on the very insects we are pushing towards oblivion.
While Milman’s book deals with the many overlapping threats facing the insect world, notably climate change, habitat loss, chemicals and light pollution, his carefully researched and highly readable account also captures a real sense of awe at the wonders of these diminutive empires. Consider that there are an estimated 400,000 species of beetles, vastly more than all species of mammals and birds combined.
The distinctive buzz of bumblebees is made by their wings flapping at an astonishing 24,000 beats per minute. This generates more G forces than a fighter jet. Some dragonflies can fly through winds strong enough to down a helicopter. The American cockroach reaches speeds equivalent to a human running at nearly 300km per hour. Bees have been successfully trained to sniff out explosives. And, while human agriculture is 10,000 years old, leaf-cutter ants have been ‘farming’ fungi in vast underground caverns for 15 million years.
One of the greatest pressures on insect populations globally is the widespread use of powerful pesticides in agriculture. A 2019 US study in soybean crops found little evidence that the neonicotinoid pesticides boosted harvests, and are of “negligible” benefit versus their costs.
While it is tempting to douse farmlands in pesticides, these also kill predatory insects, leaving farmers in a trap of complete dependence on pesticides while faster breeding species, such as aphids continue to attack crops. Agri-chemical conglomerates spend lavishly on lobbying to reduce regulation, while seeking to discredit scientists whose research points to the harm from potent chemicals such as glyphosate.
Scientific evidence did persuade the EU to finally ban neonicotinoid pesticides in 2018. A single teaspoon of one such product, imidacloprid, contains enough poison to kill over a billion honeybees if directly exposed. It is 7,000 times more toxic than the infamous chemical, DDT.
Ultimately, Milman concludes, the survival of insects may require a radical new awareness of their crucial role in maintaining the ecosystems upon which all life on Earth depends.
‘The Insect Crisis – The Fall of Tiny Empires that Run the World’ by Oliver Milman. Published by Atlantic Books. €21.