Remember the days when a long drive in high summer would make your car’s windshield look like the site of an insect massacre? If you’ve noticed that this sight is becoming increasingly uncommon, you’re not alone. Ecologists have also discovered a decline in the number of bug splatters on car windows, and some believe that it’s a sign of the much wider “insect apocalypse” affecting our planet.
A survey by Kent Wildlife Trust in the UK found that 50 percent fewer insects were splattered on car windscreens compared to 15 years ago. The survey analyzed over 650 car journeys around the southeastern UK county of Kent between June and August 2019. The drivers were asked to report the number of insects splattered on their car’s registration plate.
Compared to a similar survey carried out by the Royal Society for the Protection of Birds (RSPB) in 2004, the researchers found the number of splattered insects had declined by approximately 50 percent, from an average of 0.2 splats per mile to 0.1 splats per mile.
The researchers wondered whether this decline in bug splats was actually the result of modern cars becoming more aerodynamic and less likely to suffer from a head-on collision with a passing insect, so they actively recruited classic car owners to take part in the survey. However, even while accounting for this, a significant decline in insects was evident.
It’s not the first survey in the world to reach such conclusions either. People have anecdotally talked about this phenomenon since the early 2000s. Over the past 20 years, increasingly more scientific research has shown these suspicions aren’t necessarily unfounded.
In 2019, Danish researchers published a study using this windshield method and noted reductions of 80 to 97 percent. Another study from 2018 also used similar methods around the El Yunque National Forest of Puerto Rico and found insect biomass had fallen by 10 to 60 times since the 1970s.
All of this may be a symptom of the wider plight of insects across much of the world. Some ecologists are warning that we are on the brink of an “insectageddon,” a catastrophic collapse of life that could see 40 percent of the world’s insects become extinct within the next few decades. There are many factors behind this decline of bug life, but scientists frequently point the finger at climate change, the use and abuse of pesticides, destruction of habitat, and disease.
Other scientists argue that we should be careful about what we take from the so-called "windscreen phenomenon." To make the bold claim of a full-blown "insectageddon," we need rigorous data. While it might be an indication that insect habitats have changed and moved further from human developments – itself a worrying trend – it might not necessarily reflect a global decline in insect population. It might instead, for instance, simply show that cars are more aerodynamic than they were decades ago.
Nevertheless, any form of insect decline is bad news for us. Over a third of the world's food crops rely on animal pollinators to reproduce. Effectively, one out of every three bites of fruit and vegetables we eat exists because of animal pollinators, including butterflies, moths, beetles, bees, and many other insects.
If these guys go, we could be in a lot of trouble.
An earlier version of this story was published in February 2020.