Drivers have long since noticed: the number of insects is decreasing. Compared to the past, the windshield is hardly covered with the annoying creatures after speeding down the highway. What may be pleasant for German speeders has the potential to develop into a global ecocatastrophe. To some ears, this may sound alarmist, and that's exactly what it should: it's easy to assume that with a massive reduction or even extinction of insects, life on this planet as we know it would no longer be possible.
Our food, fresh water, hygiene and cleanliness are all threatened by the disappearance of insects. This is because they are something like the multitaskers of our ecosystem: crops and wild plants need them for pollination (according to the World Biodiversity Council (IPBES), five to eight percent of current food crop production depends directly on pollination by insects. This corresponds to an annual market value of several hundred billion euros), the decomposition of waste and our excrement is largely carried out by insects, many animals, especially amphibians, birds and fish, use insects as food, i.e. without insects there would be no frogs, larks or trout. But without insects there would also be no decomposition of cow or game droppings. Just imagine excrement lying around everywhere. When cows were imported into Australia, this scenario became a reality. Because the beetles that would have utilized it did not exist there. The native beetles were only specialized in kangaroo dung. The problem could only be solved by importing dung beetles from South Africa. Experts in Germany sounded the alarm 18 months ago.
Studies show dramatic decline
A study with data from countless volunteer insect counters came to the conclusion that insect numbers in Germany are declining dramatically. Has anyone noticed? Has it been widely reported in the press? Or was Germany perhaps just an isolated case? The last question has now been answered by a scientific overview study by researchers led by Australian ecologist Francisco Sánchez-Bayo from the Sydney Institute of Agriculture. This is the first comprehensive scientific analysis of the decline in insect populations worldwide. The authors present an overview of 73 historical reports, mainly from North America and Europe, and systematically assess the drivers behind the decline. Their report reads like a horror story. It highlights the dramatic declines that could lead to the extinction of 40 percent of the world's insect species in the coming decades. These include butterflies (decline of over 50 percent), beetles (decline of almost 50 percent) and Hymenoptera, which include ants, wasps and bees (minus 45%), as well as numerous aquatic insects. The number of insects is declining in almost half of all species. The total global insect population is shrinking by 2.5% per year. If this trend continues, almost all insects could have disappeared within a century, according to the authors.
"The impact that this development will have on the planet's ecosystem and on the survival of humanity is catastrophic," says Sánchez-Bayo.
According to the scientists, the main causes of species decline are (in order of importance)
- Loss of habitat through conversion to monoculture agriculture (a field with only one plant species is as valuable to most insects as a paved parking lot), as well as through urbanization, such as the construction of roads and houses;
- Pollution and poisoning of insect habitats, mainly from synthetic pesticides and fertilizers (the authors believe that new classes of insecticides introduced in the last 20 years, including neonicotinoids and fipronil, have been particularly harmful as they are routinely used and do not decompose);
- Biological factors such as introduced alien species that threaten the diversity of native insects; and iv. climate change. The latter factor is particularly important in tropical regions, but only affects a minority of species in colder regions and mountainous areas within temperate zones.
Only rarely do scientists become so specific in their statements, use such clear words and combine their work with a call for tangible action. "We want to wake people up," says Sánchez-Bayo. Reviewers and editors were of the same opinion here. The report explicitly recommends a rethink of current agricultural practices in order to slow down or even stop the current dramatic trends and preserve the ecologically important functions of insects. In particular, the authors mention overcoming monocultures and significantly reducing the use of pesticides. In order to stop the extinction of insects, agriculture would have to be changed on a large scale. We need to create more structurally rich habitats again, such as meadows, scrubland, etc., instead of just wheat fields and apple orchards. Fields should be made more insect-friendly, for example with flower strips and hedges at their edges. A more sparing use of pesticides and fertilizers must protect the habitat of insects.
The extent of global insect extinction has shocked even experts. It should be noted that studies on insect numbers are often associated with great uncertainties. Insect populations can fluctuate greatly from year to year, depending on the weather (for example, cold winters with lots of snow can decimate populations). Studies over long periods of time are therefore important, albeit very time-consuming and laborious. It is equally important to then summarize these many local studies in order to show a global trend. The Bayo study has now done the latter for the first time.
Media and politicians react hesitantly
As is so often the case, both journalists and politicians were slow to react. The report was barely mentioned in the daily press, and if it was, then only on the back pages (with the exception of the Guardian and the Huffington Post). Our mainstream news rarely mentions significant scientific developments, while we are treated to the annual useless rendezvous of a self-declared world elite in Davos or a baseless two-page pamphlet by opponents of pollution limits. Politicians such as the German Minister of Agriculture, Julia Klöckner, for their part, merely play down the issue and demand further findings before concrete political initiatives can be launched. It is always the same pattern: by demanding more knowledge, necessary steps are delayed further and further until it is too late. The former wine queen can hardly be expected to read such scientific studies herself. Where are those who inform her about the actual state of research?
However, the example of the popular initiative to protect bees in Bavaria in January 2019 shows that we citizens can take matters into our own hands to take decisive action against frightening developments when politicians and governments are too sluggish, blind or controlled by powerful lobby groups. People were queuing up to sign this initiative, just as if Helene Fischer were handing out free tickets for her next concert. The initiators from the Ecological Democratic Party (ÖDP) are putting the CSU-led Bavarian state government under massive pressure. With this study, they have now gained another strong scientific argumentation foundation.
About Lars Jaeger
Lars Jaeger studied physics, mathematics, philosophy and history and spent several years researching quantum physics and chaos theory. He lives near Zurich, where - as an enterprising lateral thinker - he has built up two companies of his own that advise institutional financial investors and also maintains regular blogs on science and current affairs. He also teaches at the European Business School in Rheingau. His enthusiasm for the natural sciences and philosophy has never left him. His thinking and writing always revolve around the influence of the natural sciences on our thinking and lives. His latest book "Mehr Zukunft wagen!" was published by Gütersloher Verlagshaus in September 2019.
