Just over three-quarters of flying insects in Germany’s nature reserves have disappeared in less than 30 years. Something that is likely to represent a worrying global trend.
It is estimated that 80 percent of wild plants rely on insects for pollination, whilst around 60 percent of birds rely on them for food. Not to mention we need insects to pollinate many of the fruits, vegetables, and nuts that we eat daily. Losing flying insects is a serious issue.
“The fact that the number of flying insects is decreasing at such a high rate in such a large area is an alarming discovery,” Hans de Kroon, one of the study’s authors from Radboud University in the Netherlands, told The Guardian.
There’s a number of reasons why we might be losing insects. These range from habitat loss and pesticide use to the impacts of global warming.
“Insects make up about two-thirds of all life on Earth [but] there has been some kind of horrific decline,” study author Professor Dave Goulson of Sussex University, UK told The Guardian. “We appear to be making vast tracts of land inhospitable to most forms of life, and are currently on course for ecological Armageddon. If we lose the insects then everything is going to collapse.”
The study was conducted between 1989 and 2016, in 63 nature reserves across Germany where insect biomass – the total quantity of organisms in a given area – was measured. The flying insects were sampled by dozens of amateur entomologists using malaise traps – large tent-like structures used for catching insects and funneling them into containers without harming them.
Whilst the study was only conducted in Germany, the researchers, publishing their findings in PLOS One, believe it is likely to represent an alarming global trend.
Over the 27-year study period, the annual biomass of flying insects dropped by 76 percent. Meanwhile, specifically in the summer months, when insects should be most abundant, this decline soared to 82 percent.
The reason the news is so shocking is that studies looking at the decline of all insects haven’t really been done before. Instead, research has generally looked at specific species, like bumblebees, or certain groups, like butterflies. The new study incorporated many of the flying insects that don’t get as much attention – like flies and wasps – to give a better picture of what is happening to these important creepy crawlies as a whole.
The fact that the findings come from areas designed to protect biodiversity and ecosystem function is certainly concerning. The scientists took factors that affect insects, like weather and habitat type, but found their results to be consistent regardless. This means something larger is at play, and further research is needed to look at the declines in terms of factors like agricultural intensification and climate change too.