Dutch researchers raise alarm about massive decrease in insects

The number of insects in German natural areas dropped by over three quarters over the past 30 years, according to a study by ecologists at Radboud University in Nijmegen. According to the Dutch researchers, there is no reason to believe that insects in the Netherlands are doing any better than those in the German research areas, NOS reports.

Sine 1989, German entomologists carefully kept track of the number of insects in 63 protected natural areas by capturing the animals in traps and weighing the biomass. Radboud University analyzed this data and concluded that the average total weight decreased by 76 percent over the past 27 years. In the summer, when insect numbers reach their peak, the decline is even 82 percent.

Professor Hans de Kroon of Radboud University calls the results alarming, according to the broadcaster. "Insects are extremely important to the ecosystems", he said. "They are pollinators, they are the food source of our birds and of many mammals. And if three quarters of that disappears, it has an enormous impact on the ecosystem and ultimately on us. It would not surprise me if the decline in other species, for example many songbirds, ultimately leads back to what we see here."

The researchers are hesitant to say what may have caused this massive decline. This study shows what is not the cause, according to the researchers. "The changing climate and land management can be ruled out as possible causes. What remains is that these areas are relatively small and in the middle of the agricultural landscape. Impact of agricultural expansion and the use of pesticides are absolutely factors that can play a part here", the NOS quotes.

The natural areas in which the German entomologists did their measurements, are very similar to many natural areas in the Netherlands, according to De Kroon. Some are also very close to the Dutch border. "Of course, this does not stop at the border", the professor said, according to NOS. "I think that what we see in Germany is also happening in the Netherlands and in other areas in Europe."

De Kroon believes that the tide can still be turned. "Nature has enormous resilience and we need to make use of it. I'm optimistic about that. But then we have to find the causes and actually do something about it. And in the meantime, use all caution and speed up measures we know are beneficial to insects."