A decline in the population of flying insects in Germany could also represent a threat to neighbor countries, but Hallmann believes it could be even worse.
A club of mostly amateur entomologists used traps to capture insects and measure their biomass at 63 nature protection areas in Germany since 1989. "Insects make up about two-thirds of all life on Earth [but] there has been some kind of horrific decline", Professor Dave Goulson of Sussex University, UK, told The Guardian.
"The fact that flying insects are decreasing at such a high rate in such a large area is an even more alarming discovery", Hans de Kroon, researcher at Radboud University in the Netherlands, said in a news release.
"These surrounding areas inflict flying insects and they can not survive there", said Caspar Hallmann, researcher at Radboud. The study provides that 60% of birds need insects for food and almost 80% of plant life relies on them for pollination. According to Caspar Hallmann (Radboud University), who performed the statistical analyses, "All these areas are protected and a lot of them are managed nature reserves".
"As one of the few studies assessing overall biomass this study is a useful complement to the larger set of studies on specific groups of insects", writes John Losey, an entomologist at Cornell University in NY, in an email to The Scientist.More news: Facebook, Twitter lawyers to testify in Congress on Russian Federation meddling
The researchers discovered an average decline of 76 percent in the total insect mass.
The decline is more severe than found in previous studies. Thirty-seven of the locations were only sampled once, and 26 locations at least twice, with many years in between. "Most previous studies have reported biomass declines of less than 50 percent which is disconcerting".
For Nocera, one follow up study would be to assess the trend in forests and wetland areas, which are among the most productive areas for insect populations.
"But exactly what is causing their death is open to debate". Then don't only pollinate crops and serve as a food source for countless animals - like birds, mammals, and amphibians -, but also help scientists provided valuable genetic information related to life-saving research. The researchers hope that these findings will be seen as a wake-up call and prompt more research into the causes and support for long-term monitoring.
He added: "We need to do less of the things that we know have a negative impact, such as the use of pesticides".