"This decrease has always been suspected but has turned out to be more severe than previously thought", Hallmann said in a statement.
The researchers based their findings on measurements of the mass of insects caught in traps installed in 63 locations in North Rhine-Westphalia, Brandenburg and Rhineland-Palatinate over the course of the past 27 years.
"If total flying insect biomass is genuinely declining at this rate [about 6 percent per year], it is extremely concerning", she said. "Yet, this dramatic decline has occurred".
Countless insects living in every corner of the world, prevents to conduct such calculations directly, so scientists conducting them, installing special traps in the national parks and counting the number of insects that fall in them for a certain period of time. It's not exactly a stretch to think that manmade chemicals or other human factors are also contributing to the loss of insect populations on a much larger scale, and it's incredibly important that scientists pinpoint the cause and propose a solution.
"However", he continued, "when you get an over 75 percent decline in total insect biomass, you know this is not due to a few or vulnerable species".
While noting they had not "exhaustively analyzed the climatic variables" that may have impacted populations, such as "prolonged droughts, or lack of sunshine especially in low temperatures", they also suggested "agricultural intensification (e.g. pesticide usage, year-round tillage, increased use of fertilizers and frequency of agronomic measures) that we could not incorporate in our analyses, may form a plausible cause".
It then appears that plants, flying insects, and many birds - all of which have lives that are intertwined within their ecosystems - are decreasing in species diversity, if not in other respects. These surrounding areas inflict flying insects and they can not survive there.
"As entire ecosystems are dependent on insects for food and as pollinators, it places the decline of insect eating birds and mammals in a new context", states Hans de Kroon.