A new study shows that the population of flying insects across Germany's nature reserves has dropped significantly by 75 percent over a period of about 27 years. Scientists say that the drop in populations could place ecosystems in jeopardy.
The 27 Years Of Study: 'An Alarming Discovery'
The research, published in PLOS ONE, examines data collected from 63 nature protected areas in Germany since 1989. To gather samples and data, entomologists have been using "Malaise traps" over the course of 27 years to keep track of the number of "total insect biomass" every year.
Malaise traps are tents used to capture over a thousand of samples of flying insects. They were used in spring, summer, and early autumn, operating continuously every day and night.
The data were then analyzed alongside researchers from the Netherlands and England. The study reveals a 76 percent seasonal decline, and an 82 percent mid-summer drop in flying insect biomass over the 27 years of study. Caspar Hallmann of Radboud University said that the areas in which samples were collected were protected nature reserves and yet the numbers have dropped dramatically.
The Cause Of The Decline
Scientists were stunned by the results of their study and were left scratching their heads about the primary cause behind the population decline of different insects such as bees, moths, and butterflies.
According to speculations, one of the many factors that contributed to the alarming decline was the widespread use of pesticides. Other factors include climate change and changes in insect habitat.
However, according to Tanya Latty of Sydney University's School of Life and Environmental Sciences, the decline may have been caused by a combination of different factors altogether, and not by one "smoking gun", as she puts it.
Ecological Importance Of Insects
The insect population plays a very crucial role in many ecosystems, where they perform many important functions. They pollinate blossoms, aerate the soil, and provide food for about 60 percent of bird species.
The Consequences Of The Decline: 'Ecological Armageddon'
Scientists are very worried with the current situation, because "loss of insect diversity and abundance" could place ecosystems in jeopardy and disrupt food chains on a massive scale as a result of the decline. They said the decrease in numbers have turned out to be a matter of grave concern.
"Insects make up about two thirds of all life on Earth," said Dave Goulson from the University of Sussex in the United Kingdom. "We appear to be making vast tracts of land inhospitable to most forms of life, and are currently on course for ecological Armageddon. On current trajectory, our grandchildren will inherit a profoundly impoverished world."
"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. We can barely imagine what would happen if this downward trend continues unabated." said Project leader Hans de Kroon from Radboud University in the Netherlands.