Edition 28 June 2018, by Geetanjali Gupta
It is righty said that “if all mankind were to disappear, the world would regenerate, but if insects were to vanish, the environment would collapse into chaos.” And it is this fear of chaos that has set warning bells tolling around the globe. A recent study conducted in nature reserves in Germany has concluded that insect populations have declined by a jaw-dropping 76% in 27 years.
Understandably, this damning report published in scientific journal PLos One has sent shockwaves around the globe. From ‘ecological armageddon’ to ‘dying planet’, ecologists’ reactions only understate their shock at this dramatic rate of decline. The fact that the cause for this drop is still not conclusive makes the news much more worrisome. Extrapolating the harrowing reduction in insect population in Germany, the Netherlands too has catapulted into action to analyse the health of insect populations in the country. Natuurmonumenten commissioned EIS (the Insect Research Centre) and the Radboud University to carry out their own research in nature reserves in Drenthe and North Brabant. “The number of studies with ominous reports is accumulating rapidly,” states Marc van den Tweel, director of Natuurmonumenten.
The scientists have come to the alarming conclusion that about two thirds of individual insects in the studied taxa has disappeared within three decades. In addition, the majority of the remaining species see a dramatic plunge. For example, the number of ground beetles in Drenthe has plunged by around 72%, while in North Brabant, ladybugs are down by 57% and macro moths by 66%. It is also known that of 47 species of butterflies, the population has decreased by half in the last quarter of a century. DeVlinderstichting (The Butterfly Foundation), which started the National Measurement Network for butterflies in 1990 and works closely with the Central Bureau for Statistics, compared its data on butterfly population with a German study and came to the same depressing conclusion.
While entomologists are not certain about the cause of this precipitous decline, there are some common culprits. Agriculture Minister Carola Schouten sent a report to the lower house of Dutch parliament, stating that the decline in insect groups may be caused by the use of phosphates, nitrogen and pesticides in agriculture. Natuurmonumenten too has the same stance; according to them, no other European country uses pesticides as intensively as the Netherlands. “We have to change our approach and use less chemistry, more biology and more innovation. Bulk production, aimed at the world market has no future in our small country,” Van den Tweel states. While increased usage of pesticide and fertilizers, year-round tilling and expanding farmland seem, according to the consensus, the main villains, scientists are not united in blaming rising temperatures. According to some, insect biomass is proportionately related to temperature. But others are quick to point out that not all bugs thrive on a warming Earth. In fact, a warm spring could bring some insects, like bees, out early, only to starve when there’s not enough food.
This disappearance of 75% of insects within three decades must have severe consequences. Nearly 80% of plants rely heavily on insects for pollination. Besides this, insects are a crucial component in the food chain of birds and mammals, who are feeling the squeeze in their food supply. “This is disturbing news. Such a decrease may very well be an explanation for the enormous decline in some bird species in farmlands, such as skylark and partridge,” says professor of Integrated Nature Protection Biology, Ruud Foppen. Previous research by Sovon and by the same scientists at Radboud University has also shown that insectivorous songbirds have dwindled in areas with high concentrations of insecticides.
Courses of action
While we may hate all the buzzing insects, and reflexively call the extinction good riddance, the fact remains that we cannot sustain life without insects. Not just farmers but we city dwellers can do our bit. As Roy Kleukers, director of EIS, suggests, we may use more plants in our gardens that attract insects and let the greenery grow a bit, so that larvae can develop. Sander Koenraadt, insect expert at Wageningen University, also points out that while we all love beautiful fluttering butterflies, this does not stop us from using poison against caterpillars – the fluttering butterflies of tomorrow – that eat our cabbage plants. Judging by the rate of decline of insects, it is not just prudence but a necessity to reverse the damage done, before the environment truly collapses into the chaos of an ecological armageddon.